OT: Truck problems and .....

[J Miller]

........ why can't I see the obvious?

As some here know my wife drives her own 94 Nissan PU to deliver pizza.

In the last year or so she has been complaining of various problems that I simply could not figure out.

The lights in the truk would flicker or pulsate at night, yet the alternator was putting out properly. Checked by two different places. Belts are tight too.

Running rough, power down, vibrating, noisier than normal. And the latest complaint was an intermittent hum that sounded like it was coming from just in front of the driver.

I've checked everything I know to check. I could not find the cause of the pulsating lights, and the one auto electric shop said it was caused by voltage fluctuations due to bad plug wires. NOT! The plug wires are only a year or two old and I put them in myself. And they are OEM, not cheepo's. So I checked the plug wires to make sure they are on tight and they are.

Still something was wrong.

A couple days ago I was going through our maintenance records to see what the truk needed. Well, it needed plugs, they'd been in there for 35K+ miles.
So yesterday after all the DR and pharmacy visits we hit the parts house and bought a brandy new set of NGK plugs. Came home and I popped #1 wire off, stuck my socket on the plug and found it was LOOSE. I unscrewed by hand. NOT GOOD AT ALL. It had been that way for quite some time by the looks of the carbon and soot all over the plug and plug wire boot.

Well, there is one problem right there. Loss of compression, increased voltage to fire the cylinder etc etc.

All the other plugs were tight.

Once I replaced all the plugs we fired it up and I stood there shaking my head. What a dunce. Totally different. Quiet, fairly smooth idle, for a 4 cylinder anyway. And ..... no pulsating on the dash lights. That's a new one on me. I've had loose plugs before and they never caused the vehicle lights to pulsate.

After dark my wife took off for an errand and as she left the truck sounded TOTALLY different. When she got back ALL the complaints were gone.

Duh .......... I feel like a dunce, should have caught that loose plug.


Joe

[dr walker]

Hey at least you fixed it.

[fordwannabe]

Your right Joe! your probably the first person ever to miss something like that, I KNOW I HAVE NEVER DONE ANYTHING LIKE THAT..ok maybe not yet....today. If you work on stuff long enough your gonna have stuff like this, but you found it and fixed it so no harm no foul. have a great day Tom

[kimwcook]

One way of checking things that are kind of weird is to get to a totally dark area at night, shut off all lights, leave the engine running and pop the hood. You'll see electricity and stuff dancing around that you'd never see any other time. You got it figured out now that's all that matters.

[Alan Wood]

Don't be so down on yourself J. The symptoms pointed to the electrical system not the ignition. I suspect that the confuser commonly mispelled as ECU or computer in the engine was trying to work around the problem wreakin all kinds of electrical havoc. Or the strange currents due to the spark situation were. Either way fixed is fixed.

[Glenn]

Joe,
If the truck was a couple years newer the "check engine" light would have come on. That's what my '95 4-Runner did when a plug came loose. I couldn't figure it out until the plug came all the way out! Was pretty obvious then.
Glenn
WWJWD?

[Wrangler John]

One week ago on Tuesday morning, I had taken my GMC diesel in for service. My wife had brought me back from the dealer. That afternoon she drove me back to the dealer to pick it up. On the way her restored 1986 Ford F-150 step-side began to backfire and loose power, she puled off on the freeway shoulder. When the engine burst into flame we hastily exited. Fortunately a Cal Fire pumper truck was just behind us and saw the whole thing, they pulled in and began unrolling hose. Unfortunately the whole engine and dash board burned to a crisp before they could extinguish it. A nice tow truck driver took us to the dealer to pick up my GMC.

Next day I bought her a new GMC Sierra to replace the Ford. She really loved that truck, had it for 23 years. She had complained about it dying at stoplights, so I had replaced the EGR, throttle position sensor and idle bypass valve after reading the error codes. It was running fine for about two months before the conflagration.

Upshot is I'll be a bit more careful about allowing her to drive older vehicles. That Ford had been recalled for a fuel line problem that caused engine fires in 1991, and Ford's Thick Film Electronic Ignition module was object of a recall and class-action suit. Both had been remedied, but I believe the ignition module failed again causing a backfire through the throttle body that set fire to the air cleaner element. I'm glad I was with her when it happened, so there was no harm done. Now she has On Star that monitors the vehicle's functioning, a built in cell phone function, and an emergency panic button linked to GPS to summon aid when she's alone. I rest a bit easier. We should never take these things lightly, as they can turn deadly in a few seconds.