Jeep will not run with the map sensor connected

[Fernando87mj]

Jeep decided that it doesn't want to run with the map sensor vac line connected , if I unplug it , it runs and doesn't stall , it doesn't have a fuel smell and doesn't blow out smoke like it normally would with the map vac line disconnected , if I plug it in it runs for 2-3 secs and it stalls . If I try to give it throttle it backfires from the intake and then stalls , I tried replacing the map sensor and it still did the same thing , I'm lost anybody know what it could be ?

[Fernando87mj]

1987 4.0 renix ba-10 5

New cat , muffler , o2 sensor 3 months ago btw

[HOrnbrod]

Sounds like your MAP sensor is forcing closed loop operation. To test, make sure the vacuum line to the MAP sensor is connected and not broken, then test the MAP's in and out voltages:

 

[Fernando87mj]

Thanks hornbrod

I went ahead to test it and got this from

Pin c

Pin b

[Fernando87mj]

Decided to go ahead and see how the tps and CPs were doing

 

Tps

 

Cps

 

I'm gonna go ahead and I test the fuel pressure tomorrow and see what I get , I replaced the fuel pump with a carter from napa and a fuel filter with a wix 11 months ago , it can't hurt to eliminate the possibility of a bad fuel pump

[cruiser54]

What about low fuel pressure? 

[Fernando87mj]

Fuel pressure was 8 psi , took out the sending unite and somehow the hose slipped off ,bought a new clamp and put the hose back on and all is good . Bought a new lock ring and seal and put it back together and the damn thing is leaking again when the tank has more than half :( searched up cc and saw that the p/n for a tank o ring from mopar is 5300 0575 is that correct ? Will it fit my swb gas tank ?

[HOrnbrod]

Fuel pressure was 8 psi , took out the sending unite and somehow the hose slipped off ,bought a new clamp and put the hose back on and all is good . Bought a new lock ring and seal and put it back together and the damn thing is leaking again when the tank has more than half :( searched up cc and saw that the p/n for a tank o ring from mopar is 5300 0575 is that correct ? Will it fit my swb gas tank ?

 

Yes and yes.

[Strokermjcomanche]

Dorman 55810 , better seal .

 

[Fernando87mj]

That's the one I had used and I got a leak, I made sure it sealed well , but maybe it didn't

[Strokermjcomanche]

I've never had the dorman seal leak because they center in the tank opening better with the 3 tabs . The O ring type seal has rolled on me and I had the problem you have now . Good luck with getting it sealed up .

[HOrnbrod]

Give it a thin coat of Vaseline before tightening the lock plate.