Faulty ECU/ECM?

[Cupra Turbo]

OK as some might know I've had poor starting on my Golf GTI since I bought it in March this year.

VW Golf GTI 2.0 8v SOHC Engine code: AGG (Simos Multi-Point Injection)

Now, I've had the Coolant Temp sensor replaced, spark plugs, fuel injectors, rotar arm, distribuator cap and summet else (i forgot what sorry)...

Now its still causing me grief and this morning failed to start at all and I had to call the AA!!

So, basically I've gotten the fault down to the Fuel Injection system, now I think with the Injectors etc I've got the "fuel" side covered but im still a bit bare on the "air" and "spark" side, so tomorrow I'm gonna put some HT (High Tension) leads in as its got 66k on the clock (1997 'P' reg) and they've never been replaced... but also I'm wondering about the ECU. Now this engine doesnt have an "Idle Stabilisation Valve" and the ECU controls the air flow so if its getting the correct amount of fuel but not enough air ... this would make it over fuel yes?  if so is the ECU faulty in this case? When I use the throttle to start the car it fires up pretty well, but if i dont use the throttle it coughs and splutters... so therefore im guessing its not getting enough air... whether theres a spli in a pipe is another thing too... but the garage (proper VW garage) said they've checked the pipes.

Plz this is really bugging me now and its getting to the stage where I wanna sell it and buy a... WAIT FOR IT.... SAXO!!!

yes well there cheap and im skint!...

so plz plz help out a fellow GTI owner, i wanna keep this baby its frigging immaculate on the exterior and interior, just this bloody starting problem thats causing me headaches.. im covered by warranty but only until March 2004.

Cheers

[mk1]

(good to see someone post the eng code ETC )
Deff do the HT leads as they are a weak point on VW. The poor starting, hmm, still sounds like it is too rich to me, ECU fault is poss but unlikely, the temp sensor is new, but is it working correctly?, is the ECU "seeing" the reading from the sensor?. Pull all the plugs on the fuel inj harness and check all the connections including the ECU plug. If all looks OK , down to a garage with a code reader that can read data at real time and do a cold start to see what is going on. The throttle switch and air mass sensor are also suspects, but you need to investgate further to find the culprit . Good luck, Steve.

[Cupra Turbo]

The other thing they put on was a "throttle Control Unit" and the "Throttle Body" has been cleaned out too.

Does my engine have a Mass Air Sensor? i dont think it does :-s

<---im looking at the Haynes Manual now.

They've checked all the sensors with their nice oscilloscopes and everything checks out ok.

[golfvr6]

I think your car will have an airflow meter. Did you get the car on a fault reader?

[The VolksWizard]

Has the dealer checked out the fault codes?
If the ECU is duff, they may not be able to interrogate it to read them.
I knew of a similar problem on a Mk3 1.6CL and that had had a recon ECU and was still struggling to cold start though the problem I had to fix was probably caused as a result of the original problem which was a faulty ECU.

Might be worth just trying a used ECU though the engine will cut out after a few seconds anyway thanks to the immobiliser in the key not matching.  If its under warranty I think you should insist on a new ECU, you should not be thinking of selling a car you like so much because the dealer wont fix a major fault like this.

Good luck.

[Cupra Turbo]

Well im taking the car on a 200mile run on monday... just to see if it clears summet out... if it carries on then... its going back to VW.

I'll ask for a new ECU, but Ill ask the main boss, not the dumb mechanic.

Its had alot of money spent on it and their just guessing now.

All sensors read off ok on the fault reader thingy that they plug into the socket next to the ashtray.

[golfvr6]

ECU or Fuel pump relay?

[Cupra Turbo]

How much "approx" is a ECU and a Fuel Pump Relay?

UK price please.

ta