1.8t 20v Running Issues

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Gaddz#4
Enlisted
Posts: 18
Registered for: 10 years 10 months
Car Make: VW
Car Model: Golf MK4 Gti 1.8T 6 speed
Location: Kempton Park

1.8t 20v Running Issues

Post by Gaddz#4 »

Hi guys,

I'm having real trouble with my Golf Mk4 Gti (AUQ motor).

About 2 months ago my seals went on my turbo. I sent it in to have the core replaced. Since then I have had nothing but nightmares with this car.

I sent it in to have the exhaust done and while there the turbo was re-fitted with everything being re-tightened and checked.

It was running pretty rich and it had a bad flat spot if I pushed the accelerator pedal a little bit too hard.

While trying to figure out what was wrong I have replaced the fuel pump, fuel filter, fpr, spark plugs, map sensor, had the timing checked, replaced the cam chain, replaced the injectors with second hand ones from a running car, replaced the cam position sensor and the coolant temperature sensor.

So now the issues...

The car is idling very rough and splutters and backfires through the intake. I can hold the revs steady with the accelerator and it sounds great, but as soon as I let go or rev it up it goes back to its normal trouble.
If I rev the engine once it revs up well and sounds good but from the second time I rev it onwards it hits a flat spot (around 3500 and 4000 rpm).
It sounds like the ecu is cutting something, sort of sounds like launch control... (i haven't got software on the car)
If I hold my foot flat on the pedal it revs to 3500-4000 and holds there like its cutting until all of a sudden it opens up and revs up like crazy (good crazy).

The boost gauge shows 0.6bar throughout this happening.

I have no idea where to turn or what to look for and I can't afford to keep throwing money at the car to try figure it out but keep coming up short.

Please help if you can.
Any advise is highly appreciated.

Thanks in advance
Kyle 0768445352
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chucker02
Captain
Posts: 2966
Registered for: 11 years 2 months
Car Make: VW
Car Model: Citi ADY
Location: Bloemfontein

Re: 1.8t 20v Running Issues

Post by chucker02 »

Where are you based? Send Thanas a PM, he can sort it out
Current:

2006 Citi Golf 2E, Dictator, 4-2-1

Ex:
2003 Audi A3 1.8t, Thanas Tuned, FMIC, coilies, DP and exhaust
2007 Citi golf. ADY with Spitronics 60-2, estas 282, 4-2-1, coilies
Rides thread: http://vwclub.co.za/forum/viewtopic.php?f=11&t=183329
2002 Citi golf. ADY carb, estas 282, 4-2-1, GW delarey big brake kit.
Rides thread: http://vwclub.co.za/forum/viewtopic.php?f=11&t=157603
1971 VW beetle
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Killerwatt
VWCSA Member
Posts: 4819
Registered for: 15 years 10 months
Car Make: AUDI
Car Model: S3
Membership No: missing
Location: Brakenhurst

Re: 1.8t 20v Running Issues

Post by Killerwatt »

The standard ecu is pretty good at keeping air fuel ratios in check. Was the cat removed when you did the exhaust? That could have been the smell.

The inital power issue could have been a few things but most likely a boost or vacuum leak. If it coincided with the turbo change.

Was the car ever scanned for errors or were those parts just changed blindly? Your current issues seems to be related to cam timing but it's just a guess without seeing the car.

I see you in Kempton. Pop by to Panics Place, he will be able to assist.
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