Alright we got everything hooked up and we tuned out vats. The car cranks but doesn't start. Fuel pump primes and everything but no start. Any help?

 

have you verified that it is getting spark?

 

Well we isolated that the fuel filter is not letting fuel past the inlet. I can blow through the return line and the exit tube but not through the inlet. Any tips on the corvette filter install

 

Ok well im an ahole. I mixed up the fitting to the filter.

 

Well thatdidnt fix it but we do have fuel. Spark is a no go we aregetting no spark to the plug? Wtf?

 

Typing on my droid is a pain.
We are getting zero spark. Zero at any coil. I am picking up some RPM, but not enough. Im gunna replace the crank sensor and hope for the best.

 

It seems as though this is a continuous cycle that a good number of us swappers have went through....and it seems like 90% of the time the culprit is the crankshaft sensor. Replace it and see if it doesn't fix the problem. That's exactly why mine had the same symptoms as yours.

 

Im putting all my eggs and hope into the Crank sensor basket. Ill let you guys know tonight.

 

Well, it's not the crank sensor. Narrows it down to the PCM or the harness.

 

Did you happen to do a crank re-learn? Seems like some people are having to do that, I didn't have to do it on mine

 

It will fire still needing a relearn. With the new engine/PCM/Tune Gm recommends doing a relearn, but you have to get it running first

Start with the basics, fuel air and fire. Are you sure the injectors are firing, are you sure the plug are dead

VATS doesnt control spark, heck as long as the PCM is receiving crank pos signal and the IGN is on, the PCM commands the coils to fire regardless of anything else

Test your PCM by hooking up a scan tool like TECH2 to the ALDL. Flick the IGN on and see what your sensors are showing. TPS, RPMs, IGN adv, CTS, IAT, O2s etc should all show live data

 

Pulled the plugs and they are getting fuel. Pressure gauge at the rail is showing 50+psi. Spark is missing. That's it. Spark =start

 

I know i need a crank relearn bad. It starts but idles like **** and everything else. To move it into SW's garage i had to give it gas and brake at the same time and creep in.

 

Have you checked to make sure you are getting 12 volts to the coil packs? Should be a pink wire that connects at the ignition coil bracket on the large connector in the middle. I got my money on a missing ground to the ignition coils. On the 4th gen f-bodys the ground for the coils goes all the way to the headlight and headlight door ground. Check it out.

 

Yeah I have power to both sides. Checked each coil too. I have the harness ground to the back of the head. I also have a large 4ga cable as a ground mounted to the block that runs right to chassis. I also have the factoy ground on the driver side grounded to the K. All grounds have been checked with a test lead.

 

Do a continuity test from each of the coil pins to the PCM

 

im having a simuler problem, i have spark, and gas but no start. just cranks and fires.

 

If it fires and immediately dies, then look to VATS

 

it fired but doesnt start, my cars an 86 so it doesnt have vats

 

He meant the VATS in the PCM, did you have that tuned out?

 

That's what im gunna have to do. Im gunna put my ecm in a friends ls1 car and see if it runs.

 

Ok I put my adm in my friends LS1 car and it ran better with my ecm then his. We even swapped coils. We went over all grounds and it all checks out. Still no start. Only thing left is the Speartech harness.

 

http://www.youtube.com/watch?v=zD_P3hUIlXg

Here is the vid of the start...or trying to start.

 

I think that pocket was suggesting that you unplug the ecm and check each wire coming from the ecm going to the coil harness connector. Don't actually check the ecm but just the wires. You're checking to make sure there are no opens or shorts in the wires.

 

Yeah, Im gunna do that tomorrow when we have access to test leads.
Looking over at LS1 tech, I see that I might want to check to see if teh coils are getting power when cranking.

 

EDIT...I read the whole thread, and somehow missed the very last sentence above this post haha. Sounds like you already got clued into the 12v while cranking... Oh well. I typed it, so Ill leave it...
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You have 12v to the coils and all...but is that WHILE cranking???

I made this mistake on my first go around. You have to make sure you are using a "hot while cranking" circuit. There is one that comes out of the big firewall connector. I believe its a larger gauge pink wire.

I have to say...that thing is cranking really fast. It almost sounds like you have the plugs out or something. I guess you could just have a really good battery/wires/starter combo goin on.

Check to make sure you're getting 12v while cranking to ALL of the pink wires in the engine bay. You can disconnect your starter to do this test, so that you can crank it without running the starter.

Its also VERY easy to break connection to the pink wires if you simplified the harness. Another mistake I made. Ended up having to jumper a wire from a known good pink wire, to the dead circuit. Mine was my MAF sensor and a couple other things. But my car still fired at that point. Check all the grounds like others have said too.

Good luck!

J.

 

Yeah im pretty sure we hooked into that pink wire. Battery has 750cca and I have a 2ga wire running right to the battery. Im gunna test tonight to see if this is what's clinton.

 

Well it RUNS!
http://www.youtube.com/watch?feature...&v=5XP_Und-dD4

 

Haha congrats... now what the heck was it???

 

12v switched is not the same as 12v cranking. Just an fyi