Engine Problems!

[FlySpeck]

Ok guys, need some help and inspiration here!

The car has started acting up....after cruising around 30 miles to work, or home this morning, it starts to slacken off when cruising at a steady speed and loses all engine power. If the clutch is dipped it will hunt at really low revs, occasionally revving itself a couple of times then cuts out completely.

If the throttle is pinned, it will accelerate hard, but wont rev if the throttle is opened gently or not enough, it will just splutter.

Weirdly - the induction hiss becomes very sharp and loud when it sits hunting - almost cutting out, then it dies. After a while, it will restart and run ok. EML is on, but no reader to get the codes out.

There was a bit of corrosion in the MAF plug, but after cleaning its just the same. Like I said, the oddest thing is the induction noise, its idling say, after the nonsense starts, at such low revs the counter wont display it, it will rev if the pedal is mashed, after a delay, but when its idling badly, the air filter starts to emit a loud hiss, then if it picks up for a bit (which it does a couple of times before cutting out) the noise drops to normal! Sounds like someone sucking the last of a mcdonalds milkshake when it does it, comes straight from the cone filter, not the engine, then goes quiet as it revs itself.

TPS???

Only started yesterday....I did hit a huge puddle in the dark 2 days ago, but it didnt even splutter when that happened, and now its snowing its started this crap!

Anyone else had this before I start fiddling with sensors? Still got 2 bloody nightshifts to do before I can take time to fix it but need a quick intro if I can get it, to not get stuck going to or from work....help!

I know all the usual obd stuff that can go wrong wi a car, but this may be something other VR owners have experienced? It has been decatted by the previous owner, and the O2 sensor is in the boot.....dangling from the removed cat...so the EML / CEL has been on and off because of that but it hasnt missed a beat till now.

Oh, and when this happens, it stinks of fuel (well a funny kind of fuelly / hot plastic smell) from the exhaust...and goes "brump brump brump brump" etc then revs itself twice and dies.


cheers

[christomk3gti]

could be a naff throttle body.. could be all gunked up???

Check for a vac leak aswell.

[FlySpeck]

you might have put your finger on it wi the TB gunk, that would explain the hissing, its coming directly from the filter, no vac leak as such but may be the problem.

As it drives ok for 30 miles or so before this happens, I discounted the usual leaks etc, but reckoned it must be a sensor, maf, tps etc as its perfect for the first half hour of driving then it starts acting up...

BUT it takes a big lump of throttle to cause it to rev, if the TB gap was gunked it would just not idle but would rev easy enough.....its weird.

[DazVR6]

Never seen an EML on my vr.....sure its not the oil light..?

Oh and i would deffo give the throttle body and all breathers around the pcv valve a good clean.

[FlySpeck]

well, the orange light that is the brake pad warning one, next to the red handbrake light - keeps coming on, although the handbook makes no mention of a CEL / EML etc I assume this light doubles as one?


I'm pretty sure the car is OBD1 (6 pin MAF) but surely it has a CEL?

Strange thing is, it will run like a top from cold for almost exactly 25 miles actually, and then starts acting up....

[FlySpeck]

Ok, its the MAF.

Disconnect it, and it runs sweet as a peach except it wont idle.

Connect it, and it backfires down the exhaust after a few seconds, hunts, revs itself then splutters out and dies, wont rev unless the throttle is mashed, obviously only reading higher levels of airflow but nothing below a certain level, but overfuels like crazy

[DazVR6]

well, the orange light that is the brake pad warning one, next to the red handbrake light - keeps coming on, although the handbook makes no mention of a CEL / EML etc I assume this light doubles as one?


I'm pretty sure the car is OBD1 (6 pin MAF) but surely it has a CEL?

Strange thing is, it will run like a top from cold for almost exactly 25 miles actually, and then starts acting up....

No you must have a issue with your pads coz there is no EML light, especially not on an obd1.
As for MAF's, yeh they are a known weakspot, try electrical contact cleaner before a new MAF, maybe the contacts are dirty/gunked up with oil from your induction kit.

[FlySpeck]

Ah ok cheers Daz, did wonder about that. Funny, that light is off now the ecu has been reset, but if I unplug the MAF, it comes on and stays on.......?

Must be concidence, I think if it was converted to obd2 it would have a 4 pin maf and not the 6 pin one it has now?

[DazVR6]

Ah ok cheers Daz, did wonder about that. Funny, that light is off now the ecu has been reset, but if I unplug the MAF, it comes on and stays on.......?

Must be concidence, I think if it was converted to obd2 it would have a 4 pin maf and not the 6 pin one it has now?

Yeh my vr was obd2 and was a 4 pin Maf. Thats well strange with the light though.

[FlySpeck]

i know, its doing it now. Just drove to the petrol station wi the maf unplugged, orange light is on solid, if I plug the maf in, the light goes out but it runs like a bag of spanners a few seconds after starting, and the light pops up. If i disco the maf from the get-go, the light is always on...

just bought a maf and a VAG405 Autec VAG scanner tool, £60 for that and £30 for a maf, hopefully get them monday, but might phone a few breakers up on monday if not, and keep the ebay one as spare if its late arriving.