Engine/Transmission (1994 - 1998) OMG! Could this be it?

[Shelbynut]

I posted about my friends truck that started as a cold start issue and went from an AIRDOG to p-pump to head and head studs - the whole works! And, it still won't hardly start cold, you have to crank and crank. Well, he dropped it off this am and I started looking at it. How important is the 20 -25 fuel psi? I got down to the AIRDOG as they wanted me to install a check valve and saw it was a 15psi pump for the 24v! Pureflow specifically lists 15 psi for 24v and 25 - 30psi for the p-pumps. Could this be the whole problem? From what I've found on here it sure sounds like it could be. If so. they put on a expensive hot p-pump for nothing. What do ya think?



Thanks, Dave

 

[Cosmo]

Could be. You'll want to swap out the spring on that airdog for a 30 psi spring. Just give them a call and they'll sell you the spring.

My airdog was a 24-valve kit that I had on my 6. 7, then swapped it over to my 12 valve.

 

[Shelbynut]

I finally got the spring after a week and a half. Put everything back together and it fired right up! Over 6 months and $2000 for a p-pump and the whole problem was he was given the wrong pump. To top it off, the new pump is waaaay to hot. It hits 1400* barely stepping on it from 45 to 55mph. I wonder if they'll give him his money back and put his old pump back on? The tech that worked on it even said he retested the AIRDOG and thought nothing of the 15psi.

 

[Bob4x4]

Sounds like that tech should not have the tech title

 

[JKosten]

Why did you have an Airdog on the P7100 in the first place? What failed with the mechanical lift pump?

The P7100 likes to have at least 25psi or better with a "modified" pump.

Also some trucks with cold start issues the pedal has to be slightly depressed on start up (refer to the back of your visor for "Cold Start" instructions). This will allow for extra fuelling.

 

[LNaugle]

Unbelievable... . ! People should know what shop this is as not to use them... . Sounds backyardish...

 

[Shelbynut]

I'm not sure what was wrong with the mech pump. He could crank until the batteries died and most times it wouldn't start and light pedal didn't help. Either they ordered the wrong pump or AIR DOG shipped the wrong one - neither will take responsibility. The tech did tell him when they replaced the p-pump they originally put a new one on. It had something seriously messed up and the supplier didn't have another and substituted this one. Evidently this one is supposed to be as built as can be. We'll see where it goes now. His turbo definitely isn't enough for this pump. It makes 35-40lbs of boost but spools way to slow. As long as he has the pump he might as well get the turbo to match!? What do ya recommend? I keep trying to talk him into twins, but so far he wont bite! He does tow occasionally (8k 5er) so he needs it useable.

 

[Cosmo]

If it's slow to spool, he should tweak the star wheel and/or the smoke screw.