Motor not running right.

[DANNY8]

I've got a 1991 Mitsubishi L300 van (2.0L carby). For the last few days sometimes (every 10-20 seconds) it starts losing power. Like my foot will still be down, but it dies down, then comes back to life, then dies again. Sometimes it does it until I'm idling up the road and I have to pull over and wait for it to finish cracking the ****s then it will go again for a while.

I thought it could be fuel related coz it was gettin low, but filled her up a bit but still hasn't fixed it. Put a new fuel filter in it but still hasn't fixed it.

Also tried spraying WD40 everywhere on the electrics incase it's gotten wet recently from going through puddles from our recent rain.

Any ideas?

[VT-565]

fuel pump maybe. cheap to replace, worth doing anyway.

[Deltak]

It may be an air leak into the manifold. See if you can locate the PCV valve (Positive Crankase Ventilation). This gums up over time.

Take it off the car and se if it rattles (should). If it doesn't spray "carby clean" or some petrol through it and try to free it up.

If the PCV valve is OK start the car, and using WD40 or similar, spray arround the gaskets on the manifold. You may find the leak when the motor revs up.

Just my two cents worth

[DANNY8]

Thx guys. Fuel pump seems like a possible suspect. Sprayed WD40 around the base of the carby and the intake, but nothing. Took off a hose which goes from the rocker cover to the carby (not sure if it's the PCV valve), but it stalled, started it back up and it would run without if I gave it some revs, but wouldn't idle with it off unless I had my finger on the end. But yeah not sure if that was the PCV valve, didn't look like the one's on the ol' Commo's anyways.

Might go to Repco 2morrow and get a price on a fuel pump. Doesn't the carby and intake and all that have to come off to remove the fuel pump? I think on my old L300 we had to remove the manifold b4 the fuel pump would move....not sure tho.

Took it for another spin and all through 1st seems ok, but when 2nd gets up in the revs it starts jerking, until it eventually dies (doesn't stall, just have no power, my foot stays to the floor all the time), then it starts jerking a little again and comes good. 3rd gear does it to, haven't tried 4th or 5th coz I'm in town so can't go much over 60

[VT-565]

Just sounds to me like the fuel supply is a little erratic. Let us know how you go.

[maginoodle]

i would be checking all your vacuum hoses. a few years back a mate had an L300 and he told me his dizzy was no good. so i changed it and it ran good. 2 days after that it started doing the same thing, so to rule out the dizzy i put the original one back in. it ran good, so he took it 20 mins later he was back it was running rough again. so i swapped the dizzy back over it then ran good. i then got him to watch exactly what i was doing, it turned out that where i was resting my hand was on a split vacuum hose and when i leant on it it would seal for a while the open back up later.

[VT-565]

i would be checking all your vacuum hoses. a few years back a mate had an L300 and he told me his dizzy was no good. so i changed it and it ran good. 2 days after that it started doing the same thing, so to rule out the dizzy i put the original one back in. it ran good, so he took it 20 mins later he was back it was running rough again. so i swapped the dizzy back over it then ran good. i then got him to watch exactly what i was doing, it turned out that where i was resting my hand was on a split vacuum hose and when i leant on it it would seal for a while the open back up later.

lol it really is that simple sometimes.

[Shounak]

I've got a 1991 Mitsubishi L300 van (2.0L carby). For the last few days sometimes (every 10-20 seconds) it starts losing power. Like my foot will still be down, but it dies down, then comes back to life, then dies again. Sometimes it does it until I'm idling up the road and I have to pull over and wait for it to finish cracking the ****s then it will go again for a while.

I thought it could be fuel related coz it was gettin low, but filled her up a bit but still hasn't fixed it. Put a new fuel filter in it but still hasn't fixed it.

Also tried spraying WD40 everywhere on the electrics incase it's gotten wet recently from going through puddles from our recent rain.

Any ideas?

I had those kinds of problems on my motorbike, it was that the carby needed a good clean out. You can have blockages inside the thing. Usually you have to pull it apart and sometimes even spray water through to see it.

A good clean out generally fixes it. Otherwise, a 2nd hand carby from a wrecker might do it. It could also be a blocked fuel filter.