hello

I have some problems with my Croma. It is 120 8v mutlijet.
Car starts normal but engine dies after around 5 seconds, every time. No fault codes stored. Injector nozzles were checked and are ok. My mechanic does not have a clue what is wrong with the car. Anyone alse with similar problem?

This is a tough one, it could be any number of things. I personally would cover the basics first by ensuring there is adequate fuel supply starting at the tank end and working forward, I am surprised there are no error codes because something is obviously not doing it's job, the other possibility and I don't know if this is right, some years ago I heard of a car with similar isssues and it turned out to be the immobiliser cutting in after a few seconds because the pickup coil around the ignition lock was faulty not allowing it to pick up the key code signal, a new coil cured the problem, that car would run for a few seconds and then cut out but restart if the key was removed then reinserted. As I say that is only a stab in the dark but you never know. Best of luck.

I agree it's strange that there aren't any fault codes stored. I don't suppose there's any chance that something could have been bypassed or mapped out in the past?

Could you check the simple things - when was the oil last changed, what does it say the dpf's condition is, does the mileage match what's on the odometer? At least if we can rule out an "adjusted" ecu we could trust it maybe?

If it's mysterious then it's 100% guaranteed to be the EGR valve, in my bitter experience anyway (sigh).

Joking aside, it's probably a good place to start looking. Here's my sorry tale - different symptoms but no warning lights...

https://www.fiatforum.com/croma-ii/314200-ing-croma-broken-down-again-any-ideas.html

Doofer said:

If it's mysterious then it's 100% guaranteed to be the EGR valve, in my bitter experience anyway (sigh).

Joking aside, it's probably a good place to start looking. Here's my sorry tale - different symptoms but no warning lights...

https://www.fiatforum.com/croma-ii/314200-ing-croma-broken-down-again-any-ideas.html

Click to expand...

Almost everything except a flat tyre seems to be linked to the damn things sometimes.

What do yoi think? Blank the egr off completely, give it a go and see what happens?

After mine broke down, it would restart for a few seconds before stalling. No lights or warnings - the low oil pressure one was just a one-off that never happened again.

I'd assume the EGR valve was fully open, so was suffocating the engine with its own fumes. It seems to me that the computer detects if it can't open it and displays a message, but doesn't care if it can't close it. This is the exact opposite to what would be logical - the engine would run fine with it stuck closed but they're probably only guarding against you removing it, as that would be bad for the environment or something.

immobiliser is working said mechanic.
I am going to try my luck with different mechanic. Firs he will need to check egr
thank you for your replys.

Good luck, fingers crossed you get it diagnosed quickly.

In case you haven't got it already get a VAG KKL cable off ebay and download multiecuscan so that you can have a look at what the ecu says for yourself. It's a lot more helpful than just looking at a code on a fault reader screen.

And try blanking off the egr anyway just in case. A thick piece of tin with 2 holes drilled for the bolts that keep it in place will do the trick for a simple test. It will throw on the check engine light on the dash and report insufficient reflow on multiecuscan but the car will run anyway. If it cures the problem get a new egr and a swirl mod gasket.

It doesn't take too long to fit and is very accessible at the top of the engine.

Another common and even easier to diagnose fault is the airflow sensor. Just unplug it, start the car and see if that helps.

Does anyone think that it could be a fuel problem?

Might draining / changing the fuel filter help?

Also, what kind of condition is your air filter in?

car still does not run. They are suspecting that the connection in the ECU connector for injectors is not ok. When car dies one of the injectors goes to +/- correction limit and then safety shut down. Saved errors are injector signal fatal. Injectors shut down in same sequence as firing order is.

Sorry to hear that.

Did you eliminate the egr valve and airflow sensor?

yes EGR and air flow are not problematic.
i am pretty sure that there is poor contact on the ECU side. Will try to sort this on tuesday and we will se . Lets hope for the best.

Have you tried disconnecting the maf?

Or check the ignition feed to the EDC Control unit.Its like something is turning it off like the key switch.

Or if you suspect an injector with to much static leak back,use the test kit on the injector returns.I can give you the part number of mine if it helps.

Or if by looking at the correction and compensation values you can pin point the bad injector,blank it off on the common rail with a ball bearing and flare nut.Then attempt to start it.This is what we do on industrial common rails.The values dont really help to tell whether its a fuel issue or a mechanical issue,they are there to show really what the fuelings doing to bring each cylinder near 100% efficency.

injectors are 100% ok. tested on Test bench. And also if you switch their position error does not move with the injector. Before I put new connectors on the injector side of the wiring inj. 1 was problematic. Now with new connectors error moved to inj.3.
correction can go up to -/+ 3 and anything above that injectors are switched off so the engine wont burn a hole in the piston. if I hold throttle above 50% everything is ok as soon as throtle comes below 50% Correction on inj.3 goes to +3 and engine dies.

Yesterday I checked connectors on the ECU side of the wiring and they are in wery poor state. I tried to squezze them a bit it is preety much impossible and now car dieas after one second. So I am almoast 100% sure that the cause of this problem is poor connection. Now I need to find new connectors to sort this out and everything will be ok (hope so)

ok but the connector to the control unit must be ok ish to let it start in the first place.There is a test kit that plugs on to the injector and the harness then plugs into this.It comes with an led and so you can watch the pulses every time the injector fires.As i say with the correction factor its hard to differenciate between fuel and mechanical fault.good luck.

ok I dont know what to do anymore.
Wiring from ECU connector B to each injector 100% ok. New crimp connectors on both sides (original tyco). Wires are not damaged. Engine starts without problems but still stops after few seconds. Saved one or more following errors p0262 (inj1), p0265 (inj2), p0268 (inj3), p0271 (inj4)

According to Fiat Croma elearn:
This error is detected during the diagnosis of the junction unit final stage if there is a short circuit to earth/positive or break in the connecting circuit at Pins xx and yy of the junction unit. The fault is memorized directly as soon as it is recognized. In this case the engine is switched off.

I followed the diag procedure from Elearn how to check if the wiring is faulty and everything is ok....:bang::bang::bang::bang::bang::bang::bang:

Internal fault on the EDC control unit?Remember the injector harness is just an extension of this circuit.I wounder if an injector soliniod has shorted internally.Really speaking the control unit should shut the current of to the offending injector.

Watch the requested and actual mass air just before it dies, if the actual mass air goes down drastically it's likely the EGR is going wide open. Watch the rail pressure to see if for some reason the injectors are suffering with the diesel pressure feed to them dropping off.

finaly
faulty ECU. ECU was sent to two different experts and first one said that ECU is ok and second expert found some problems (dont know what). He also did some simulations for 48 hours without any problems and faults after his repair. After that car worked without problems above 1500rpm and engine stalled below 1500rpm. He suggested that we need to try with different ECU so he programed another ECU and car worked without problems. Old ecu back and problems are here again.