motor turns over. no fire.

well im not proud of this and im about ready to pull my hair out over it but after putting my ported heads on the motor turns over but wont fire. it definitely has fuel. i can smell it. the coils are getting power but i don't know how much. it may not be enough for them to fire. i pulled one of the plugs and connected a coil to it and had zack turn the motor over. i got alittle shock but i didnt see the sparkplug spark. after several attemps i got nothing. i know the coils are getting atleast 6 volts. i put a test light on one and it lit up.

pulled the cam covers and checked the crank sensor ring. its on right with the prongs facing forward. about to double check the timing but i know i timed the motor right.....i just dont get it. i dont even get a pop when its turning over. no bang no nothing.

so with out further adue.... HELP!!!!!!!!!!!!!!!!!!


p.s. keep the prodding to a minimum. im frustrated enough......

How'd it go with double checking the timing?

Have you tried hooking you a set of jumper cables just to give it a little boost? Can't really think of anything else, if you have fuel and air, you must be missing spark. Have you tried reflashing the tune?

I know he reflashed the tune and tried other tunes.

Its a weird deal, pulleys spin, starter turns, you can smell fuel. Almost sounds like starter is disconnected and. Just spins.?

It did say check charging system at one point, but thought it was due to him flashing the car at that moment.

Everything plugged back in correctly? Timing would be suspect, but you said you have checked and are sure its correct. Puzzling

Do you have the motor grounded?

Try beating on the starter while someone turns the key. Might just be a fluke deal that the starter went.

Nevermind, you said the motor was turning over, just not firing. That means starter is working.

i have 2 theories only one of them really valid.

1: i mistimed the motor in which case it would have to be 180 degrees off to not smash a valve and still turn over and not fire. unlikely at best. still possible

2:the ignition system is getting voltage but not enough to fire the coils so it lights my test light which only requires 6 minimum volts but isnt firing the coils which requires 12 volts.

i double checked all the grounds. i just dont get it

passenger head cam and timing mark



driver side head



crank timing mark. driver side chain is right behind it and timed on the same timing mark and tooth

did you try hooking up a set of jumper cables to it from another car?

Is it possible the tune could be suspect?

Hate chasing grimlins!! Sorry your having trouble Jared, hope you get it figured out. Sounds like you've put some work into the motor!

Im sure you've gone through the checklist of "to do's". If everything is hooked up correctly, timing is correct, everything is accounted for....then what remains that you cant see I would double check.

David has a point, might be the tune if there is nothing else holding the motor back from starting.

ive still got a few things to check before the tune. i dont believe these heads could flow enough to cause the old cam tune to not start but with big cams and a good heads it is possible.

im about to yank the manifold off and check the connections under it. all thats there is the knock sensors. head temp and the connections that go to the o2 sensors. the thing is even if those were disconnected the motor should just go into limp mode. im wondering if i didnt switch the o2 sensor wires. im not even sure its possible since ford uses key plugs but gonna check.

gonna pull the fuel pump relay after that and crank it for a bit. once i put the relay back in if its to rich it should at least crank for a few seconds before flooding.

pretty strange. all you did was change the heads & cams? the wiring harness pretty much lays exactly so it's nearly impossible to mess up. what book did you use to do the swap.

when i did mine i used the online ford manual. i can send you the link if you want it

found it: http://iihs.net/fsm/?dir=167&viewfil...der%20Head.pdf

i used the ford manual as well. followed it to the dot.... some one just suggested that the pats module could be active which would keep it from starting.

hmmm good point, but i would wonder why it would have done that.

i move it around the garage several times without starting it. could have tripped it. dont see why it would though. i;ll go check in a second

You have verified that you are getting fuel and spark yes?

havent varified spark. i know the coils are getting power....just dont know how much. test light says they are but it only requires 6 volts not the full 12 that the coils require to fire.

i dont thinks pats is active. the security light comes on during the start up dance the panel does when you turn the key to auxiliary then it goes off and doesnt come back on.....dont think its the pats module. still got some more tests to do.... definitely scraping the bottom of th barrel here.

Instead of a test light use a multi meter and see what kind of voltage you are getting to the coils.

Oh and like someone else said double check the ground lead.

i would try completely unhooking the engine harness again and then putting it back on, 1 connection at a time. gotta be spark, or maybe needs more air? have you tried crankng with the pedal pressed down?

Still a no go? Dammit Fluffy. You need to finish so we can start.......


If you need more help let me know. I gotta take the Hoe back in sometime this week cause it's still leaking some oil and/or diff fluid....Stupid Chevy...

Anyways, like I said, don't think inside the box, nor outside the box; think about a whole new box. Go back to basics. Remember my o-ring? Remember your crank pulley? Clear your head and go back to the basics. Aaron and George both had good suggestions. Did you post on svt or some other site besides the Shelby or S197 sites? Much like on here and that site(s) you told me you posted on, there are very knowledgeable people out there that can help you think about a resolve from the different box point of view. Just b/c it's svt doesn't mean that there isn't someone on there that can't help you find a resolve.....

I know you don't want to, but go stop by Archangel and talk with Kurtis or one of his guys. Or go by and see Mike at pinnacle, either one has lots of experience building modular 3V engines and I'm sure can help point you in the right direction.

at this point im not sure what it is. tunes my only idea. i find it hard to believe these heads flow so well that the old tune wont even fire at all. but i guess it is possible. these are pretty odd heads.

i stll havent been able to varify spark so its still on the table. still a few options. have greg coming over Thursday, he had a few ideas and he's bringing some specialized tools i dont have. at this point i just want to be able to drive my car. i need some thunder!!!!! gotta feed the addiction!

Let us know if you get it figured out, hopefully Greg has the answer. Dont drive yourself crazy, it will start...just have to have patience.

thanks guys. i had to take a step back and take a few deep breaths. i've driven myself up the wall trying to trace the problem in my head. no matter how i look at it i keep coming back to the same answer.

If you timed it 180 out it will be low on compression. Please show a pic if the crank timing mark. Do you have a way to check injector pulse? Stock cams? Does it crank like itc has compression or does it free wheel? Tune should not keep it from starting. If you have injector pulse it is not PATS. Oil pressure while cranking?

Sorry your having trouble with this.. There are a few things I would check for sure.. I would start with listening for the fuel pump.. If you can't clean the ground and reinstall.. By chance it could of been crapped up with fluid and things not letting it ground correctly. Don't know a lot about these motors but I have run into this problem before.. I know coil packs can be very sensitive to fluids getting on them and they can "short" out.. Try resetting your ecu them reinstalling your new tune..

Best of luck

i have pictures of the timing marks above. ive checked fuel and i know its getting it. going to double check timing again tommarow and finaly varified spark.