Help! 1992 C4... No Start!

[jrclark32]

I have a 1992 C4 with a 6-speed. She's been sitting for a few months, and when I got her uncovered and fired her up she ran for about 30 seconds, then just dropped dead -- as if I'd turned the key off. Now the engine just cranks and cranks... not so much as a sputter.

I've had this problem before, and the first time it was the ICM, the 2nd time it was the coil. I've only driven a few thousand miles since both of those were replaced.

I have good fuel pressure, and there's spark. I'm no expert, but it seems to me that when you mix air, gasoline, and electricity together something should happen.

I am, however, a little confused on what to look for with spark. I'm used to pulling a spark plug, and looking for that nice blue spark, but I've been told that I should use a spark tester on the LT1. The instructions say to set the gap to 10mm for electronic ignitions (which seems WAY too wide to me), and I'm seeing orange/white when it fires. What should it look like?

Could my coil be bad again already?? Would I get spark at all at the plugs if it is?

Thanks for your help guys!

 

[vetteoz]

Try
Lt1 No Start Diagnostic - Mainstreamtopics - Your General Forum

 

[onedef92]

Have you pulled the ECM codes? Could be a bad Optispark Module but more likely a loose or bad connection from the coil to the Opti.

 

[surfer93]

Ok, let's start at step 1.

Check fuel pressure while cranking, does it stay stable(40+ psi).

Yes, coil can spark and be weak. Do not think it is the coil.

Not likely the opti and have you pulled codes?

Have you tested the fuel for water and contamination?

How was the car running before stored?

Did you top off the tank and put a stabilzer in the gas?

What is the condition of the SP wires?

Did the car just die, sputter or slowly die?

Give everything you know, so we can help you better.

 

[John Robinson]

Critters

Carefully check for chewed wires or a nest built inside of the air filter or throttle body. It seems that there are some critters that look for nice dark warm places to set up housekeeping and storage vehicles are their favorite target. The next uninvited guest is corrosion so check the connectors to make sure they are clean and making good contact especially the connector on top of the opti. Then check the grounds.

 

[jrclark32]

Thanks for the replies guys... I've been out of town and haven't been available to screw with it until today.

Fuel pressure is 40 lbs and holding with key on, and jumps up about 5 or 6 while cranking.

I have spark, but it does seem to be a bit weak. Again, I've never used one of these spark testers before so I'm not really sure what it's supposed to look like there.

No Codes.

The plug wires look pretty good.

I stabilized the fuel, and the car ran perfect before it was parked. That was a period of about 3 months, and my roommate occasionally started it and let it warm up. He said it started and ran fine every time.

When it died on me, it was just like turning the key off. No sputters, nothing. Now it doesn't even try to fire when it's cranking.

I haven't checked the fuel... but I'm honestly not sure how to go about it. Is there an easy way to drain a small amount? Could I take it somewhere to have it checked, or is there a procedure?

The grounds look okay, but I'm going to clean them all and see if that helps.

I appreciate the advise and help!

 

[boomdriver]

Thanks for the replies guys... I've been out of town and haven't been available to screw with it until today.

Fuel pressure is 40 lbs and holding with key on, and jumps up about 5 or 6 while cranking.

I have spark, but it does seem to be a bit weak. Again, I've never used one of these spark testers before so I'm not really sure what it's supposed to look like there.

No Codes.

The plug wires look pretty good.

I stabilized the fuel, and the car ran perfect before it was parked. That was a period of about 3 months, and my roommate occasionally started it and let it warm up. He said it started and ran fine every time.

When it died on me, it was just like turning the key off. No sputters, nothing. Now it doesn't even try to fire when it's cranking.

I haven't checked the fuel... but I'm honestly not sure how to go about it. Is there an easy way to drain a small amount? Could I take it somewhere to have it checked, or is there a procedure?

The grounds look okay, but I'm going to clean them all and see if that helps.

I appreciate the advise and help!

Be sure to look at fuses...ecm, inj, and any others that might be associated with the engine controls.

Also, look at the fusable links behind and under the battery. Those are all mounted to a "jumper post" and if the wrong one blows....it won;t run and it'll be darn hard to figure out. Easiest way is to check continuity either side of each link. No real easy way to do it...Pull the battery panel off and start digging.

 

[jrclark32]

Water!

So here's an update... after checking and cleaning electrical connections with no change in symptoms, I collected some fuel using the relief hose on my fuel pressure gauge.

It's almost all water. I put some in a tin can in the driveway, shook it up and threw a match in and it was immediately extinguished.

I siphoned all the fuel I could get out of the tank into a bucket, and it looked like there was 3 or 4 gallons of water mixed in with about 5 gallons of fuel.

I put in 4 gallons of new fuel, along with some HEET additive and octane boost, and I'm now very slowly trying to get the water out by repeatedly cycling the fuel pump and draining a few ounces of water (and what looks like a white detergent, which I'm hoping is a result of the additive) at a time.

I'll keep you posted on progress, but I'd appreciate any suggestions to ease/speed up the process.

 

[boomdriver]

So here's an update... after checking and cleaning electrical connections with no change in symptoms, I collected some fuel using the relief hose on my fuel pressure gauge.

It's almost all water. I put some in a tin can in the driveway, shook it up and threw a match in and it was immediately extinguished.

I siphoned all the fuel I could get out of the tank into a bucket, and it looked like there was 3 or 4 gallons of water mixed in with about 5 gallons of fuel.

I put in 4 gallons of new fuel, along with some HEET additive and octane boost, and I'm now very slowly trying to get the water out by repeatedly cycling the fuel pump and draining a few ounces of water (and what looks like a white detergent, which I'm hoping is a result of the additive) at a time.

I'll keep you posted on progress, but I'd appreciate any suggestions to ease/speed up the process.

I recently did a semi-cleaning of my tank and contents....its not easy to be good at this and be SAFE...

its pretty easy to pull the fuel tank sender assy and get that out. Nine 10mm bolts. Then you can reach IN the tank to wipe it out after its been siphoned out. Use a "bulb" siphon, its safe, easy to use and will get 99% of the liquid and suck up any trash.
That sender assembly (pick up tubes/return tube/float & pump) will need to be wiped down and any rust removed because its steel and its likely to rust more after being submerged.. Get a new tank gasket also. Thats $4 that you GOTTA spend.

With the top access, you can now siphon the tank and SEE inside to guide the hose to suck up all the trash and moisture. You're going to have to clean it well. Rust is a huge enemy. All that water will lead to lots of rust and plain dirt. The tank needs to be emptied and then wiped out by hand. While in there, you might want to start asking everyone involved just how 2 or 3 gallons of water would get inside the gas tank of a car that was started each month..? interesting.
Plan on getting a new fuel filter, Pump and a pump screen, they will BOTH be clogged.

it would be easier to have almost any other problem....A tank full of water is not as simple as dumping it and refilling. Water in injectors is a probllem, injector screens plugging up, fuel regulator...it all has to be cleaned well, not just a bottle solution. Before anything else can happen that tank has to be sterilized and all filters replaced.

All it takes is a couple tablespoons of water to ruin your day....a couple gallons in a fuel injection system? Thats damage.
Good luck with it,.

 

[John Robinson]

Removing fuel

If you take the fuel line and the return line off the fuel filter(Your going to replace it anyway) an use a air hose with the pressure set real low you can pressure the tank by using the return line. Be ready to have a heavy stream of fuel from the return line when you take the air hose away from it. Oh and put out all the cigars, mood candles, water tank pilot lights before you do anything. This is a job best done in the wild outdoors.

 

[boomdriver]

If you take the fuel line and the return line off the fuel filter(Your going to replace it anyway) an use a air hose with the pressure set real low you can pressure the tank by using the return line. Be ready to have a heavy stream of fuel from the return line when you take the air hose away from it. Oh and put out all the cigars, mood candles, water tank pilot lights before you do anything. This is a job best done in the wild outdoors.

Thats kinda scary ! hnoes



Call me a whimp, but 9 bolts is less stressful, to me anyways..

 

[jrclark32]

Okay... things are improving slowly but surely in this ridiculous situation.

I got a good sample of what was coming out of the tank and analyzed it in a local lab. What was mixed with the fuel is a combination of a little water and household grade cooking oil.

I may post a "heads up" in a new thread about this one... I think I've been the victim of a fairly creative scam. 2 days ago, I saw a note under my windshield wiper that was almost illegible aside from a name and phone number. I called the number out of curiosity, and it was some guy who had supposedly seen me working on the car and wondered if I'd be interested in selling it "as-is." Seems to me pouring an oil-based substance in the fuel tank of a car you're planning on owning might be hard enough to find to frustrate an owner into selling it for a little bit of nothing. I would hope that oil instead of water would also eliminate the potential long-term damage of rust.... next purchase on ALL my vehicles: Locking gas caps.

Anyway, back to the process. I think I have all the crap out of the tank, and a new fuel filter is installed. It's running, but running rough and dropping cylinders intermittently. I assume the next step is cleaning injectors. Should I just take it somewhere and have a pro fuel service done? Can anyone recommend a place to have that done? What should the next step be after that?

Thanks!

-John

 

[John Robinson]

Your next step

A report with your local police and then contact your insurance to see if they will cover the cost to repair under vandalism. Hope you kept the note.

 

[boomdriver]

A report with your local police and then contact your insurance to see if they will cover the cost to repair under vandalism. Hope you kept the note.

2nd that !

I'd be filing charges and getting the police report in place. This clown was planning on low balling a sale with a car that was smoking and running like crap....who knows if he'd done that to someone else. Thats as dishonest as stealing it. if it was'nt him, someone put the mazola in the tank...did'nt crawl in there by itself.

As far as the motor....Pull some spark plugs and see how they look. The gas would keep the veg oil from plugging the injector screens, but it would foul the plugs. If you have any plugs that are black or caked with carbon flakes, clean then with a wire wheel in the drill and re-install. Once cleaned they will be ok unless they are real old and need to be replaced anyway.

The veg oil (cooking lube) is fairly harmless.
I like the Lucas inj cleaner. Its one of a few inj cleaners that actually works. A dose of the Lucas, some clean plugs and it'll be good as new.

Glad that you got to the bottom of this. Sorry it was criminal actions.

 

[John Robinson]

Follow up

You have not updated this since the 6th and inquiring minds are waiting to hear as Paul Harvey would have said. Now for the rest of the story. Some of us old retired members follow these threads like are wife's follow soap operas. The difference is we learn useful information and soon find ourselves making freinds with a common interest

 

[Jeb]

You have not updated this since the 6th and inquiring minds are waiting to hear as Paul Harvey would have said. Now for the rest of the story. Some of us old retired members follow these threads like are wife's follow soap operas. The difference is we learn useful information and soon find ourselves making freinds with a common interest

Yeah...what he said.

 

[jrclark32]

Hey guys... Sorry it took me so long to give you an update on this. I've just been so frustrated with the car and the situation that I'm over it at this point.

I filed a police report, but that was a worthless endeavor entirely. They flat-out told me it wouldn't be investigated, and acted half indignant that I wanted to waste their time with the report anyway.

To add insult to the previous injury, while following the advice to "just keep driving it and work that crap out of the system," the transmission started acting up. The saga ends with it stuck in 2 gears at once, towed home, and locked in a building until I have time and money to deal with it.

I appreciate all your help and advice on this... I'm sure I'll be begging for it again when I dig back in to get her going again.