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Its me again! I am still having problems. I have replaced: injectors, fuel pressure regulator, CTS, TPS, CPS, rear vac harness, cleaned the TB, new TB to intake gasket, several new fuel filters, valve cover gasket, refreshed grounds twice and have also done #'s 1.3.4,5,6,7,8,9,10,11,25 of cruisers Renix tips. All of these have made improvements but still not out of the woods yet. It seems to run fine from a cold start but once it gets to operating temp it will develop a slight miss that progresses into a rough idle then a random stall and flooding which results in a very hard to start condition. Come back the next day and it will start back sometimes after some cranking. Turn it off and it will start right back until it warms up and the cycle continues. Could this be a MAP sensor problem?

:banana: :banana: Okay, didn't find anything that addressed my current issue whilst performing a little search, so here goes. My 1992 MJ 4.0, 5-speed with ~80K on it is great to start when cold: it takes like one good revolution of the motor and idles great....problem it is hard to start when at operating temperature....like when I go to start it after 20 minutes at the grocery store. Couple things I thought it was related to that I fixed recently: 1. CPS replaced (slightly improved idle) 2. IAC replaced (no change) 3. New battery (was going bad anyway....slightly improved start...not really though) One thing I keep thinking about is the fuel pressure... I have a gauge at the rail (thanks Hornbro!)...IDLE= 41 PSI, anything greater than idle is 49 PSI. I have larger injectors and the appropriate FPR...the question is this: is there supposed to be fuel pressure just before the engine turns over (key ON)? and just after the engine is shut down...? My situation is that the pressure goes to 0 PSI right after the motor is shut down and when the key is ON and I hear the fuel pump for a second....I heard there was a valve in the fuel pump that could go bad? Any help would be great. Thanks! :cheers: