Jump to content

2.5 TBI idles great but refuses to rev


Recommended Posts

You know, I never thought of that but the CPS is more of a magnet than an electrical contact. Course I don't see any harm in removing the rust as I, and don't quote me on this, but I don't think rust has a lot of magnetic properties so it could be causing an issue.

Link to comment
Share on other sites

  • Replies 67
  • Created
  • Last Reply

Top Posters In This Topic

40 minutes ago, Dickinson County Comanche said:

I actually just tried to probe the CPS for the correct voltage and I got nothing. Could it be that the flywheel got a little bit rusty due to sitting out exposed when there was no transmission on it?

And when I say “nothing” I mean no voltage at all. It will still run with it reading 0 though

Link to comment
Share on other sites

1 hour ago, eaglescout526 said:

Woah! Is that a flex plate?

Yep. I’ve never seen a 2.5 with an auto except for this one. Cleaning it didn’t help, but I’m still sure it’s something to do with the CPS. I checked the CPS on my 89’ and it came back perfectly within spec so I almost wonder if maybe the CPS isn’t bad or positioned incorrectly. I’ll have to check in the morning and see

Link to comment
Share on other sites

It actually revs again! The CPS mustn’t been positioned correctly so after a quicky adjustment it actually revs again. Absolutely no power at idle-~1750 or so but after that it picks up and goes. Any ideas as to why it might do that? I know the EGR valve is no good so I’ll have to fix it eventually.

 

I also lost a tire on my test drive. Pour one out for the poor Walmart cheapo specials

8FE4BD58-193F-4D95-A097-7E65BD36B95C.jpeg

Link to comment
Share on other sites

2 minutes ago, eaglescout526 said:

Does the ISA operate? Is the throttle all the way closed? My thoughts on crap idle is the ISA not being adjusted right.

 

As for the whole issues, I am glad it was just the CPS.

I should have clarified better, it idles fine, just when you try to give it gas at idle-~1750 it runs like crap. If the ISA is the little stepper-motor thing that pushes the throttle plate open, it does function correctly.

Link to comment
Share on other sites

4 minutes ago, eaglescout526 said:

Entirely possible. EGR is se to open up upon the opening of throttle so we can move to replace the EGR. I’ll see if there is a testing procedure on the EGR solenoid. 

The diaphragm on the EGR is totaled. I have an extra EGR solenoid to place in to see if it’s working or not

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...