coil change, now won't start and run...

Was having a problem with my 1994 RMW starting in damp weather...] live in SW Washington not too far from the ocean, lots of rain and fog. Car would start on dry sunny days, but those are pretty rare around here.

Did some searching on the forums, and it appeared that replacing the coil and coil wire were common fixes for this. So, replaced the coil (the original coil tower looked like it came up from the Titanic, just a ball of corrosion, same withe the coil wire).

Car would start, then immediately die. Over and over and over. I finally screwed around with the coil wire after cutting a narrow strip of Scotchbrite and cleaning out the coil end of the coil wire. It started and ran for about 15 seconds. Could not keep it running any way. So...

I decided to replace the coil wire. Good idea, not so good execution. Getting the coil wire off the distributor wasn't quite as easy as getting off the coil. But, with a couple of picks and some silicone spray, managed to pop the baked off boot from the distributor.

Put some dielectric grease in the distributor end of the wire, pushed it on as far as it would go, could hear the coil end click on, go to start.

Start, immediately die. Over, and over and over. I'm stumped. Anybody got any ideas? I'mm pretty sure anything that got unplugged or unfastened got replugged and refastened. One of the ground wires that attaches to the coil stud broke it's head off, but I replaced that with another crimp-on connector.

Thanks for any ideas of what I'm missing.

Check your ignition module. It is subject to the same weather conditions, and can fail. Use white heat sink paste, not dielectric grease between it and the mounting surface.

I'll do that. I note in some of the posts and in the FSM they speak of a grease that comes with the coil and goes on the back of the coil bracket where it contacts, the cylinder head. The coil I purchased had no such grease with it.

Pull a spark plug and check for spark before you do anything else.

Then, suspect ICM. Also: check the opti vacuum harness. Then... check fuel pressure ;-)

That may be difficult as there's only one of me. Can't be turning the key and be under the hood at the same time.

You connect the fuel pressure gauge line to the test port, and put the gauge on the driver's side windshield wiper. Get in, turn key, look at pressure. Does it go to around 40psi? No/Yes? Try to start.

That I can do. I'm assuming, though, with fresh fuel filter and new fuel pump...

But we all know about assuming. I'll give it a shot.

Something just came to mind. The left side air pump, where the hose u-turns and goes to the exhaust manifold, on the upper section, the hose is split and there's a small T inserted on the hose. Can't find a loose hose anywhere. The FSM shows no hose spliced in. Am I crazy? Anybody know what or where that hose is or goes to?

Okay, that's it for now. I think.

Jim - the ground cables that attach to the stud at the coil/ignition module are prone to corrosion and cause all sorts of weird behavior when they fail. Might want to double-check them.

Yes, and those wires are small/brittle, and easy to break as you found already. Inspect the other ones carefully.

News from the front (no pun intended)...

Okay, had already ordered ignition module, so it arrived yesterday. Installed this AM. No difference, turn key, vroom-die. Vroom-die. Fuel pressure, 40 psi key on, vroom, drop to 30, die. Back to 40 psi.

So I started thinking. I'd been having some problems with my 86 S10 Blazer. Start, then die. That was from the plug coming out of the MAP sensor on the air cleaner.

So, I unplugged the MAP (MAF?) sensor behind the air cleaner. Vroom. And vroom, and vroom. Runs like a champ. Plugged the sensor back in, kept running, a couple little stumbles, but I think that's because the resonator wasn't back plugged in in front of the throttle body. Plugged that hole back up, and it's running.

I've only got 15 miles on the new fuel filter and fuel pump, so I was relatively sure those weren't the problem.

I was really surprised that unplugging the MAP (MAF?) sensor let it start right up, though. Voodoo.

Thanks for all the suggestions, where I live, there's not a lot of wisdom to tap. But I am gonna let the shop in the next town over do my rear shock replacement. Taking the old collapsed air shocks of and installing KYB Excel-G's. I don't have a lift, or an impact...and they'll do it for a hundred bucks.

The maf is the circular aluminum thing in the intake tube. Unplugging that puts the PCM into speed density mode, basically a set of parameters that removes the maf and its data from the air fuel tables.

Good work!

100 is fair for the shocks. Not a difficult job... with a lift, good tools, extensions, and skinny arms, lol

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$100 to install rear shocks, is $100 well spent.  Those upper bolts on the rear shocks are a royal pain in the rear. I've done it twice, there won't be a third time!

Tom

I have heard of that working before, but did not think of it, as I do not have to deal with LT1s.

That MAF was used on numerous vehicles, including Hondas and Isuzus. If you can get a spare OEM factory one from a local junkyard or even off of FB marketplace, that would be wise. Use rockauto.com to see the cross reference.

Just thought I'd let you know, well worth the 100 bucks to install the rear shocks. Even got pickup and delivery!

That's great service, Jim, you're lucky to have a shop like that.

yes, this engine will start and then immediately shut off if the MAF is interrupted as then it cant measure any air flow, such as if you leave off the resonator.