Yes, Another "Help Me With My Miss!" Thread.

[Horns]

I know what you'll all say, and yes, I've diagnosed the problem. I'm just kind of at a stand still right now and am looking for input. Maybe someone else has had the same problem?

Here's the deal, truck wouldn't start. This was because the ground wire on the fire wall had come loose. I put a new self tapping screw in it, and wala, it starts just fine now. But for some reason as soon as I did that, this thing has an absolute HORRIBLE miss. I mean, it's back. Like popopopopopopcracklebangledouchepopop kind of miss.

Checked timing, it's fine, check distributor and all of it's components, they're fine, checked coil, it's fine...

Oh, and my speedo is stuck on 80? wtf? So I'm guessing I've got a short somewhere, just don't know where.

 

[Horns]

Ignition module, have't checked that yet...

Be back with an update, in the mean time, give me suggestions.

 

[ChrisAU]

Sounds like you fried something. I'd go with the ICM with the speedo pegged.

 

[great white]

No SES light I assume?

Was it working fine before you changed the ground?

 

[1997chevydriver]

What are the odds you snagged a wire on the backside of the firewall with the self Tapper?

 

[Horns]

Sounds like you fried something. I'd go with the ICM with the speedo pegged.

That's what I was thinking at first, but when the ground was loose, before a put a new self tapper in it, the speedo would jump up when I would try to start it as soon as I let back on the key.

No SES light I assume?

Was it working fine before you changed the ground?

Correct on both. No SES light, and it was working great.

What are the odds you snagged a wire on the backside of the firewall with the self Tapper?

Thought of that too, checked and there was nothing wrong.

 

[great white]

First I would remove and reinstall the ground.

I can't tell from your sig what year or engine you are talking about, but 6.5 PCM's are very sensitive to grounds. So sensitive that if you move the PCM ground off the passenger rear intake manifold bolt to the water jacket block off plate you will have all kinds of "electronic" issues.

It could be possible you're seeing a different version of this "sensitivity" to resistance.....

 

[Horns]

1994, 5.7 TBI. Cammed and Tuned.

 

[jdyates]

Definitely A ground. Did you check the ground straps? The grounds next to the fuel pump relay? Battery, battery-block, check them all.

 

[Horns]

Grounds are all good.

Just checked the module, it was working great. Checked the TPS and the IAC, both were good.

I think I'm gonna turn this into a "Why is my speedo pegged" thread. I bet if I find the problem to that, I'll find the problem to my issue.