Rebuilt head, car not starting, help!

[hella 325]

you cant have the motor 180 out in an m20... not possible... on the crank the #1 cyl is at TDC twice for every one cam rotation. once when cyl one is fireing (dist is down) once when 6 is firing (dist up) so there is no way to be 180 out. the cam gear and the dist rotor only go on one way.

how would the fireing order be off?

[modifiede30]

Have you checked whether you've reversed the impulse sensor and crank sensor plugs?

Check that your AFM is working, not just moving freely. Usually the results wouldn't be this harsh but you might as well check.

When you installed the timing belt, did you manually crank the engine a full rotation before tightening down the tensioner?

[arsevader]

you cant have the motor 180 out in an m20... not possible... on the crank the #1 cyl is at TDC twice for every one cam rotation. once when cyl one is fireing (dist is down) once when 6 is firing (dist up) so there is no way to be 180 out. the cam gear and the dist rotor only go on one way.

But if you removed the head, your dist could be firing on the exhaust stroke rather than the compression stroke. Though I guess if you are absolutely sure the timing marks are fine, then it's probably ok.

The firing order could get messed up if you plugged the spark plug wires into the wrong spots on the cap or at the plugs.

James

[nando]

are you SURE you got the plug wires in the right order? I had a similar problem (car sounded like it wanted to start, but wouldn't) and it turned out that I had #6 and the coil wire swapped.. doh! once I got it wired up correctly it started right up. I checked it a couple times before and didn't notice.

otherwise I would get a timing light or some other way to check that the timing is correct. make sure the rotor is in the correct orientation, it's possible to put the "key" that it screws onto incorrectly (it's held on by the same bolt that holds the cam gear on). The one I had actually had 2 notches in it because the shop that had put my head together before me put it on wrong and torqued it down that way (making a new "notch"), which also caused me some major headaches..

[hella 325]

The cam gear only goes on one way, and the "key" is part of the cam gear.

I also am 100% sure the plug wires are correct, they are IE wiers and have lables, but to me sure i put a Ohm meter to them to make sure. they are correct.

I am sure the T|O mark on the toothed wheel and the notch on the cam gear are lined up.

I also know the impulse sensor and CPS are not swapped b/c if they were swaped then there would be no fuel or spark present.

[modifiede30]

The cam gear only goes on one way, and the "key" is part of the cam gear.

I also am 100% sure the plug wires are correct, they are IE wiers and have lables, but to me sure i put a Ohm meter to them to make sure. they are correct.

I am sure the T|O mark on the toothed wheel and the notch on the cam gear are lined up.

I also know the impulse sensor and CPS are not swapped b/c if they were swaped then there would be no fuel or spark present.

I believe that you'll get fuel without the CPS correct, but am unsure about spark. I thought both are still active. If the fuel relay is disconnected, spark is cut, but I believe the CPS isn't the same setup and fuel and/or spark will continue.

[hella 325]

with out the CPS the spark doesnt know the engine is turning so it wont fire

[Jordan]

Russell, it is obvious to me you know far more then anyone that has replied thus far. Everything I was going to mention you've already addressed.

If you have fuel/spark but no start I would make sure cranking speed is enough, and make sure you have GOOD spark by actually pulling a plug out and grounding it to the valve cover.

[nando]

The cam gear only goes on one way, and the "key" is part of the cam gear.

trust me, it can be put on wrong. that's how the head core I bought last year came, but I didn't think about it until my car wouldn't start.

[hella 325]

thanks jordan, yup I have also checked for good spark and I am running a brand new starter for fear of slow cranking RPM. Should have added those to the list up top too.

I hauled the car to a buddy's shop today. Turns out my theory from the get-go was dead on. It seems the spark is igniting on the piston upstroke, kinda stopping the piston from goin over TDC. In other words my timing is SUPER advanced. which explains many of the symptoms i'm having. Now, i just have to figure out why its so advanced. what could have thrown it off.

nando please explain how it can be put on wrong? without jamming the crank gear on in the wrong orientation and torqing it to high hell.

[modifiede30]

Does the 87 read crank position from the engine crank wheel or the flywheel?

[hella 325]

engine, like the later models.

[modifiede30]

Check to make sure you have the proper clearance between the crank sensor and the wheel. Also, if you have a stock ecu chip, might want to throw it in to see if there is any change. When you did the work on the head, did you disconnect any other wires aside from the TPS and ignition wires?

[nando]

thanks jordan, yup I have also checked for good spark and I am running a brand new starter for fear of slow cranking RPM. Should have added those to the list up top too.

I hauled the car to a buddy's shop today. Turns out my theory from the get-go was dead on. It seems the spark is igniting on the piston upstroke, kinda stopping the piston from goin over TDC. In other words my timing is SUPER advanced. which explains many of the symptoms i'm having. Now, i just have to figure out why its so advanced. what could have thrown it off.

nando please explain how it can be put on wrong? without jamming the crank gear on in the wrong orientation and torqing it to high hell.

don't ask me, I didn't do it. there was actually a second notch dented in the key from being torqued down in the wrong position (when I put it in I thought I had it in the real notch, but I had it in the "new" one). also, the cam gear would still be on straight, it's seperate from the key that holds the rotor on. I ended up using the one from my old head so I wouldn't accidentally put it into the wrong notch again.

this head also had a bent rockershaft when I got it, which took me about 2 hours with a hammer to get out (this was after I'd removed the cam), and was so obviously bent it wouldn't even roll on a flat sufrace. they should slide in like butter; so much for pro shops doing good work..

[hella 325]

hmm.... i guess i can take tha cam gear off ad check the key....