Its fine.. and yea im gonna have to check it..ill test for air in fuel while im there too. So question when my truck sits over night and i start it, it idles at like 500rpm for about 10-20 seconds then climbs up to 800-850 rpm.. u think this is and issue along with my low power or is that normal? Also i see everyone saying they move there afc forward and back but when i put mine on it only goes full forward i cant move it back at all? Thanks!

 

As for the AFC, I don't think you're talking about the same thing because if it moves one way, it will move the other. There isn't much movement in it, only a 1/4" or so. It's a very rough adjustment and a little goes a long way.

 

Yes i mean the afc.. when i set it down on the pump it will only seat the whole down if i have it all the way forward.. then once its seated it will not allow me to push it back at all.. its like the foot is gettin caught on something

 

That doesn't sound right. Hm.

 

OK.. I also have a 98 12valve.. And had just a little puff of black smoke, even after turning the star wheel and full foward on my fuel plate.

I am going to say you have low fuel pressure. 4X4 already called it.

Today, I installed LarryB's fuel pressure adjusting banjo bolt, and it made a big difference in throttle response and power. This in turn, created more black smoke out the exhaust.

Its an easy install. Part # OFV-A $46 and allows you to easily turn up the fuel pressure with the stock pump.
Actually.. I ordered the entire kit, that includes the fuel pressure gauge, however, they only sent part of the order. I didnt wait for the rest of the package, to install this part. The rest of the kit is on its way.

 

Well see a guy a my work had a ofv for our pumps with shims in it to make it run higher psi to test if the lift pump would keep up with the higher command of pressure..i put that in and it didnt change a thing.. maybe my lift pump is starting to go.. ill have to check pressure.. im guessing this is my low idle issue too at first start up.. but the afc thing idk whats up with that.. all i know is when i put the afc foot down between fuel plate to seat it down all the way it has to be full forwarf to seat and i try pushing on it backwards and it jus wont budge.. idk if its maybe because i have starwheel cranked all the way?

 

Cranking it back would be one way to find out.

 

Yea i will have to try that.. i will be away til monday so i will try all this next week and get back..

 

Ok checked my fuel pressure at idle it jump from 12-21 psi.. idk why it jumps.. and 2500rpm its at 26psi

 

That is low. I dont recall, but i presume you had done the simple things first, such as replacing your fuel filter and cleaning out the fuel filter housing? I had a lot of nasty debris in the bottom of mine.

I also have a 98 12v. My pressure is at a near steady 28-30psi at idle.