HELP! changed head gasket on 7m and now it doesnt start!!! - Toyota Nation Forum : Toyota Car and Truck Forums

psupra · 08-07-2006, 09:03 AM

Hi everyone,
recently me and a mate have changed the head gasket on my 7mge engine, it is our first time working on these engines and we pretty much figured it out (or so we thought) But when we got it all finished and went to start it, we got nothing. -The starter motor still kicks, there is still spark, i THINK there is still fuel pressure as i can smell it and there is a backfire comming out of the intake pipes about every 30seconds. Anyone got any ideas? Also there is a water leak comming from somewhere, but we can probly find where thats comming from ourselves.

Any help is much appreciated
cheers
-Psupra

Jeeves · 08-07-2006, 09:14 AM

1) Find the water leak.

2) CONFIRM Spark and Fuel. If you have both, there's something else wrong.

3) If spark is lacking, check cam position sensor.

***toyomoho*** · 08-07-2006, 03:43 PM

Could be a loose water hose clamp, check for a leaking head gasket.

Backfiring is sign the valve train or engine timing is off. Check basic engine timing. Look at the distributor rotor (if you have one) and see where it is with engine crank set at 0 degrees and the No1 cylinder at the top of the compression stroke. Should be at the No1 plug location on the distributor cap. Make sure the valve train timing is correct (cam and crank relationship).

Jeeves · 08-08-2006, 10:58 AM

I don't think the car actually starts since they're not 'sure' they are getting fuel.

***toyomoho*** · 08-08-2006, 02:56 PM

He did state he could smell fuel and the engine was backfiring out of the intake manifold. As such, this sounds more like a timing issue, valve train, engine or both.

Jeeves · 08-08-2006, 03:30 PM

Quote:

Originally Posted by toyomoho

timing issue

The cam position sensor will cause all of the above symptoms.

psupra · 08-08-2006, 11:41 PM

I'm pretty sure we are getting fuel. The spark plugs all worked fine. And we have the main crankshaft set to 0 with the first piston being on the top of the cylinder. The distributor is also set to the first cylinder so that isn't the problem either. These things, I'm pretty sure of, are not causing it.
It sounds like the cam position sensor is the problem. Could anyone tell me where I could find it?
As to the water leak we'll figure that out by ourselves.

Thanks again

Pascal

Jeeves · 08-09-2006, 12:44 AM

Wait, 7M-GE? Non-Turbo? The Turbo has one, the N/A doesn't.

psupra · 08-10-2006, 04:42 AM

yea, its a non turbo. Ill set the main crank to 0 btdc, and then ill check the cams, then ill check the dizzy. Quick question tho, how do i know if piston number 1 or 6 is on the compression stroke? casue isnt 1 and 6 simultaneously compressing and exhausting? Anyways, ill get back to ya after i check.
thanks
-psupra

Jeeves · 08-10-2006, 09:37 AM

Pull the spark plug out of #1, and throw a long screw driver down the hole. When it reaches it's maximum height, you're golden.

psupra · 08-10-2006, 12:51 PM

Hey everyone,
I finally figured out that my cams were off by a little bit, but the problem is fixed now. The car started and we've figured out where the water leak is coming from. I guess it'll be ready to go on the road soon. Thanks again for all your help.

Thanks
-Pascal