Please Help-rough idle-backfire and more
 

i am still pretty new to all this and apologize but i cannot find answers to my problem with my car. it is a 1984 gs 1.1 12A entirely stock. The car idles really low almost like its going to stall. it backfires really bad when i decelerate. and the car has absolutely no power. i have changed fuel filter spark plugs distributor cap and one bad coil. when i pull one of my plug wires off the first top spark plug closest to the front of car the car dies which it should i think. but when i pull the wire off the bottom one closest to front it doesnt change the idle of the car at all and there is no spark at all. the car is also flooding itself. its really hard to start and takes forever to even warm up enought that it will stay running at low idle. i dont even know where to start with these issues.

oh and very rarely it will idle properly and run good for about five minutes but its rare and hardly ever happens

bad motor

Sounds like your leading ignition is not firing. Perhaps your leading ignitor is bad. You can swap the ignitors (little black boxes on the distributor). If, after the swap, you have leading spark (lower plugs), but no trailing spark (top plugs) the ignitor is bad. Removal of the top front (trailing) plug wire should make very little difference in the rpms. The leading plugs supply most of the power.

Where to start? Spark plugs. Rotaries burn oil. If it isn't burning oil, it wouldn't even turn over. If its running too rich, the plugs with fowl. I recently had this happen to me this winter. Next check timing. Same thing will happen. All the fuel/oil won't burn. Check the throttle stop screw, it may be loose. Still nothing? Adjust the throttle sensor. Does the carb have a vac leak? Better check that. Here's a funny one: I just rebuit and stripped my carb and its been doin something similar. I tried everything, to no end. Started messin with the air bleeds and at one point took it for a drive and it ran great. Came back put a new air horn gasket on, and again, it wouldn't stay runnin. Again last night I was messin with it and got it runnin awesome, I left it runnin and put the rest of the screws on the air horn. Soon as I got the first one in, the damn thing died. THE DAMN GASKET WAS TOO THIN!!! Messed up the float settings. Don't be too quick in thinkin the motors shot. Save some money and check everything involved in air fuel spark... Any other suggestions guys? Feel free to start laughin at my gasket problem as well... Lol

The top plugs are the trailing, and the lower plugs are leading. It dies when you pull the lower wire because you have no leading spark. Check the leading (rear) coil, the leading (I believe forward) ignitor, and all wiring connecting the two. The problem your describing points to an ignition problem, and should be a simple fix.

I'm not intending to bash anyone here, but DON"T DO ANY OF THIS YET. You're describing a very simple spark issue, and if you start messing with adjustments and carb stuff, you'll have a whole new set of problems to diagnose when you get the LITTLE spark issue resolved. Chances are you'll change your ignitor or coil, and as long as you haven't set anything out of adjustment, it'll run perfect.

Make sure you have good spark. After it runs well for 5 minutes (you said that it runs well for 5 minutes and then dies), check your compression. both are cheap (good comp. tester is ~$20) and it will tell you if you have spark or compression issue.

You have already identified the reason for the issues you are experiencing (no spark on lower plugs). The leading (lower) spark plugs do 95% of the work, the trailing plugs are basically for emissions.

Here's what I would do in your shoes:

1. Swap the coils around, then check for spark again on the leading plugs. If you now have spark, then that means you need a new coil.

2. If swapping the coils makes no difference, then switch the ignitors around (little black boxes mounted externally on the distributor). Check again for spark on the leading plugs. If you now have spark, then you will need an ignitor (find a used one).


A couple of things to note: the fuel pump will only run once the car senses spark on the trailing ignition system. So if you had a bad ignitor, and swapped them around so that now the bad one is in the trailing position, then the fuel pump will not work until you get a good ignitor.

When mounting the ignitors, it is a good idea to use some heat sink paste between them and the dizzy to help with thermal transfer.



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Man, at least you have the right screen name 'cause Wacky is exactly what you are sometimes! :lol:

Come on wacky, this isn't the FD section...

+1 on ignitor, you should also clean all connections, they could be getting corroded.

Yes. I definitely agree that he should be checking for proper spark 1st. I just added my problems into the thread. Lol.

i did put one new coil in and it has a very weak spark and usually no spark. if i switch the coils it does change the spark plugs that are working to not wotking and vice versa. but sometimes the new coil switches to full power and the other coil has no spark or very little. im wondering if it is my pickups in the distributor but i went to order them and they ar $150 i just dont want to spend the money on them if thats not even the problem

If changing the coil changes the symptom, the problem is not in the pickup coils - - it's in the part that is moved, or its connections.

Did you swap the ignitors? Used ones are readily available for a reasonable price.

I got the same similar problem but mines I believe it's corrosive tank, but I did learned some new today and I will check my coils and my distributor connections as well. Good luck with your project.

The igniter transistors are known to go bad. They are fairly delicate. They "gate" 12V through them to pulse, or trigger a release of (how much?) around 30,000 volts. Unfortunately, the way the coils are mounted in the fender with the terminals in such close proximity to the ground and each other, and wires criss-crossing, etc, all it really takes are a few arcs to kill one of those igniters.
Observe the coils and associated parts in the dark as the car is running to see if there is any blue arcing happening.
I don't know a lot about ignition, but that's been my own experience. The other thing that can happen is the coil and igniter contacts (brass) get dirty and a good wire brushing really makes a difference. Sometimes this alone can fix an arcing problem. Electricity wants to go in the path of least resistance.

ok so i swirched those two black boxes and it switched it like you said the opposite coil was working. funny thing i left it switched like that hop in my car to go price one out and half way down the road the car dies. i never realized i shoulda switched them back so i had to do it on the side of the road. anyways when i did that and went to bensons they said a new one will be $340.00!!! i called a bunch of wrecking yards in my area and one of them has two 2nd gens but none of the 1st gens. where can i get good used parts near renfrew. im close to ottawa and pembroke and such.....

look in the for sale section, or for parts cars in your area. you're looking for j-109 ignitors. It's probably a good idea to have a couple spares on hand. I'll go out to my garage in a bit and see how many I have on the shelf. I might have enough that I can spare a couple for a smokin deal.

Brian

IIRC, there is a compatible, readily available, cheap replacement for them.

Or you could grab that second gen ignition and go with it. Or do what I'm doing grab a couple of GM hei igniters and hotwire them in. I'm getting a pair that are designed for an 80's chevette and all I will have to do is build a heat sink for them. They're like 20 bucks a piece

not necessarily true. it may be year dependant (i'm no 7 expert) but my 85 is currently running on leading only, until i source a replacement ignitor for my trailing plugs.

So if I'm following you, here:

You were having a problem with the ignition while the ignitors were in the original positions (ignitor A in socket a, and B in b)

You switched the ignitors (Ab & Ba), and the car started working well enough to drive it.

You left them switched, went to the store, headed back, and the car stopped.

You switched them again, back to the original bad position (Aa & Bb), and the problem went away again?

That should be impossible if an ignitor is actually at fault, unless both are intermittently bad... or the primary ignitor is overheating, maybe due to a partially-shorted coil.

When he swapped ignitors, he regained leading spark but lost his fuel pump (which will only run if you have spark on secondary ignition (unless it has been modified)).