I have been having a heck of a time getting my car to run right. It's an 86 z28 with TPI. The problem started with a no start. The pickup coil was bad so I replaced it. It took me forever to get the distributor back in right because my harmonic balancer has slipped a LOT. I found TDC by sticking my finger in #1 spark plug hole and feeling for compression. Then I stuck a straw in there to feel when the piston came to TDC, then dropped the distributor in.

THe car started but ran like CRAP(surging and backfiring real bad) ANd it didn't matter where I moved the distributor to. I Tried moving 180* out too, which didn't help.

My neighbor, who builds race cars, suggested replacing the ignition module. This helped a lot(doesn't backfire anymore, and surges very little.) but it still has problems. When I disconnect the EST wire to time it, (keep in mind, I have to do this w/o a light because the timing mark is so far off) it will idle and sounds good, no matter where you put the distributor. If you rev the engine, it shudders real bad. My dad says it sounds almost like it misses on all 8 cylinders and sometimes it will knock to. It won't idle at all(but will run if you give it gas) with the EST connected.

The neighbor said he doesn't think it's a tooth off because you can advance it enough so it won't easily start, and retard it enough it starts real easily. Anybody have any suggestions on what to try? This is really driving me up the wall. Thanks so much for any light you guys could shed.

~Arnold

P.S.
I have replaced:
Ignition module
Distributor Cap
Pickup coil
Ignition coil
Spark plugs

Rotor and spark plug wires are three months old

 

Get a timing light and FIX the timing mark other wise it's hopeless becaue you don't know where you are, remember your talking JUST a few degrees when timming an engine and you need to know where the h*ll you are.

 

Sounds to me like there are plug wires out of order. Timing won't make an engine "shudder real bad".

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"So many Mustangs, so little time..."
ICON Motorsports

 

I have a timing ligh but how I would I fix the timing mark? We have checked the plug wire order countless times...Thanks for the suggestions.~Arnold

 

I'm assuming that it was running okay before the no start problem, right?

It's possible that one or more of the new parts you changed is bad. A guy at the parts store might have dropped one of the plugs and fractured the insulator. The same could have happened with the dist. cap - and so on. You've changed a lot of parts, so there are a lot of variables here.

If you want to take the time, I would start putting the old parts back on to see if you can isolate the problem. If you want to save some time, but spend some money, you could have it hooked up to an analyzer, which should tell you exactly where your timing is set, verify your firing order and tell you what cylinder(s) has weak or no spark.

Good luck.

 

You know, i own a 1986 IROC Camaro 305 TPI, and i had a problem similar to yours. I crawled underneath the car, and found that my knock sensor was unplugged. I don't know if this helps or not, but just something you might want to check. My computer sure as hell didn't say anything to me about not getting a reading from the disconnected knock sensor, it was just chance that i bothered going underneath the passenger side of the car, and happened to notice it disconnected.

Good luck!

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1986 IROC Camaro
305 TPI "LB9"
3.23 gears
Doesn't know enough about cars.
AIM: jesusathome

 

Put the engine at where you think TDC is, mark the balancer with some chalk, and then preferably scribe the balancer across the outer diameter and then to the center ring so you can check to see if it slips again.

Best idea is to replace it, once they slip, they will only get worse. I have seen balancers rub a hole right through the timing cover. You wanna replace that too? Me either.