Crank but no start. (Page 1/2)
jjd2296 JUN 18, 10:11 PM
First off I’ve checked a multitude of posts on this topic but nothing similar to my situation. So here is the breakdown

New freshly built custom 3.4 set up with supercharger
Was installed and started up no problem.
Drove it home, noticed that my AFR was perfect at idle but lean when I attempted to accelerate (from 14.7 at idle to 17.6 on acceleration so I babied it on highway)
Assumed it was a tune issue
Took off-ramp and car died, slow starter crank and drained battery. Had to get a tow. Got under car and noticed the police battery cable to the starter was exposed at the base with the copper almost touching the starter casing, fixed that.

Since then I have checked the following:

Replaced starter, distributor, coil, plugs, icm, wires, confirmed good battery, good tps, good iac, good ecm coolant sensor, good o2 sensor, have crank and white spark on plugs, compression is amazing in all cylinders, no slop or delay in rotor cap when I hand crank engine. It’s not 180 off. Set the tdc on number 1 confirmed with sound of air coming out number 1 with plug removed and finger over hole and double Check with camera. Tdc marking on balancer is in perfect location , therefore outer casing has it come loose. Perfect fuel pressure, pump primes, fuel pump relay works, pressure hold at 42psi for more than 5 min before it begins to drop very slowly. tech moves when I crank (manual car. Moves to about 200-300 rpm (but not quite 400) tested injectors and they are good (confirmed by installing rail and injectors on another build)

Fuses are all good. Tested signal from harness to injectors and all good, swapped ecm no change.


No codes, and the weird thing is it wants to go but no matter what I try only exhaust manifold on number 1 and 6 get hot. All others are cold to touch. I’m at a loss. It doesn’t really get that flooded with all the cranking either.
1985 Fiero GT JUN 18, 10:47 PM
My only thought is something timing related, I just replaced my heads, and entirely lost my timing, it took like 5 hours (admittedly on 3 hours of sleep) to get it timed, I went through every problem imaginable (spark plug wires were going around the distributor the wrong direction, timed to the wrong mark on the balancer, found that out and timed to the right mark...180° off. Then fixing that I timed to the wrong mark again, that was fixed fairly quickly)

Make triple sure to find TDC cyl 1 (right rear cyl), mark that line with some white paint, make sure the plug wires go clockwise on the distributor, time it by having someone crank it while you use a timing light, and looking for the white painted mark. Make sure the aldl is jumpered, so the timing can be set correctly without computer interference.

You should smell gas after just a few cranks, it may not get worse smelling, but you should smell it, I got timing roughly set with the starter motor, with the fuel pump fuse removed, so there's no fuel.

jjd2296 JUN 19, 08:23 PM
It’s. It an issue with the distributor setting. I’ve redone it 10 times back to TDC and on compression stroke and yes the wires are in the correct order. That said I haven’t tried doing it in aldl mode with a cold engine. I was always told to do it at TDC on number one. It always starts up that’ way then once warm I put it in aldl mode and time.
Patrick JUN 19, 08:43 PM

In case it might be helpful, Here is my writeup for setting the static ignition timing on a 2.8 V6 engine.
jjd2296 JUL 07, 02:22 PM
further update on what ha been checked, still wont fire up, it sounds like it really wants to but it just wont. Any suggestions would be great, but please read what I have done and confirmed working to date.

I have checked the following:

Replaced starter, distributor, coil, plugs, icm, wires, confirmed good battery, good tps, good iac, good ecm coolant sensor, good o2 sensor, have crank and white spark on plugs, compression is amazing in all cylinders, no slop or delay in rotor cap when I hand crank engine. It’s not 180 off= (confirmed)

Set the tdc on number 1 confirmed with sound of air coming out number 1 with plug removed and finger over hole and double Check with camera.
Tdc marking on balancer is in perfect location , therefore outer casing has it come loose.
Perfect fuel pressure, pump primes, fuel pump relay works, pressure hold at 42psi for more than 5 min before it begins to drop very slowly.
Injectors are all good, confirmed by taking good injectors and fuel rail from another build that fired up.
Tech moves when I crank (manual car. Moves to about 200-300 rpm (but not quite 400)
Cat isnt plugged, I disconnected the exhaust from the cat to confirm. still wont fire up.
Fuses are all good. Tested signal from harness to injectors and all good, swapped ecm no change.

what is left to check? could the timing chain have skipped? but if it did would I not be getting compression in each cylinder about 140 psi? my compression in each cylinder is amazing when tested with a leak down tester and placing each cylinder at TDC for the test. the pressure is so go it actually pushes the cylinder down in the camber a little.

could I have a stuck lifter? or a PR that popped off? when it died while driving it just died no sound. I have double confirmed that the battery is good as well. it cranks but doesn't want to go, I can hear it trying and number one and six exhaust manifolds get hot, not hot enough where I cannot touch them. and exhaust manifolds 2345 are cold to the touch compared to 1 and 6. I'm at a loss.


any help would be appreciated.
cartercarbaficionado JUL 07, 07:00 PM

quote
Originally posted by jjd2296:

further update on what ha been checked, still wont fire up, it sounds like it really wants to but it just wont. Any suggestions would be great, but please read what I have done and confirmed working to date.

I have checked the following:

Replaced starter, distributor, coil, plugs, icm, wires, confirmed good battery, good tps, good iac, good ecm coolant sensor, good o2 sensor, have crank and white spark on plugs, compression is amazing in all cylinders, no slop or delay in rotor cap when I hand crank engine. It’s not 180 off= (confirmed)

Set the tdc on number 1 confirmed with sound of air coming out number 1 with plug removed and finger over hole and double Check with camera.
Tdc marking on balancer is in perfect location , therefore outer casing has it come loose.
Perfect fuel pressure, pump primes, fuel pump relay works, pressure hold at 42psi for more than 5 min before it begins to drop very slowly.
Injectors are all good, confirmed by taking good injectors and fuel rail from another build that fired up.
Tech moves when I crank (manual car. Moves to about 200-300 rpm (but not quite 400)
Cat isnt plugged, I disconnected the exhaust from the cat to confirm. still wont fire up.
Fuses are all good. Tested signal from harness to injectors and all good, swapped ecm no change.

what is left to check? could the timing chain have skipped? but if it did would I not be getting compression in each cylinder about 140 psi? my compression in each cylinder is amazing when tested with a leak down tester and placing each cylinder at TDC for the test. the pressure is so go it actually pushes the cylinder down in the camber a little.

could I have a stuck lifter? or a PR that popped off? when it died while driving it just died no sound. I have double confirmed that the battery is good as well. it cranks but doesn't want to go, I can hear it trying and number one and six exhaust manifolds get hot, not hot enough where I cannot touch them. and exhaust manifolds 2345 are cold to the touch compared to 1 and 6. I'm at a loss.


any help would be appreciated.


sounds like you need to ohm out your spark plug wires and clean your plugs with brake clean and a little bit of fire after it evaporates. it sounds like fouled plugs to me or a dead spark from a cracked plug or something. the dying while driving sounds like it was very sudden so maybe pull the easy to reach valve cover (1/4 stuff can take it off with the 2.8l intake intake installed but it kinda sucks ass) and check for anything that looks off. you could also just move around your distributor until it fires off since it's doing what my 84 did which for whatever reason could not be timed properly
edit: have you tried spraying starting fluid or cheap autostore brand brake clean (has to be flammable) down the throttle body? the supercharger won't really like it (unless it's the oem style which doesn't care) but if it fires off then your injectors decided to be weird and stop working correctly

[This message has been edited by cartercarbaficionado (edited 07-07-2024).]

Patrick JUL 07, 07:42 PM

quote
Originally posted by jjd2296:

white spark on plugs



...which means nothing under atmospheric pressure. Outside of the compression chamber, a healthy spark will easily snap across a full 1/4" gap to ground.
jjd2296 JUL 17, 07:37 PM

quote
Originally posted by cartercarbaficionado:

sounds like you need to ohm out your spark plug wires and clean your plugs with brake clean and a little bit of fire after it evaporates. it sounds like fouled plugs to me or a dead spark from a cracked plug or something. the dying while driving sounds like it was very sudden so maybe pull the easy to reach valve cover (1/4 stuff can take it off with the 2.8l intake intake installed but it kinda sucks ass) and check for anything that looks off. you could also just move around your distributor until it fires off since it's doing what my 84 did which for whatever reason could not be timed properly
edit: have you tried spraying starting fluid or cheap autostore brand brake clean (has to be flammable) down the throttle body? the supercharger won't really like it (unless it's the oem style which doesn't care) but if it fires off then your injectors decided to be weird and stop working correctly




so I have changed the wires and plugs, still wont fire up. it does sounds like some misfires or bogging, the starter is working hard. next step I think is to take the top end off and check the valvetrain. that said, if I have perfect compression on a leak down test of each cylinder, how could I have an issue with the valvetrain? unless its a dislodged pushrod on one of the exhaust side lifters etc? would that make sense as the cranking by hand with a wrench is super hard at certain points in the rotation. could a collapsed lifter or two cause this as well? I have scoped all the piston bores and I don't see and valves stuck open that for sure. I just want to know if im on the right track and next logical step is to pull the top end off and look at the valvetrain.
jelly2m8 JUL 18, 04:37 AM
Your not providing enough information. First what are you using for an intake manifold? it has widely been proven and accepted without doubt the biggest chokepoint of a Fiero 2.8 is the 2.8's upper intake manifold. History has proven most 3.4 swapped Fiero's with a 2.8 intake manifold has ended up for sale......
jjd2296 JUL 18, 09:45 AM
It’s not the intake. I have a highly
Modified PPG style intake and bored TB. This set up ran on the old block but I blew it up with a head gasket failure. That’s not the issue. Like I said it started up on install and drove before it died on the highway. And I think you
Missed the fact that I have a v5 supercharger on this too.

[This message has been edited by jjd2296 (edited 07-18-2024).]