Greetings: I have tried to find an answer by reading back through older posts, but didn't see my particular problem addressed. If it has been, I appologise. My wife's work car is a Pontiac 6000le station wagon, 1987, with 2.8 l multiport fuel injected, A/C, power everything. After checking a lot of things, I narrowed it down to cyl #4... The spark is weak, missing, erratic, you name it. This became especially noticable after it got wet recently. I did everything I know of to dry it out. (At one time, I was a certified small motors field mechanic, not multi-cylinder, water colled, computer controled automotive engines, to be sure, but some things are still the same) These efforts worked. one time. But not this time. I have subbed out new, and known good, spark plug wires and spark plugs, and found that it is cyl #4 that is the problem. This engine has a "spark pak", rather than points and distributer. There are six 'towers' that plug wires attach to, but I do not know if this is a 'wasted spark' system or not. (I understand how that works, it ain't new, even to me!) What I don't know is, how, or even if, I can/should try to replace the coil(s) and/or any electronics that controls it (them). (I should mention, I have a progressive form of MS, and can no longer work, and a lot of this auto type work is not easy for me anymore. Nor do I have a lot in the way of tools, or diagnostic type equipment) Money is also an issue, being on Social INsecurity, due to my disability, plus, we live way out in the sticks, far away from any friendly repair shops. (Or even parts houses) What are the landmines I might run into if I try to do this job myself? What should I look out for? What special tools, if any, would I need? Would I really need to buy OEM replacment parts? Or are there any acceptable aftermarket brands that I could rely upon? (This car is our only decent one as far as gas mileage goes... My wheelchair van is a gas guzzler big time!) Can anyone explain to me, why, if this IS a wasted spark system, ONLY #4 seems to be affected? We have owned this car for about 8 years, and, for such a cheap, and high mileage piece of GM crap, has been actually pretty reliable. Only real repairs we've had to have done: An injector, fuel pressure regulator, crank sensor, vacuume hoses, starter, and all the usual little things. (Batt, tires, exhaust, brakes, Etc.) This car has another, possibly related, issue. (Or not, I can't be sure) It looses coolant. It had a leaking heater core, which I thought I had cured. (No more antifreeze mist on the inside of the windshield, puddle on passenger's side floor, you know) The exhaust does smell a but off, but then, it always has, even when we first got it, when it ran fine. It does not seem to burn or use oil. But the coolant recovery tank neither gains, nor looses, any coolant. But it's going somewhere! No obvious leaks I can find. Cap is good too. Could a leak be hidden AND be leaking onto/into electronics for the spark control or computer? I can't seem to get the spark stuff dried out. I wiped everything down with alcohol and a clean rag, sprayed with silicone, swapped out (One cyl at a time) with known good/new plugs and wires, and did all the obvious things I know to do. It's ONLY cyl #4 that has the missing/weak sparks. Watching with a plug grounded to block, I see sparks that seem to be 'double', (Wasted spark?) sometimes single, sometimes missing for rather long periods of time, and often miscolored. (Anything from yellow to blue, and anything inbetween) If this IS a wasted spark system, why would ONLY number 4 be affected? That one, I really don't get. Once in awhile, it will even 'jump' away from the grounded electrode, seeking a return to ground via a longer path. (This may be due to engine vibrations causing my temporary grounded plug to loose a good ground, I suppose) I tried to make sure I had plug grounded well, though. (I actually TIED the plug down to an engine mount) What do I need to fix? Any help will be greatly appreciated! (Please remember, I have limited income and resources, I can't just go out and buy some fancy engine analizer, code reader, or whatever, even if we had such around here. Which we don't. We have ONE gas station, which dosen't even have a for-pay air hose!) Thanks to all for taking the time to read this. Sincerely: Junkman aka Chris Kingsley, Iowa, USA (Where in the world is THAT?.... Nobody knows!)
- posted
17 years ago