Motor cranks, sometimes sparks.

[Greek]

Just assembled the motor after fixing a massive BHG. Everything was assembled, and it was double and triple check.

Put in a fresh battery, and it cranks just fine. But it cranks a whole shit ton before it fires at all. When it does fire, it is extremely sporadic and sounds like ass. At first I though the problem of it not starting was the timing, so we messed with the CPS and aligned the pulley a lot. Still no dice. Used a timing light, but it wouldn't flash. So by checking for spark, we found that it would randomly spark very sporadically. Swapped out different plugs and wires, same thing.

Another thing is that since I bought the car with BHG, I knew it has sat for a while. Upon checking the last registration: the motherfucker has been sitting for 3 fucking years. So the gas is obviously shit. I can see that being a problem, so would the bad gas be fucking up the plugs and cause them not to spark?

What could be causing this?

 

[toyotanos]

Common problem that's been seen on many 7M powered vehicles is the CPS wires cracking and shorting out. If you wiggle the wires coming out of it they will sometimes stop shorting!

 

[jetjock]

If everything was "double and triple check" it would run. That said it sounds like timing...

 

[Greek]

Common problem that's been seen on many 7M powered vehicles is the CPS wires cracking and shorting out. If you wiggle the wires coming out of it they will sometimes stop shorting!

I'll check for this, thanks.

If everything was "double and triple check" it would run. That said it sounds like timing...

It's a Supra, since when is it supposed to run without giving us a headache?

The timing was redone literally almost 10 times. The pulley was aligned and the CPS was correctly positioned.

 

[lewis15498]

Common problem that's been seen on many 7M powered vehicles is the CPS wires cracking and shorting out. If you wiggle the wires coming out of it they will sometimes stop shorting!

THIS.

Defective CPS/wiring.

 

[Greek]

It can't be the CPS, we took one off a running car and it did the exact same.

 

[Moy]

if you have a running car to test parts with, I'd say try the ignitor and/or coils

I hate doing a swap part "diagnosis", but it's easy if you have a running car on hand :/

 

[lewis15498]

Retry your timing light test on all the cylinders. If its a bad coil, you should only have an issue on two cylinders. Also, test your timing light on a running car to make sure the light isnt defective.

 

[Greek]

If I have to I can try. Does it sound like anything obvious or common?

---------- Post added at 11:00 AM ---------- Previous post was at 10:51 AM ----------

Retry your timing light test on all the cylinders. If its a bad coil, you should only have an issue on two cylinders. Also, test your timing light on a running car to make sure the light isnt defective.

We tested the light on all 6, no flash. We also tested it on another car and it worked no problem.

 

[lewis15498]

We tested the light on all 6, no flash. We also tested it on another car and it worked no problem.

Do you have a multimeter? If not its time to buy one.

Test your igniter as described in the link below.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=15

Save the link, the TSRM as a whole is very useful.

 

[3p141592654]

In your double and triple checking you checked for codes, right? A bad CPS will set one, so will other problems.