engine help

joemama · Post by **joemama** » Sat Jun 10, 2006 10:19 pm

Having a problem with my engine, it has compufire electronic ignition, bosh bluecoil, 2 barrel holley bugspray. The holley is new to my 1915 engine, previously I was running a single zenith 32, 2 barrel. The engine starts and idles fine, but as soon as you try to accelerate, it dies, if you let the throttle come back to idle, it idles just fine again. The accelerator pump is working fine, and the float valve is also working fine. I had been thinking I had a carburetor problem, but now think maybe its ignition related. I have never has a problem with my ignition, and dont know if this could be a symptom of a problem with the electronic ignition, or maybe a weak coil? Any help would be appreciated, this is driving me nuts!

tpinthepack · Post by **tpinthepack** » Sat Jun 10, 2006 11:23 pm

Sounds lean, more gas needed on acceleration. You may need a bigger idle jet. I only owned one bugspray, and that was 1986. It had a huge flatspot that drove me nuts. I eventually got it going with a larger fuel tank tap, big fuel lines, and drilled the idle jet out. But that was 20 years ago. There must be an old timer out here that can help. Good Luck

Gene-C · Post by **Gene-C** » Sat Jun 10, 2006 11:45 pm

try opening the idle mixture screws a 1/4 turn at a time, & see if that helps

joemama · Post by **joemama** » Sun Jun 11, 2006 4:24 am

Defenetely on the right trak with the suggestions about needing more fuel on acceleration, I pulled the air cleaner off and worked the throttle until it hit the huge flatspot where if you keep the throttle there the engine actually stalls, and then I sprayed brake cleaner into the carb and the engine immediately responded. I also had a timing light on it, and the spark never faltered. As I previously mentioned, it idles just fine, and the accelerator pump squirts, but perhaps I need to try a richer setting on the pump, I will try that next. Is the accelerator pump the only component of the intermediate fuel system? I read somewhere that originally in other applications this carb came with a power valve, but that has been replaced with a plug for volkswagen applications. Tony, do you remember where in the idle jet you drilled? The jet looks like a regular jet, but also has a long tube that comes out of the bottom of the jet, like a nozzle, do you drill out the jet and the end of this tube? Thanks guys.

tpinthepack · Post by **tpinthepack** » Sun Jun 11, 2006 1:02 pm

I don't remember off hand where the jet is. But I want you to test one more thing. When the accelerator pump sprays, make sure it clears the butterflys completely. If the fuel spray hits the shaft, or butterflys at all, it will hestitate also. As I recall, when you accellerate the remainder of fuel in the idle circuit should dump in the manifold through progression ports. THat is why the larger idle jet helped. You keep the mixture screw adjusted to idle well, but whe you hit it, the excess helps the accelerator pump. Then at high speeds you only run on the main jet. I would prefer you purchase another set of jets to drill out for tuning. And use jet reamers, and guages, not a drill bit. Good Luck.