Hi all,
I have a '81 GTV6, and a recently rebuilt 3.0 engine by Alfa Import Centre in New York. I've experienced hesitation in the gas pedal, especially at low speeds / little gas ever since then, it has never run right and I've spent thousands of dollars with different garages trying to tune it or make it run right. It feels hesitant, shaky, it fluctuates in its consistency when the gas pedal is held at the same angle. It's subtle but definately there. I don't think it lacks power when the throttle is pushed in deeply. At least, not that I can notice. I've had this problem for years and it's ruining my driving experince. Over these years I replaced a lot of things, but I really have run out of ideas.
Also, on the german motorway I had some oil being thrown onto the exhaust manifold on the driver's side recently, creating a big cloud of white smoke a few weeks back. I think it came out of the oil measuring stick-tube. It was hot and we were going really very fast (210 km/h). I think since then it's more hesitant. It didn't run dry on oil or anything, it was just a little, but it certainly scared me senseless. The fact that it couldn't go any faster than 210 km/h on the meter disappointed me though. I have a 2.0 four cylinder that gets up to that speed as well.
I suspect the ignition system. I've had a 'bobine' (thing that makes the spark, sorry don't know the english word...) with a crack in it before and it exhibited some similar behaviour then. The 'bobine' is fine, so is the rotor, cables, distribution cap and so on (all new). Therefore I'm suspecting the ignition module. Would that be a possibility? Or perhaps the main computer? I had an ignition module fail on me before when it was really hot a few years back, perhaps the new one is just shaky? They're hard to come by though, so it's not easy to test.
Then again, I'm really not sure, and my garage has no idea. Any pointers would be great. I know about the 'L-Jet guide' but that takes three days to work through and all kinds of tools I do not have. The garage can't find it either but then again, it's not their driving experience and they seem to be satisfied much earlier than I am.
Today I've spent 5 hours on the following:
- Cleaned all major grounds (including ECU)
- Checked all hoses for leakage with soap solution (I have greg's red hoses set)
- Fixed an iffy connection on the green wire going into the distribution housing (what's that for anyway?)
- Cosmetic stuff
It still doesn't run well. I'm beginning to also suspect that I might have poor injectors. When unplugging cylinder 4 when idling I hardly notice a thing. I also noticed a rattling in the lower parts of the engine when idling and at low revs. Could that be a busted oil pump? It's decisively not a 'knocking' sound.
Re: Poor running, hesitant, etc.
What ECU are you using, a 3.0 litre or 2,5litre(from your origional engine)? Have you done a compression test on the cylinders to check if the engine is OK? Is the camshaft timing correct? Good Luck! I am sure someone on the forum will be able to help you.