Hello all, I'm new, first post. I either have a bad part out of the box or a real problem. I bought a 66C10 with a 6 cylinder 250. When I got it it ran fine sitting still. When driving I get to 3rd gear it dies and takes a long time to restart, then it will run fine again. The person I bought it from hand an electric fuel pump installed, which I didn't like the sound of anyway, so I installed a mechanical fuel pump. (Also replaced a nasty looking fuel sending unit) The new pump did nothing and it installed way too easily I think. I expected some resistance on the pump lever. After getting zero puming from this thing I took it off, cranked the engine until the cam offset was all the way facing the pump and put the pump back on. The lever doesn't even touch the cam as far as I can tell. There should be some resistance, right? So, did I get the wrong fuel pump? It looks like the right thing but I didn't have one on there before so there's nothing to compare it to. Also, I can't move the lever by hand at all. Should it be all that stiff? Or maybe this engine isn't what I was told and I've ordered the wrong fuel pump. But do they even vary from one to another on a chevy inline 6 cylinder? Thanks in advance for any advice! Sundy
There should be a rod between the cam and the fuel pump lever...kinda looks life a short push rod. Yes that lever should be that hard to move..if it moves at all.
L6 Fuel Pumps There is NO PUSH ROD ! that's a V-8 thing . First things first : with over a 1/2 tank of fuel , disconnect the pumps inlet hosepipe , the fuel *must* come gushing out in a stream as big around as the inner diameter of the pipe else there's crud in the tank or some other bad thing and it'll never be right until the fuel GUSHES out with only the siphon action . Always remove the tank for proper cleaning ! . It gushes ? good : If you take the fuel pump off and hold it in your hands and work the lever , it *must* make rude noises loudly or it's no good . be careful as it'll also squirt a 3/8" stream of gasoline right into your eye . It's possible you installed the fuel pump upside down , then the lever wouldn't rub on the cams oblong pump circle . In a pinch , you can always find any old SBC pump and install it upside down , that'll work as a test .
How I fixed my fuel "supply" issue.... Sundy, I have a '66 C10 with a 250 ci inline six. When I hauled it home on a trailer in '07, it ran but had front end damage. Fast forward to '12 finally got it road worthy. I had the same issue as you describe, runs fine at an idle, but as you go through the gears, it dies. Then hard to start. I too replaced the fuel pump with another mechanical pump and still the same issue. I should have checked the tank pick up sock first. I found that it was all gummed up with varnish from sitting. There were enough holes left to get fuel for running at an idle but not enough for running under a load. Mine would die as I shifted to 2nd gear every time. Once I discovered the clogged up pick up sock, I removed the unit, cleaned it with carb cleaner, blew it out with compressed air and that fixed it. Your mileage may vary, but that is how I resolved the issue on my '66 C10.
Thanks for the replies. I put this same question in another forum and got answers, didn't come back to this one until today. Yes, upside down. Since I got this truck with an electric fuel pump I used the shape of the blank plate as my guid for how the mechanical pump should go on. Someone had put the blank plate on upside down so...I copied that. But first, I used the electric pump to pump a whol lot of dark orange gunk out of the tank. New fuel sending unit with a sock so should be much cleaner gas reaching the carb. It starts and runs but I need to set the timing again, I temporarily removed the distributor to change the gasket on the side plate. That gasket was out of place and leaked plenty. I didn't mark how the distributor was aligned...oops. next. Thanks again
Progress ! Just use a light to set the base timing to TDC ~ 10 degress BTDC , no more than that . most will run the best with TDC timing .
