fuel problem - need advice.

Pongo · 05-05-2002, 07:37 PM

My mustang has a 302, 650 Holley and a holley intake. The car runs fine for about 20 minutes then (after its warm) if you get on it hard a few times it will die. I have a see thru fuel filter and when it dies it is dry. After 3 to 5 minutes the car will start and run fine until you drive it hard then it will stop sending fuel to the carb again. can fuel pumps work only part of the time like this?
Thanks!

Steve

mustangII460 · 05-05-2002, 09:10 PM

Good observation on the filter drying up.

Fuel pumps go bad just like people go bad. Sometimes people dont wait 20 minutes though.

Mechanical pumps are cheap to replace and one that pumps a higher volume may be the way to go. A stock replacement will probibly do though, in your application.

Pay close attention when installing the new one. The arm on the pump meets a lobe on the front of the camshaft. The lobe pushes down on the arm to pump fuel to the motor. A slight resistance should be felt when sliding the arm into and under the lobe. (Not a big deal doing this.)

While the pump is off I like to blow air back towards the tank to clear the line. Somtimes with old cars, crap clogs the lines up. Ive used a 12volt tire pump if a compressor cannot be had, works just the same. *Losen gas cap.

Re-adjusting your carb would'nt hurt either.

Pongo · 05-05-2002, 11:14 PM

Thanks for the reply

Looks like Ill swap it out some time this week.

Steve

jwboner · 05-06-2002, 01:03 AM

I'm guessing that your filter is under the hood an not by the tank. A second thing to look into is vapor lock of the fuel in the line going up to the pump. If this is the case you can either try to keep heat as far away from the line as possible or to get an electric pump mounted as close to the tank as possible. If vapor lock is the problem getting a new mechanical pump won't help much if at all.

Pongo · 05-06-2002, 01:15 AM

MMMmm - Yes vapor lock! Thats why I worded the question the way I did

It just may be... Ill let ya know. The pump is new enough to exchange so Ill swap it out anyway.

Steve

05-05-2002, 07:37 PM	#1
Pongo Registered Member Join Date: Apr 2002 Location: Springfield, Mo Posts: 18	fuel problem - need advice. My mustang has a 302, 650 Holley and a holley intake. The car runs fine for about 20 minutes then (after its warm) if you get on it hard a few times it will die. I have a see thru fuel filter and when it dies it is dry. After 3 to 5 minutes the car will start and run fine until you drive it hard then it will stop sending fuel to the carb again. can fuel pumps work only part of the time like this? Thanks! Steve

05-05-2002, 09:10 PM	#2
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	Good observation on the filter drying up. Fuel pumps go bad just like people go bad. Sometimes people dont wait 20 minutes though. Mechanical pumps are cheap to replace and one that pumps a higher volume may be the way to go. A stock replacement will probibly do though, in your application. Pay close attention when installing the new one. The arm on the pump meets a lobe on the front of the camshaft. The lobe pushes down on the arm to pump fuel to the motor. A slight resistance should be felt when sliding the arm into and under the lobe. (Not a big deal doing this.) While the pump is off I like to blow air back towards the tank to clear the line. Somtimes with old cars, crap clogs the lines up. Ive used a 12volt tire pump if a compressor cannot be had, works just the same. Losen gas cap. Re-adjusting your carb would'nt hurt either. Last edited by mustangII460; 05-05-2002 at 09:20 PM..*

05-06-2002, 01:03 AM	#4
jwboner Registered Member Join Date: Jun 2001 Location: Under the hood Posts: 164	I'm guessing that your filter is under the hood an not by the tank. A second thing to look into is vapor lock of the fuel in the line going up to the pump. If this is the case you can either try to keep heat as far away from the line as possible or to get an electric pump mounted as close to the tank as possible. If vapor lock is the problem getting a new mechanical pump won't help much if at all. __________________ 65 fastback 347 DFI injected w/vic jr, TFS heads, MSD, cable clutch TKO, 3.70 9", tc subframe conns, custom traction bars, griffen alum radiator, armored fuel cell, and torq thrust D's Retrofitted Prelude seats. Vintage Air underdash kit. Fiberglass here and there too More on the way all the time.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Fuel or Air Problem	Screaming_302	Windsor Power	3	08-05-2003 01:23 AM
help diagnose problem	RB92GT	Windsor Power	2	06-08-2002 04:53 PM
Fuel Problem	WallyGatorFL	Windsor Power	1	07-16-2001 09:58 PM
Please help with Fuel Pump problem.	gt93mustang	Windsor Power	11	05-14-2001 11:57 AM
Anyone seen this problem with Fuel Sump??	stanglx347	Windsor Power	3	01-01-2001 03:08 AM

05-05-2002, 11:14 PM	#3
Pongo Registered Member Join Date: Apr 2002 Location: Springfield, Mo Posts: 18	Thanks for the reply Looks like Ill swap it out some time this week. Steve

05-06-2002, 01:15 AM	#5
Pongo Registered Member Join Date: Apr 2002 Location: Springfield, Mo Posts: 18	MMMmm - Yes vapor lock! Thats why I worded the question the way I did It just may be... Ill let ya know. The pump is new enough to exchange so Ill swap it out anyway. Steve