91 C4, was running until I decided it needed a "tune up."


I thought I had the timing stuff down but now that I must do it again, it's kicking my butt. I looked at my old thread and did everything again, but it's not working. Here's where I'm at. All spark plug wires are in the correct position. I made sure that the wires are connected and tight at each end. The ignition module plastic thing that holds a pink and brown wire broke and I assume that the pink wire goes to the positive sign on the ignition module, and the brown wire goes to the side marked with a "C." If that is incorrect perhaps this is my problem.

When I replaced the cap, rotor, spark plugs, wires, ignition module, etc, I moved the base of the dist with the cap off, and didn't make any markings. I have not however removed the distributor completely. I just moved it around a bit. To get back to TDC I put my finger on #1 position until it blew my finger off. I then aligned the mark to the "0" position on the balancer. I then removed cap and saw that the rotor was pointing to #1, so I assumed that I was already at TDC. When I start the car, it rumbles horrendously and quits. So I'm stumped because I think I'm at TDC at the compression stroke. when I move the cap as far counter-clockwise it can go, it barely starts and stumbles right away loudly. When I turn it as far clockwise it can go, it seems better but still stumbles and stops right away. Could I have set it on the exhaust stroke without removing the dist?

 

If the piston pushed your finger away then you were at TDC compression and not TDC exhaust, just as you suspected.

It sounds to me like the initial (static) timing is correct and isn't your problem.

What happens if you split the difference between the two extremes?

Something is missing (no pun intended)

hth,

Jim

 

Same thing happens, it starts and dies. Can anyone comment on the color of the wires from the ignition module. on the end where there are two prongs, one brown wire connector goes on one and a pink wire goes on the other. Which one connect to the + side. I assume the pink goes to the + connection.

 

When the #1 piston is TDC the mark on the harmonic balancer will be at 0*. The rotor needs to be pointing at the left rear corner of the plenum and/or towards #1 cylinder. Install the cap the correct and disconnect the EST wire. Get out the timing light and make sure your at 6* on the timing mark.

Credit this to AGENT86

 

Hey again, I need help if you have the time. I believe I did everything correctly on setting the timing. There is one thing that I may be messing up however. After the air blows my finger off and I'm at the compressions stroke, the hash mark on the balancer is never exactly on zero. To get the hash mark to zero, I've been using a socket wrench on the bolt on the upper pulleys to make the adjustment so that it's exactly on zero. Is this my fatal mistake? I know on the Haynes Manual it does states to "turn the crankshaft with a large socket and breaker bar attached to the vibration damper bolt that is threaded into the front of the crankshaft." I think perhaps by just turning the upper pulleys to make the adjustment, I created a bigger problem. Hope that's not the case, thanks for your time.

 

Hmm, I never moved the balancer to get #1 TDC. I was able to put my finger over the #1 spark plug hole and with my other arm, turn the key to tap the engine over. Once #1 was TDC it blew my finger off. I checked the timing mark on the balancer and it was at 0*. Any time you move the HB it throws the timing off.

Try the method I used. You might have to get someone to help with bumping the key, if your arms are not long enough.

 

Once you get the #1 piston TDC, make sure the rotor is pointing as I mentioned above. Tighten the hold down bolt snugg and install the cap correctly. Make sure the spark plug wires are routed correctly to each spark plug (the FSM shows where they go and I don't think the Haynes manual does). Then, disconnect the EST wire and try and start the engine. You may have to rotate the dist some to get it to start. Once it is running on it's own, use the timing light to verify timing. Set at *6 BTDC and tighten the hold down bolt. Recheck the timing to verify the dist didn't move. Then stop the engine and connect the EST wire and start the engine again. The timing should now be at 22-24* or 12 o'clock position.

I remember you having problems getting the dist to drop in correctly a few months back.

 

I'm sure you not doing this but I helped a guy once who was timing his engine on the wrong bank i.e. using #2.The engine will actually run and with your symptoms!!!.

 

First off, car ran fine before I decided to replace spark plug wires, spark plugs, cap, rotor, and ignition module, and ignition coil. I never fully removed the distributor when doing this, but I did move the base of the distributor which is what I think threw off the timing. It wouldn't start after doing all this.

I'm definitely and have always been using #1 to get to TDC. perhaps my marking on the plenum is incorrect? Any chance that I will feel air blow my finger off on the exhaust stroke? Okay, here is exactly what I've been doing to get at TDC. Hopefully someone can point out if I did something wrong:

- I always assume that tach/bat connections on the cap are facing 3'oclock before trying to get to TDC.
- All spark plug wires are unplugged from the dist, Bat connection from dist is removed to disable ignition system as instruced by Mr. Haynes Manual, and tach wire is left in.
- #1 Spark plug is removed.
- Bumped the engine until air blows finger off.
- Use upper pulley bolt to adjust balancer to get exactly on zero.
- Dist is removed and put in so that rotor points at mark on plenum - Where exactly should this mark be? I put ithis mark right across where the #1 spark plug wire goes on the dist.
- Reconnect everything and start. Car doesn't start and will make a weird harsh noise at times. Since it ran fine before all this I'm hard pressed to think that it's something else besides timing.

 

Do you have a repair book?
Its probably not the timing.
It should start where its at, or moving it one way or the other should get it to pop.

I suspect something else. Last car I did was a 93 T-bird and in order to set the engine timing you have to pull a plug in the engine wirring harness. It isolates the computer from the static timing.

If you don't do this the computer will handle the timing automaticly.

Thats why a repair book is important.

The kids car a 67 Mustang wouldn't start, he changed the points, plugs, timing, etc. It still wouldn't stay runing. It would start but would'nt stay running. I hooked a hot wire to the coil and it ran like a new car.

Go back to the start and look at everything that you did.
Get a repair manual.
Don't give up.
You'll get it.

 

Like everyone else that responded to your post I would love to know if you got it fixed and what the problem was.You have been very quiet,want to let us in on the secret?

 

Well I definitely gave up trying to figure it out myself. I did mess up the timing before and with the forums help, corrected it and got it running great. After the new plugs, wires, etc., and the fact that I didn't remove the distributor this time around, it definitely should of start it seems. I'm definitely missing something here, and I still think it's the timing, and for some reason it can't be corrected by getting it back to TDC.

It simply will not start. So I took off the gloves and let the corvette win this round. I had the car towed on a flatbed to a local shop owned by a guy that goes to my church. It was a good opportunity to get the A/C serviced and ready for the rest of the summer as well. You can't win all the battles, but hopefully I can win the next one. I'll let you guys know if the shop can get this thing running again and what the problem was. Here is the vette on it's way to Corvette Heaven:

 

We all sooner or later can't fix at least one.
Nice looking car.