did some work, now rough idle and backfires

[alwaysFlOoReD]

I have a 91 Ranger racetruck. I recently pulled the motor to change a leaking rear seal. At the same time I changed the valve cover gaskets and installed some SS JBA headers. It runs rough and idles down to ~800. I took a quick look at it doesn't seem that I dislodged any injector plugs. All the wires are firmly on the sparkplugs. What else could there be?
Thanks,
Richard

 

[Big Jim M]

first thing I'd check would be a vac leak. Has great vac leak symptoms.
Big Jim

 

[RonD]

That would be my guess as well.
Lean idle missing(back fires) and higher than normal idle would point to vacuum leak.

What engine is it?

TFI or EDIS
Check firing order, I often KNOW it is right, until I check it a 3rd time, lol.

 

[alwaysFlOoReD]

Thanks guys.
It's 4.0/5spd, EDIS, and I did have the wires all off, I'll double check.

Richard

 

[alwaysFlOoReD]

It was firing order....oops

Sent from my XT1032

 

[RonD]

5, 6, 4 always gets me
Good work

 

[alwaysFlOoReD]

Ha, it was 1 and 2 swapped.

Sent from my XT1032

 

[RonD]

Not an easy one to admit, cred goes up with that one, lol, not that you needed it

 

[Mark_88]

Yeah, I did the same thing on my 3.0 when I first got it...but I was working on 4 bangers all along so I had a good excuse...good catch though...and I've even done this with my first 2.3...and I seem to recall some alcohol involved with that happening...

 

[alwaysFlOoReD]

I feel pretty silly. Its not as if the 123 order of the coil is different than the order of the cylinders. I'm glad that firing order was mentioned as I may have been stuck for months. [emoji12]

Sent from my XT1032