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Author Topic: Intermittent lack of fuel flow?  (Read 3652 times)

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Offline Draekon

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Intermittent lack of fuel flow?
« on: August 20, 2015, 10:48:14 AM »
I have a weird fueling problem that I cannot track down.

Car starts right up as it should. Idles fine in my driveway. If I take it for a drive, it'll work fine for a few miles and then stumble and sometimes stall.
I looked down the carb after it stalled a couple times and activated the the throttle, and there was only enough gas to squirt out the first time.  So it seems as if the fuel bowl is emptying.

I have a new fuel pump and new fuel filter.  I have also tried another carb, with mostly the same results.  The pickup filter in the tank is not clogged, and I could not see anything floating around in the tank that would cause a random but temporary clogging.  Everything that I have tried has made the problem less severe but still persistent.  I also tried driving around without my fuel tank cap on, still had the problem, so its not a venting issue.  The return line is not clogged, there is plenty of gas flowing back into the tank.

Any ideas on what it could be?
« Last Edit: August 20, 2015, 10:52:49 AM by Draekon »

Offline amcfool1

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Re: Intermittent lack of fuel flow?
« Reply #1 on: August 20, 2015, 10:53:55 AM »
ignition module could be failing, check ICM, coil,  wires, etc good luck, gz

Offline Draekon

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Re: Intermittent lack of fuel flow?
« Reply #2 on: August 20, 2015, 11:21:44 AM »
I replaced the ignition module over the winter, along with the spark plugs.  Ignition coil is new since the problem started.  Spark plug wires should still have plenty of life.

Offline amcfool1

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Re: Intermittent lack of fuel flow?
« Reply #3 on: August 20, 2015, 12:03:37 PM »
there was a guy just recently on theamcforum that went through the exact same problem. never did pinpoint the EXACT failed part, but it was somewhere in the ignition, maybe distributor pickup. Long story short, he ended up scrapping the entire electronic ignition setup, and installed an old school points distributor. Problem solved, car runs great. good luck, gz

Offline eaglefreek

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Re: Intermittent lack of fuel flow?
« Reply #4 on: August 20, 2015, 02:30:46 PM »
Maybe install a clear fuel filter so you can verify for sure there is a no fuel issue. If so, what is the condition of the fuel lines at the tank? Does this happen when the tank is full and less than full? Sometimes there can be a hole in the pickup. Also, never rule out a part just because it is "new". Many new parts are substandard nowadays and fail prematurely.
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Offline Draekon

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Re: Intermittent lack of fuel flow?
« Reply #5 on: August 20, 2015, 02:51:33 PM »
The fuel lines look fine, although I don't think I'd be able to tell if there was a pinhole or something.  The ignition module is the only new part that I haven't tried replacing since the problem started.

All of this has been with about 1/8-1/4 tank of fuel.  I'm hesitant to fill it up in case I need to drop the tank.

I'll try the clear fuel filter to try to verify whether or not its a fueling issue.  Where would you recommend installing it?

Offline eaglefreek

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Re: Intermittent lack of fuel flow?
« Reply #6 on: August 20, 2015, 03:26:12 PM »
Anywhere after the pump and before the carb.
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Offline eaglefreek

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Re: Intermittent lack of fuel flow?
« Reply #7 on: August 20, 2015, 08:43:10 PM »
Another option is to install an inline fuel pressure gauge, after the pump and before the filter. http://www.summitracing.com/parts/mrg-1564
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Offline Billman

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Re: Intermittent lack of fuel flow?
« Reply #8 on: August 21, 2015, 12:12:36 PM »
I had the same symptoms and replaced a lot of the ignition parts as you have. My car would run fine up to 45 mph and then wouldn't go any faster. I would replace one part and then test drive it then go change another all to no help. I finally dropped the tank and pulled the sending unit, since there are no direct replacements available I just cleaned the pickup screen and put it back in. The problem hasn't returned since.
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Offline amcfool1

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Re: Intermittent lack of fuel flow?
« Reply #9 on: August 21, 2015, 12:14:20 PM »
hi sending units/socks available from Blasers. gz

Offline eaglefreek

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Re: Intermittent lack of fuel flow?
« Reply #10 on: August 21, 2015, 02:21:15 PM »
hi sending units/socks available from Blasers. gz
For SX4's? I know wagon ones are available, but I'm not too sure the SX4 ones are.
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Offline macdude443

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Re: Intermittent lack of fuel flow?
« Reply #11 on: August 21, 2015, 02:49:03 PM »
SX/4 units aren't available from what I've read.  Only wagon.  Different tank.

I had a faulty, brand new ignition module that would often stumble and cut out pretty violently.  I thought I was running out of gas.  Replaced the filters and all.  No change.  Put another module in and never had the problem again.  I installed a Motorcraft module direct from Ford.  The one that was bad was from Standard Motor Products.  Usually I've had good luck with them.
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Offline Draekon

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Re: Intermittent lack of fuel flow?
« Reply #12 on: August 21, 2015, 03:10:59 PM »
I'm going to try to a clear filter first to try to narrow it down between ignition and fuel.  I'm pretty certain that it is fuel since none squirts out the second time I hit the throttle with the car off after it stalls.  But I've been wrong plenty of other times about whats causing a certain issue.

I replaced the pickup sock around 4 years ago, it looked fine when I pulled it, so I don't think that its the issue.

Offline Amc1320

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Re: Intermittent lack of fuel flow?
« Reply #13 on: August 21, 2015, 09:38:04 PM »
I had to remove the sock, it was ruined

I added a clear filter before the fuel pump.

I agree with that Eaglefreek said, I like to see the gas flowing to I can figure out whats going on.

Might be a longshot but my dad had a heck of a time with his concord cutting out like that, it was his float in his carb had gotten stuck somehow. it would literally run out of gas then fill back up and so on, took us forever to figure it out
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Offline Draekon

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Re: Intermittent lack of fuel flow?
« Reply #14 on: August 28, 2015, 01:04:36 PM »
I put on a clear fuel filter inbetween the carb and the regular filter. When it dies, there is still fuel in the clear filter. So its starting to look like its not a fuel issue.

I also tried replacing the ignition module, still has the same issue.

So here's my list of what is NOT the issue so far:
-Carb
-Fuel filter
-Fuel pump
-Fuel pickup sock
-Fuel return line
-Fuel vent
-Coil
-Ignition module
-Spark Plugs

Anyone have any other ideas?

Offline macdude443

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Re: Intermittent lack of fuel flow?
« Reply #15 on: August 28, 2015, 01:11:35 PM »
Next time it dies, pull the air-horn off of the carb and see of there is actually fuel in the bowl.  You may have a sticking float/inlet valve.  You may also have a pickup tube that is bent in the tank and during acceleration/on hills, the fuel level drops below the tube and it starts to cut out.  This happens with my SX/4 when the fuel level gets too low and I start up a long hill.  Suppose you could also run a new piece of line to a portable gas can and see if it still does it.
« Last Edit: August 28, 2015, 01:16:04 PM by macdude443 »
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Offline carnuck

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Re: Intermittent lack of fuel flow?
« Reply #16 on: August 30, 2015, 12:05:42 AM »
An LPOS (little piece of you know what) can bobble between the filter and needle/seat and do that or if the fuel lines on the OEM 3 line filter are mixed up.
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Offline Draekon

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Re: Intermittent lack of fuel flow?
« Reply #17 on: September 06, 2015, 06:18:02 PM »
I took off the two hard lanes that are between the pump and the carb and blew them out. They seemed to be free of any crud. After that I went for a test drive and it died on me, but this time the clear fuel filter was empty. After trying to restart it a couple times, I looked at the filter again, and it was still empty, but fuel started to slowly pour into it from the inlet hose. Perhaps there is something in the main fuel tubing that is clogging it occasionally?

Offline vangremlin

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Re: Intermittent lack of fuel flow?
« Reply #18 on: September 07, 2015, 01:59:24 PM »
I was having a problem where the rubber fuel hose after the filter was crumbling and little pieces of rubber where getting stuck in the inlet to the carb.  If you've replace that hose then it shouldn't be a problem.
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Offline 2xEaglewagons

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Re: Intermittent lack of fuel flow?
« Reply #19 on: December 15, 2016, 12:01:37 AM »
Hello
I know this is an old thread but i couldnt help but reply.
I searched forever for this same problem.
New fuel lines,new fuels pumps,new modules ect.
Finally threw the sock/filter in tank in the garbage.
The sock filter can look clean but it is not.
It can also collapse,plugging intake/pickup tube.
Car went up hills like a bullet!
Its good to check the sending units solid tubes for cracks.
Install the clear filter before pump,,they dont always look full.
I also keep my tank half or full all the time for steep hills.
Good luck!
Randy H.
Mission B.C.Can.

Offline IRON HORSE

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Re: Intermittent lack of fuel flow?
« Reply #20 on: January 21, 2017, 10:28:24 AM »
Hello Everyone,

       I suspected a small hole in my fuel line that I was finally able to verify by using a piece of thick wall clear tubing between the pump and the steel line. With the engine running I was able to see bubbles of various lengths as the fuel was sucked into the pump .. the more demand on the engine the longer the bubble. I replaced the entire fuel line and that solved the problem. Hopes this procedure may help someone in the future...

                                                                                     Later, Iron Horse :o
« Last Edit: January 21, 2017, 10:33:25 AM by IRON HORSE »

Offline Draekon

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Re: Intermittent lack of fuel flow?
« Reply #21 on: January 22, 2017, 02:47:03 AM »
Im pretty sure my issue is with the pickup tube in the tank. I ended up replacing the main fuel tubing from the tank to the pump to no avail. If I keep the tank on the less empty side, I don't seem to run into any issues. I suspect that I have a hole in the pickup or something similar.

 

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