gkent
Well-Known Member
He already did - read the whole string.
Last edited:
Fuel Issue on my 69 RR
- Thread starter jimm69
- Start date
He already did - read the whole string.
gkent
Well-Known Member
Seriously ?!?!? Do you do that for Holley or Carter or is testing fuel pumps a hobby ?
jimm69
Well-Known Member
by prime, I mean dumping gas in carb
well, pulled the fuel pump off and hooked up vacuum gauge and pushed in the arm. i couldnt measure the vacuum but i was able to see it get some vacuum. i then pulled out the rod. the end against the cam was very concave. not sure if that is normal. can anyone tell me what the length of the rod should be? i did take the plug out and hold the rod against the cam and cranked the motor. i can see the rod moving so i at least know the cam is not hurt or at least not hurt badly. from what I see, the rod appears to be the problem. can anyone confirm this?
well, pulled the fuel pump off and hooked up vacuum gauge and pushed in the arm. i couldnt measure the vacuum but i was able to see it get some vacuum. i then pulled out the rod. the end against the cam was very concave. not sure if that is normal. can anyone tell me what the length of the rod should be? i did take the plug out and hold the rod against the cam and cranked the motor. i can see the rod moving so i at least know the cam is not hurt or at least not hurt badly. from what I see, the rod appears to be the problem. can anyone confirm this?
gkent
Well-Known Member
That rod end should be flat. The fact the rod moves just means there's still an eccentric on the cam - it doesn't mean it isn't totally galled !! Unfortunately that's going to require a little more disassembly to determine !!
jimm69
Well-Known Member
this one is obviously very worn. i am hoping that the engine builder used my old one and it was worn before the new motor. hopefully the cam is not worn badly. i know the cam still has a lobe because i pushed the rod up against the cam with a screwdriver and cranked the motor. i dont have any way to measure the amount of lift on the cam, but there is obviously lift there so that is at least a good sign. I just ordered a new one from summit. should be here tomorrow. hated to pay the $10 shipping cost on that, but i guess i would spend that in gas to drive there to get it in person. Wish me luck
PurpleBeeper
Well-Known Member
This is a good point. I still think it's the pump going South, but your symptoms do line up pretty well with an accelerator pump issue. Why don't you take a look inside the carb? Is your accelerator pump squirting?
Jimmy69, yep, I'd replace that fuel pump rod. If worse comes to worse, you can at least "peek" at the fuel pump cam lobe through the distributor hole.
It is pretty baffling why you can prime it and then it runs.....accelerator pump would explain that.
jimm69
Well-Known Member
well, brought the pump and rod to work with me today and had some guys in the shop help me out. put a vacuum gauge on it and pushed the arm. it was creating vacuum and seemed to be holding. I couldn't get any kind of suction on the car so that tells me that it should be either the rod or cam not pushing hard enough on the pump while in the car. Measured the rod and it was 3.11" without taking into consideration the concave end so it is actually a little shorter. correct length is supposed to be 3.22" so I think that is a significant difference. Rod is supposed to arrive today. I will install when I get home and see if that cures the problem. I may still have to tune the carb. Got the carb used from a buddy and bought a tune kit with rods, springs, and jets. I was told to put the carb back to factory specs before I make any more changes. Guess I will see how it all goes.
jimm69
Well-Known Member
OK....got the new fuel pump rod installed and sounds like most of my issues are gone. car now starts and idles great but still bogs at rapid acceleration. Stanton suggested maybe an accelerator pump issue. How can I check that? I ended up putting my Holley carb back on so we could go to the show. car ran great but still want to put edelbrock back on so everything bolts in correct position and air cleaner is placed properly as I have the air grabber assembly on the car.
just started car this morning and no priming required....yayyyyyy!!!
can anyone tell me how to check the accelerator pump without just replacing it? maybe another problem? I did buy a tune up kit for the edelbrock and put the carb back to factory springs, rods, and jets.
gkent
Well-Known Member
You can bench check that. Carb need to have fuel in it at normal level. Sit the carb flat and open the throttle while looking down the carb. You should see fuel squirt out of the squirters into the primary bores. The squirters usually sit towards the top of the carb.
If it is getting fuel now you have to play with it to determine if its getting too little or too much. There are guys out there who know WAY more than me on this topic but I tend to think a bog is too much air therefore you want to increase the fuel. On Eddys I think this is done with the arm adjustment. On Holleys you would change the pump cam or the squirter.
If it is getting fuel now you have to play with it to determine if its getting too little or too much. There are guys out there who know WAY more than me on this topic but I tend to think a bog is too much air therefore you want to increase the fuel. On Eddys I think this is done with the arm adjustment. On Holleys you would change the pump cam or the squirter.
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