KA24E Stumbles and misfires

[kyle1911]

I have a KA24E that stumbles and misfires at idle and occasionally around ~2500RPM whilke driving.

It has 220 000KMS and has an odd oil disapearing over 3000kms problem, it has no traces of burning oil in the exaust, I belive it is the valve cover gasket as I can see traces of oil around it.

I checked all connections with:InjectorsMAFSTPSO2 sensorPulled plug wires to see if I could isolate the problem but that turned nothing.

Also I pulled the plugs and it appears that its runnign lean on cyl 2

There is a crack all the way around the stock manifold between cylinders 2 and 3 but I do not belive the loss in backpressure would be the cause.

What other solutions should I check?Is there anyway to check the timing without a light?

[eddiec]

thats quite a few miles. i'd check youir vacuum lines to see if any are cracked/broke. my de was stumbling and idle was off a little. found a cracked vac line and fixed it and my problems.

to check the timing just listen to the motor. after loosening the distributor, turn it a little in both directions. the exhaust note will change as you adjust the timing. just set it when it sounds the best and you'll probably be in the ball-park. the best way to set timing has to be with a scantool like consult that tells exactly waht the timing is all the time to the degree.

[kyle1911]

Yeah, I checked and there are no vac lines that are cracked.

I am not loosing alot of power, it feels like im running on 3cyl or less, it started bucking and loosing alot of power when I turned on any of the accessories. leading up to backfiring along with loosing power to the point that I had to pull over on the highway. once the manifold came back to regular temps I could keep up to highway speeds again.

I have a feeling it is the distrobuter rotor as it seems like its skipping some cyl on the rotation.

what do you think is the cause?

[ca18datsun510]

has the car had a tune up recently? if not, change the cap and rotor, etc.

could be a bad plug wire. check the intake for holes. soemtimes the rubber cracks and causes the mafs to get screwy

check back after this

[kyle1911]

No tune up recently, I replaced the alternater yesterday cause it appeared to be loosing power while i was driving causing it not to spark. I also put on new plug wires and rotor cap, eye balled the timing.

The problem is more consistant when the engine is warmed up.

When I am coasting and get on the accel about 25% it goes dead as in no combustion than jumps to life with less power than ever.it stumbles when i am driving and backfires occasionally when i start to accel while moving.

I also checked vac lines for leaks with no sucess,.

[NateDogg]

I would look at the fuel system. Leaky injectors, clogged fuel filter and a failing pump can cause the symptoms you describe, especially with an old KA24E.

P.S. You guys got the power on over there yet?

[kyle1911]

why would it backfire if it were a fuel problem?

[NateDogg]

A leaky injector will dump more fuel than the engine can burn, causing the excess fuel to shoot out the exhaust. When a car backfires, fuel is exploding in the exhaust.

[kyle1911]

I am fairly sure it is not a leaky injector as the plugs were a little white.Would the stock FPR or fuel pump surge like that under load?I also used injector cleaner recently to see if it would get rid of the minor hesitation problem i doubt thier connected but the cleaner fuel additive could have fubar'd my injectors

[NateDogg]

I've never heard of a fuel system "surge". You might want to clean the connections of all the electrical sensors and shoot some brake cleaner on the MAF resistors.

If the plugs are white then you are most likely detonating. This could be too much timing, a lean mixture (vacuum leak) or messed up sensors.

Next I'd check your coolant temp sensor for proper values. Then clean the electrical connections.