Idle issues on my GQ petrol.

[Pegged]

Hi peoples, I've got a 1989 GQ Petrol Nissan Patrol and been having some idle issues.

When I'm driving around It's all good, but stop at lights or just idle it starts to run really rough and most times stall unless I do the old heal and toe trick to keep the revs up.

Vaccum lines, fuel filter all good and the timing is all fine so I'm lost unfortunately guys.

Really appreciate any feedback anyone can give me...

Thanks in Advance!

[Johnno]

Is it duel fuel by chance?

Sounds like the idle jet may be a bit blocked. Would be good to give the carby a clean out and see how that goes.

[Pegged]

No mate its just petrol. good advice ill try that this arvo and let you know....Thanks for that!

[Bloggsy]

Maybe the air intake manifold gasket?? Mine blew a hole in the gasket in the middle of the night on the way back from up north (WA). It was pretty severe from what I was told at the time, so much so I had to get the carby fixed. If I kept the revs up it would not stall when coming to a stop, but it would every now and again miss whilst driving if I drop the revs. Not saying this is your prob but could be something to check??

[Pegged]

I think you may be on the money there Bloggsy, just opened it up and saw the gasket had some cracks and looked a bit rough.

I'll get one tomorrow and see how it goes.

Thanks mate! :)

[Bloggsy]

I think you may be on the money there Bloggsy, just opened it up and saw the gasket had some cracks and looked a bit rough.

I'll get one tomorrow and see how it goes.

Thanks mate! :)

Good luck, hope that sorts it out for you.

[Pegged]

Success!!!

Thanks Bloggsy, replaced the gasket and it seems to be running 10 times better...

Ill double check tomorrow when i go to work but looking good.

Thanks for that mate. :)

[Bloggsy]

That's good to hear mate. fingers crossed

[Pegged]

Bloggsy, thanks for your advice, I took it to work today and it was fine, nice and smooth, didn"t stall, all good!

Thanks for your good advice, saved me money and a lot of guessing! :)

[Bloggsy]

Good to hear Pegged. Not sure about the advice bit - LOL!! more of something I experienced with mine, but glad to hear it helped. Happy 4wdriving :D

[Morton]

would this cause a backfire in the motor in my 4.2 petrol GQ? I recently had a massive backfire that blew a hole in the muffler, forgot about the killswitch & dumped heaps of fuel & started it up, it has since idled badly & backfires severly when coming down the gears to a stop, it damaged a plug which I replaced all six, runs much better at revs but then goes rough at idle & stalls, there does appear to be a slight sucking sound but it is to close to the carby to be sure it is the carby alone, would this cause the car to run rich or be fumy?

[Silver]

leaking inlet manifold gasket should let more air in for a given amount of fuel = lean, not rich, I think. If you have EFI I don't know what would be happening - but you mention a carbie, so I guess no EFI :-)

If we are talking about one of the gaskets in the carbie itself, then that's beyond me too :-)

Is the plug you refer to a spark plug, and was that damaged when the unburnt fuel in your muffler went ka-boom? I'm no expert, and can't see a connection, but if it happened at the same time, maybe there is a connection?

[Morton]

I think it was due to the timing being 20deg advanced, things were open when they shouldnt be, to much fuel in NO1 pot & down the inlet & exhaust manifolds, NO1 spark plug was cooked & not firing, the old muffler didnt like it much either, torn a 6in hole in it, I reset the timing, changed the plugs & adjusted the fuel & idle, it is alot better but not quite right, I think the inlet manifold is leaking as it idles up & down, I cant fiddle to much as it is over heating atm, I pulled the thermostat & tested it, found it was sticking so will replace it this week then have another go

[Silver]

G'day Morton,

A leak in the inlet manifold will make the engine run lean, which will generate heat.

If severe enough, a lean mixture will melt the top of pistons.