Random issues, can anyone help? UPDATE, ISSUES PAGE 3!!!!!

[katconcarne 0]

Finally got my vr back today, yay!

The problem;

1. Starts ok most of the time but sometimes takes a few (like 7) turns to fire up. This is because it sometimes takes the fuel pump a while to figure out it should be doing something. Anyone know why / how i can fix it?

and more importantly,

2. When accelerating there's no compensation fuel for the acceleration so has a flat spot then picks up and general performance is also down. Number 6 was overfuelling to the point of causing a misfire while other 5 cylinders running lean. Misfire cleared up when a fresh plug was fitted, and has been ok today.

Diagnostic test showed TPS was working, but came up with these faults;

G28 sensor

G40 sensor

ECU blocked

Lambda probe low voltage (passed emission test on MOT)

Fuel mixture adjustment limit exceeded

Whart's new;

2.9 rado throttle body, raceland manifold and a full service including plugs, headwork, chains, tensioners, clutch.... (you get the idea).

Can any of you clever people help me?

Has anyone ever fitted a 2.9 rado throttle body to their OBD1 vr and had problems?

Thanks guys, Katie (@)

[Jk* 0]

Im kinda new to the VR seen, but i would say with those mods maybe a remapp MAYBE necessary, and im kinda thinking that with those faults that they need fixing. Ideally replacing the parts?! Just my amateur opinion.

[mk3anni 0]

Remap not really needed.

What did you use to get those codes???

Vag-com or something else???

[gav_113 0]

hi katie.... ive got a 2.9 rado TB on mine and its even been bored out! came off a race spec engine i believe. anyway ive had no probs with it. your car would still run fine without a remap. i would say it is prob a sensor gone down and its chucking loads of fuel in, that would cause poor starting etc. hope this helps u?

[katconcarne 0]

Thanks gav, that takes the TB worry off my mind and now i can focus on the sensor idea, that's a good place to try first.

Steve, used a brand new snap-on solus diagnostic computer,

G40 is cam timing (hall) sensor and G28 is the crank sensor, but the guy said there was no signal from the crank sensor and bad connection to the cam sensor. Do you reckon these need changing or is it more likely to be a wiring issue? Any ideas where i should start with this? Would these timing sensor faults cause fuelling issues (major flat spot around 2500rpm)?

Thanks guys, i really do appreciate the help, sorry if i'm being a bit annoying it's just i've already been to 5 different mechanics and they're just not helping! Aaaaargh!

[mk3anni 0]

Would make more sense to change the sensors, or at least make sure there plugged in and the connections are good.

It would cause a flat spot because the ECU wont know where the engine is in its cycle, so the timing will be out by a country mile.

I'd start by cleaning the plugs on the sensors. If that doesn't solve it see if you can swap them for known good sensors, if not, get some nice shiney new ones.

[katconcarne 0]

Thanks dude, will try that ASAP, the way this is atm i think i'll be buying some sensors.

(@)

[tinny22 11]

kat if you want to try my sensors no probs but mine is a obd2 will that make any difference let me know you can call any time .if you are have probs i can call

tinny22

[mk3anni 0]

Crank sensors are slightly different between early and late but i think the only difference is a sealing ring.

[tinny22 11]

thanks steve hows your vr doing

tinny22

[mk3anni 0]

Ok thanks mate, cost me about £1500 in the last 2 months, i keep telling myself its worth it!!! Hows yours???

[gav_113 0]

kate ive had a similar prob with my vr, it was idling bout 1500-2000 all the time? went to loads of garages put it two computers, every one said it was the idle valve? changed it 4 times checked all wiring to ecu etc

today i changed TPS and all is fine again? but it didn't come up on the diagnostics?

so if i was u i would try and borrow a few sensors off peoples cars b4 u start buying loads, lucky 4 me i have a spare engine!

[mk3anni 0]

She didnt mention an idle problem and if the sensors are showing up they'll be causing the car to loose power.

[stockers 1]

was the flat spot happening after the chain work?

only there was chain work done on my last vr before i owned it and the timing was out,loss of power and a flat spot at 2000 revs, stealth adjusted the chains and all was fine

[katconcarne 0]

yeah flat spot after chain work. i think i'll eliminate the sensors being the issue first and if i still have the flat spot then i'll be heading over to stelth, thanks stockers.

tinny i'll give you a call to see when we can come round if that's still ok then i can try your sensors. thanks alot mate.

car runs mint on idle gav.

Thanks guys (@) fingers crossed it's just the two sensors i need to fork out for!

[mk3anni 0]

Stocker is right, could well be chains, but if the work wasnt done by stealth, and you get them to re-time it, they will charge you a shed load!!!

Re-timing the car properly is a gearbox off job.

[katconcarne 0]

Agreed. Just hoping it's gonna be the sensors! Don't think it'll be timing issue as it was done professionally and they're going to check over the work / fault codes on friday so i should know more by the weekend.

Like i said, fingers crossed!!

(@)

[stockers 1]

hope all goes well and its a £20 sensor, keep us informed

[lee060 3]

timing being out could cause the cam n crank sensor codes to be thrown up along with the mixture , correct ???

[katconcarne 0]

fuelling still not right when engine warm. it's running lean and there's no fuel compensation for acceleration so has flat spot on acceleration regardless of engine revs. any ideas?

i've replaced the cam timing sensor, sorted crank sensor, car went back on diagnostics and codes cleared. then re checked after drive and no faults, yay! performance seems a bit better now!

timing checked and is perfect. engine vacuum tested, showed all ok. so there must be some other fuelling problem.

hope someone has an idea, are fuel pumps known for being a problem with pressure drop? is it worth me getting an uprated one?

thanks, Katie

[gav_113 0]

have u checked fuel pressure with a reg?? i once had a kinked fuel pipe and that messed up fueling. wot about new fuel filter?? just sum ideas..

[Mk1dubzter 0]

Hi katie

the codes need to be cleared first off...

once this is done when problem occurs it will throw up crank sensor fault ..if crank sensor is faulty

running lean could well be maf sensor ...

[katconcarne 0]

Thanks mk1dubzter,

So the latest is, I've had the pressure of the fpr checked and set to standard, a walbro fuel pump fitted and new filter too. The timing has been checked and is perfecto. The engine has been checked for vacuum leaks (by spraying lynx all over it!).

There is still a problem with fuelling and it's got worse, really struggles to accelerate and will pop and bang to get past 3000rpm, driving really slow everywhere still sometimes struggles to set off. Any ideas?

There are no fault codes being thrown up, but will get it back on VAGCOM asap to check again. Could this be the crank sensor still, or does any one have any other ideas?

Does anyone know where I can get a crank sensor from for a reasonable price?

Cheers guys, hope someone can help,

Kat (@)

[mk3anni 0]

I'm certain its the crank sensor.

Thats exactly the symptoms i had when mine failed and it didnt throw up a fault on vag-com

[katconcarne 0]

That's decided that for me then Steve, thanks for the quick response. I wasn't sure with it not throwing up the fault anymore, I guess I need to spend some more money! Fingers crossed this works, I've got no funds left after this!

The VR is worth it!