2L 16v problem, please help.

[Steve75 0]

From cold my Corrado is fine. After it's warmed up, the problems start. Suddenly it loses power especially as I am moving from stationary up through 1st and 2nd. I will be accelerating and it will just jerk almost to a stop then the revs kick back in and it flies forward. After this has happened, the car is idling at 1500 - 2000 and is quite erratic. Often if I have warmed the car up, leave it then start it up after 30 mins there is absolutely no power. Foot down the revs very slowly build up with a popping noise coming from the engine, like it's clearing something out. Then after a few minutes of this it's ready to go. It was also losing water before the head gaskett was done last weekend but don't yet know if it still is or not. Things I have done so far: head gaskett, new radiator, water pump, fuel filter, oil filter, ISV, Distributer and cap. The cam chain and belt are fine, the engine looks immaculate. Does anyone have any ideas or please can someone point me to a similar link? Thanks.

[davidwort 0]

Have a good search here on the forum, I'm sure there's a few posts with similar problems.

 

a few things to suggest are:

get the fault codes read, the 9A ECU isn't great for this, but it might pick something up

check all the vacuum lines and inlet pipes for leaks and splits

do the basic resistance tests etc for the temp senders, hall sender on dizzy etc, a Haynes passat manual 88-91 will cover the 9A engine

suspect the lambda sensor, they seem to cause a lot of probs on 2.0 16v's

try running the engine with both electrical connectors to the metering head removed, this should force the ECU to run the engine in basic get-you-home mode and by-pass a dodgy reading from the lambda

possibly clean ISV -although this doesn't sound like the problem

make sure the air plate in the metering head moves smoothly

check system fuel pressures with the correct unions and fuel pressure gauge

[Steve75 0]

Dave, thanks for getting back to me, I heard the lambda sensor can cause idling issues but I didn't think it could cause that much of a problem. Definitely gonna check it out now. Once again, thanks for your help with this..

[Roger Blassberg 0]

Ignition switch hasn't been mentioned. It's always worth changing that - it's a fiddle but cheap enough.

 

Best wishes

 

RB

[Jim 2]

I'd say the lambda probe is a possible place to get looking there, along with all the vac lines and air intake pipework. Even a small leak in one of those can noticably affect the running of the car, so if you've got a fairly hefty leak you may end up with very unusual results. Arm yourself with a can of carb cleaner and start spray it around all the black pipework in the engine bay.. spray it around the joins, etc in the pipes with the engine running and listen for any surge in revs or change in the way the car is running.

 

Going back to the lambda, a faulty one of those can produce wild results. Watched a car with a duff lambda once, and it would barely idle - virtually stalling, misfiring, belching out black smoke, very difficult to rev.. I wouldn't have ever thought a sensor could affect the car that badly to the point where it looked like something was mechanically very wrong with it! Its very common on the Corrado that its not actually the lambda that is broken, but actually the wiring to it which has gone brittle and snapped with age so.. have a good a poke around down there!