This has been going on for a long time. It just seems to have gotten worse and is now embarassing!
When the motor is cold, it is really hard to start. Usually, I have to pump the throttle like 6-8 times and then crank it. With a little throttle feathering, it will generally start. Lately, it's been a little tougher. It starts to catch but not quite. Eventually, I guess it becomes flooded. Last night, I was screwing with it and it backfired (exhaust) so freaking loud it scared the neighbors. I've got $40k in this damn thing and the neighbors prob. think it's some old junker that never starts.
Also, when I do get it lit, the engine "bounces" unless I floor it. Above 3000 rpm, it smooths out. Below 3000 it bounces. It's exactly like the ignition is being cut off and back on once per second. After I've let it run (above 3000 rpm) for say 10 seconds, it idles smooth as silk. ??????????????? I'm inclined now to think this has something to do with the ignition. A real idiot installed my pertronix distributor. Maybe it's there? Maybe the old ignition switch itself?? Ideas???
Here are some things that it's not:
1) fuel pressure (guage inside the car stays right at 7 psi
2) vacuum- 12 manifold at idle and 10 in gear (manifold). It does not really "bounce" with the engine (slightly but a result of not cause)
3) timing- I've played with every possible timing and vac advance setup. Once running, it's very smooth and very powerful.
4) Carb- doubt it....it's a new Speed Demon 650 and again, it runs perfectly once running and warm
5) Choke- don't think so....I've tried it with the choke operating (closed) and also set to simply stay open all the time....maybe, but I doubt it.
6) plugs- new
This is such a pain!!! I know if I take it to some mechanic, he's gonna charge me $500 and not fix a thing. I need to determine the issue. I'm really thinking it must be electrical (but why only when cold???)
When the motor is cold, it is really hard to start. Usually, I have to pump the throttle like 6-8 times and then crank it. With a little throttle feathering, it will generally start. Lately, it's been a little tougher. It starts to catch but not quite. Eventually, I guess it becomes flooded. Last night, I was screwing with it and it backfired (exhaust) so freaking loud it scared the neighbors. I've got $40k in this damn thing and the neighbors prob. think it's some old junker that never starts.
Also, when I do get it lit, the engine "bounces" unless I floor it. Above 3000 rpm, it smooths out. Below 3000 it bounces. It's exactly like the ignition is being cut off and back on once per second. After I've let it run (above 3000 rpm) for say 10 seconds, it idles smooth as silk. ??????????????? I'm inclined now to think this has something to do with the ignition. A real idiot installed my pertronix distributor. Maybe it's there? Maybe the old ignition switch itself?? Ideas???
Here are some things that it's not:
1) fuel pressure (guage inside the car stays right at 7 psi
2) vacuum- 12 manifold at idle and 10 in gear (manifold). It does not really "bounce" with the engine (slightly but a result of not cause)
3) timing- I've played with every possible timing and vac advance setup. Once running, it's very smooth and very powerful.
4) Carb- doubt it....it's a new Speed Demon 650 and again, it runs perfectly once running and warm
5) Choke- don't think so....I've tried it with the choke operating (closed) and also set to simply stay open all the time....maybe, but I doubt it.
6) plugs- new
This is such a pain!!! I know if I take it to some mechanic, he's gonna charge me $500 and not fix a thing. I need to determine the issue. I'm really thinking it must be electrical (but why only when cold???)