no power after new head gasket - Toyota Nation Forum : Toyota Car and Truck Forums

SUE ASKEW · 10-03-2009, 02:08 AM

1990 corolla 1300, ran real well untill head gasket blew, replaced head gasket & planed head, assembled fine but engine has no drive at over half throttle, stripped carb & cleaned=same result.
Checked to date: swapped carb with unit from “good” car= same result, swapped fuel pump= same result, checked cam timing, ign timing, compression, all vac lines & non-return valves in correct position.
Installed video camera in engine bay to check secondary butterfly is opening at full throttle under load, result= it is.
Swapped inlet manifold in case one of the vacuum valves on the back was shot=same result.
it never misfires just doesn’t pull, top speed is 110 kph !
Kinda run out of ideas now !
If anyone has any suggestions, that would be very welcome.

***REN69*** · 10-03-2009, 11:18 AM

I'm thinking something was done wrong at reassembly, was this done by a shop or yourself?

SUE ASKEW · 10-03-2009, 02:59 PM

Work was done by ourselves. No hassles with the job, went like all the other head jobs we have done. No water leaks and compression normal.

We suspected cam timing might be off but double checked and all okay.

The motor behaves like vacuum secondary is not opening but video camera confirmed it is, although a vacuum gauge on the line to the secondary diaphragm shows no vacuum at any point.

Flashmn · 10-03-2009, 03:33 PM

recheck the cam timing, sounds like you've installed them wrong, theres the timing marks and the installation marks, recheck them.

SUE ASKEW · 10-13-2009, 02:58 PM

Many thanks for suggestion, however the cam timings have been compared with an identical engine and are set correctly.

Since last message can verify that fuel pressure is fine and there is no
obstruction in the fuel tank.

Any more suggestions would be welcomed. This is probably the most
frustrating problem we have encountered in a very long time!

1jzdreamer · 10-13-2009, 03:05 PM

3 possible culprits.

Fuel
Spark
Vaccum/Air

With a bad vaccum leak it will not have power, is the intake manifold leaking at the head? You didn't leave anything in the exhaust (rag or towels to plug/cover it up) which could be jammed at the cat now restricting exhaust right?

SUE ASKEW · 10-20-2009, 02:33 AM

problem now sorted! Thanks for all suggestions.
The mechanical advance retard device was ceased on the distributor shaft, and was not advancing the timing at high rpm. This conincidently must have failed at same time as head gasket replacement and had nothing to do with it. Simply bad timing.