Fuel pump check valve test????
Thread Starter
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
Fuel pump check valve test????
Good morning CF gurus....
I am trying to follow Lars method for checking if my 78's fuel pump check valve is properly functioning....And will try that later today..
My ? is if it fails the test is it possible to just replace the bad check valve without having to replace the whole fuel pump itself????
I have a stock 350/auto trans and nothing else added...
mk's78
Mike
I am trying to follow Lars method for checking if my 78's fuel pump check valve is properly functioning....And will try that later today..
My ? is if it fails the test is it possible to just replace the bad check valve without having to replace the whole fuel pump itself????
I have a stock 350/auto trans and nothing else added...
mk's78
Mike
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
No, fuel pumps cannot be rebuilt. Just replace it.
Lars
Thread Starter
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
From Lars TIB...
From your Tech Info Bulletin: " #2 Bad fuel pump----You can check for a leaky checkvalve in your fuel pump by running the engine for a minute and then shutting it off.. Wait about 5 minutes and then loosen the fuel line at the carb. If the checkvalve is good there will fuel pressure at the carb when you disconnect, and gasoline will spray out forcefully when you loosen the line. If gas does not spray out and you only get a dribble of fuel, your check valve is allowing drainback."
FWIW..I did the test and only got a dribble of fuel..other than that the carb/engine seems to run ok...I notice the pedal pumping most when I don't start my vette for a week or more??? Of course It is not a daily driver....
Thanks so much for your input Lars
mk's78 Mike
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Hi Lars....
From your Tech Info Bulletin: " #2 Bad fuel pump----You can check for a leaky checkvalve in your fuel pump by running the engine for a minute and then shutting it off.. Wait about 5 minutes and then loosen the fuel line at the carb. If the checkvalve is good there will fuel pressure at the carb when you disconnect, and gasoline will spray out forcefully when you loosen the line. If gas does not spray out and you only get a dribble of fuel, your check valve is allowing drainback."
FWIW..I did the test and only got a dribble of fuel..other than that the carb/engine seems to run ok...I notice the pedal pumping most when I don't start my vette for a week or more??? Of course It is not a daily driver....
Thanks so much for your input Lars
mk's78 Mike
From your Tech Info Bulletin: " #2 Bad fuel pump----You can check for a leaky checkvalve in your fuel pump by running the engine for a minute and then shutting it off.. Wait about 5 minutes and then loosen the fuel line at the carb. If the checkvalve is good there will fuel pressure at the carb when you disconnect, and gasoline will spray out forcefully when you loosen the line. If gas does not spray out and you only get a dribble of fuel, your check valve is allowing drainback."
FWIW..I did the test and only got a dribble of fuel..other than that the carb/engine seems to run ok...I notice the pedal pumping most when I don't start my vette for a week or more??? Of course It is not a daily driver....
Thanks so much for your input Lars
mk's78 Mike
Lars
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Thread Starter
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
Mike
JFYI: The lead off line states: "My standard propaganda info pasted below-this is a little long, but I try and cover all the bases and questions that have come up over the past 30 years of doing this, so be sure to read it all. Contact me with any questions. Thanks" Which I did when I called you and left you a brief message.....
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Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Hey there Lars I did in fact download it from an email I sent you asking about rebuild/shipping cost/turn around time info and when you replied I immediately downloaded and printed the 8 page Technical Information Bulletin Rev. AC 2-29-15 which I am reading as I respond..
Mike
JFYI: The lead off line states: "My standard propaganda info pasted below-this is a little long, but I try and cover all the bases and questions that have come up over the past 30 years of doing this, so be sure to read it all. Contact me with any questions. Thanks" Which I did when I called you and left you a brief message.....
Mike
JFYI: The lead off line states: "My standard propaganda info pasted below-this is a little long, but I try and cover all the bases and questions that have come up over the past 30 years of doing this, so be sure to read it all. Contact me with any questions. Thanks" Which I did when I called you and left you a brief message.....
Lars
Thread Starter
Racer
Joined: May 2011
Posts: 373
Likes: 6
From: Dover Delaware
Any time Lars
1 ? 4 U....I am going to go with a new fuel pump and is it really necessary to go with an OE AC Delco or should I let my Vette specialist make that choice based on local availability??? Although it is not anywhere near NCRS status it is almost completely stock though....
Thanks so much for your patience and help...I'll be making arrangements tomorrow for the new FP
MK
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Now at least we are on the same page
1 ? 4 U....I am going to go with a new fuel pump and is it really necessary to go with an OE AC Delco or should I let my Vette specialist make that choice based on local availability??? Although it is not anywhere near NCRS status it is almost completely stock though....
Thanks so much for your patience and help...I'll be making arrangements tomorrow for the new FP
MK
1 ? 4 U....I am going to go with a new fuel pump and is it really necessary to go with an OE AC Delco or should I let my Vette specialist make that choice based on local availability??? Although it is not anywhere near NCRS status it is almost completely stock though....
Thanks so much for your patience and help...I'll be making arrangements tomorrow for the new FP
MK
Lars
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
I just put a new fuel factory style pump after the engine rebuild. The car was fine for a couple of weeks but then it started to be hard to start after setting for a day.
Now it seems like it is get harder to start (longer cranking) the longer it sits.
I have read all of the postings and tring to determine if it is the carb or a bad fuel pump even though the pump is only a couple of months old.
I have also replaced the fuel filter with the one that Lars recommended. Although the one I had in it also had the check valve in the front of it.
Now it seems like it is get harder to start (longer cranking) the longer it sits.
I have read all of the postings and tring to determine if it is the carb or a bad fuel pump even though the pump is only a couple of months old.
I have also replaced the fuel filter with the one that Lars recommended. Although the one I had in it also had the check valve in the front of it.
Last edited by LenWoodruff; Aug 2, 2017 at 02:27 PM. Reason: Adding more information.