Cranks but won't start.

[DeCaff2007]

All, the V8 swap is now complete so I'm starting a new thread, because now we are on to troubleshooting.

Just in case, 89 with a 94 5.7L 5-speed.

I found the aforementioned miss. Somehow, the #8 spark wire was disconnected. Upon connecting that, it started right up, gave me a few hiccups, one or two backfires through the TBI, but was still running. So, I continued to run the engine break in.

So, I'm sitting there, RPMs screaming @ 2500~ish, watching and listening for anything that could wrong. A couple minutes in, the CEL comes on. I decided to shut down and scan the codes. I got a 12 and a 13 and that was it. I've read that those mean diagnostic mode. How can I have a CEL with no other codes?

Anyway, before I shut it down, the engine was coming up to about 180° and I must say it sounded STRONG.

After scanning the codes, cranked until the cows came home and now no start again .

I'm going to wait until it completely cools off to see if that makes a difference. Reason being is that every time it started before, the engine was pretty much ice cold.

I know everyone is probably sick of telling me like it is by now... but.. suggestions?

 

[Jeepwalker]

See what happens when it cools down. If it starts back up, then there are different things to think about.

But for now, just the basics: Is the base timing right? All vacuum like it should be?

Have spark? What's the fuel pressure? Injectors have a signal? Is the ECM wire from the battery in good condition? I know you don't want to hear those things.

 

[DeCaff2007]

See what happens when it cools down. If it starts back up, then there are different things to think about.

But for now, just the basics: Is the base timing right? All vacuum like it should be?

Have spark? What's the fuel pressure? Injectors have a signal? Is the ECM wire from the battery in good condition? I know you don't want to hear those things.

On the contrary! I want to hear every suggestion that anyone can think of because I am out of ideas.

Spark: I'll say yes. I'm testing for spark with an inductive timing light. It's all I have.

Fuel Pressure: Last I tested, it was 10 PSI. Not what I'd like to see, but I know that that's within spec.

Injectors have a signal: I'll say yes because I put my phone on top of the TBI and hit record. There's clearly a spray of fuel from the injectors during cranking.

ECM wire from battery: No idea. It's something to check. Where exactly is it?

Base timing: I've been through this again and again lol. I'll check it yet again if I have to.

Vacuum: Ah, so I went ahead and pulled each vacuum line and tested them for leaks, one by one. They all passed. The only vacuum line I did not reattach was from the vapor canister to the TBI. I didn't like how the connection looked, so I capped it off at the TBI.

I did notice that the coolant temperature sensor wire had somehow made contact with the header on the driver side and it burned RIGHT THROUGH the insulation, letting the wire make contact with the header. That sensor, if I've read correctly, is the one that sends the signal to the ECM, not the gauge on the dash.

I did fix the wire, but that has had no effect on the no start issue.

Alright so I'll have to continue this sometime tomorrow. Very busy day ahead of me

 

[WICruiser-97]

So you have spark, fuel, and presumeably compression (unlilkely to go away just from shutdown) so the likely culprit would be timing of the spark. Seems like the fact that you have fuel would indicate that the TBI unit is getting some information to deliver fuel - I would think that means the ECM is probably working.

I believe in that vintage the timing is pretty basic - distributor setting related to crankshaft position. You may want to check to see if the timing is close to TDC on #1 using your timing light while cranking.

Another option would be your basically flooded, may be better after cool down unless the plugs are fouled. Pull one plug and look at the condition - wet with fuel?

 

[DeCaff2007]

So........ the answer is, after the engine cools off, it start's right up. It idles like CRAP, but it fired right up.

EDIT: I forgot to add, I did pull one of the plugs yesterday before the engine cooled completely off and after all that cranking. Definitely not fuel soaked. I could detect a hint of fuel odor but it was dry as a bone. Otherwise, the plug looked completely normal.

 

[DeCaff2007]

Alright I went ahead and ordered one of those calibrated HEI spark testers. Some of y'all seem to swear by them. It'll be here in a few days.

I also went ahead and ordered the fuel pressure tester adapter for testing fuel pressure straight off the TBI. No more pulling the fuel filter off. Again, it'll be here in a few days.

One thing I didn't think of was to set base timing with the advanced timing control unplugged. Guess I'll go check that lol.

I need to voice that I'm concerned with letting the engine simply idle (to set timing) without having completed the break-in process. I'm about 3 or 4 minutes into it.

 

[DeCaff2007]

Ok one more update here and I may have found the problem. These Hedman headers are causing more problems than they were worth. There's a wiring harness going from behind the engine to underneath the master cylinder. It was laying right on the drivers side header at cyl #7. The header burned right through that 30 year old heat shield and the plastic mesh behind it. I caught it just in time to stop it from burning through the wires, but oh man there's some crispiness back there lol!

Also, found this on #7 plug wire...

You must be registered for see images attach

Guess what caused that. Yep, it was touching the header on the passenger side.

Lastly: I think I need a better solution for a distributor, cap, and rotor. I'm guessing most of us have the type of distributor cap that is held on with just those two little screws on either side? Well, one of mine has completely stripped out and the cap wiggles freely, even with the other screw as tight as it will go. That can't be good.

Also, the Wife and I played the "bump the key" game as I held my thumb over the #1 cylinder and watched the intake valve open and close, then felt compression... and watched the distributor AND the timing mark on the harmonic balancer. SO much easier with two people.

Stabbed the dizzy.... the rotor seems to point towards either the #3 cylinder or the upper radiator hose. There is no in between, which would be pointing at the #1 cylinder. I kept it pointing towards #3 cylinder and it seemed to like that better.

Barely started. This whole time, I've been testing for spark on JUST THE #1 CYLINDER. I guess that doesn't mean that THE REST of the ignition system is ok.

So, with that, does anyone have suggestions on a better distributor? I'm currently running Rock Auto chinesium (because it was cheap at the time).

 

[termite]

Stabbed the dizzy.... the rotor seems to point towards either the #3 cylinder or the upper radiator hose. There is no in between, which would be pointing at the #1 cylinder. I kept it pointing towards #3 cylinder and it seemed to like that better.

Have you pulled the drive gear off the distributor and spun it 180? I've not looked at one closely but maybe spinning it on the roll pin will get you to the #1 when you stab it.

Edit following post 17: This is likely bad advice although it may be necessary with chinesium quality. I.e. if the drive gears are meant to be clocked a particualr way then installed 180 off during assembly. Approach with caution and keep track of the change in case it makes matters worse.

 

[DeCaff2007]

Have you pulled the drive gear off the distributor and spun it 180? I've not looked at one closely but maybe spinning it on the roll pin will get you to the #1 when you stab it.

I haven't even thought of such a thing. I mean that shouldn't be necessary, but I can take a look at it.

To be honest, I'd rather a higher quality distributor.

This seems to get "ok" reviews.... thoughts, anyone?

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[SNCTMPL]

This is a better choice.

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