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JTD problem, EGR maybe?

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egr
5.1K views 35 replies 10 participants last post by  adrianuxx  
#1 ·
Hello!

My Alfa 156 CW Q4 1,9 JTD is making me crazy.

The engine starts and run smooth at idle. But it does'nt react on throttle. After planting the throttle a long time it starts coming op towards 2500rpm when it wakes up and runs as normal from 2500rpm and upwards.

Wheb driving the past days it is like this from time to time. Sometimes it runs normally, and sometimes it is "dead" under 2500rpm.

No check engine lights or faultcodes.

I cleaned out the EGR this evening. Engine ran fine for a short time, then it started to do as before.

Some clues? Soon I trade it in for a petrol engine or something :mad:

/Gustav
Alfa 156 Crosswagon Q4 1,9 JTD
 
G
#2 ·
I had exactly the same symptoms with my 147 8V 1.9jtd about 2 years ago. To prove it just disconnect the wiring at the egr and drive. You will get the yellow engine light but the low down performance will be back. Buy a new EGR then get fault light reset. What kind of mileage you done mine was fine till about 85,000 miles/5 years old?
 
#3 ·
MAF? MAP also needs to be cleaned as more than likely thats all blocked with dirt, make sure you dont let any of the dirt fall into the inlet manifold as it could prove unlucky. also to check if it is the maf just unplug it and see if it reacts better. or do a diagnostics and see what shows up... you could also have split turbo hoses
 
#7 ·
It started this morning! Ran fine for a while, then started to be dead below at low revs and working fine just after.

The EGR is clean. And the hole to the inlet manifold as well. But is it possible to disassemble it more and lubricate it? Can I remove the black plastic cover at the electric end?

The MAF, is the one located after the aircleaner, right?! Not cleaned, yet. Just clean it with alcohol?

If I remove the electrical connection, does it only work at low revs, or all the way but with warning light on? Is it possible to block the opening in the inlet manifold and trick the EGR so that it believe it is doing something but actually just blows in to a steelplate or something?

Buying a new one is also an option, but I need the car to work fine until the new one arrives.

Thanks for all answers so far!

/Gustav
 
G
#17 · (Edited)
Hi Gustav, it works all the way up and down the rev range. The chances are that your EGR is working to a fashion and it is generally sticking at the lower revs in the open position, this is what is bogging down your combustion at low revs. I went down the same road as all these guys are suggesting and changed my MAF, cleaned the MAP to no avail, the split in a turbo hose is another red herring unless it is a completly severed, this results in more black smoke than lack of power.(been there done that) I disconnected my EGR and ran it for a month(just to confirm nothing else, admittedly yellow engine light was on all the time) before biting the bullet and fitting a brand new one, from shop4parts (sorry Jason, who is also a very good egg!)

I think the EGR fault can be different on certain models, some have feedback potentiometer with three connections in the plug and mine had 2 connections without feedback potentiometer (2004 model). My fault would not clear until cleared by PC or code reader. So maybe one that clears after three starts is on the feedback versions?

You could of course unbolt the solenoid part from the valve and tye it up in the engine bay if you don't want the yellow light, but this will close the valve and prove the EGR is the problem
 
#8 · (Edited)
Gustav: Yes :) The solenoid side seizes up with corrosion on that one. Search for the thread on how to strip it down and do it (it's from a vauxhall forum initially -same valve). Basically drill a 3mm hole in the end of the plastic case and drift out the assembly carefully. Put a screw in the hole on reassembly to fill it in.

Don't be too scared of doing it, it's quite easy but make sure you can't lose the internals while you're pulling it apart :D

Doubt you'll gain any advantage by unplugging it - it'll just stay in the position it's stuck in, IF it's stuck of course. You can't blank it off without registering a fault on the mjet models but you CAN get a perforated blanking plate that reduces the amount of gas / soot going through the EGR system.

Try and avoid cleaning the MAF just yet. Try the EGR first.

have you checked all the hoses (intake, vacuum etc) for splits as well? bear1 is right about the MAP as well - mine was choked up.
 
#9 ·
Gustav: Yes :) The solenoid side seizes up with corrosion on that one. Search for the thread on how to strip it down and do it (it's from a vauxhall forum initially -same valve). Basically drill a 3mm hole in the end of the plastic case and drift out the assembly carefully. Put a screw in the hole on reassembly to fill it in.

Don't be too scared of doing it, it's quite easy but make sure you can't lose the internals while you're pulling it apart :D

Doubt you'll gain any advantage by unplugging it - it'll just stay in the position it's stuck in, IF it's stuck of course. You can't blank it off without registering a fault on the mjet models but you CAN get a perforated blanking plate that reduces the amount of gas / soot going through the EGR system.

Try and avoid cleaning the MAF just yet. Try the EGR first.

have you checked all the hoses (intake, vacuum etc) for splits as well?
This is what i did and the car worked a dream afterwards. only problem was the MCSF warning was constantly on.
 
#11 ·
make sure you clean the MAP or else you will still have power problems, what happened with me before i bought a new MAP was i cleaned the egr thoroughly and put it back, no smoke but still lack of power, so i removed the MAP and that was knackered, bought a new one and cleaned the old one in case i would need it but all the power came rushing back. with regards to the maf no point in cleaning it as if it works it wont be for long. or you could just do a diagnostics and see what shows up, quickest and easiest way for you to know exactly whats wrong - if you do the diagnostics and it shows up as boost pressure sensor then its more than likely your MAP which is dead :thumbs:
 
#12 ·
One other thing to note: EGR fault should clear itself after three starts of the car, if everything is working OK (found out after the first time i cleaned mine and...erm...ahem...forgot to re-attach the connector!)
 
#14 ·
if you look at the egr from the front with the cover off move a bit to the left and you will see a many electrical wires and then screwed to the inlet manifold is a black L-shaped piece of plastic with a connector, thats your MAP takes 1 minute to unscrew it and unplug
 
#15 ·
Ok, thanks. I think I saw it yesterday, now I know what it is!

I'm more and more in to making a steelplate to go between EGR and manifold(block it). I know it is illegal but it just temporary until I can sort out the problem. Will tha engine crash or will it work just fine, just that the exhaust values(NOx) will be slightly wrong?
 
#16 ·
by crash you mean that engine will get destroyed i presume, it shouldnt but your turbo wont like it after a while, if i were you i would just clean the egr all over again, sometimes you might miss something, also it might be worth seperating the valve from from the egr and check that the spring is working correctly as if its damaged or anything then you will need a new egr
 
#18 ·
It is the EGR valve. Cleaned it and lubed the axle, but no effect. It opens a teeny weeny bit and the low rev respons is gone. Pushed the valve back to closed, mounted it on the manifold, and disconected the contact. Works like a charm! Ignites the "check enigne" light though, but nice to know wwat the problem is.

I'm going to make a plate between valve and manifold just until I get a new EGR. I have the same one as you have with only two pins. I have a OBD reader so I can take away the code later.
 
#20 ·
Nope, no error codes what so ever. Not until I disconnected the cable to the EGR, then it came on. Deleted the code when putting the steelplate between EGR and manifold, works like a charm and no error codes. Have driven abaout 50km since, still working fine.
 
#21 ·
I had exactly the same problem a couple of weeks back. However, went to eBay - ÂŁ30 for a cleaned Vauxhall egr. Took it apart to check solenoid etc before installing it. All ok. Sorted the problem and I now have a spare, once I've overhauled the old one. Car drives nicely again. Needed to clean the soot out of the inlet manifold when the egr was off though.
Interestingly though, I had very similar symptoms a while back, but it turned out to be a loose electrical connection to one of the injectors. Nothing up to 2500RPM then off like a shot. Resoldered connection did the job.
 
#22 ·
Sorry, forgot to reply my solution.

Disassembled the valve even more and cleaned the inside of the solenoid as Broadbandylegs describe. Rubbed, cleaned and lubed the piston so that it ran smoothly. After this operation the EGR works again. Probably you have to do this with a couple of 10000km between. Also installed at plate with three holes on the inlet of the EGR, this to reduce sooth clugging the valve.

Pictures here.

http://alfapower.nu/viewthread.php?tid=29693

Sorry for the Swedish language ;-)
 
#23 ·
Hi Gustav. Yeah it's the solenoid side that's the key to keeping the EGR working. I'm making it a yearly service item on mine as it does get a little bit of ingress over time (and at 600 miles a week i'm sure it'll be ready!). I think i'll try that blanking plate you've done next time it's off!

cheers

Dave
 
#24 ·
The plate actually is available at Alfa Romeo on part nr: 71751469. Or make your own, it's really easy, and cheap.

After some more km's my car is still running fine. With working EGR =)
 
#27 ·
ive ran a blank with a single hole as a test, started at 4 or 5mm and got fault code, increased hole size 1mm steps and ended up with a 9mm hole.this seemed to keep enough flow to keep ecu happy.
tried it for a few tanks and found no benefit so went back to std.
 
#30 ·
Yep, a hole is a hole, but hopefully a smaller hole will make it last a bit longer before clogging.

Blanking it needs fiddling with the ECU, and I don't know who does that in Sweden unfortunatly. Otherwise this would be the best and you would'nt have to worry about the Egr anymore. Tried to blank mine with a plate without holes, worked for a few km, then faultcode for unsufficient EGR function.
 
#34 ·
thats not really blanking it(their plate keeps enough egr flow to keep ecu happy), thats their answer to the problem. i like to think of it that the smaller hole or holes may or may not reduce egr flow, as they more than likely increase the egr gas velocity through the reduced area and also probably help cause turbulance to keep soot particles suspended in airflow and also mix better with manifold air to help prevent a power dip on egr opening.
 
#35 ·
I have made a plate with three holes, and that works. But I tried a solid plate first and then I got the faultcode. That's blanking for me, sorry for the misunderstanding.

Gustav, using tapatalk