Here we go. You guys are gonna LOVE this problem

[crazybiker]

Alright, I took the car out for a drive last night, started all good.

Then, on the way back, driving straight line, it started stuttering. As if the ignition was being turned on and off really fast, repeatedly. That happened for a few seconds, then stopped.

After that, everytime, the car would attempt to idle, it'd stall. So slowing up for a set up lights, and coasting it, would have the car stall. Reversing in my drive-way, car would stall (That is NOT cool. Fence AND telegraph pole coming with virtually NO steering and brakes).

I have NO idea what it is.

This happened before, and I replaced the CAS. That wasn't the problem the first time. So I replaced the TPS. That seemed to have fixed it, but obviously didn't, the problem returned. So it's not that either.

The thing is though, it doesn't happen all the time. It is VERY intermintent.

I was just speaking to Greenfoam about it, and he suggested a few things.

ECU - Possible. Not sure.
Coils - Can't be. They all wouldn't fail at once.
Plugs - Shouldn't be. Were replaced less thant 5000kms ago.

[Tom_1569]

Coils - Can't be. They all wouldn't fail at once.
Plugs - Shouldn't be. Were replaced less thant 5000kms ago.

Could be missing enough (the stutter) to cause it stall at idle, but Id be checking out the DFI module before coils.

Plugs - Not uncommon to get a shotty plug, did you have the problem with your old plugs? If you didnt, whack your old ones in or a known working set and see.

[Eliminator]

DFI module which controls the coils would be a good place to start, if its happening after the motors being driven for a while then it will be an electrical parts failing due to heat.

[crazybiker]

Could be missing enough (the stutter) to cause it stall at idle, but Id be checking out the DFI module before coils.

Thing is, it only did the major hiccup once. It didn't miss when it was stalling. It was just that one occurance basically.

Plus, it doesn't miss when I give it a boot full.

Plugs - Not uncommon to get a shotty plug, did you have the problem with your old plugs? If you didnt, whack your old ones in or a known working set and see.

From memory it was fine before hand. Yes, get 1 dodgy plug, but SIX. I don't think so.

DFI module which controls the coils would be a good place to start, if its happening after the motors being driven for a while then it will be an electrical parts failing due to heat.

I was thinking DFI module. But is there anyway to test the DFI module without going out and buying a new DFI module?

[Tom_1569]

Thing is, it only did the major hiccup once. It didn't miss when it was stalling. It was just that one occurance basically.

Plus, it doesn't miss when I give it a boot full.

From memory it was fine before hand. Yes, get 1 dodgy plug, but SIX. I don't think so.

I was thinking DFI module. But is there anyway to test the DFI module without going out and buying a new DFI module?

Ok, if it only stuttered once, then I doubt its the DFI aswell, as they will really stutter/miss underload (giving it a boot ful). Same with the plugs really.

It still has the symptoms of a TPS, but you've replaced it, and I havent heard of a faulty new one of them.... YET.

[crazybiker]

Yeah. The TPS is damn near bloody new.

It's barely done 1000kms.

[danja]

Does the 3800 have an IAC valve? That's where I'd be looking, given it's an idle stalling issue.

Is it perfectly fine when the throttle is open?

[Eliminator]

I agree as well, i thought once the problem started it kept stalling, but if your going flatout and its accelerating fine with only the sinle hiccup id doubt it is the coils or dfi as they would only get worse especially under load.

dry solder joints in the ecu sounds like a possible issue, try changing one over with one of your mates maybe? and im guessing you have no fault codes?

[crazybiker]

No fault codes.

Possibly an IAC.
Possibly an ECU.

Greeny suggested the ECU.

I'll give the IAC a clean. What's the suggested way to clean it?

[danja]

I'll give the IAC a clean. What's the suggested way to clean it?

Carby cleaner should do it. You'll find there's tons of gunk inside the thing (lots of black carby cleaner dripping out). Do the best you can, if that seems to fix it you might just want to invest in a brand new one. They are only about $30 from memory?

[crazybiker]

I was just speaking to greeny again, and he suggested that it more than likely shouldn't be the IAC.

Not with the miss whilst cruising.

It DEFINITELY has to be electrical.

The chances of it not breaking down in higher revs, IS possible, just rare.

They can really break down at any revs.

Greeny still reckons that the DFI is the culprit.

[VrWagz1]

Only because its not logging a code, i say it is likely the fuel pump could be worn, fuel filter blocking up or intermittant wiring fault to the fuel pump, failing fuel pressure regulator.

I would also be looking at water ingress in an electrical plugs

[DavoVP]

Mine does the same thing aswell, but its a manual, so its not so much of a drama more an anoyance,

After i exhausted all the posibility's ( runs on gas aswell ) I learnt a nifty trick that seems to saught it out.

If the car dies when you let off and wont idle, what i do it, hold it as close to possible to idle with my foot and slowly ease my foot off the go pedal while giveing the car time to adjust, if the revs drop to much, you went to fast, repeat again untill it settles.

I also get a stupid wierd high idle from time to time, but that vanishes by its self.

The other way i found if fixing it is turning my aircon on, seems to work well. idle dies down or picks up to right where its ment to be.


Without fail though it always runs well on petrol no matter what.

Its worth a try man.

[crazybiker]

Only because its not logging a code, i say it is likely the fuel pump could be worn, fuel filter blocking up or intermittant wiring fault to the fuel pump, failing fuel pressure regulator.

Fuel pump and fuel filters are fairly new. Plus. It's fine up at the limiter

Mine does the same thing aswell, but its a manual, so its not so much of a drama more an anoyance

Mines a manual too.

After i exhausted all the posibility's ( runs on gas aswell ) I learnt a nifty trick that seems to saught it out.

If the car dies when you let off and wont idle, what i do it, hold it as close to possible to idle with my foot and slowly ease my foot off the go pedal while giveing the car time to adjust, if the revs drop to much, you went to fast, repeat again untill it settles.

I also get a stupid wierd high idle from time to time, but that vanishes by its self.

The other way i found if fixing it is turning my aircon on, seems to work well. idle dies down or picks up to right where its ment to be.


Without fail though it always runs well on petrol no matter what.

Its worth a try man.

But I don't want to fix the problem temporarily. I want it completely fixed.

[Eliminator]

whatever the problem is its going to be a hit & miss until you actually find the fault if its a heat related issue causing an electrical part to play up

[danja]

I was just speaking to greeny again, and he suggested that it more than likely shouldn't be the IAC.

Not with the miss whilst cruising.

It DEFINITELY has to be electrical.

The chances of it not breaking down in higher revs, IS possible, just rare.

They can really break down at any revs.

Greeny still reckons that the DFI is the culprit.

I'm not going to claim to know more about VN's than greeny But I'd still give the IAC some carby cleaner to loosen her up anyway - for a $2 can of spray and the 10mins it takes, what's to loose?

[Vg-ute-mad]

Learn by my mistakes and don't spend any more money with d.i.y. Take it to a E.F.I specialist and get them to hook it up to the diagnostics machine. I had the exact problem with mine, and even though you have replaced the C.A.S, mine turned out to be the C.A.S and oxygen censor. They went at the same time lol.

[VN_Luke]

Truly intermittent problems that aren't readily re-created are, in my experience, generally a sign of poor connections or busted up wiring.

I would be looking at all the connections in the engine bay and to the ECU. - particularly all the connections for the relays in the fuse box in the engine bay. (these have a nasty habit of pushing through the plate they sit in when you replace a relay - which makes them intermittently connect/disconnect)

so what I would do to start with, is open the hood, start the car - then start moving and jiggling every bit of wiring/electrical equipment/plugs/sensors/relays/fuses/etc that you can see until the car stalls.

Then repeat and repeat until you can consistently make the car stall. Once you've done this you will have a much better idea where the fault lies, and you have a starting point for cleaning connectors and checking wiring etc. - try starting by jiggling the relays in the main fuse box in the bay with the car running - (i have a sneaking suspicion that it will be the EFI relay not contacting properly)

Have you done any electrical work at all to the car in the last few months?

Has anything been exposed to water moreso than usual?

[James_yo7]

i didnt have time to read all the replies so this may have been covered but maybe something like simple fuel pump??

[pow3rslave]

i had mine stall at fullish lock going round a corner. when the car stalled the steering lock pin kicked in and it mounted the kerb. i was having problems with the speedo sensor at the time, and i got a new one and never had a problem again. is yours ok?

[crazybiker]

Well, I know that my Speedos working fine.

At Luke, I guess I'll have to try that.

[VN_Luke]

well, i know that my speedos working fine.

At luke, i guess i'll have to try that.

have you done any electrical work at all to the car in the last few months?

Has anything been exposed to water moreso than usual?

. ...

[crazybiker]

Sorry. I was at school on my laptop, I couldn't easily give a full reply.

I've done electrical work, I ran a sender wire from the engine bay into the cabin for my gauges. But I can't recall if it was then that the problem started occuring.

I hit the engine bay with a gerni a while back aswell.

[VrWagz1]

A dude a while back was having troubles with rough running. He found heaps of water i think it was in the plugs under the engine bay fuse box.

[crazybiker]

Well, I've just been fiddling around with the car, and I've pinned it down to electrical

Na. It's something with the ECU.

As I wriggled the connectors going to the ECU, it would make the car stall. I also pin-pointed it down to the blue connector, the small one. Now, we don't know whether it's the connnector itself, or it's the ECU end.

Anyway to test WITHOUT getting a second-hand ECU?

I really hope it is the ECU end though, I don't want to have to change the entire wiring harness.