Ok guys my name is Aaron. i have an 87 sr5 runner. love it. i replaced the head over this winter. i went to try to start it and it will try to fire, but then after a couple attempt it backfires threw the intake. it actually blows the intake off the filter box!!!!! I think its a timing issue. But i didn't change the position of the timing chain. Any ideas???? Im trying to avoid taking the head back off.

 

have u check to make sure all your timing marks are lined up? sounds like u have distributor 180 out. set motor at tdc number one and see it is pointing that the correct spot in the cap.

 

I agree that the ignition timing could be 180* off. Also double check the firing order and make sure that none of the valves are too tight. I would think an intake valve that is not closing could cause a bad backfire like that.

 

i thought it was 180 out also. But i have checked this, and the timing chain, and see if it is at tdc. and it all checks out. it acts like the firing order is off. 1,4,3,2 i think is what the book said. idk. i almost want to pull the timing chain and see if it was installed wrong the last time it was done.

 

Try 1-3-4-2 It will run better, but if that doesnt completely work, try turning the distributor 180

 

I agree, firing order is 1-3-4-2.