98 GMC 5.7L Intake

[96silverado]

I just finished changing out the intake gasket on my son's truck. The problem I am having is with the timing. Here is a list of things I have done.

• The cam position sensor and the crank position sensors are aligned, no P1345 code.
• Shot brake cleaner all around the upper intake, no leaks.
• OHM'ed out the injectors, all good.
• The distributor is in correctly, TDC & the arrow with the 8.

Things I have not done:

• Flash the PCM. I do not have the tech II scanner.

The only thing I have found is that at "idle", if you want to call it that, if I shoot brake cleaner into the throttle body the idle levels out for a second. With the air breather case in place there is a serious vacuum sound coming from the throttle body. I double and triple checked everything against my 96 5.7L and the only difference is the vacuum sound. Oh, I checked the vacuum with a guage and it's reading 5 to 7 inches. I know it's supposed to be around 22.

UPDATE: I just finished cleaning the IAC, it was working but I don't know why it's being forced open so far.
UPDATE: Fuel pressure is 60 PSI.
UPDATE: MAP sensor is working correctly.
UPDATE: MAF sensor is working correctly.
UPDATE: I give up! I'm taking it to the Chevy house but when they tell me what the problem was I'll post the answers for everybody else.
UPDATE: Well, I took it to the Chevy house....The answer the gave me was there is a stripped out screw on the distributor, NOT THE PROBLEM! I made them flash the PCM, it didn't change anything but atleast I don't feel like a complete idiot for giving them $100.00 for a stripped out screw. I'm bringing it home and I'm going to try and reset the timing.

Last Update: It was a faulty fuel regulator. I'm not going to go into long explaination but the fuel regulator on the fuel injector plug in was bad. I guess I knocked it around too much or something.

Any tips are greatly appreciated.

[johnnywoodward]

This really is a pain, I ALWAYS have trouble with these...however its very simple. Sounds like your on the right track but just make sure it really is at tdc. There ARE marks on your harmonic balancer and the timing cover. Then make sure the metal contact is pointing at 8. Thats it...you litterally don't have to do anything else. If it still isn't right do it again. Thats really all I can say. Hope this helps oh and w/ the oil pump I just keep picking it up and putting it down until the pump lines itself up.

[maxwedge]

.Obviously either the timing is retarded, ( cam/crank synch) or more likely you have a vacuum leak. The iac is trying to compensate for the skewed idle that you will have with such low vacuum. you mave had the intake gasket slip down. 1345 may not set immediately if the cam crank synch is out, using a scanner is the only way to get the synch on target.

[98GMCpickup]

How can you be sure that the intake gaskets were the only leaks? There does not seem to be any bad parts of the gaskets. Should I go on to the heads?