Delayed and Lumpy acceleration Mk4 GTI 1.8 20V

[mak911s]

Hi Guys

Never had any problems really with the car, but this time looks like i may need a trip to a main dealer. ? ching ching ??

As of tuesday this week, the car has no get up and go.  Acceleration delayed and when engine does pick-up, its lumpy.  

Had all the plugs out and all look nice and brown.  car ticks over fine.  MPG fine according to trip computer, i reckon its better than usual though  

Had all the plug leads off and on and WD40 every connector i could see in the engine bay.  Still the same.

Cars a 98S 1.8 20V GTI and only done 39K miles, loses no oil or water.

Any ideas

[golfvr6]

Could be the dreaded coil packs, or a dodgey air flow meter.

[topher]

think its a non-turbo ? which means no coilpacks... agree on the air mass meter... posted answer to same question in mk4 section.

[mk1]

Ign leads ?.
Steve.

[kniterider]

right could be one of a few things matey!!!

leads etc will be fine (no problem on non turb 1.8 20vs)

it could be one of 3 things

right MAF sensors can fail or become 'dirty' these can be cleaned with a solvent areosol but some times has no effect,

or theses a temp sensor that fails (?20) with tells the ecu the engine is cold etc so adjusts fueling to suit (which can cause probs)

or (throught my experience after my engine rebuild) then inlet camshaft postion sensor can fail with will coasue seriously under powered performance and its also very lumpy and has some serious flat spots!!, i swapped mine and all was returned to good state!! (i also had 4-50 mpg readings whilst this was faulty!)

these are worth a try let us know how you get on!

Gaz

[mak911s]

Cheers for the responses guys

GTI is a 1.8 20V non turbo.

going to try the MAF first.  If cleaning it can solve problem, how is this done.  

How can i be sure it is the MAF.  No VAG-Com so was thinking of just disconnecting it going for a spin.  No change means its the MAF maybe?? but not sure how ECU will respond.  6 beers in me know so maybe tommorow.

Any ideas where i can get a cheap MAF also.  Breakers doesn't seem a sensible option if these parts fail often.  Parts pretty cheap in US < ?100 inc shipping

Gaz, your wheels are now shod on the brother in laws 1.6 MK4.  They cleaned up a treat.  

Mark

[topher]

disconnecting the MAF sensor will actually force the ECU to return to factory defaults for air metering. so if you unplug it.. and the car runs better, it's your maf sensor up the stuff (see my reply in mk4 section for advice on cheap maf sensors)

Chris.

[golfvr6]

I don't think unplugging the MAF is a good idea, the ECU will resort to a set reading, so the engine will probably run even worse as it will be unable to adjust properly to different air flow.
I tried disconnecting it once on the vr, the car would run but when you put your foot to the floor, it didn't want to know.

[golfvr6]

Has the 1.8 20v got no coil packs?
The 2.0 20v in my Passat has them.

[kniterider]

nah the 1.8 20v non turbo has one individual coil pack, which is not known to fail un like the individual coil packs ittted to the turbo models !!! (i have four coil packs for sale !! ?35 the lot!!) lol


Gaz