I Have a 1995 Ram 2500 with a 360 (Z code engine) that has a mysterious engine problem. It hesitates at first on acceleration, then if you quickly let off the throttle it gets worse, or sometimes dies. It also hesitates badly when you are trying to drive slowly (like in a drive through, or a parking lot), and when trying to reverse. The problem seems to be stronger when the truck is at full running temp. It also seems to lope or buck (if that makes any sense) while at crusing speeds(most noticable at or around 45mph, then again around 60mph) almost like it is hesitating.

I have replaced the fuel pump assembly, installed a new O2 Sensor, replaced the PCV valve, Installed a new reinforced intake plenum cover (from Hughes) along with new intake gaskets, checked my MAP and TPS sensors, Checked that all my injectors are working correctly and ohm correctly, replaced my spark plugs/wires/cap & rotor, ran sea foam (2 cans) in the fuel, and another full can through the vacuum lines/intake manifold. None of this did a thing, I still have all the original problems. Oh, and I have no check engine light on either.

Has anyone experienced a problem like this, or know what might be causing my nightmare?

Thank You

 

does it pull any codes?

 

code 12, and 37.

12 is because I've disconnected the battery, and i've been told 37 is because I don't have a tow package, which means i don't have a trans temp sensor, which is what code 37 is for?

 

Sounds like you have some sort of vacuum leak. The increased presence of air is countered by the enriched state of the motor(when cold). This is probably whythat symptom is more evident at operating temperature. Rough idle?

Just a suggestion but have you checked your cat? Seen them do some wierd things to vehicles.

 

clean your throttle body

 

+1 on the cat converter.
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if you get a new cat converter, get a magnaflowdirect fitconverter from summit racing. its like $160,and its made of stainless steel. it also made my truck sound better

 

heres a link 2 summit (if u need it, clean throttle body first):http://store.summitracing.com/partde...429+4294838974 . the price is differnt because i bought mine 2 years ago

 

+2 for the CAT. I also got the magnaflow direct replacement. My Ram sounds great and runs better. Try removing o2 sensor and see if there is a difference. It will be loud, but if it runs better than the cat is plugged.

 

id say vaccum leak and bad cat converter. too much backpressure will make it buck.