First time posting and would like some advise on a problem i am having. i just acquired a 1995 dodge dakota 4cyl, 5speed manual. I can't get past 50mph. I have already replaced oil, spark plugs/spark plug wires. This truck at around 150K miles... No problems when turning on the truck, also i don't have any check engine lights. Any suggestions would be great... Thank you.

 

When my 1988 was doing that, I found out I had, in no particular order:

1) Bad vacuum hoses causes vacuum leaks.
2) My old throttle body (TBI, it's a 1988) was not firing well.
3) This was right before I replaced old plugs and wires as part of a tuneup.
4) What I think was the MAJOR contributor - my catalytic converter was plugged up.

So, I'd get that cat checked - you've done a lot of my other steps already.

RwP

 

Does it idle pretty well? When you try to go past 50, is it just falling on its face or is it missing and cutting out, like its running out of fuel? If it misses badly, it could be a stopped up fuel filter, but at any rate, check fuel pressure.
If its just falling on its face and will not go faster then 50, I would bet on a stopped up converter.
But all of us are just guessing without further test, ie fuel pressure, etc.

 

I agree with the comments from Ralph and Ragtop. About a year ago, my '92 bogged down about 10 minutes after getting on the road. Couldn't get above 30. About 500 yards later, a huge explosion under truck. The exhaust pipe had torn away from a nearly completely blocked catalytic converter. Back pressure from explosion blew out 02 sensor and egr.

 

Sorry for late reply, i am only able to work on this truck on weekends.

Update:

since the truck is a 95 i went ahead a replace the following:

- fuel pump
- fuel filter

I was able to cut off the CAT and tested it and i still have the problem of not being able to go over 50mph. So at this point i am kind of loss on what to do next.


- truck turns on with no problems..
- idles fine
- when at 5gear @ 50mph, gas peddle on the floor but just feels like thats all i can get out of it.

- will check fuel pressure today..

EDIT#2

tested fuel pressure today
- after fuel filter i have 30psi
- 18psi at the Carb.

I don't know if i have the 2.2 or the 2.4L engine.

Thank you for the support so far...

 

You really need the factory service manual.

The 1995 copy I have states that it should be 14.5PSI +- 1PSI - so if it's 18PSI, your injectors are having problems opening up and firing.

The manual does specify to remove the return line, and check pressure with it blowing into a container to see if it drops. If it does, your return line is restricted. If it doesn't your fuel pressure regulator is bad, and again checking the FSM it states that the 2.5 (the 1995 motor) has the FPR at the top of the throttle body (Before anyone else answers, no, this isn't the V6/V8 with the FPR at the fuel pump at the tank!)

RwP