Running Great, Hiccup, Cough, Cough, Puke

[Mattburn87]

I just installed a different transmission and backed it out of the garage to find that it's now not running correctly. It will run smoothly and then all of a sudden hiccup, cough, and sometimes just cut off. I replaced an in-line fuel filter. Wires are around a year old and all seated tightly, vacuum lines seem to be tight. I'm not even sure what else to look for. Previously I had experienced a random hesitation occasionally, but very rarely. I don't have a clue if it's the same. The truck is supposed to make a 650 mile trip on monday and at this rate it won't make it far.. I looked at a bunch of existing threads, but they didn't seem to be quite the same... Anyone have an idea?

Thanks guys

 

[Big Jim M]

I just installed a different transmission and backed it out of the garage to find that it's now not running correctly. It will run smoothly and then all of a sudden hiccup, cough, and sometimes just cut off. I replaced an in-line fuel filter. Wires are around a year old and all seated tightly, vacuum lines seem to be tight. I'm not even sure what else to look for. Previously I had experienced a random hesitation occasionally, but very rarely. I don't have a clue if it's the same. The truck is supposed to make a 650 mile trip on monday and at this rate it won't make it far.. I looked at a bunch of existing threads, but they didn't seem to be quite the same... Anyone have an idea?

Thanks guys

Have you tried running it up in rpm? Will it get to 3,000? Does it backfire any when it hiccups? Cutting out is usually a lectric problem.. Does that ride have TWO fuel filters? Did you take engine grounds off and forget to replace em?
Big JIm

 

[holyford86]

pull codes and check for pinched/broken wires.

 

[CraigK]

Once again - disconnect the O2 sensor (at the Y-pipe/cat flange) and see what happens . . .

CraigK
ASSUME the vacuum line to the tranny is A-OK? (AT? MT?)

 

[Mattburn87]

Thanks guys for your help... after a nights sleep, ideas from you, and ideas from some other posts around, I checked around and found I had knocked the ignition module on the distributor a bit loose. Thought I had checked every connection but guess I forgot one. It's running like a champ now... hope it makes it to Philly tomorrow! Have a great day and thanks!