Hey all,
I am looking for a while on here to see if I can find an answer to my issue. I couldn't pinpoint it so I figure id ask. I recently had a new jasper 5.2l installed in my 1996 ram 1500 4x4 sport. The old motor was having issues(low compression high mileage) and I decided to replace new instead of rebuilding.

The issue im having is the lack of power and poor fuel mileage with new motor. I average 9.5-10.5 mpg. The old motor was getting 13.5-14 even with issues.
Things done when motor installed,
New crank and cam sensor
New pace setter headers
New magna flow hi flow cat
Summit racing cat back exhaust 3"in dual 2 1/4 out
CAI

I've checked for vacuum leaks, fuel pressure, timing, etc.

I had garage put on scanner and the tps is at .6v at idol and 3.8 wot we feel this could be the issue but im asking all if anyone thinks is could be something im not thinking of.

Thanks to all

 

I would rent a live scanner and see what the truck is doing while driving.
of topic, I just got the summit cat back 3" dual and the driver side mandrel bent tube was off so bad and the pass. could have been better. I had to send it back, gonna have a muff, shop do it. how about u?

 

Did you check the plenum on the new motor?

 

pipeking: I had the garage put it on the scanner multiple times. they drove with it and in the bay. their saying its the tps. but im not buying it. I would figure it might hurt my power up hills if not getting full throttle but wouldn't would cause me to drop 3mpg but in not an expert.
my exhaust is perfect fit no issues there.

Stewie01: I did not check the plenum yet as honestly until I read a post earlier today I didn't know of the problem. I would figure with jasper being a reputable engine builder they would have tested this before selling it. I will be checking it Thursday when I can get my truck back into my shop where its not 9 degrees out.
I will update what I find and if replacing the tps helps at all.

thanks

 

Did the new Jasper motor come complete with an intake manifold? I ask, as most long blocks I've installed do not come with an intake - the intake is re-used from the old motor. Did you install the new motor or did you have a shop do the work?

 

the shop did all the work I believe they used my intake but all gaskets and such were supplied by jasper. I would say the plenum gaskets would have been part of them.

 

But did they change it? Take a quick peek down your throttle body, see what ya see.

 

may sound dumb but if you still cant find anything check the cat. ive seen shops leave rags in some strang places.

 

That would have been long gone & burnt up!. Cats get fkn HOT!.

 

well I peaked down the throttle body and guess what I see inn the intake. you got it oil residue!!! I cant see down to the corners with the mirror but my friend has a scope camera were going to look down into the corners. the magnet test shows that it is the original metal plate not the upgraded aluminum one.

Pissed the jasper certified installer would not have recognized this and at least recommended to upgrade it as jasper does not include it with the new engine.

I will be bringing it back to the garage after it get some pics of the oil down in the intake and hopefully they will work with me on the replacement.

thanks DF for the help and info I will post after replacement on performance and fuel mileage.