Need help diagnosing misfire and reading plugs

[dynoman]

I would check and clean with contact cleaner all connections at the ECM / powerlogger & injector harness . That blip in injector pulse width & duty cycle looks like a bad connection . Also those plugs I suggested work well with E85 and they are $15 a set . Sam

 

[Mr.Spool]

Since I changed out my radiator in October I have had some random misfiring that is sometimes noticeable at idle and more apparent when getting on it. But I have been taking it easy until I can figure this out. But it doesn't always happen.

I took out the plugs and to me they look okay except the #3 ground strap is a different color than the others.

I run e85 on this car.

I checked compression and they were all between 140 and 150.

# 3 is the middle, #1 is on the right.

This is the other side of the engine

I checked the ohms on the plug wires and they are all good.

The plugs are not uniform.gapping,fuel injectors,fuel delivery,proper air distribution and good spark,just to name a few all contribute to a good running car.if fuel pressure and volts are there then get the injectors clean.does the car have a power plate?btw on a fast spooling combo 23lbs at part throttle is not uncommon

 

[Mr.Spool]

Forget to add your mv are way low,I don't tune gas cars down that low unless on c16

 

[Chuck Leeper]

When you take a pic of a plug, include a shot that shows the grnd strap in a position that the timing mark can be easily read.
It looks to me as tho some of the plugs have the timing mark too far over the bend..IE: too much timing.

 

[monteperformanc]

I would check and clean with contact cleaner all connections at the ECM / powerlogger & injector harness . That blip in injector pulse width & duty cycle looks like a bad connection . Also those plugs I suggested work well with E85 and they are $15 a set . Sam

I will check and clean all those connections thanks.

 

[monteperformanc]

The plugs are not uniform.gapping,fuel injectors,fuel delivery,proper air distribution and good spark,just to name a few all contribute to a good running car.if fuel pressure and volts are there then get the injectors clean.does the car have a power plate?btw on a fast spooling combo 23lbs at part throttle is not uncommon

It does have a power plate. I turned the boost down and afr is much better. It's probably too rich now. I was probably running too much boost for the tune in the chip. But the injector pw spikes are indicating something else is also going on. I have a lot of things to check. Thanks.

 

[Pronto]

Maybe try an injector noid on that cylinder that looks funky. Wiggle the harness at both connectors.

 

[Mr.Spool]

It does have a power plate. I turned the boost down and afr is much better. It's probably too rich now. I was probably running too much boost for the tune in the chip. But the injector pw spikes are indicating something else is also going on. I have a lot of things to check. Thanks.

Ok.with the boost turned down and richer Afr get a plug reading off that Afr.

 

[84BuickGNYorkPA]

monteperformanc,

You need to check your TPS voltage at idle and WOT engine off of course. Seem like your TPS is not set correctly at WOT. I'm assuming you have a scanmaster and know how to read it, if you need assistance read this http://turbotweak.com/scanmasterinstructions.pdf.

Chuck

 

[monteperformanc]

Even running richer the plugs look the same to me. I took the powerlogger and ecm out and cleaned all the connections, even though they looked pretty good. TPS is 4.30 key on/eng off, but it only gets to 4.17 at WOT. The last time I adjusted it I could not get any higher without going past .46 at idle. I looked at some older logs and it is running much leaner now than it was a year ago. The only thing I changed since then was replacing the stock downpipe with a 3", and sealing exhaust leaks. The fuel pressure is just not rising 1:1 with the boost. I've known for some time the fuel pump is borderline, so I think I'm just going to get a new one. Probably a DW300. And to add to all this, my wide band O2 crapped out. It just stays on 7 almost all the time.

But here's the thing. Ever since I turned down the boost, the cutting out has gone away completely. I brought it up to around 25 (it was up like 28-30) and it's still not doing it. I'm going to keep it under 25 for now.