mikeww1962 Posted August 28, 2011 Report Posted August 28, 2011 Hi everyone: a quick question for those in the know. I am working on restoring my 48 Plymouth coupe and last time I drover her she would die any time lots of power was need like up hills and punching it on a straight section. Today I had a bit of time so I pulled the carb and a friend will rebuild it for me, but I also checked the fuel pressure with a Vacuum/pressure gauge. Cranking it over with the starter (on a 6V system) I was only able to obtain 2.25 Psi. with steady cranking. From what I've read I was hoping for 3.5. Is the lower pressure due to the slower crank speed, or might I have an issue there as well? Any thoughts appreciated. Mike. Quote
james49ply Posted August 28, 2011 Report Posted August 28, 2011 slow cranking will most likely lower the pressure, but what you really want is volumn, I belive that a half quart in a few seconds of cranking would be required. could your float level be low and cause you to run the carb dry? Quote
greg g Posted August 28, 2011 Report Posted August 28, 2011 8 to 10 ounces for 12 fuel pump strokes. pressure with engine running should be between 4.5 and 6.5. Bogging on hills could also be timing related. Quote
mikeww1962 Posted August 28, 2011 Author Report Posted August 28, 2011 slow cranking will most likely lower the pressure, but what you really want is volumn, I belive that a half quart in a few seconds of cranking would be required. could your float level be low and cause you to run the carb dry? We did have the carb apart a few months ago when I first got the car and adjusted the float level to the specs in the manual...should be OK on that. While the Carb is out being rebuilt I will try and draft a friend to help with some sort of volume measurement... Quote
mikeww1962 Posted August 28, 2011 Author Report Posted August 28, 2011 8 to 10 ounces for 12 fuel pump strokes. pressure with engine running should be between 4.5 and 6.5.Bogging on hills could also be timing related. Would too much advance cause this? Seemed to be OK if I was slower in getting it up to speed on the flat... Quote
Niel Hoback Posted August 29, 2011 Report Posted August 29, 2011 Late timing wil make it sluggish, not advanced timing. Quote
mikeww1962 Posted August 29, 2011 Author Report Posted August 29, 2011 Thanks for all of the info - looks like I have some sleuthing and learning to do! That's the fun though right! Quote
MarkAubuchon Posted August 29, 2011 Report Posted August 29, 2011 So what is the fuel pressure levels? Quote
Jim Saraceno Posted August 30, 2011 Report Posted August 30, 2011 http://www430.pair.com/p15d24/mopar_forum/showthread.php?p=262018#post262018 Follow this link for fuel pump testing procedures. I would guess if you have just rebuilt your fuel pump and are only getting 2.25 #s of pressure, you have some type of blockage. Do you have fuel filters in the line somewhere? Quote
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