Random eternal misfire/ plugs fouling

Random eternal misfire/ plugs fouling

Postby smokinjoe [OP] » August 12th 2015, 6:25am

So seems a lot of us are having awful misfires.

It started on a 400 mile road trip. Like a fish hitting a line.

Kept getting worse.

Changed plug wires, rotor, cap. (Distributor new a month ago.)

New MAP sensor, IAC valve. New plugs, coil swapped with no help.

Stupid shop replaced my spider claiming a puddle of fuel in intake manifold. $1300 bill and misfire continues.

Turns out they knew this but changed the plugs and gave it back to me.

2 passenger side rear plugs are oiled and fouled. (not sure of others).

Mechanic admitted he thought it was a leaking valve seal allowing oil into cylinder.

Don't know where to look next. Motor is only driveable at large throttle openings or none at all. Terrible jerking anywhere else.

We need the great minds of this forum to crush this problem. Very stressful drive with wife & baby in van. (sure you guys are sick of hearing of that).

Any ideas?
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Re: Random eternal misfire/ plugs fouling

Postby Lumpy » August 12th 2015, 7:13am

smokinjoe wrote:
So seems a lot of us are having awful misfires.



I've read about two.



smokinjoe wrote:
Any ideas?


I think you're too emotionally involved with your van's problem. Cars don't respond to emotion and the boogey man. They respond to mechanical and electrical force applied in the appropriate place. It's not a child. It's a hunk of steel. Apply intelligence, not emotion.


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Re: Random eternal misfire/ plugs fouling

Postby chevymaher » August 12th 2015, 1:25pm

Compression check. even if it is having oil like a freight train it would run right. Just smoke.

Check the EGR tube for raw oil. Check the egr. Scan it and see what the timing is doing at that speed. Excessive blowby makes a PCV pump oil into cylinders. EGR's just suck when they work right.

If all it is doing is oil and fouling the plugs. Close the gap up to 30 thousanths. Make the spark stronger. Idle is not as steady but it is firing better at the speed it is having a issue.

Block the EGR and drive it. Disconnect the PCV with new plugs in those cylinders.,

Since what your supposed to do isn't working, It time to think outside the box. Try things and that will help you find and diagnose the problem.

Buddy had a 75 dollar wrecked chevelle ran 12's at the strip consistently for 8 years. Smoked like a freight train forever floored. But it didn't miss. He changed one plug once a month the whole time he owned it.

So even if the engine has a problem you can work around it and it be a good engine for years to come. Once you figure out what is wrong.
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Re: Random eternal misfire/ plugs fouling

Postby smokinjoe [OP] » August 12th 2015, 3:39pm

My EGR valve is blocked, should I unblock it?

I also thought of running wires directly to the coil to give it better signal/power.

Will start trying you suggestions Maher but whats the PCV?
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Re: Random eternal misfire/ plugs fouling

Postby chevymaher » August 12th 2015, 6:58pm

smokinjoe wrote:My EGR valve is blocked, should I unblock it?

I also thought of running wires directly to the coil to give it better signal/power.

Will start trying you suggestions Maher but whats the PCV?

Nope EGR blocked only makes it run better. So it is something else.
PCV is in a valve cover, passenger side on my year. Hose running to TBI or intake somewhere. Straight passage for crankcase oil to get into the intake. If it is drawing to much air.
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Re: Random eternal misfire/ plugs fouling

Postby smokinjoe [OP] » August 12th 2015, 9:03pm

So I found a guy in my hood who is/was a GM certified tech. He has the GM scanner computer thing. He Plugged it in and found nothing.
On my 95 there are 2 sets of wires going to the coil. One 2-wire and one 4-wire. When he re-routed the 2 wire it seemed to help but persisted.

He then unplugged the timing plug from the harness and turned the distributor cap to optimize advance/retard I am guessing. This seemed to help too but cant be sure til I road test it tonight after rush hour.

Can I buy those wire harnesses at rockauto? Napa said they don't do that stuff. (the wires going from dist to coil)
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