Ran fine until..... need some help. (2 Viewers)

[69FJ40NJ]

69 FJ with SBC, TH400. I have been driving it around, hit cars and coffee which is about 25 minutes from my house, no issues other than being loud do to the exhaust leak. I replaced the plugs over the past weekend, she ran fine. I replaced the AC units face plate and knobs with the wiring connections, exact same ones, just switched the wires. She ran fine. Yesterday, my buddy charged the ac, it ran in the driveway for about 30 minutes with intermittent reving, no issues. Air was cold but not crazy cold. Took it for a drive after work with the ac on, drove around for about 15 -20 minutes, then ac head unit made this horrid grinding sound so I turned it off real quick and at the next light she stalled. She has never stalled before. Drove back through my neighborhood, down my street and it died at the base of the driveway. Had to push it up the driveway.

It tries to start but will not turn over. I can hear the fuel pump working, and the electric fan works as well.

My guess is that ac has not been run that long in a long while and something shorted, all fuses are good, so it has to be a wire somewhere. I was also told to look at the AC clutch. So my question is, can I just disconnect the power to the compressor and see if she starts?

Any other suggestions? I will also check power to the distributor this evening as well.

Easy on the newbie from NJ.

Thanks

 

[peesalot]

My guess would be the a/c comp took a s*** and froze or the magnetic clutch shorted. I would remove belt and check a/c comp for spin smooth, then use a 12v jumper to engage clutch to make sure it functioning. A fuse could have popped or the comp may be locked up. The fact you were able to start it once after noticing the symptoms makes me lean toward frozen a/c comp.

 

[pb4ugo]

Idk what "it tries to start but will not turn over" means?

 

[peesalot]

It means the ac comp is frozen or sticky and it will try to turn but no go is my guess.

 

[aztoyman]

If you're sure it was the A/C compressor making the noise, take the belt off. If the bearing for the clutch failed it will lock up the pulley whether the clutch is engaged or not.

I'd think it would smoke the belt before it stalled your engine though. A short should have blown a fuse so I would look things over before trying to start the engine.

If it locked up and doesn't turn over, make sure you have oil and coolant. Maybe try to turn it over with a ratchet and socket first. Unless you mean something else by "won't turn over"

 

[69FJ40NJ]

By not turning over, the starter cranks the engine, it just keeps trying but does not start.

 

[charliemeyer007]

It needs air, fuel and spark at the right time. I would use a tester across each fuse (bad ones can be hard to see). See if a plug is actually getting spark. Check your fuel filter, a clogged one can induce a stall. Once a paper element is wet with water (hard to see), fuel will not really pass until its dried out/changed.

 

[pb4ugo]

By not turning over, the starter cranks the engine, it just keeps trying but does not start.

So the engine cranks or turns over, it just wont start. Does it have a carb or is it fuel injected? If it's carb'd, is it getting fuel? Does the carb squirt fuel thru accelerator pump? Do you have spark?

 

[69FJ40NJ]

I have a fuel filter, so I will change that tonight. I will check to see if I have spark as well. I still think it is related to the AC since the rig ran fine for months until yesterday after we charged the system.

 

[69FJ40NJ]

Changed fuel filter, checked all the fuses again, compressor spins freely.

Checked spark on two plugs, no spark. Have power at coil. I am guessing its the ignition control module.

 

[45Dougal]

Managed to dislodge a cable to the distributor in the process of recharging perhaps?

Just a thought, but does the alternator share the same belt as the AC?
Maybe worth checking its OK too.

 

[70fj40]

No start could be related to AC work but diagnosing each separately is best. Coincidence and FJ40’s seem to go together.

 

[69FJ40NJ]

So, changed the ignition control module, still a no go.

Tomorrow I will check every plug for spark, check voltage of battery before I pull the power wire at the distributor and check voltage and see if there is a drop while cranking.

 

[45Dougal]

Did you trap a wire in the head unit when it was installed perhaps?
If its not been used for a while then could also have rodents or bugs living in the AC fan/duct - rodent damage to the wiring would do it. Any debris blowing out?

When you changed the spark plugs, did you use the same heat grade? Maybe combined with your exhaust leak you could have overheated your coil or ballast resistor during stationary running?

Maybe a few photos will help diagnose?

 

[pb4ugo]

GM Chev V8 HEI distributors are pretty robust and very common. They're a get dist. The control module is usually the common failure. Evidently that's not it. Be sure your getting 12 volts to it. B4 spending a ton of money on it, keep in mind you can probably find a complete one used for under $50 and likely closer to $25. Sbc's and bbc dist are interchageable. Thru the yrs I've collected a bunch of them for free. You can find aftermarkets with caps and coils for around $100 or more. Summit and jegs.

 

[69FJ40NJ]

Today's adventure.

Checked battery, over 12 volts, close to 13.
Disconnected power at dist. and had 12+ volts.
Cranked engine while power was disconnected, dropped between 8 and 9.
Took apart cap and check the ohms on coil, all good.
Ran wire straight from dist. to battery, cranked as usual, but didn't start.
Pulled and check cylinder 1, 3, and 5, no spark.

Borrowing a dist hopefully tomorrow and see if that resolves the issue.

I chased wires today, lots of s*** not connected to anything.

Is this fuse box on the engine side of the firewall typical? If so, what is it running?

 

[69FJ40NJ]

Did you trap a wire in the head unit when it was installed perhaps?
If its not been used for a while then could also have rodents or bugs living in the AC fan/duct - rodent damage to the wiring would do it. Any debris blowing out?

When you changed the spark plugs, did you use the same heat grade? Maybe combined with your exhaust leak you could have overheated your coil or ballast resistor during stationary running?

Maybe a few photos will help diagnose?

There is crap in there, I shop vac'ed as mush as I could. When it ran when I got it, that when all the crap blew out of the unit. The other day it was blowing cold, not ice cold, air with no crap blowing out.

I bought e3 plugs, just used their cross reference tool, same thing I did with my firebird.

 

[69FJ40NJ]

Another newbie question, why would they take out the mechanical fuel pump and install an electric pump? I have a worked 400 in my FB, it has around 400 hp running like a monster on a mechanical fuel pump.

 

[Kschep]

More pics of engine compartment - specifically carb area….
Have you pulled off the air intake off the carb and check and see if your fuel bowl is evening filling??

 

[69FJ40NJ]

More pics of engine compartment - specifically carb area….
Have you pulled off the air intake off the carb and check and see if your fuel bowl is evening filling??

Yes, and it is.

The PO was in the distributor, there was (i replaced it) a missing bolt holding on the cover and one missing bolt holding on the coil (still missing).