ok...found no spark....

[MI95Cobra]

i checked and i had no spark....so my timing might of been right...i'm going to get another distributor friday...hopefully thats my problem....also when i tested for no spark...my car backfired and i saw smoke on my passenger side in the engine bay....i couldn't tell where it came from...but it really didn't smell like something was burnt...does anyone know what that could of been about???
jimmy

 

[red95gtconvert]

The TFI module is mounted on the passenger side engine bay, it is by the air intake. If it is fried you will have no spark so don't count your distributor out just yet.

 

[HISSIN50]

Jimmy, If you have no spark, it's hard to generate a backfire.

Double check or post up exactly what you did and what is happening - it might save ya some cash.

To expand on Red 95's idea: If you want a no brainer way to see if the signal to spark is reaching the coil, put a test light across the two small wires going to the ignition coil. Have someone crank the car. If the test light flashes, the TFI is sending a signal to fire the coil.

Good luck.

 

[MI95Cobra]

ok...lets see 2 months ago (when i got my work truck) i decided to tear my car down and install my cam and different heads(i got heads from a 93 cobra that had been re-valved and spinged and milled down)...well when i brought it back up and tried to start it all it did was turn over and backfire occasionally....everyone i talked to(here and other places) said it sounded like i was 180* out and asked if i got my timing chain marks right.....so i turned the dizzy 180* difference but still had the same results...after second guessing myself i took it back down to the timing chain and yes my marks were lined up....so then i tried again to start it but ihad the same results...it'll turn over and occasionally backfire but thats it...i called and asked my father(old home school carb mechanic)...he said i think your valves are to tight from your rocker arms...so i loosened them and tightened them to the specific torque by my chilton manual....still nothin....so we pulled the distributor and reset the dizzy another 10 times or so...then we noticed i had no oil on my rocker arms and on the heads....we're think ohhh f**k.....so he called a mechanic he knew and he said that the oil pump could be out or the shaft or even the distributor....he asked if we were getting spark...we said yes because it was backfiring.....he said that not neccessarilly....and the oil could be because it takes pressure to send it....and it has to be running.....so i tested by putting a screw driver into the number one spot and turned it over and had no spark, but it did backfire...after that i noticed a little smoke on the passenger side...i couldn't tell where it came from...

 

[HISSIN50]

Oh boy.

Just to be totally sure, I'd waste one minute and pull the coil wire off the dizzy. Put a plug on the wire and ground the threads to the intake. See if you have spark. You just wanna be real sure that you dont have spark or that's a lot of wasted diagnostics (I dont like the screw driver method personally - too large of an air gap on a car with a partially discharged battery can give false results).

When the dizzy was restabbed, the rotor was always around #1, right? On older stuff where there is no PIP reference point, you can do crazy things to a dizzy that you cant with a magnetic pick-up equipped dizzy.

Was a compression check done just to ensure you're lookin good (given the milling, etc)?

I'll stop there. And apologies if you had other threads about this stuff and I'm being redundant.

Good luck Jimmy.

 

[final5-0]

Jimmy

Maybe its just me that has missed the boat here

You are using oem ped rockers ... Right
Whether you tighten them loose at 20 or tighter at 24

Makes no never mind as there is just not that much difference.

The difference of pre load between those two values won't mean much

IF

Your heads have been cut so much the valves might be hanging off
the seats or barely touching them.

No compression sure does make one suspect something along those lines

about the spark .........

Did you do the simple plug in the coil wire thing, spin it over
while looking for spark method like JT suggested

Hang in there man ... You'll soon get it going

Grady

 

[MI95Cobra]

ok...i went up and talked to a certified ford mechanic at a local ford dealership....i explained what i did and what it wasn't doing...i asked about the tfi module and he told me how to check it....so basically he told me to bypass the module by using the starter solenoid on the starter and to check the ignition switch harness under the dash...i did both and nothing has changed....so should i now check the ignition coil??? i replaced it already...i have 2...my old 1 and a new 1....also how can i check the distributor???

 

[MI95Cobra]

ok...i have spark....so my module is good...whats the next basic thing to check???

 

[HISSIN50]

You noted smoke and back fire or after fire when you were cranking it. I'd try and check your timing at this point.

Good luck.

 

[reddy351]

Ok. How much has been milled off the heads? My machine shop guy (old high school buddy) said that you start running into port alignment problems when you start taking more than .060" off these heads. You'll also need to mill the lower intake to keep things all lined up, but I don't think that's your problem, here. I have a set of GT40's in the garage that he is going to mill and VJ for me.

My money, though, would go to pushrod length. As Grady said it. If the pushrods are too long, the valves won't close all the way. (Causing backfires! Fuel+spark=BOOM! Valves not sealed let the BOOM out, into the exhaust. Backfire.) That's what I'd check, next.

 

[MI95Cobra]

i'm going to pull my push rods and check and see if bent.....i think that may be my problem....also...should i invest in a diagnostic scanner????

 

[MI95Cobra]

ok...i'm pulling my pushrods and checking to see if bent....then i also got a diagnostic scanner for $30...so hopefully....we'll see...