Hey guys, need some help troubleshooting this one on my 1990 YJ 4.2l....
Just finished installing a newly rebuilt Motorcraft 2100 carb (from the eBay guy everyone seems to recommend) then completed the Nutter bypass mod.
- bad miss throughout RPM range
- rough idle
- seems to buck and surge, especially around 1200 rpm
- stalls after driving for short period of time at relatively steady state RPM
Here's some background info:
- Carb installed correctly, checked for vacuum leaks.
- Linkage adjusted
- timing 8 degrees btdc, dist vacuum now ported, as per Nutter instructions
- the two idle mixture screws set (in tandem) to obtain max vacuum at idle
- fuel pressure checked and correct, new fuel filter and pump
- EGR vacuum connected correctly
- tune up parts are about a year old but in good shape, plugs are 6 mo old
At this point, Im kind of getting to the end of my list of things to check. I was having this same issue before the Nutter and carb swap, but it does seem worse now. I had hoped (obviously) the carb swap and Nutter would fix these crappy running issues.
As mentioned before, this is a 1990 YJ with a 4.2l and manual trans
Im running out of ideas.
Thank you in advance.