Jump to content

2.8 to 2.5 conversion problems


Recommended Posts

Back again guys this time it's a fuel problem was going up a hill it had been bucking for about 40 miles finally it died mid way up the hill it'll start and run for about 10 seconds and die. So I changed the pump fuel pressure regulator vacuum lines etc.... now it'll start perfectly and stay running but has zero power and if you Rev it it almost dies after letting off its also back firing through the throttle body I'm guessing a voltage problem to the pump but any other options would be great to check into

Link to comment
Share on other sites

Since you replaced the vacuum line to the regulator, I assume you went to the MPI 2.5?

 

TBI 2.5 requires 14-15lbs pressure and the MPI requires 49lbs (IRRC?)

 

Which pump did you use?

 

 

The MPI or carbed filter will flow....not worried about that.......but I would not trust the low pressure hosed and clamps at 50lbs.

Link to comment
Share on other sites

this was all done before i got the truck i have a copy of the title to the engine its a 2.5 out of a 93 cherokee....... i hooked up a fuel pressure tester first prime its over 20 after that its below 20lbs it also has a filter for a 93 cherokee hooked up i just replaced it actually... and i used a sending unit and pump out of a 93 cherokee as well pump and sending unit are brand new filter is brand new vaccum lines have been freshened up, and the regulator is brand new as well.

Link to comment
Share on other sites

tried old pump in brand new sending unit and tried brand new pump in new sending unit both produced same numbers the ballast resistor does not look healthy though was wondering if there were specs for what the voltage should be at while running so i could see if there is a possible voltage drop while the vehicle is running.... not sure scratching my head on this one may try to replace the ballast tonight and go from there

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...