Hey there guys, wonder if I could get as quick bit of advice. Mates got a 289 sat in an XR Falcon, he reckons it's lost a bit of power over time. Still goes alright, it's just that when you give it a pump of the go pedal, it hesitates. Trying to get an idea of what to look for first. Oh and he's running it on avgas. Engine is mid street level build, but I don't know what internals are in it. Timing seems to check out ok. All leads get good spark to them. Haven't pulled plugs yet, but I'm figuring that might yield a big clue. Pretty sure there are no intake leaks. Now after that, would I be looking at fuel mixture? Or timing? Whats the most common cause? It seems we give it a big gulp, and it's either not igniting well enough or the carb pump is off. (Holley 600, 4bbl).
Check the timing first. Check that the advance is working. Check that your vacuum at idle is right for the cam you have to help determine if there might be a leak.Then make sure the pump squirter works as soon as the throttle is moved.
Thanks Johnnie, nice to know I was getting close to being on the right track. I pinched off the vac advance hose, and it didn't make much difference if any. Distributer is an electronic job, with the big box bit hanging off the side near bottom, I'm guessing it's a factory ford unit. The pump did seem to be working, but will have to take aircleaner off to check again. Let you know how I go later. And, will get some pics, she's a nice old beast.
Quite often when any carberated motor sits, the accel pump, which is the lowest part of a Holley, gets plugged up. I strongly suspect the accel pump, while it may be working enough to allow it to run, isn't delivering enough shot to produce good acceleration.
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