Strange problem?

[kyle-reece]

I've got a 1990 e39a vr4 and I've had it in the shop to fix this problem before but no luck..

First of all every now and then the car won't start, il have to give it gas and mostly on the 3rd time I crank it, it'll start up.

If I've been going above about 80km and the car is quite warm, when I come to a complete stop the car will stall on me but start first pop straight away. If I rev the car up a bit before I come to the stop it won't stall?

The strangest problem that happens hardly ever. Is when I'm cruising the car will all of a sudden start jerking and my revs will be jumping every where and back firing like I'm running out of gas. I usually have to pull over let it cool down abit then she's good to go.

Its got all new coil packs, plugs, leads, starter motor, idle control sensor.

It's got a 3" exhaust, waste gate, bov, 450cc injectors, and a td05 20g running on 10 psi. The car was doing this before the new turbo by the way.

 

[evo-gsr]

Sounds like some kind of fueling issue to me.

 

[4piknup]

Post a log...

 

[evo-gsr]

Australia Post won't send human waste Jack !

 

[Ross Cox]

Jamo may have it. Check fuel pump pressure, before and after the filter, that may indicate clogged fuel filter. If you still have the original fuel pump it may be a bit stuffed. Replace it with a Walbro 225. They are an excellent replacement. I would maybe think about getting 510cc injectors although running a 20g at 10 psi the 450cc should handle enough fuel.
Good luck, I hate intermittent problems.
Cheers
Ross

 

[kyle-reece]

Yup just put some 510's on and just wound up the idle control up abit. Seems to be working fine for now. I'll change the fuel pump after the new year and look and getting a tune

 

[4piknup]

Australia Post won't send human waste Jack !

Post it to jamo and put some perfume on it.

 

[evo-gsr]

At least I know where we stand now Jack....

 

[4piknup]

Its a race to the bottom rung as far as Im concerned.

 

[kyle-reece]

What kind of boost could I run with 510s, 255 walbro and a 20G?

 

[kyle-reece]

Okay so I've had the fuel pump replaced and it's now 90% solved.. However SOMETIMES the car will still stall while idling, it will just decide to cut out on me. And some times the car will have a slight miss and splutter cut out for a second then carry on as usual. This will happen when cruising in either 4th or 5th gear doing 40kph+.

I've spent a lot of time and money already, fuel pump, plugs + leads, new 20g turbo, chopping and changing between my injectors, idle control motor, alternator and starter motor + a lot more. I'm really losing my patience with it as I'm not mechanically minded to do a lot of the jobs myself and no mechanic or sparky has been able to solve my problems. I NEED HELP! I'm willing to pay membership and buy stickers if that helps..

Also my alarm has a mind of its own sometimes beeping while arming/disarming and sometimes not beeping. Not sure if it's important but who knows!?

 

[evo-gsr]

Did you also change the fuel filter by any chance?

 

[kyle-reece]

Yup fuel filter was replaced a few months ago

 

[BMGTZ]

dodgy immobiliser?

 

[evo-gsr]

Try bypassing the immoboliser and see if that helps?

 

[kyle-reece]

Is it a basic job? Where do I start haha

 

[4piknup]

Look under steering column with lower cover off. A fat wire will be cut and will have thinner black wires . You need to rejoin the fat wires.

 

[EVO-00X]

You might also have a vacuum leak and producing very low vacuum at idle, causing it to stall on you when you slow right down.

 

[kyle-reece]

The car will barely stall when I slow right down now. Since I've had the fuel pump replaced, the cars been pretty much fine. I drove around for hours yesterday and the car didn't skip a beat. Today however... Car spluttered, and stalled at the lights and was spluttering all the way down the road. Revs all over the place then cut out took me about 5 mins to get it started again..

 

[MDK87]

Have you blocked the fast idle air valve off?
I can't remember where it is on the cyclone manifolds.
Buggered FIAV doesn't usually cause sputtering under high loads or hard starting, but it'll usually cause the idle revs to 'hunt' - go up and down on it's own, like you described.
Who knows, maybe you have a weird one, or maybe you have a FIAV problem in conjunction with another problem.