power enrichment or WOT problem

[bob442]

So i cant figure this problem out. when i get into power enrichment or WOT the car misses, or Bop's, not back fire, its like one or more cylinders are cutting out due to fuel or timing. this was starting to happen before i did the timing chain, now it has gotten worse. the car will run great with no load, or rev up to 7000rpm in neutral, but under load it a miss, something is causing the motor to miss and a scann too is telling me jack, all my sensors are working and reading, i was convinced it was my 24x sensor as it stopped reading after 1700 RPM but that was a no go. any ideas? i had good compression on all 6 cylinders.

[Superdave]

weak coils, bad plugs?


what's the plug gap?

[SappySE107]

weak coils, bad plugs?


what's the plug gap?

That was my first thought as well.

[TGP37]

I had a bad spark plug cable do that to me. Found it had much higher resistance. Removing and reinstalling several times can break the connections.

Also had a center electrode insulation come loose and drop over the spark gap doing the same thing. Didn't expect that

[bob442]

i figured if it was a spark issue it would back fire but it doesnt, it just dropped power like a fuel cut. plug gap is not really adjustable but i think its 45 or 50, they are ac delco iriduims, idles great everything is good till power enrichment or over 3000 rpm

[SappySE107]

You can gap iridiums. If its not firing, its just dropping a cylinder. Misfire would be if it was firing at the wrong timing.

[TGP37]

i figured if it was a spark issue it would back fire but it doesnt, it just dropped power like a fuel cut. plug gap is not really adjustable but i think its 45 or 50, they are ac delco iriduims, idles great everything is good till power enrichment or over 3000 rpm

The break still conducts at low load because the juice can overcome the resistance in the cable and spark gap. But when load increases, resistance at the spark gap increases and a break in the cable can be enough to prevent the spark arcing across the plug gap.

Testing Ohms across a 6 spark wires and compare should prove or rule out this possibility.

[dskopek]

Mine will rev clean right to 7000 RPM without boost with .045 gap but when I get into boost(8PSI) it will cut out above 5500 RPM and just misfire, the fix was to regap to .035 with no other changes. The plugs are standard AC Delcos

[TGP37]

Mine will rev clean right to 7000 RPM without boost with .045 gap but when I get into boost(8PSI) it will cut out above 5500 RPM and just misfire, the fix was to regap to .035 with no other changes. The plugs are standard AC Delcos

Right, because the resistance between the electrodes increases as you go into boost (more air/fuel between the electrodes). But Bob isn't boosted so his gap should be fine. I greatly suspect a spark plug wire was damaged from unplugging while attempting to fix other rising issues. It happens and is the reason why I got a boot puller.

We'll see, I'm sure he'll find the problem in time.

[3400-95-Modified]

wideband reading?

[bob442]

I'm gonna try the wires and test them tonight. I have had them on and off alot. I've had my unfair amount of issues but I hope they are coming to an end. Re surfaced my headers, made new gaskets and wrapped them this past weekend, and upgraded to 10mm rockers and this seemed to make everything so quiet now... My air fuel reading drops down to 12.6 on power enrichment so I doubt it's spark related. If it was it should go wayyy lean



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[TGP37]

I'm gonna try the wires and test them tonight. I have had them on and off alot. I've had my unfair amount of issues but I hope they are coming to an end. Re surfaced my headers, made new gaskets and wrapped them this past weekend, and upgraded to 10mm rockers and this seemed to make everything so quiet now... My air fuel reading drops down to 12.6 on power enrichment so I doubt it's spark related. If it was it should go wayyy lean



Sent from my iPhone using my iPhone at work cuz I have nothing to do

Don't feel bad, I got a short I have to track down. Came out of no where, no messing around with wires at the time it started acting up. Having less hands on experience then others, I ran into my share of headaches.

I feel I'll find it quick once I start tapping fuse ports for resistance to the ground. But the Sun has been really brutal recently, can't take the heat atm. So I just let her rest for now.

If it was easy, everyone would be doing it!

[bob442]

So found this problem, remote start tach sens wire on a injector. It's been there for 2 years, and recenty it stopped working. Now I just have one other issue which is a little pop or back first on wot shifts at 6400rpm+ it's pretty loud
Also I tested the plug wires all is good and well.

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[bob442]

Problem has fixed itself now after driving for a While


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[TGP37]

Problem has fixed itself now after driving for a While


Sent from my iPhone using my iPhone at work cuz I have nothing to do

That's cool.....hope it doesn't turn intermittent . Today seems like a nice driving day for the NE region.