Help needed with problem diagnostics.

Nov 28, 2003 10 Replies
E

I have a 96 2.0 Golf. NonUS model. Digifant fuel inyection. Yes, Digifant..



It has a driveability problem I will try to describe:


-starts perfectly, first try every time.



-idles perfectly.



-no smoke of any kind.



-very good mileage.



-Bucks violently if I depress the gas pedal too fast. Otherwise, ok.



-Seems to have a large lag on the gas pedal. I press it, count 1 seconda, engine responds...



-When shifting, drops to idle waaaaay too fast and makes smooth shifting very difficult. Shifting becomes a juggle consisting of raising RPMS back to 1500 before releasing clutch. Too fast, it bucks, too slow RPMS not up far enough and it almost stalls.



-has about 80% of the power it should. more power cold than hot.



Any ideas? Everything checks fine, no DTC...



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S

Vacuum problem? MAF? Maybe the fuel filter and/or pump.

Just thinking off the top of my head.

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E

changed all hoses does not have a MAF

believe me, Ive tried a lot of things :)

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J

I'm from the UK and i've been reading so many posts on this problem since my golf 1.4 Mk3 has been doing it. Replaced my fuel filter to no avail, getting VW to look at it soon, the more i read the more i think its the MAF.

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D

There's your problem right there. Digifant in a '96 Golf!? Was this a transplant? Did it ever work properly?

If yes, I'd suspect the throttle switches. Unplug the connector at the throttle body and bridge it with a paper clip. See what happens. There should be no resistance across the terminals at the full throttle and idle switches. Bentley/Haynes has a procedure for checking the switches methinks.

Darryl.

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P

I would clean the throttle body and the throttle body intake with throttle body cleaner. Clean it real good and check the intake hose for cracks. It sounds like that is your problem. The more power cold than hot is the key to the troubleshooting.

A set of new spark plugs, cap and rotor wouldn't be a bad idea either after you clean the TB...

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E

Original. SouthAmerica market car. Its not even the same Digifant you had, as it has no MAF. They replaced it with a vacumm sensor integrated inside the ECU module :)

Will check. I have a feeling this might be it... Maybe the IDLE switch is stuck in the idle position?

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E

ok. will do that. this car has no MAF, it has a vacumm sensor instead...

spark plugs are new, stock VW. cap, rotor and cables are at least 2 years old.... not a bad idea to just go ahead and change them.

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M

Also try cleaning the ISV. The coolant temperature sensor also is a common source of trouble and is cheap to replace. I had some idle issues with my A2 1.8 Digifant and resetting the ECU fixed it, although I'm not sure if the procedure for resetting the ECU is the same on your car as on mine.

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B

I'd say your problem is likely more than one thing... but the hesitation is probably due to arcing spark plug wires. Lightly mist them with wather and watch for arcing. Do this at night so you have an easier time seeing it.

Bob

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E

they are likely stock... (7 years old at least) so I will replace them...

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