89 cherokee, I've done A LOT of work on it, but never got over the engine having a lot of issues (low compression, burning a lot of oil, head gasket issues, etc), so I had my engine replaced with a rebuilt Renix era engine. BUT I have a problem I had with my previous engine, that I seemed to have fixed, but is back with my replacement engine. It will stall at low speeds, mainly in parking lots where you do a lot of on and off the gas, even if you try to drive gently. It also seems to idle a bit rough, even when warm... They swapped over most of my sensors, since they were new. but not the CPS, they put a new OEM one on.

I will take it back to them if I need to but if its just a simple adjustment and it doesn't have to go back into the shop, that would make my day.

vacuum tube to the map is nearly new. new plugs/wires/cap and rotor, iac, tps, and they were adjusted correctly.

 

Sounds like a bad misfire, or even a vacuum leak. Usually with a vacuum leak it will stall out when you hit the gas. Did they replace the intake manifold gasket, throttle body gasket, etc. with new ones? All new vacuum lines? any cracks in the intake tubing? Brake booster hose? You can try locating vacuum leaks by spraying brake/carb cleaner around vacuum lines with it running. If it revs up all of a sudden, you found your leak.

How does it run at higher speeds?

 

I wonder if they indexed the distributor properly. Tip 13.

Or, did they forget to put the dipstick grounds on the block?

Or, did they put them on over a painted surface?

 

I will check.

Its not a missfire, its like the idle just drops too low, and so it dies.

new gaskets, I've replaced almost all of the vacuum system recently, and it looks like it was all hooked up correctly. I had replaced the brake booster not too long ago.

Grounds look good. but I'll check them again.

Once I hit the gas it runs fine, it seems like its an idle issue. I do not have a tach, which is really annoying.

 

Grounds need to be refreshed, not just looked at.