04 Cobra no crank after breakdown

[fallingup693]

Hey guys. Just got done rebuilding the top end after a timing chain guide was dislodged and bent all of my valves. Engine would turn before I put the heads on. Everything was fine. Rebuilt the top end. Everything turns over by hand. Hook everything up and it wont even attmpt to crank. Starter doesn't even click. I don't think it's a ground because I only undid one ground, and now it's connected again. Although when the car broke down on the highway and I had to pull over. It wouldn't crank or click or do anything after I pulled over either. Do you think there was a safety mechanism that tripped when all of this happened? Any thoughts?

 

[fallingup693]

bump

 

[ViciousJay]

ahhh yes. the fuel button in the trunk. look there its a safety switch that needs to be flipped back.

 

[Parts-is-Parts]

ahhh yes. the fuel button in the trunk. look there its a safety switch that needs to be flipped back.

OP said the starter would not engage.

Re-check wiring OP.

 

[fallingup693]

Wiring looks good. It happened after the car shut down on me on the highway as well. Starter would not engage.

 

[hotcobra03]

i had issues with 1 of the grounds in front of battery...there are 2 ...the 1 on the right broke at the ring...while driving...car just shut off....key did nothing but still had lights/radio

another area i had the stud on engine mount snap..caused no crank..
we ran a jumper cable from battery ground to engine..it cranked right over

 

[fallingup693]

Figured it out guys. I have an aftermarket car alarm that the ignition wire was going through and the voltage wasn't traveling through the alarm system. Thank's for all of your input and giving me a place to start.

 

[fallingup693]

ok, so a lot of tinkering around. Car would crank, but wouldn't start. Thought I had the timing all wrong. So I took the motor back apart. Retimed it, and put it all back together. Does the same thing. Crank it, and it still wont start. It sounds like a little fluffy poof of a backfire every once in a while while cranking. But doesn't even want to try to crank over. Any idea?

 

[hotcobra03]

check for 12v power at coils and injectors,,if you have power than check the other wire,signal from pcm..

on recheck was the sensor ring for crank sensor there?

 

[fallingup693]

check for 12v power at coils and injectors,,if you have power than check the other wire,signal from pcm..

on recheck was the sensor ring for crank sensor there?

If you are referring to the crank trigger wheel then yes. I hooked an extra spark plug up to one of the coils and it was definitely sparking. Fuel pressure is at 40 psi. But I haven't checked to see if they are actually firing though. Hopefully that's the cause. I wouldn't know what else to check.

 

[hotcobra03]

you do have the air inlet connected,and maf plugged in?,,

are you sure you have fuel? pressure is 1 part how about flow,

when was the last time fuel filter was changed?

have you tried a shot of starting fluid

 

[fallingup693]

So today i did a spark check again and had spark. I also let the fuel injectors run onto a rag and there was plenty of fuel coming out. So I did a compression test and tested the cylinders. All of them read exactly 70psi. Is this normal for a newly put together motor before it is started for the first time? Or should I be really worried....

Did I do the timing wrong again? Or maybe the valves aren't sealing properly? I got the extra heads off of an aviator motor in a junk yard with about 60k miles on it. Maybe the valves were bent to begin with? When I took apart the aviator motor to get the heads off for use on my cobra I noticed that the secondary chain was broken..... hmmm

 

[cj428mach]

So today i did a spark check again and had spark. I also let the fuel injectors run onto a rag and there was plenty of fuel coming out. So I did a compression test and tested the cylinders. All of them read exactly 70psi. Is this normal for a newly put together motor before it is started for the first time? Or should I be really worried....

Did I do the timing wrong again? Or maybe the valves aren't sealing properly? I got the extra heads off of an aviator motor in a junk yard with about 60k miles on it. Maybe the valves were bent to begin with? When I took apart the aviator motor to get the heads off for use on my cobra I noticed that the secondary chain was broken..... hmmm

I think if you'r under 100 its bad news. Most new engines are probably 140+.

 

[fallingup693]

I think if you'r under 100 its bad news. Most new engines are probably 140+.

My question is could timing throw it off that much without bending valves?

 

[hotcobra03]

when you did timing wrong was it on this build?

you did not take heads to machine shop for inspection and frenshen up

 

[fallingup693]

Well, sounds like a good excuse to send the heads off to MMR for porting and rebuild

 

[blwn03sonic]

I'm doing the same. I pulled the motor because of a bad exhaust valve that failed on the leak down test. 32% loss from that side. I sent the heads out for a rebuild. Hoping I can install the timing chains with no problems. Good luck man


Sent from my iPhone using Tapatalk

 

[fallingup693]

I'm doing the same. I pulled the motor because of a bad exhaust valve that failed on the leak down test. 32% loss from that side. I sent the heads out for a rebuild. Hoping I can install the timing chains with no problems. Good luck man


Sent from my iPhone using Tapatalk

Hey thanks man. Yea, just cleared it with the wife. Hopefully I can sell my ZX-6R soon to get the money for the rebuild. MMR quoted me about 2600 for slainless valves, bronze valve guides, new seals, comp springs, their max port, stock 03-04 cams, assembly, decking and shipping. Not too bad I think.

Are you going through MMR for your build or someone else?

 

[Cobra03SC]

Thats a pretty good price, the compression should be alittle higher than that even for a fresh motor and rings. I believe mine was around 110 when it was 100% never ran before.

 

[blwn03sonic]

Mine was at about 175-180 psi.


Sent from my iPhone using Tapatalk