Rough running

[Billy Mild]

Wife drove the car today. She said that it was almost bucking when in traffic today. She mentioned this on the drive back from work. She noticed it at highway speeds.

It has been the hottest its ever been the past few days. I wonder if that has anything to do with it at all. I also thought maybe my air duct is getting too soft and collapsing.

I will start working through the troubleshooting guide in the Shop Manual. 8cam do you have a page that you started with?

[BigJohn]

It's been a hot week; is the car running hotter than normal?

[Billy Mild]

The car is running right in the middle of the gauge. I have a haibeck tune so that probably helps.

Sent from my Nexus 6 using ZR-1 Net Registry mobile app

[Billy Mild]

Threw the scanner on it this morning. The car was bucking 2 minutes after leaving my driveway. If at any time I open the throttle close to full throttle it smoothes out.

I noticed my IAC counts are higher than normal and the BLM counts seem a bit off. I pulled over and unplugged the IAC and the idle was really high like 2000 rpm. I shut the engine off and plugged it back in. The idle was normal but the IAC counts were still high.

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Sent from my Nexus 6 using ZR-1 Net Registry mobile app

[Billy Mild]

Would a bad IAC cause rough running at all?

Should I try reseating all the ECU connectors and chip before doing any other troubleshooting?

[Billy Mild]

I drove the car this morning after giving it a full weekend break. The car ran smooth as ever and had 0 issues on the way to work. I'm starting to think it has to do with outside temp and when the engine is warmed up.

This leads me to believe it is an electrical issue.

[Billy Mild]

After work the car ran rough intermittently. The only thing I can see is the BLM is way off between the right and left side. Also the IAC counts are higher than normal.

At this point I'm thinking O2 sensors (Standard Brand), ECU, or IAC would be bad. The O2 sensors could possible cause these kinds of issues.

Any ideas?

[Billy Mild]

It was even worse today on the way to work. At this point I am honestly considering selling the F'ing thing. Nothing really seems out of whack.

Does anyone have a spare ECU without a chip that I could borrow and swap in to see if that alleviates all my problems??

[Paul Workman]

Intermittent issues are the worst. I had a similar issue with my 95 LT1 car; took it to the shop, only to have them say: "No problem found". But, before I reached home, the rough running cropped up again.

That issue is what prompted me to buy a scanner and do datalogging on the fly. That's when I found one of the O2s was shorting out, intermittently, causing the ECM to flood that side of the motor with fuel. BLM on that side went nuts too - along with injector dwell time on that one side.

Point is, if you can datalog in real time, you might be able to catch what is going on. Mind you, often it didn't throw a code either.

But, have patience. Once you have your "Ah-HA!" moment, all this trouble will fade away to be forgotten. Trust me. (I've been there, done that several times!!).



Paul.

[2ljd]

Paul,

If you don't mind me asking, what scanner/program did you get?