Cute. So what about the fuel pressure readings I got?

 

I reread your earlier posts and can't see anywhere if you said you have dual gas tanks or not. Do you or just a single tank? Also your posts indicate some times the engine is running just OK and then things go bad. If you are testing the FPR/pressure, it would helpful to try and test at the time the engine is running badly, rather than when cool or running OK. This is not easy to do. And although I do not believe in just replacing parts and hoping for the best, at this point, if you have not replaced the FPR yet it may be the next thing to do. I have some suspiscions about dual tanks and would like your response on this. Thanks.

 

The pressure was checked when it was running bad. I drove to my freinds house (about 12 miles) and we checked the pressure when I got there. And it was running bad as we checked it.

I do have dual tanks.

 

The truck runs the same on both tanks. Front tank has a new sending / low pressure pump unit in it.

 

I checked the fuel pressure last night and here is what I got -

42 with the vacuum hooked to the FPR
37 without the vacuum hooked to the FPR
The pressure held or went up a little when the truck was shut off.
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Did you post that right? I mean is it backwards from what you intended to write or is that the actual readings?

If it is its backwards then and you have a problem there, the pressure reading should be on the lower side with the vacuum line on, and get a higher value when the vac line is removed.
Say 30lbs at a idle vac line connected, 40lbs with the vac line removed and plugged.

 

Yes they are right. I wrote them down as we checked it and I just double checked what I posted with what is on the paper and that is what I got.

 

Does this mean the FPR is bad and needs replaced?

 

Well the FPR seams to react to the vac line being on or off, did you check the vac line and make sure it has good vac to it? Doesn't leak sucking air somewhere along its length.

If the vac supply is working correctly yea with those readings I think I'd replace the regulator.

 

I didn't check the vacuum line with a gage but I did put my thumb against it when it was pulled and it has a ton of vacuum.

 

technical difficulties.

 

more cute for you.

__________________
"To believe is to know you believe, and to know you believe is not to believe." ~ Jean-Paul Sartre

 

Yeah those pressure reading are bad news, it should run between 32-35psi with vacuum and jump to about 40psi without vacuum or when the throttle is opened. Change the regulator and test again.

 

I got a new regulator last night and will install tonight. I will recheck the pressure and update you all tomorrow.

 

well i changed my regulator and removed the platinum plugs and put new copper motorcrafy plugs. now the truck doesn't want to run right. idles fine and sounds good, drove it down the road and i can only go to 3rd gear and run about 30 mph. my manifolds got cherry red on both sides. so now i am running lean. i know the timing is of a bit, but not that much to really hurt it. seems to me when i drove it, the more i pushed on the gas the crappier it ran, but when i let off of the throttle a bit is acted like it picked up and wanted to run fine, push down on the throttle again and seem to act up again and sounded funny.

 

my manifolds got cherry red on both sides.

Glowing manifolds is a sure sign of Late ignition timing, also burns up spark plug wires quick.

Check base timing, verify the computer does advance the timing.

Connect timing light and either remove/install spout shorting bar while watching the timing mark or use the self test "engine timing test".

Engine timing test: Run the KOER test (Key on, Engine Run), the computer will hold the timing advanced approximately 20% over the base setting for 2 minutes after the last trouble code or system pass code.
Verify the timing is advaced with a timing light durring that 2 minutes.

Example;

If the base timing is 10deg BTDC, the acceptable timing light reading should be in the range of 27 to 33deg BTDC.