1997 Yukon Loss of power

When going up hill it seems to loose power and gets very lazy, once up hill power resumes and everything is good again.... Fuel preasure regulator problem????? Fuel pump going bad??????? Completely new tune, new fuel filter and air filter... Currently onboard I have headers, air intake and trottle body separator.

What is the fuel pressure at? Check pressure cold with engine not running. Then with engine running both cold and warm. Turn the engine off and watch the pressure for 5 minutes.

Any codes stored? Even if the check engine light is off, you should get it scanned.

Has the intake manifold gasket ever been replaced?

//2000CAYukon

Never had check preasure, but will and post results, no significant codes..... Currently plan on rebuilding engine in Mid March. Looking into boosting around 350 HP. Hopefully this will aliviate the problems. Thanks for the tips

What are the signs that you have to replace the intake manifold gasket?
Thanks

What are the signs that you have to replace the intake manifold gasket?
Thanks

Tankster, the reason I asked about the intake manifold gasket was because the timing is not set with a timing light. Many times after the intake manifold gaskets are replaced and if the cam retard is not set with a scan tool, misfires can happen causing power loss under load.

On the Vortec engines 96-99, it is common for the intake manifold gaskets to leak coolant.

//2000CAYukon

Oh I see.Has anyone had the TBI gasket go? What does the truck do when it goes? '95 yukon
Thanks

Oh I see.Has anyone had the TBI gasket go? What does the truck do when it goes? '95 yukon
Thanks

When mine went I had a pretty high idle. Basically is creates a vacuum leak and the ECM tries to compensate for the extra air entering the system (it sees the system running lean so it adds fuel).

//2000CAYukon

We had this happen w/ our 97. We got it back in 98 and took it back to the dealership. At the time GM came out with an advisory(not necessarily a recall) that addressed this problem. They recommended a complete tune up, that the dealer took care of for us. Since then we haven't had any problems.
Hope this helps!