My 91 4.0 had some serious problems reving got better at higher rpms and if I let it run all day while on the trails so I replaced my map sensor and made a lot of difference but still have hesitation when reveing gets better at high rpms still. But map sensor did make a word of difference. What else should I check

 

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And it won't start unless I have the pedal to the floor

 

Fuel pressure good?

 

Yep. After some research it ended up being the temp sensor. Still takes a bit for it to start

 

Any body got a ifea

 

Try posting in English for better results. What is the problem exactly? And didn't you just post that the CTS fixed whatever was wrong?

 

I thought that I read that too????

 

Hesitation and not starting unless the pedal is to the floor sounds like the throttle position sensor. Check it out, rule it out and go from there.