Problems After Replacing Head Gaskets

[RPS13Drifter]

Hey all,

I recently did the timing belt and head gaskets on my girlfriend's 1997 ES300 (1MZ-FE). Since then my car has had a bad rhythmic-stumbling Idle and power loss problems. When in park, the Idle is worse than when stopped and put into drive. It will bounce between 500-700 RPMs, and once it has warmed up it stays between 600-650 RPMs and bounces about 2-3 times a second. There is also a problem with it's power curve. From about Idle-2500 It pulls fine, I then feel a loss in power from approx. 2500-3700. After that, the 3700-4700 range pulls very strong, then gets progressively weaker from 4700 to about 6000, and then it shifts. I did both a vaccum and compression check on the engine to see if i could solve the problem. The vaccum check showed 15 mmHg that jumped up to about 17-18 mmHg every time the engine stumbled (a few times per second), and the compression check gave me approx. 240 PSI on all cylinders (done with warm engine at WOT with all the plugs out). I am very confused. There are no vaccum leaks, the head was cleaned and resurfaced, and I tightened everything to spec!

Could this be due to improper valve timing? Thats all I can think of!

Any other thoughts?

Thanks!!

[branshew]

sounds like the timing is off.

[amf1932]

Could this be due to improper valve timing? Thats all I can think of!

I'm almost 100% sure that's your problem. All it takes is one cog off on your timing belt to create this situation. Recheck it.

[Toysrme]

Cam timing.

[RPS13Drifter]

Ouch, I had a feeling that was it. Somthing about tearing back into it again just kinda makes ya wanna give up and bring it to a garage. Well, thanks for the help everyone! Your input and opinions have been very helpful!

-Matt