ALFAGTV6.COM

AussieGTV6 · Post by **AussieGTV6** » Mon May 16, 2005 4:10 am

Hey all, its been a few years since i have posted on an Alfa Forum as i havent been driving the GTV6 alot.

So i have been working on the car and its running perfectly when its cold, but as soon as its getting warm it falls in a heap and starts to misfire and drop cylinders out. Wont rev, and eventually stalls.

So far have done Injectors, fuel filter, fuel lines, drained tank and replaced fuel, fuel pump is working and good pressure. Spark plugs, leads are all ok, distributor cap and rotor replaced. Basically everything seeems to be fine. I have just got a new ECU temp sender so going to install that tomorrow and see if it makes a difference.

Anyone have any ideas?

Octopussy · Post by **Octopussy** » Wed May 18, 2005 8:05 pm

Could be a faulty AAV (aux air valve). It lets more air in on warm up so I'm guessing maybe its not closeing when the engine warms up causeing bad air/fuel ratio.

AussieGTV6 · Post by **AussieGTV6** » Wed May 18, 2005 8:47 pm

Thanks for that info, i am going into the worshop tomorrow to have another crack at it so that will be the first thing i have a look at. Im pretty sure its not any earthing problems as the car hasnt been driven in the rain once in the past 7 years and has lived undercover in a relatively dry environment. All the earths look totally corrosion free. In fact the whole car is corrosion free

So thanks again and i will post back here when/ if i remedy the problem.

AussieGTV6 · Post by **AussieGTV6** » Mon Oct 10, 2005 7:43 pm

Hello all, this is just a quick cry for help as the Gtv6 is still not running!

The problem is still that it will run perfectly when starting from cold, but only for about 60 - 90 seconds. It then falls in a heap and drops cylinders and runs very rough, eventually stalling.

The work carried out so far is as follows.

New fuel pump, fuel filter, fuel lines replaced or cleaned, and fuel pressure checked and is ok. Injectors removed and sonic cleaned and tested, all ok.

All usual air leaks checked and are ok.

All electrical earths checked and ok.

New spark plugs, new rotor cap and rotor button, spark plug leads all check ok, and have tried other ones with no change.

Have done Greg Gordons tune up routine and all checks out ok including sensors, injectors etc.

Have tried different air flow meter from running car with no change.

Tried new fuel pump relay with no change.

Tried new ignition coil with no change.

Fuse box all clean, uncorroded and check out ok.

In short we are looking for a problem that is out of the ordinary, and i would appreciate any help.

Seb · Post by **Seb** » Mon Oct 10, 2005 10:32 pm

My money would have to be on the dizzy. I´ve had similar symptoms when my rotor and cap was totaly worn. If You havn´t yet, try a new distributor cap and rotor.

Cheers /Seb

SamW · Post by **SamW** » Tue Oct 11, 2005 2:45 am

It could also be the exact opposite of what Octopussy wrote, maybe the AAV is working, but the actual idle speed is set too low, that would be when the engine is cold the AAV is supplying enough air to the engine, but as it closes, the true idle control valve is set to low and you loose your idle.

Does the car rev up any when it starts to die? If not, this would kill my theory. It also sounds like it could be an eletrical connection that is corroded and as it warms up, it starts to loose the contact. But that opens up all sorts of places to look...

Mottic · Post by **Mottic** » Tue Oct 11, 2005 4:56 am

You've done some good investigating, and eliminated a lot of possibilities. You did not however mention whether or not you've checked your fuses - I know, I know, trivial right? It's the least intrusive and you'll get lucky every now and then. #s 5 and 8 are FI and fuel pump on an '84 - can't speak for the earlier cars. I'm going to assume that once it runs for 90 seconds then dies, it won't fire up again for at least an hour or so - correct? If that's the case, I'm going to go with Seb on this one and suggest that you have a look at the distributor - I encountered the same scenario once upon a time... See if you can get your hands on a cheap used one and simply swap them out. The internals of the dist. contain a hall effect sensor that, when not functioning properly, create precisely the symptom you've described.

Best of luck - let us know how you make out.

MerrilGordon · Post by **MerrilGordon** » Tue Oct 11, 2005 11:26 am

I think Ryan (Mottic) may be onto something there although I have not had that same experience.

Here's another thought; have you pulled one of the cylinder injectors and had it spray into a jar when starting and idling the car? I'm wondering if the cold start fuel injector is providing the initial fuel and the others are not taking over the task. Probably a dead end, but worth a look.

Merril

75evo · Post by **75evo** » Tue Oct 11, 2005 11:42 am

How about the ignitor (the module under the coil). I know Chip had that problem with his 3.0. Would die after 3 laps on the track with no spark.

AussieGTV6 · Post by **AussieGTV6** » Wed Oct 12, 2005 4:43 pm

Thanks all very much for your suggestions and help.

I had another "play" with the car yesterday and pulled the AAV out and tested it as per Greg Gordons tune up specs. It is functioning correctly and closes fully when heated up, and is about half open when at room temp. I live in a quite warm part of Australia so it would seem that it is set up perfectly for our climate.

I have removed the injectors had them serviced and tested and they are all fine. I put them back in with new O-rings and new rubber inlet tubes that join the manifold.

I have used a fuel pressure guage to monitor pressure during start up and when the engine faulters the fuel pressure does not drop.

If you pull the spark plug leads off when the engine faulters there is still spark being delivered to all spark plugs. You can hear the spark jumping across from the lead to spark plug and i have been zapped a few times

I have tried a different temp sender with no difference.

The engine starts perfectly and revs very clean and sweet just as it is meant to do. It is firing on all cylinders and there is absolutely no sign of any problems. It sounds and feels perfect. Then it just suddenly faulters and thats it. You can keep it running by using more throttle but it is very rough and obviously not running on all cylinders. Then it eventually just dies.

So i was reading your posts and yes i have thought about the ignition module under the coil, but the fact is that there is still spark being supplied when the engine faulters, so i havent tried exchanging it for another one. The same goes for the actual distributor itself. I have replaced the rotor button and cap and spark plugs but havent tried a different distributor as yet.

As for the fuses, yes i have checked them, cleaned all the terminals, repaced the fuses with brand new ones, and run a volt meter over them to ensure that there is equal voltage on both sides. Its all very frustrating

So i shall battle on and check and re-check everything, but i am really running out of ideas. I may have to accept defeat and get the car towed up to a guy i know who is an Alfa Romeo expert. He has shelves and shelves of spare parts so its going to be easy for him to just keep on trying different things untill he finally gets the one thing that is playing up. Again thanks for all your help.

Post by **Zamani** » Wed Oct 12, 2005 11:41 pm

How about the L-Jetronic ECU? I had that go bad on me. It would die randomly.

AussieGTV6 · Post by **AussieGTV6** » Thu Oct 13, 2005 12:44 am

Hey Zamani.

I had thought about the ECU, but they just dont go wrong that often so i havent tried swapping it over for another one yet. It just doesnt seem like a ECU problem, i mean the car runs fine at start up so why would it suddenly change? As far as i am aware the ECU does not have a cold start setting as this is taken care of by the AAV, so i just cant see how the ECU could suddenly malfunction? The other thing is that it does it at basically the exact same time every time i start the car, almost like there is a sensor that clicks over and tells the ECU to either run too rich or too lean? I was thinking that if it was the ECU it would be an intermittent problem that would happen randomly and not at the same time every time.

Driving me nuts trying to find this fault

GTV6GPTT · Post by **GTV6GPTT** » Thu Oct 13, 2005 3:04 am

does the car drive?

if u hold the revs does it stall?

does it turn off always after the same amount of time?

has the AFM been touched\opened

SamW · Post by **SamW** » Thu Oct 13, 2005 3:06 am

This is a good one, you are right that it is strange to have it start and run well cold, then die as it warms up, almost like it is still trying to run a cold mixture as it warms, but I would not expect that to be such a sudden change. It really sounds like your fuel pump is not running, but you said you have checked for pressure. This sounds a lot like my car when I had FP issues. Maybe the AFM is not providing the proper signal to the ecu to keep the injectors firing, have you done any investigation into the AFM?

All I have for you is to recheck each connector and maybe swap an AFM if you have a spare one. Keep us posted.

DaveH · Post by **DaveH** » Thu Oct 13, 2005 4:06 am

It could be your ecu. The AAV, Thermo time switch, AFM.... several of your FI components are monitored or receive voltage or ground from the ecu.

Also have a look at the thermo time switch. He is also looking a bit guilty right now...

Open up the BMW 528i L-Jet schematic I attached for reference. It's a bit easier to read than the Italian L-Jet translation.

GTV6 Runs Perfectly Cold, Dies After 2mins. WTF?