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Topic: New issues after the fuel pump change (Read 4324 times) previous topic - next topic

New issues after the fuel pump change

Well after all I went through on the fuel pump change the car runs like hell now.

I switched from the original to a 155 lph pump, but now it seems like it’s not getting enough fuel. 

Tell me what you think-


First of all the car will barely start.  Before the change the old pump was loud, but the cars started right up.  Now I have to turn it over for 8-12 seconds before it will even sputter.

When I get on the gas, it seems like the car has no power, and it revs a lot higher before it finally changes gears.

Occasionally when I speed up to try to pass or whatever, the car starts sputtering and jerking around.  As long as I go slow, I’m fine.

I was afraid that the pump might turn since it was smaller than the original hose and twist the fuel line, so I tried to clamp it down well, but I know it still may have moved.  Especially since the filter sock was different and I was guessing at the angle.  I can easily see that twisting the pump and crimping the hose inside the tank.

Before I drop that $@*&%$ tank again, is there something else I need to adjust after switching to the bigger pump, or does it sound like something is restricting the fuel flow?

Thanks for any input.

Re: New issues after the fuel pump change

Reply #1 –
Bueller?


Bueller?

Re: New issues after the fuel pump change

Reply #2 –
did you check your fuel pressure? didnt drop a assload of rust into the gas tank when u switched pumps did you? that could clog it

Re: New issues after the fuel pump change

Reply #3 –
I didn't check the fuel pressure.  Honestly I am still at the rookie stage when it comes to working on cars, so I'm not even sure how to do that.  What would be teh easiest way to check it?  How hard is it to hook up a fuel pressure gauge?  Sure should be easier than dropping the tank again only to find out "that ain't it".

I tried not to get rust in the tank, and went so far as to clean out all the  I could get to with my little hand pump.  I don't think that is it, but it looks like I'm going to have to drop the tank again this weekend anyway, so we will see.




On a side note it is my rookie status that makes me post these questions so frequently, but I really do appreciate people jumping in and offering any suggestions.  I wouldn't even be able to keep the car running without you guys and this site.  So....Thanks.

Re: New issues after the fuel pump change

Reply #4 –
Ok, so as not to competely rely on you guys I have been researching fuel pressure gauges a little.

Long term should I go with electric? Do I need an adjustable fuel pressure regulator?

Short term, do you think this would work until I could work on a cleaner install of the gauges, etc?



Homemade Gauge

Re: New issues after the fuel pump change

Reply #5 –
if your just using the gauge for testing/diagnosis  autozone sears napa etc  sell them  no idea on price maybe $30......  they just screw onto the schrader fitting (looks like tire valve)  on fuel rail.  no ideas on permanent dash install other than you need an isolator so fuel is not entering passenger area

Re: New issues after the fuel pump change

Reply #6 –
OK got a gauge, so what sort of pressures should I be seeing?

Re: New issues after the fuel pump change

Reply #7 –
rock solid 40psi.

If you drive with it hooked up, you get to see your real problem.  Hook it up to the schrader valve, duct tape the tester to your windshield and take it for a drive.

If your needle moves during your shifting,, the pump aint worth a dime.

I bought a supercharge v6 pump and it does not move even when i floor it.

whats all this talk bout the FPR?  Yeah,, you might as well get a new one but if your old one is not bad,, dont think you could compensate by adjusting or changing the fpr.

trust me,, put the guage on your windshield and drive it. it only makes sense to troubleshoot in a manner that is as close to the problem as you can get,,ie-problem while the car is under loaded conditions.

Re: New issues after the fuel pump change

Reply #8 –
OK I've got an 88 302 SO, and if I have it on the right valve I'm only getting about 10-15.

Am I missing something here? 


If not it looks like at least I've narrowed it down to the pump


.....right?

 :wtf:

Re: New issues after the fuel pump change

Reply #9 –
jcassity,

unless I'm on the wrong valve I don't think my gauge will reach the windshield.

Re: New issues after the fuel pump change

Reply #10 –
not sure thats the right one eh? well,, unhook your guage.  turn your key forward,, now turn your key off.
use a pointed thingy and push into the needle on the schrader valve,,,,,,did you get gas to come out? does it smell like gas?

mines homemade, 100psi water guage,3ft hose, end fitting.

you fp sux.
better find out why.

drop the tank
unhook the elec conn
unhook fuel lines

clamp a hose to the fuel feed tube (hint-inline with filter)
find you a water guage lying around somewhere
clamp it on the other end of your hose.
rehook up your elec conn(need to turn your key forward for this option) or supply your pump with direct battery.
if fuel presure is still 10-15psi, get a new pump
if it is like wwwwwaaaaayyyyyyy up there like 90, its good and your problem is up the line.

Re: New issues after the fuel pump change

Reply #11 –
Man I get NOTHING out of there.  I can tell it is releasing pressure, but I get no fuel. Is there a valve on the return line?

I just put this new pump on, and I’m thinking the fuel line in the tank must have gotten crimped.

Thanks for the help.  I think I’m just going to have to drop the tank again this weekend.

Re: New issues after the fuel pump change

Reply #12 –
thats the spot


forgive me as I am tired but the pressure does vary  I think 32 with vacuum on fuel regulator and 40 w/o.................if you only got 15 you got a problem  maybe fuel filter maybe pump pickup maybe just got a defective pump

Re: New issues after the fuel pump change

Reply #13 –
looks like we are all posting at once..........i'm out now good luck

Re: New issues after the fuel pump change

Reply #14 –
Get you some good rubber fuel line and clamp it to the gage and the other end directly to the output of the fuel filter(disconnect the fuel line to the engine). Turn the ign sw on and off 3-4 times and observe the pressure. If its still low, you'll be dropping the tank. If its high (80-100 psi or more), you have a bad filter or a problem with the fuel pressure regulator.

I did this same test on a TC that would barely run a while back and got 25psi. After I changed the pump pressure went to 85psi, had to repl the regulator to get the proper 32-39 psi.