Hey guys, I'm new here. I've owned my '72 GSX clone for about 3 years now. It was my second car and the first I payed for myself. Anyway, to my question. I've recently replaced all the rocker arms and both rocker arm shafts. They were chattering horribly because the rocker arms were loose on the shaft and the shafts were severely worn. Anyway, since then the ticking has stopped but now when the car is under acceleration it will sometimes 'skip' and then pick up again. It's like it dies for a split second and then it's fine. It will not do this all the time either, just occasionally. The car has a slight spark knock I haven't been able to fix yet and the carb might need adjusting. Is the combination of these two problems what's causing this? Could it be the transmission or rear axle? The car is completely stock except for a mild cam and a new carburetor. Thanks for any suggestions!
I had that same problem with a '71 350 I used to drive. I tried everything, and the only thing that helped was advancing the timing about 6 degrees. I don't know if the balancer slipped, but it worked like a charm. If you already have a spark knock, you may not be able to advance it any further. Maybe your vacuum advance is not working.:bglasses:
Does it skip more when its cold out? Is there any difference whether the engine has just been started or if it been running for a while? It could be bogging. You should take a look at the accelerator pump in the carb. Look down the bores and quickly open the throttle, it should send a nice stream into each primary. If its a q-jet it might also be that the air valves are opening too soon. If advancing the timing doesn't help and its not bogging, I can't really think of what else it might be. I once had my car "skip" on me before, but it was cruising on the highway and it hasn't done it since. I still don't know what caused it.
First thing to do is look at your timing. See what your initial timing is, whether your mechanical advance is working, and how fast it comes in, and finally what RPM your total timing is all in. You can do this easily with a dial back timing light. If you have a regular timing light, you can still use it. Make a second mark 1 3/4" clockwise around on the balancer from TDC. This corresponds to 30* When you rev the motor, with the light attached, the timing mark will move up towards the timing tab. At some point it will stop moving up, and you can read the total timing off the timing tab. If it stops at 2* on the tab, you have 32* Check to see if the advance stop bushing in the distributor has fallen off. This will allow too much total advance, and pinging. I assume you have given the car a good tuneup and checked the simple things first. Your problems could be as simple as two ignition wires that have been reversed. It's happened to the best of us. Good luck.
Mine used to stumble only when cold. I changed the accelerator pump and that didn't help either. Advancing the timing fixed it well and it didn't ping with regular gas. (89 octane back then).:bglasses:
thanks! Hey guys, thanks a lot! What a knowledgable group! I didn't think I was explaining it good enough but I guess I was! I'm almost sure it's the timing because I've had problems with it before. It was pretty cold out when I drove it and it did it when I first started driving it and after two hours of driving it (it did it on the way to college, a 2 hour drive). The carb is a Rochester 2-barrel. I'll look at the timing when I get back home and have access to a timing light. The car has had a complete tune-up so that rules out anything simple I'm guessing. I appreciate all the help you guys have been already! I'm sure I'll have more questions for you guys in the future. The guy who had the car before me didn't do a good job with restoring it so everything will have to be redone. Thanks a lot!
If your distributor is stock, and timing is at stock specs, you are giving up alot of performance. The stock specs are 4* BTDC. Initial timing needs to be at least 10-12* Also make sure your vacuum advance is hooked directly from the carb to the distributor, and that it is working. Let us know what your timing is.
Something noone has mentioned that I had a problem with was my points where "skipping". Cold or hot under acceleration. Replaced the points and found out mine was about to break in half.
Yup, I think that falls under the heading of the simple things, they'll get ya every time:laugh: :laugh:
If your still running points, throw 'em out:grin: Go with a good factory HEI, or an MSD electronic distributor. I chased a stupid miss and surging problem for awhile, about 10 years ago, I have since gone electronic and havent looked back. I cant believe alot of people are still using points. Mark
Thats a nice car. You should really consider sticking a 4 barell on it. If I had one Id give it to ya. The first time you out crusing the city streets [25-25mph] And you snap open all 4 & the tranny kicks down into passing gear. ..... The smile will last for weeks. And a good HEI is also a good idea that or run dual coils. A HEI can be better but I found out with "old" points cars that dual coils will get you the right spark. Just take two coil wires and merg them into one. Its a very cheap way to get more spark. Just check the point wear more often.
