Alfa Romeo Forum banner
1 - 20 of 56 Posts

·
Registered
Joined
·
129 Posts
Discussion Starter · #1 · (Edited)
Hi
I’d welcome a few ideas on troubleshooting a morning starting problem with my old car that I need for work (done >250k klm)

Symptoms:
Used to always start first time, then took a while to fire up on first crank. It would stop cranking by itself even though the key was in the crank position (I thought this was weird). Now struggles to start first time, but cranks strongly until I release the key. Usually starts second go but sometimes not convincingly. Problem only occurs in the morning (20 Celsius), never any issues rest of the day.
Generally driving OK, no performance issues that I have detected, perhaps a the odd splutter
Battery tests ok with carbon pile load tester. Voltage drops from 12.6 to 12.3 over night. Having to keep on charger. Alternator is charging OK. Starting issues do not appear to relate to battery voltage
I know I have a main bearing seal leak and there might be oil in the bell housing… not sure if that can interfere with the crank sensor operation
No fault codes stored
Recent repairs:
Fuel rail pressure sensor replaced. Crank position sensor replaced after stalling/starting problems (last repair). New battery July 2020. Starter replaced Feb 2021. Alt replaced Sept 2017. Plugs not due to be replaced.
Cam belt due for replacement at the moment
Troubleshooting so far:
I thought maybe the fuel pump relay might be dicky and swapped the fan and fuel pump relay - no change
Ecuscan tells me the actuators and relays work, fuel pressure is regulated at ~50 bar, lambda signals from each bank are the same, battery voltage 13.7v at idle. Don’t really know what else to check.
I carefully sprayed some gas around the engine bay looking for keaks, no change in RPMs
Spark plugs were dry sooty black but that was after idling for 10 mins, electrodes OK
Sprayed the MAF with some dedicated cleaner
Thanks
Duncan
 

·
Registered
Joined
·
4,127 Posts
Obviously you have diagnostic equipment.
Charge voltage through diagnostic equipment is a little low but OK.
Have you looked at live data and selected engine rpm whilst cranking? That checks the crank sensor.

How old are spark plugs?
Look at live data- things like spark advance to check that the system is trying to start it. Ditto check "starting authorisation" in live data for the same reason.

It could be you have an ignition switch issue but be guided by the results to these questions.

Sometimes the spark testers which fit on end of spark plugs are a great way to see if the coils are firing. It can save much checking of other stuff.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #3 ·
Obviously you have diagnostic equipment.
Charge voltage through diagnostic equipment is a little low but OK.
Have you looked at live data and selected engine rpm whilst cranking? That checks the crank sensor.

How old are spark plugs?
Look at live data- things like spark advance to check that the system is trying to start it. Ditto check "starting authorisation" in live data for the same reason.

It could be you have an ignition switch issue but be guided by the results to these questions.

Sometimes the spark testers which fit on end of spark plugs are a great way to see if the coils are firing. It can save much checking of other stuff.
Just a quck thanks and short reply as it is bed time here.
Yes I have a few tools but soon run into the knowledge wall 😬
Thanks for the crank sensor check method.
Plugs have probably only done 1/2 of their 100k life (not much driving since COVID)
Do you mean check spark advance during cranking? What should I see?
Not sure what starting authorisation is, I will check this out. What inputs are there for the authorisation - crank signal will be one I am guessing?
I have a COP test probe to see what is happening during cold start. Might be able to quickly check all coil packs if I am quick. If I was to use an old school spark plug tester how are the fuel injectors disabled?
Why would the car start first go during the rest of the day?
I should check to see if morning starting, stopping, and restarting shows different behaviour.
Testing could be tricky, and maybe take a couple of days as the cars will start on second or third go. Will have to use the logging function I guess.

cheers
 

·
Registered
Joined
·
4,127 Posts
Starting authorisation is just the OK via the immobiliser.
The ignition advance is just a way of checking that the module outputs are functioning.

Don't keep the plugs in for 100k km if you don't like changing coils. On that score, I suspect marketing people put pressure on engineers to schedule plug changes at 100k. They always look in poor shape by then. Even worse, the BKR6EKPA plugs are an alternative to the PFR6B plugs which I find superior. They are the type used in 24v Busso engines.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #5 ·
Thanks Fruity
I am still to complete the testing. Will do it tomorrow morning and report back.
Plugs are BKR6EKPA. Used to use single earth iridium ones in in my 33 because they were a bugger to get out.
Is it OK to spray WD40 or electrical contact cleaner down the ignition key lock, if there is a contact problem (although I am not sure it would get through the barrel and onto the contacts)?
I will try turning the ignition on twice before starting to see if there is a petrol pump priming issue and also look at the MCU fuel pressure to see if it sags a lot before starting. I believe it should hold pressure for a while.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #7 ·
Fruity, here are the test results. Do they tell you anything?
Did not get any data for ENGINE STARTUP. SPARK ADVANCE no data (software problem maybe), but no pinging

My observations ——
G1:
IGN ON: fuel tank pump is working , 7 bar, stable. I think his is normal.
CRANK 1: crank sensor working, high pressure duel pump working at 50 bar

G2:
IGN ON: Fuel pressure did not sag. Rising fuel pressure (after first crank) - not sure what this indicates? (Fuel filter replaced Feb 2021, pretty sure I also replaced the LP pump at some stage)
CRANK 2: FP and RPM OK

Still not sure about ignition system. Will have to check this tomorrow when it is cold using the COP probe.

Rectangle Font Parallel Pattern Electronic device

Rectangle Font Line Handwriting Parallel
 

·
Registered
Joined
·
4,127 Posts

That is really all that is needed to test spark plugs. The engine can run with these on for test purposes. The brighter the flash, the more energy is needed to make the plug spark which means worn plugs. No flash may indicate the coil cannot provide enough energy.

I'm not sure why your system does not display the spark advance. It should be around 6 degrees at idle and is a little more than a Twinspark engine uses (for obvious reasons).

The drop-out in engine rpm, especially on graph 2 is harder to answer (time count around 10-183). What would be really helpful is to see if you can get a graph or just check the live data when it won't start. When running, it seems OK apart from the rpm signal drop out but if the ECM saw that, it may record it as a fault code but not necessarily so. It depends on conditions. AFAIK, it is more likely to record an rpm fault code if the engine was running at speed, say 3000rpm and then nothing.

High pressure fuel pump delivering 50 bar pressure at idle seems good. That is what my JTS does.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #9 · (Edited)
Thanks Fruity

Not sure those spark probes would be visible in the hole with the coil pack inserted? Do you think they work on the 2.0 JTS?
I won’t be able to do anything more for a few days and get back to it after..
I might be able to read ignition advance using an OBD dongle and an app on my phone.
The RPM drop out was me stuffing around 🤭, I think I had to quickly turn it off and on to get the computer working, sorry should have indicated that. Just ignore that for now.

What is the best way to find the cause of a current leak? My battery stays at 12.6v for a long time when not connected to the car. When connected it drop to 12.3v overnight without opening the car doors (selespeed pump). It is also OK under load as mentioned above.

Thanks
Duncan
 

·
Registered
Joined
·
4,127 Posts
To check for current leak, it needs a multimeter connected in series to one of the battery leads. The trouble is door latches must all be in the closed position (even though some doors are open), same with bonnet. Then when all is switched off, after about 2 minutes, then disconnect the battery lead from the battery terminal so that all the current goes through the meter. Then you can look at the current draw. Even with alarm on, it should be not more than 0.03 amps, possibly half that.
Care must be taken though as any power left on may drawn too much current and blow a fuse in the meter. Ideally a inductive tester would be used to measure residual current drain.

I'd have the battery tested with an electronic analyser first though.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #11 · (Edited)
Fruity

Battery drain issue: Using a sensitive DC clamp meter on the negative cables. While the interior courtesy lights are on there is a draw of 10s mA only. However, when the lights go out (doors closed, no keys in ign.) the current drain jumps to almost 1 A. I don’t understand the test results. What could be the issue .. a relay gone short circuit in the off position ? Are there any ignition circuit relays (I don’t think there is for this car) ?
I am fairly confident that the battery is OK.

First start of the day issue: Battery/cranking OK (voltage remained >10V during start, also using a jump starter to support the battery made no difference either). Coils are firing OK when the car is running.
I need to check the coil firing on the first start - not done that yet. Needs two people, and only one go per day.

duncan
 

·
Registered
Joined
·
4,127 Posts
As you have been able to measure battery current draw (door latches set to closed manually but doors open), the way to trace the current draw fault is to pull fuses one by one and see which one makes the biggest difference. Before doing that, is there any non standard car hi-fi. Has it been wired to a permanent supply rather than through the ignition?
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #13 · (Edited)
All electrical equipment is unmodified, except for LED bulbs in the boot (pulled them out already but made no difference)
I could try a second key fob with a different immobiliser transponder chip
Going to replace all fuses with those that have the exposed terminals for ease of testing.
 

·
Registered
Joined
·
4,127 Posts
To recap, does your management system display data for injection time and spark advance whilst cranking?
If not, what is displayed for engine startup and key position when ignition is on (MAR)?
Rectangle Font Parallel Screenshot Number
Rectangle Product Font Material property Screenshot
 

·
Registered
Joined
·
4,127 Posts
If you are measuring residual current draw, the car must be in exactly the same condition as it is normally left. As I stated before, the door latches, bonnet and boot must all be set to closed even though the doors are open. If the alarm is set, set it on. Then wait 2 minutes before making any measurements. The the current draw is then more than 0.02 amps, start disconnecting the fuses one by one to see which circuit the current draw is in.
If it is higher than I stated, list which circuit makes the biggest difference and by how many amps.
I should have stated, because your car is Selespeed, don't attempt to measure current drawn within at least 2 minutes of opening doors or having the ignition switched on. I'm not sure how much current the pump will draw and I don't wish any damage caused to your multimeter.

I don't see any point trying a different key. What does the status of engine startup state?
What does MES state battery voltage is when ignition is on?
Do you have a multimeter to measure battery voltage? If so, what is it (ignition on)?
How old are the spark plugs? Are they in good condition?

Hopefully you will have the spark plug testers soon to confirm if spark plugs fire. I realise the plugs are down a well but there should be sufficient darkness to see them. I find they work on TS and JTS. If everything is in good order, the spark should be quite weak. If the spark plugs are worn, the spark must jump a larger gap so the spark is stronger.
 

·
Registered
Joined
·
4,127 Posts
I only properly read your last post after my last 2 posts. Sorry. You can use these posts for information but I'd check spark plugs anyway. For information sake, I prefer the PFR6B plugs to the BKR6EKPA plugs. They are cheaper and the BKR6EKPA were only offered as an alternative anyway. I'll disconnect my coils and see what my battery voltage during cranking is and report back.
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #17 · (Edited)
NGK plugs are 50K klm since new
I ordered some spark indicators but who knows when they will arrive, COVID is going crazy here in Oz.
MAR: engine light, brake light, oil pressure light, battery light. Engine startup parameter shows not data in MES.
Car Speedometer Steering part Vehicle Gauge

Personal computer Computer Font Operating system Display device

I only have the free version of MES (ver 3.5 and 4) and can only monitor 4 parameters. I also have a OBD dongle and an app. Neither show any spark advance signal during idle or revving. Engine key position only ever shows MAR.
Computer Personal computer Rectangle Font Screenshot


Battery voltage was low this morning so did these tests at about 12.3V
I never really fully trust the DC clamp meter at low readings. Zeroing it out means disconnecting the battery cable and then the car goes through its startup routine again
I will latch all the doors and bonnet and then check again. Get back to you with the fuse results.

Really appreciate your help 😀
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #18 ·
I latched the bonnet and drivers side doors. All accessories off. Everything else closed.
Key off: battery 12.7V, with Dc clamp meter zeroed, 30mA stable when battery reconnected
Then this sequence——-
MAR: 12.7V
Key off: 12.7V, 33mA
Passenger door open: 2.2A with int light on
Passenger door closed: 300mA stable
(If the clamp meter does not return to zero after disconnecting the battery at the end of the test I will stop relying on this result)

I replaced all the fuses with probe-able ones. Monitored clamp meter during replacement - clamp meter timed out during process so not sure if anything significant was detected.
With the car sleeping: I measured the voltage drop across each fuse and determined current - nothing much to report, some had a few 100ths millivolts, some started high and stabilised low, all less that 20mA). I have a high quality DMM I used for these measurements.

If I can replicate the high current possibly seen previously on the clamp meter, I will do this again
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #19 ·
I only properly read your last post after my last 2 posts. Sorry. You can use these posts for information but I'd check spark plugs anyway. For information sake, I prefer the PFR6B plugs to the BKR6EKPA plugs. They are cheaper and the BKR6EKPA were only offered as an alternative anyway. I'll disconnect my coils and see what my battery voltage during cranking is and report back.
I ordered PFR6B, take one variable out of the equation
 

·
Registered
Joined
·
129 Posts
Discussion Starter · #20 ·
Gave the clamp meter the flick.
With the DMM in series, 10A range, the sleeping current draw is only 16mAdc. I am going to monitor battery SOC while connected today to confirm battery drain again.
I load tested the battery again using a carbon pile: it delivers 270A at >10.2v for 15 sec and it holds voltage for at least several days (tested before).
 
1 - 20 of 56 Posts
Top