Drivability issue - fuel related (I think)

[pgman]

As a couple of you know already, I am working on a 1985 Spider 2.0 with Bosch EFI. The car sat idle a long time before I bought it but it starts and idles very well. In fact, I now have it on the road (semi-officially) and have done a few 90 minute trips to sort out what needs fixing and what can wait a while.

I have a vibration when I apply power in any gear that I'm convinced is a sticky u-joint. I am going to have to tackle that one at some point but my bigger issue right now is this:

After I drive about 40 minutes or so (around town or steady cruise on the highway) the motor will just randomly lose power as if starving for fuel. Once this begins, there doesn't seem to be any way to fix it other than to shut the motor off and let the car sit for a good long while. I'm not 100% certain this problem is fuel related, but I can say only that the sound of the external fuel pump changes quite dramatically right before the engine dies out. Of course, I cannot hear this when I'm underway, but if I'm sitting still the change in the sound is very noticable. It gets very faint and almost muted for about a half-second and then the engine dies. I tried disconnecting / reconnecting the fuel pump relay(s) under the package shelf a couple times. The terminals were rather corroded looking and I noticed that one of the relays was pretty warm - not exactly hot...but very warm. I'm guessing this isn't normal, but I wonder if the heat in the relay is caused by excessive current in the pump circuit or just by bad contacts internally (or even just the corroded terminals). Of course, I imagine it is possible that there is something clogging the pickup in the tank, too. The previous owner claims he had the tank pulled, drained and cleaned before he sold the car, because the fuel went bad from sitting around. In fact, I can still smell the stale fuel smell sometimes, so I am not sure where to turn next. The car runs great, other than this one issue.

My question here, I suppose, is can anyone tell me a good place to start troubleshooting this? I don't want to buy two rather expensive fuel pumps if I don't need them. I am pretty sure the external pump is okay because it sounds right to me - except right before the engine cuts out. How can I tell if the in-tank pump is working? I am wondering if that pump is becoming erratic and, when it cuts out, the external pump is cavitating from a lack of fuel. The sound it makes leads my suspicion, but I don't want to get tunnel-vision and miss something obvious.

Thanks in advance, if anyone has any ideas.

[spiderserie4]

On an 85 spider you will have a combination of L-Jetronic and Bosch, in other words you have 2 ECU's...is that right? (One under the rear shelf, the FI ECU, and one behind the rear passenger side wall carpet, the Ignition ECU)

I believe on the 85 you do not have the inertia cut off switch (grey plastic cylinder thing under the hood on the passenger side firewall), so that can be ruled out........otherwise that would have been my first suspect!

you will not hear either fuel pump whirr just with the ignition on - the system does not work like that.

If you can, next time the engine cuts out, look at the Tach and if this drops to zero whilst the engine cuts out, this points to fuel problem.

Check the relay (fuel) fuse, this is a common failure point. The bullet style housing (next to the black Bosch drive/fuel relay near the ECU) is not the best design and can cause an intermittent connection and many have changed this for a flat blade fuse holder. Whilst you are there just make sure the fuse is an 8 amp.

Check the drive relay (fuel relay) connections again and thoroughly clean them with contact cleaner and an old toothbrush and the relay plug itself. Remove the fuel relay and put a voltmeter (red lead) to terminal #87 on the relay socket (not the relay itself, obviously!)and the black lead to ground, and then get someone to crank the starter, what voltage does it read?
If you suspect the relay, change it..., they can be very expensive, depending where you go, IAP sell them for 250 bucks!! (Bosch 0 280 230 001, same used for many BMW's, just search that number on ebay or google, sometimes there for 80 bucks or thereabouts)

Test the intank fuel pump - connect battery power straight to the thickish pink/white (+ve) wire and the black (-ve) ground wire going to the top of the tank pump (do not test the pump out of the car - ie dry - you will ruin it - does it whirr? (see photo for wiring)

Check the intank pump rubber "stepped" hose (undo the 6 screws, pull out the fuel pump and carefully inspect the hose (see photo) Check also the intank fuel filter sock is in place and not fallen off and floating in the tank somewhere) - if your gas level drops to below half and this hose has a crack in it, it will suck in air, rather than fuel. The intank pump needs to be working as it does the job of delivering fuel to the main under car fuel pump.

[pgman]

Thanks for the ideas, Anglo. The tank was nearly full, and I previously had lifted the in-tank pump (I didn't completely remove it) and the intake sock was securely attached and didn't look bad. I didn't specifically check that stepped hose (ignorance prevailed in that instance). With regard to the specific ignition / EFI system...I'm not certain if there is one control box or two. I know there is one under the package shelf (behind passenger seat on LH drive model). There are four distinct pieces of equipment at that location.

The ECU / EFI controll box - the largest of the four items

The fuel pump relay (gray color, metal enclosure) - looks like the "classic" Bosch "cube" relay.

The barometric pressure sensor (black plastic housing, bolted to the side of the bracket which holds the ECU

One more non-descript plastic module that looks like a relay but it is physically larger than a typical relay. This module is perhaps 3 inches long and has a single plug attached. It fits in a little spring steel bracket attached to the ECU mounting bracket.

To my knowledge, there are no other electronic modules in the car. If there are any, I sure haven't seen them yet, and this car has factory A/C, so I'm not sure where they would have squeezed them in under / near the dashboard.

Is it possible that the fuel system components are slowly failing because of the ethanol fuels we're forced to use here in America? I know that there was a point mid-eighties when all USA-spec cars were supposed to have been switched to ethanol-based fuels. I cannot remember which year that was, or if imports were part of this transition.

Again, thanks to all for their thoughts and ideas.

P.S. - by the way, the tach needle never drops when the motor cuts out. I was thinking that, if it did, it might indicate and ignition system fault. I am not sure how it would point to a fuel related problem, but I can only ask the question out of ignorance as to how the EFI works. Please enlighten me if you would. I don't want to assume ANYTHING here, as I am still learning the intricacies of this automobile.

[spiderserie4]

"One more non-descript plastic module that looks like a relay but it is physically larger than a typical relay. This module is perhaps 3 inches long and has a single plug attached. It fits in a little spring steel bracket attached to the ECU mounting bracket.".............

that non descript module () will be the drive/fuel relay!
the typical small bosch cube is the main relay.

looks like this (here labelled "drive relay")

[pgman]

AHA! Okay, the "non-descript" thing I mentioned is, in fact, the drive relay. My fuel relay is not plastic, it is metal...and it isn't bolted to anything. It is just laying back there on the floor. This makes me wonder if it is not original and if somebody just found a relay and popped it in there. Part of the "fun" of restoring one of these cars is figuring out what the long string of previous owners did to **** them up! I really appreciate the photos and the genuine interest in my success, Anglo. I meant to ask you if you got my mailing address (for the dash vent). If not, please let me know and I will send it again.

[spiderserie4]

I'm Spiderserie4 BTW......Anglospider has the dash vents.......

If you can, post a photo of your relay/ecu set up back there. I ask because the fuel relay on the later Bosch Motronic cars is indeed a small bosch metal cube (like on my 1990 spider with Motronic!)....on your car the fuel relay should be that tall black plastic thing. (note: drive relay means fuel relay!) The small metal relay should be the main relay on your car.

[pgman]

I'm Spiderserie4 BTW......

..and I'm the village idiot - thank you very much. It's early here...my apologies.

[pgman]

If you can, post a photo of your relay/ecu set up back there. I ask because the fuel relay on the later Bosch Motronic cars is indeed a small bosch metal cube (like on my 1990 spider with Motronic!)....on your car the fuel relay should be that tall black plastic thing. (note: drive relay means fuel relay!) The small metal relay should be the main relay on your car.

Spiderserie4, I will see if I can get a photo later today (which means you probably won't see it until tomorrow). Work schedules may prevent it but I do, indeed, have one metal relay and one larger (taller) plastic one. The metal one isn't attached to anything, other than the socket and wires to it and the taller one is clipped into the little spring steel clip which fixes it to the side of the FI controller mount.

Thanks again.

[anglospider]

Hi, this IS Anglo

Spiderseries4 knows far more about this stuff than I do but I don't think he mentioned in-line fuel filter (maybe I missed it). Isn't there one under the car in the fuel line that needs replacing every so often?

[spiderserie4]

very good point Anglo......such an easy and cheap (and important!) item to replace! I replace it at least every two years, it is cheap insurance against clogged fuel delivery.........and if, as pgman says, the PO had the tank pulled, drained and cleaned and did not do the main under car fuel filter, that is reason alone to do it now!

[pgman]

Hello again.

For what it's worth, I did change the filter under the car. What ran out of the old filter resembeld mud...which is why I have an on-going concern that there is still a TON of bad stuff inside the tank. I've kind of made up my mind that I just need to drop the thing out and see what is going on in there. I don't know of a safe way to check it while it's still in the car. I guess I could siphon off as much fuel as possible and then use a light to look down inside. I tried pulling the in-tank pump and sender out once already but I cannot figure how to get the intake sock through the hole in the top of the tank. I was afraid that I'd knock it off and then it would fall into the tank - never to be seen again.

Tonight, after work (I only had a few minutes of daylight left) I ran the engine at idle speed for about 10 minutes. To be honest, the external fuel pump doesn't sound that great. I remember the sound of these Bosch pumps from the old SAAB and Volkswagen cars of the same era. I am not sure these cars used the EXACT same fuel pump as the Alfa, but I would not be surprised to learn that they did. In any event, my fuel pump sounds like it is changing speed a lot, which COULD be a bad relay or socket - so I'm going to check that stuff first, as well as the ground. I just wonder if enough dirt got sucked through to do the damage. This is why I'm leaning toward just dropping the tank.

I'll report back once I know more - thank you all (no matter what your name is ) for your help. I greatly appreciate it. I'll get this little beauty back in proper order - I just know I can do it. I just need to take some time and be methodical. All will be well.

[spiderserie4]

mud coming from the filter is not a great sign! I would pull the filter again and see if it is clean, if not it sounds as though you should pull the tank and get it properly cleaned inside.
As to hearing the fuel pump, I can't even hear mine over the sound of the engine. I can feel it is working if I crawl underneath and put my hand on it with the engine idling. So, I am not sure you should be hearing anything, tbh!
My late 80's mercedes pump did make a whirring noise that I could hear easily, but I think the alfa pumps are much quieter.

As for pulling the sender, its true that sock filter might pop off, but you can likely fish it out again, or somehow grab it with long nose pliers just before it pops off. Mark the orientation of the sender before you pull it as it needs to fit back exactly the same way, so that the filter sock fits into a small baffle at the bottom of the tank.Then look into the tank with a torch and it should be spotless.
Last thing you want to do is clog the injectors!

[MikeH]

Next time it fails, bridge the fat terminals on the fuel pump relay slots in the fusebox with a piece of thickish wire 3mm(?) if the pump runs again, it's the relay. If not, sounds to me like the pump is on the way out. Fuel starvation of the main pump tends to make it noisier, not quieter.

I don't know this particular install, but I've owned and rebuilt VW golfs with Bosch LJet management. It's a common system to many '80s and '90s cars.

[MikeH]

A further thought... if it fails, check for vacuum in the tank - undo the fuel cap and see if you get a rush of air trying to fill the vacuum. Might be blocked breathers in the tank are causing your fuel pump to work against increasing vacuum, and then give up.

Not all that likely, but quick and easy to check.

[pgman]

...check for vacuum in the tank - undo the fuel cap and see if you get a rush of air trying to fill the vacuum.

Actually, it DID do this once when I was having this symptom. I stopped for fuel because I wasn't sure if the gauge was reading correctly. When I removed the cap, a very large amount of air either escaped or went in - I'm not sure which. If this is the problem, what do I do to correct it?

BTW, when this problem occurs, the outboard fuel pump sound changes, but it doesn't necessarily get louder or softer. It almost sounds like it's bogging down, and it sounds "raspy" (for lack of a better term). My question is, how do I know if the in-tank pump is working correctly? If THAT pump was failing, would it necessarily starve the outboard pump of fuel? I would think that, once a siphoning action started, the in-tank pump would be somewhat suprefluous but I don't KNOW this to be true. Of course, cornering and acceleration / braking dynamics would probably disrupt the gravity flow of a siphon, so the in-tank "lift" pump is probably always needed (now that I think about it). I am inclined to just bite the bullet and replace everything, but I'd sure hate to spend the money if it wasn't needed.

I spent all morning today pulling the prop shaft. I noticed a pronounced vibration in the driveline that was very high-frequency, so I figured it had to be the prop shaft. It turns out that the center bearing support was shot (the bearing was just flopping around in there) and the front cushion disk was broken in two places. I have parts on order, and there is a driveshaft specialty shop in town who says they can pull everything apart and rehab it (as long as I supply the parts) for a low price. After this is sorted, I think the little beauty will be ready for the open road. I still need to put the new top on, but I'm not sure I'm going to do that myself. I might take it somewhere to have that fitted - it looks like quite an involved job.

Thank you, everyone, for your thoughts and support. If anyone has anything else to suggest with regard to this fuel starvation issue, I would be very glad to hear it.

[spiderserie4]

Good you found that shot propshaft hanger bearing! That will make a big difference. You're replacing the bearing and the rubber support, right?
Just make sure your shop that does the work marks the propshaft before removing it, or they will unbalance your prop and it will really vibrate! (they ought to know this, but worth politely mentioning it when you drop off the car, as you just never know these days!)

As you might be tackling the in tank fuel pump, these vidoes are to do with smell of fuel in the spider trunk, but there is some useful stuff on removing the in tank pump etc and, as always, pictures are worth a thousand words!

Video 1 shows the yellow/black one way check valve in the back, that you should be able to blow through one way but not the other. I'd check this is working.
Video 2 shows how to remove the intank fuel pump, and shows you its componant pieces.

Fixing the Gas Smell in the Trunk of an Alfa Romeo Spider, part 1 - International Auto Parts - YouTube

Fixing the Gas Smell in the Trunk of an Alfa Romeo Spider, part 2 - International Auto Parts - YouTube

[pgman]

Thank you "4" for the links - that was very helpful. I wasn't sure if I could fold the in-tank filter "sock" to get it out of the tank, which is why I didn't completely remove the sender / pump the last time.

Since it looks like the rear portion of the exhaust system has to come off to get the tank out, I think I may just try to do what I need to do through the access portal in the boot area. I don't know what is in the tank in terms of debris (if anything) but if the previous owner was being truthful, I would expect it to be reasonably clean in there. The sock on the in-tank fuel pump looked nice and white (clean) from what I saw, so if someone told me it had been replaced recently, I could have believed it. Still, I'd like to check things out to be sure. Also, I want to check the float. My gauge only reads to 3/4 tank - even when it is topped up. I am wondering if this is because the float is "sinking". I am sure this will all be fairly easy to sort out. I just need to manage the time. I am going to get a length of fuel hose and connect it to the in-tank pump, then energize it. I just want to make sure it is delivering a proper volume of fuel. If it is, then I can at least put that part of this diagnosis to bed. The exterior fuel pump looks easy enough to change but I wonder if anyone has used the less expensive replacement pump - it is significantly less money than the Bosch or the other brand-name one (I forget which it is).

I will post back here when I know a little more. For now, thank you all for the help and the insight. There aren't many of these little Alfas on American roads anymore - at least not around these parts (Central Florida) so there is little help for me outside of the online community.

[MikeH]

Originally Posted by pgman

Actually, it DID do this once when I was having this symptom. I stopped for fuel because I wasn't sure if the gauge was reading correctly. When I removed the cap, a very large amount of air either escaped or went in - I'm not sure which. If this is the problem, what do I do to correct it?

BTW, when this problem occurs, the outboard fuel pump sound changes, but it doesn't necessarily get louder or softer. It almost sounds like it's bogging down, and it sounds "raspy" (for lack of a better term). My question is, how do I know if the in-tank pump is working correctly? If THAT pump was failing, would it necessarily starve the outboard pump of fuel? I would think that, once a siphoning action started, the in-tank pump would be somewhat suprefluous but I don't KNOW this to be true. Of course, cornering and acceleration / braking dynamics would probably disrupt the gravity flow of a siphon, so the in-tank "lift" pump is probably always needed (now that I think about it). I am inclined to just bite the bullet and replace everything, but I'd sure hate to spend the money if it wasn't needed.
.

Based on experience of working with L-Jet (Digifant) VW Golfs, if the lift pump isn't working, the main pump gets a lot louder, because it's running dry and pulling air instead of fuel (which means it's getting less resistance). The lift pump picture in the previous posts looks pretty much identical to a golf one.

Sounds like that's not happening with yours - It seems more likely that your pump is struggling to pull against vacuum. The breather pipes should allow the tank to draw air to replace the volume of fuel which has been removed by the pump. If they're blocked up then this won't happen.

Does the fault replicate on your drive, if you leave the car on idle for a while?

If you drive the car till the problem occurs, or run it on the drive, and then remove the fuel filler cap or a breather, then the removal of the vacuum should allow the pump to start running again, without the long wait you normally experience. If you look under the car when the problem occurs, you might even see the tank 'sucking in' and releasing when the fuel cap is taken off. Not a good situation to continue with, as metal tanks aren't designed to flex much!

I wonder if the previous owner had the tank 'slosh sealed' from the inside. It's possible that this could block a small breather pipe. It's also possible that they're blocked up with old rust and muck. An old speaker magnet dropped into the tank (drill it and put a tying wire through it if you want to get it back) can be handy to attract any rust that's floating around in the tank. There's usually enough metal left in the rust flakes for that to work!

My feeling is that you should be able to diagnose this before you take the big step of dropping the tank back out for a full check.

[pgman]

Mike,

Your train of thought is somewhat consistent with what I'm experiencing. This problem seems to crop up only after driving a while. For example, a quick trip to the grocery and back doesn't seem to bother it much. A longer drive (say 30 miles) is when it starts sputtering and dying. The last time this happened, however, I pulled off the roadway and opened the tank cap. No air rushing sound, and the car didn't run any better afterwards. I know that is kind of contrary to what I said in the first sentence, but other times it DID have an air rushing sound and then the car DID run better afterwards. I suppose it's possible I have two seperate issues going on.

Let's just say I DO have a clogged vent, how do I go about clearing it? Is it as simple as flushing / soaking that little one-way check valve in the back? How about that opaque plastic tube that runs up to the front of the car - where does that end, and what if IT is clogged? I watched the videos - they were very helpful in understanding the basic outline of how this evap-emissions system works, but I just don't know where to spray the carb cleaner. I am going to pull the in-tank pump / sender again for sure. Now that I know how it comes out I don't feel so much trepidation. I want to see what is in that tank. Is it possible that I'm just sucking up so much debris that, over a longer drive, the in-tank pump just runs out of fuel (thus starving the whole works)?

[MikeH]

Can't say I've had that problem and had to solve it, but it struck me as a possible diagnosis. I know people who've had problems with blocked breathers on other cars.

If taking the cap of doesn't solve the problem though, it suggests that's not your issue. That means I'm back to thinking you should try bridging the relay next time it fails.

However, it might be that your fuel pump is starting to fail. I don't know the LJet setup on a Spider. Does the pump run in a fuel bath, or is it just a regular inline pump? I've seen both sorts of setup on VWs, depending on the age of them. If you can get to it, it would be worth checking the temp of the pump, under normal running, and again when it's just stopped. If it's seizing up I'd expect it to be getting warmer due to the internal friction.

Sucking up debris can also be a cause of failure on longer runs, so that's definitely worth checking.

[spiderserie4]

there are 2 fuel pumps, the intank submersed pump (a puller pump) which delivers fuel to the main fuel pump under the car.
Both work together and both need to be working.

That is why I said earlier, you need to check the intank fuel pump is even working - don't take it out, just jump it directly from the battery (correct terminals to use shown in my photo above)....takes 2 minutes to do.

If no whirr, then its bad, chuck it out.

[pgman]

...don't take it out, just jump it directly from the battery (correct terminals to use shown in my photo above)....takes 2 minutes to do.

This is my plan - it seems to be the most fundamental piece of the troubleshooting since this pump starts the whole process (by lifting the fuel up out of the tank). I just have to wait until this crazy tropical storm gets out of the area - geez...almost 20 inches of rain in the last three days! I certainly cannot work on fuel related things indoors, so I can't do anything for at least another day or two.

To answer Mike's questions, the in-tank pump is basically a sump pump - it does operate mostly submerged (except for probably the last 1/4 tank). I am guessing it is necessary because the high-pressure pump just can't create the suction necessary to draw fuel up over the top of the tank. I don't know how much pressure the in-tank pump actually builds, but I'm going go out on a limb and say it's not much.

I'll check back and report my findings once I've checked it all. For now, thank you so much for the suggestions. Any other thoughts or tips are always welcome.

[MikeH]

The other way to test the lift pump is to disconnect the electrics from the main pump, and then you should be able to hear it whirr if the ignition is on. That way it also tests the wiring to the pump, as well as the operation of the pump itself. I learned that one the hard way when I megasquirted one of my Sciroccos.

[pgman]

I'm back from a little break...and I've got the propshaft back in (with new bearing, carrier and rubber donut). WOW - what a difference a couple dollars in parts makes! The car drives SO much better now.

That said, I'm back to diagnosing this engine cut-out issue. I really believe it is starving for fuel, and I'm particularly suspicious of the tank / in-tank pump. I haven't tested the pump yet but I picked up a new one last night - it was in stock at the local auto parts store (which surprised them more than me, I think). They even had a new intake screen - these parts must fit something else! Anyway, I figure that, if I'm going to go through the trouble of removing the sender / float assembly, I might just as well replace these parts while I'm in there - the pump and screen were only $55 US.

So, I'm going to try this first and then, if the problem doesn't go away, I can at least know to look at the other pump. My goal is for this car to be a "regular" driver (if not a daily one) so reliability is fairly important. My girl lives about 85 miles from me so I need to be able to make it to her on the weekends! It's important!!!

I just have to say that I am thoroughly enjoying this car - even though my relatively short drives are generally marred by a finicky engine that wants to run sometimes and then just dies without warning. This problem, whatever may be causing it, is temporary and I will find and fix it eventually. I hate to throw parts at it, but I need to see inside the tank anyway, and for the cost of replacing it, the in-tank pump is certainly worth changing while I'm in there. I'll keep this thread going until this is resolved, but thank you all for your help.

[pgman]

It's been a while - time does fly. I discovered that there was still a prett good amount of debris in the tank - as well as very stale gasoline (despite filling it with fresh) so I siphoned out as much as I could and a lot of the debris came out with it. My local auto parts store happened to have the in-tank pump and screen IN STOCK. I was shocked, but it was all there $50 US, so I replaced both parts. It would seem the problem is solved. I had a couple hour long journeys since then - some of which was on the freeway. The car pulls very well now - to 90+ MPH on my GPS. I didn't dare push it beyond that. So, I think the issue was probably a combination of debris in the tank and a weak / failing in-tank fuel pump. Now, I just need to get this top installed so I don't have to be so paranoid about driving it. As it is now, my trips have to be very carefully planned and not too far from home because I'm fearful of a rain. The roof leaks badly.

For now, I'm going to consider the engine cut-out issue solved. Thank you all for your help. Next is the top...then, who knows.

For now... Cheers, everyone.