Ok, I had to take the dizzy out to get at the ignition mod. What size are those little bolts that hold it on? I don't seem to have a socket that fits

Today being Thanksgiving and all, no stores are open anyway, (to buy a new tool or parts), but I was hoping to diagnose the problem this morning..

Happy Turkeyday everyone!
Mike B

 

You don't have to remove the TFI or the distributor to check the ignition system, and it takes a special thin-walled socket to get those screws out. Most parts stores sell one for ~$5.

 

Steve you are the man.

I got the screw/bolts out with a "modified" needle nose pliers

If I had the proper socket I could have left the dizzy in, but it was easier to screw with out of the truck.

After doing the resistance tests on the ign mod, the GRD to PIP IN shows no reisistance reading. All others test in specs. I will replace the module on Saturday, and buy a thin walled socket, is that a 7/32's? Or is it metric? 5mm is too small and 6 mm seems to walk around them, 7/32 seems just a shade too big....

Let me know if you know!
Cross your fingers that this is it!
Mike B

 

Dang it all to HELL! I replaced the Ign Cont Mod (it was bad) but the truck still won't idle and it misses like crazy when I push on the accelerator.

Just for kicks I sprayed a little carb cleaner into the throttle body while I had it "running" It cleaned the idle right up and reved like an SOB. Could this indicate FUEL problem? Or would it do that even if it was getting enough gas?

What should the fuel pressure be on my truck? Where do I connect the pressure gauge? By the way new fuel filter 3 weeks ago ( I thought that was my original problem)

Please help!

Mike B

On my way to sears right now to get the fuel pressure gauge.

 

i have not toyed with this probem too much but when i went to the local vo-tech school for auto tech we cam across quite a few trucks that had a leaking gasket causing a vaccum leak the gasket is where the upper and lower intake meet and from what im told this is a real common problem

i know of a backyard mechanic way of testing for this but it may not be entirely safe and im sure fte doesnt want that mentioned here by me so ill leave my post at the fact that the gasket as a possibility seeing as how the carb cleaner picked up the idle for you

good luck tdc

 

Well I tested the fuel pressure. The "engine off pressure check" tells me that I only have 39 psi, the manual says I should have 50-60. The next test it tells me to do is the "underpressure test" that checks the regulator. It says that I need to pinch off the rubber fuel line after the regulator and see it that causes the pressure to rise significantly. Sounds like I need another body to check this one

Well maybe I am onto something with the fuel pressure, maybe not. Just thought I would let you where I am at.

Mike B

BTW I don't think the gasket is the problem. The carb spray trick only make the idle go up if I shoot it directly into the intake. But thanks for the heads up.

 

Well I am back, I did the "underpressure test" No change in pressure. So that means it is not the regulator, but could be a restriction in the input line or a bad pump. I think it is a bad pump.

By the way, I pulled the codes. I get a 26 and a 34.

So I read what that means,

26: VAF out of range during self test. (what is VAF?)

34: PFE/EPT sensor fault/high exhaust pressure/PFE/EPT sensor fault. (What is PFE/EPT?)

That high exhaust pressure makes me wonder about a plugged cat

Chime in with your thoughts,
Mike B