Check engine light
 

Hello All,

I had my mechanic do a tune up on my 94 gti a few days back. plugs, wires, distributer cap, rotor and fuel filter. Ever since that my check engine light keeps coming on and off every 10-15 mins at random times. Is there anything I can chcek myself before I take it back to him. All the wires are secure and i'm sure he gapped the plugs right, but is there anything else besides that I can check so that I dont have to waste 1/2 a day at his shop and miss work?

I guess I should mention that whenever the light does come on, the engine misfires, dont know if that helps you guys.

temp
 

check your gauge on the bottom left... water tempp... where is it at... sometimes the older GTI tend to over heat alittle bit and have the meter near or on 110...

pick up a haynes manual for the car. It has a section on how to trouble shoot the check engine light. There are also all the codes so you can see exatcly what is wrong with it. I used it for my gsr and it wrked out great.

you have to get u'r car scanned.. u can't check the engine codes u'rself like on a honda.

OKAY GUYS! So i got it scanned...came up "Idle air control valve leak" Changed the part...which cost me $70 and the light is still coming on. WTF!!! such a piss off...I really dont want to pay agian to have it scanned but doesnt look like i have a choice

I dunno V-Dubs too well, but - idle air controll valve does exactly what it sounds like - it controlls yer idle electronically , but if its also fed by a vacum line thats the problem point, otherwise Id say its a bad gasket between yer IACV and yer intake. Have that area inspected, run yer engine at idle and stick a straw (or something like that) to yer ear and the other end near the problem part and listen for a leak (high pitched whine, or a suction sound)

where bouts are ya located? - I've got a OBD2 scanner (16 pin I believe) and I can scan ya cheap (like $10-20) - not sure if it'll do yer VDub, but its worth a try if ya want

I say take yer ride bakk to the mechanix and bitch him out, let him fix it at his expense (government kinda regulates mechanics parts and labour for aprox 5,000kms or 3 months), so go bakk and fuss

does it misfire at idle, upon acceleration, cruising speed?????

If you've fixed the supposed issue and all looks fine, and you're still getting the CEL, try looking at your o2 sensor. When your car runs too rich/lean your ECU picks up on it, and could cause misfiring/bucking. You say the light goes off eventually, which means the ECU is trying to fix the issue, but to no success. Start with the o2 sensor and work from there.

if it was the O2 he would have had a fault code for that too...

either way, I'd first check to make sure you have no vacuum leaks... if everything is ok, i'd get it scanned again... if it's the same code, then i'd look into the wiring that's going to the ISV.