motor won't go above 3000rpm
 

I have a problem...frankly I'm stumped. My 1998 dodge 1500 2wd 5.2L, recently started to run bad. I had a check engine light come on saying multiple cylinder misfire (5,6,7). It has no power and is ruff on the shift, I can put it in park or neutral and I cannot get it above 3000 rpm, I have todrive it like a big rig (fully loaded) and cannot pull out infront of anyone, at least a quarter mile. Once it is up to speed, it runs down the road just fine.I have given it a tune up (wires, plugs, rotor, and cap), even did a fuel system cleaner. I have been reading and think that it may be a bad IAT, exhaust leak, or even the Holly module in the rotor. I was wondering how to check those because I'm not made of money, and I don't like to replace parts when I don't have too.

RE: motor won't go above 3000rpm
 

1st thing i would check is that the cat is not cloged , it sure does look like it , does it rattle at all ??? craw under and bang on the cat and see if you hear anything (make sure the cat is cool so you dont burn yourself)

RE: motor won't go above 3000rpm
 

This sounds exactly like what happened to me when my TPS failed. Was it sudden or has it been sneaking up on you?

If you have a digital odometer, turn the key to on (but don't crank the engine over) and off like this:
on-off-on-off-on and leave it in the on position and see if there is a code displayed on the digital odometer. post that code here and somebody will be able to tell you more.

edit, sorry you already stated the code.

I'd agree with pa and check the cat first, there was a recall on those several years ago.

RE: motor won't go above 3000rpm
 

Definitely sounds like a plugged cat.....thats the thing I would check.......my truck did the same thing when the cat was plugged

RE: motor won't go above 3000rpm
 

Crazy, Mine did the same thing, but it was throwing Cyl. # 1,2,7,8. I ended up putting a new motor in, as many people thought it was valves/lifters/etc. because everything elsewas replaced. The engine was throwing more misfire codes, and we changed the ECU.. Now the O/D comes on and just stays on yet the truck will still shift into O/DThe truck is at a trans shop now because someone suggested it was the solenoid pack in the trans. Can you please let me know if you figure it out? Thanks

RE: motor won't go above 3000rpm
 

Did you give it a tune up before or after it started doing this? The last two plug wires towards the cab on the drivers side have to be routed specially, I believe, otherwise it will cause cylinder misfires.

Other than that, +1 for checking the cat. After that, I'd check the sensors mentioned earlier.

RE: motor won't go above 3000rpm
 

Check the catalytic converter
and the exhaust behind it, because pieces of the cat's guts can get loose and clog in the muffler and tailpipe too.

A bad ignition coil,
or wiring to or from the coil
can cause the engine to be unable to go to high rpm

same thing with a fuel pump assembly that is going bad or has a suction filter covered over with gunk from a bad tank of gasoline.....check for the psi of the fuel as you try to go to higher rpm

RE: motor won't go above 3000rpm
 

Another vote for having the catalytic converter pressure checked. I rebuilt my engine and when I took it for a test run I was getting the pre-rebuild misfire CEL and my truck struggled to make it up small inclines. The cat was clogged and once replaced it was like having a new truck.

RE: motor won't go above 3000rpm
 

Yup sounds kind of like that Catalytic Converter is clogged to me too.


When my TPS went bad it didnt' act like that. It just would surge going down the highway if you had cruise control set was the only time I noticed it. It would just jump up 300 rpms or so then back down then do it again a minute or so later. I replaced the TPS and it fixxed that but maybe it can do other stuff when it goes bad too that mine didn't. I don't know.

RE: motor won't go above 3000rpm
 

thanks to all, I will take it by the shop in the morning, to have them pressure check the cat. I banged on it but I don't hear anything rattling. also, to add the check engine light sometimes goes off, but doesn't change the way it acts, and will blink.