Need Help Troubleshooting a 1994 F350, I'm desperate!

Tony396 · 07-15-2007, 12:35 AM

Ok..this one has me pulling what is left of my hair out. I know there are a ton of you out there who know more about this than I do so I am hoping someone out there can help.

1994 F350 Crew Cab Dually, 460 gas, 2wd, Auto, loaded. 168K, Ford reman motor at 120K and Trans at 125K. Very well maintained, never given me a lick of problems towing all over the country.

About two weeks ago, have cruise on doing 70 on an 80 mile trip. Starts to buck, snort, come back to power, buck, snort, backfired through the pipe, then runs well for another 20 miles. Switched tanks in the middle of the snorting and made no difference. Coast off road, sit for a minute, starts right back up. Limp to dad's.

Change module. Starts right up. Run 80 miles home, no problem.

Week later, making same trip, go all the way there with no problem. Truck sits for 3 hours while I load it. Go to start, nothing. Will crank, no light. Change module again, coil, cap, rotor, wires, plug.

Go to start, will not start...might stumble once or twice, but no start. Get pissed. Crank the ever living crap out of it and after 20 seconds, lights. Drive up and down street a few times, all is good. Turn off and on a bunch of times, all good.

Take 50 mile trek to Bridgeport area. Not one problem.

Truck sits for 20 minutes. Once again, crank, crank, crank, finally lights after 15 seconds.

Drive 100 miles home...not one missed beat.

Get up in the morning, starts right up. Go 20 miles, no snorting, but cuts completely off. Pull over, hit key, lights right up.

Truck sits for 20 minutes. Go to start, lights, goes 5 feet, dies. Starts right up again, goes 10 feet, dies.

Leave sit for 5 days. Go on vacation.

Come back, change fuel filter. Starts right up. Several times. Drive 10 miles to NES, as I am making the turn into the track...snorts, but keeps running. Pull into lot. Sit for 10 minutes, go to start, nothing. Crank for 20 seconds, nothing.

Sits all night...come out at 11, lights right up, drive 10 miles home. Restarts right up 10 minutes later.

What the hell could this be???????

Thanks in advance for your help.

Tony Pietrofitta (use to be a C/SA driver...)

Mike Hedger · 07-15-2007, 11:02 AM

Couple of questions, when it is acting up do you get a check engine light, have you hooked up to the computer to see if it has any codes, and have you ever replaced the pick up in the dist.? Fords trucks of those years are bad about the TPS going out and doing the same thing you are describing. The other thing is if the pickup in the dist is going bad it could cause this type of problem but I would check on the TPS first. I would only use Motorcraft parts as well. Hope this helps, Mike

Steve Calabro · 07-15-2007, 01:23 PM

I would also monitor the fuel pressure

Fred Holdorf · 07-15-2007, 02:09 PM

Just got through with a simular problem on a '90 Econoline chassis. I too shotgunned the ignition, but it turned out to be fuel system related. Changed both the low pressure pump in tank and high pressure pump on the frame rail, replaced the reservoir filter (on frame rail) and new fuel filter. All is well and I'm not getting towed in anymore. Hope yours is cheaper to fix, but think it's fuel system related. Good luck, Fred

Rich Biebel · 07-15-2007, 03:46 PM

My '96 GMC 454 had a somewhat similar series of problems a few years ago. Engine was stunbling and shutting off and wouldn't start and other times would run fine. I had it towed in one morning, changed the fuel filter and it was good for a few days. Engine quit again a few days later and I could restart it and go a few blocks...luckily I was near work. Pulled the fuel tank and changed the pump but bought a parts store model and had to swap some parts from the OEM unit to the parts store model. Ran ok for a day or two....than same deal. Towed in again! Put a fuel pressure gauge on it and drove it around......it was losing fuel pressure when it started to run bad. Replaced the fuel pressure regulator...no easy task on a Votec 454......didn't move 20 feet before it stalled and ran like crap again........pulled the tank again and spotted the problem!! Dirt and crap in the bottom of the fuel tank and the fuel pump filter sock had a lot of fine silt/rust type material on it causing the sock to suck closed. My old eyes never saw it the first time I pulled the tank as I put a rag over the tank opening and never really looked closey at the sock/filter. I bought a new GM pump that comes complete, cleaned out the tank and never had a problem again. Porbably got a load of dirt from a gas station that had bad pump filters. Some low priced station that's staffed by Taliban gas pumpers got me ! I change my fuel filter often after that experience...........Check your fuel pressure !

Real Racer · 07-15-2007, 05:24 PM

Check Tfi Module Connector.
They Have A Propencity For Loosening Up And When Not Fitting Well Will Cause Your Type Of Issues.
Heat Gun On The Connector While Pushing On It Then Tape It Tight.

07-15-2007, 12:35 AM	#1
Tony396 Junior Member Join Date: Jun 2003 Location: North Hanover NJ 08562 Posts: 19 Likes: 0 Liked 0 Times in 0 Posts	Need Help Troubleshooting a 1994 F350, I'm desperate! Ok..this one has me pulling what is left of my hair out. I know there are a ton of you out there who know more about this than I do so I am hoping someone out there can help. 1994 F350 Crew Cab Dually, 460 gas, 2wd, Auto, loaded. 168K, Ford reman motor at 120K and Trans at 125K. Very well maintained, never given me a lick of problems towing all over the country. About two weeks ago, have cruise on doing 70 on an 80 mile trip. Starts to buck, snort, come back to power, buck, snort, backfired through the pipe, then runs well for another 20 miles. Switched tanks in the middle of the snorting and made no difference. Coast off road, sit for a minute, starts right back up. Limp to dad's. Change module. Starts right up. Run 80 miles home, no problem. Week later, making same trip, go all the way there with no problem. Truck sits for 3 hours while I load it. Go to start, nothing. Will crank, no light. Change module again, coil, cap, rotor, wires, plug. Go to start, will not start...might stumble once or twice, but no start. Get pissed. Crank the ever living crap out of it and after 20 seconds, lights. Drive up and down street a few times, all is good. Turn off and on a bunch of times, all good. Take 50 mile trek to Bridgeport area. Not one problem. Truck sits for 20 minutes. Once again, crank, crank, crank, finally lights after 15 seconds. Drive 100 miles home...not one missed beat. Get up in the morning, starts right up. Go 20 miles, no snorting, but cuts completely off. Pull over, hit key, lights right up. Truck sits for 20 minutes. Go to start, lights, goes 5 feet, dies. Starts right up again, goes 10 feet, dies. Leave sit for 5 days. Go on vacation. Come back, change fuel filter. Starts right up. Several times. Drive 10 miles to NES, as I am making the turn into the track...snorts, but keeps running. Pull into lot. Sit for 10 minutes, go to start, nothing. Crank for 20 seconds, nothing. Sits all night...come out at 11, lights right up, drive 10 miles home. Restarts right up 10 minutes later. What the hell could this be??????? Thanks in advance for your help. Tony Pietrofitta (use to be a C/SA driver...)

07-15-2007, 11:02 AM	#2
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: Need Help Troubleshooting a 1994 F350, I'm desperate! Couple of questions, when it is acting up do you get a check engine light, have you hooked up to the computer to see if it has any codes, and have you ever replaced the pick up in the dist.? Fords trucks of those years are bad about the TPS going out and doing the same thing you are describing. The other thing is if the pickup in the dist is going bad it could cause this type of problem but I would check on the TPS first. I would only use Motorcraft parts as well. Hope this helps, Mike __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication

07-15-2007, 01:23 PM	#3
Steve Calabro Member Join Date: Jun 2007 Location: New Jersey Posts: 198 Likes: 225 Liked 43 Times in 12 Posts	Re: Need Help Troubleshooting a 1994 F350, I'm desperate! I would also monitor the fuel pressure __________________ Steve Calabro 1199 STK, SS

07-15-2007, 02:09 PM	#4
Fred Holdorf Junior Member Join Date: Oct 2003 Location: Minden, Nv Posts: 44 Likes: 0 Liked 0 Times in 0 Posts	Re: Need Help Troubleshooting a 1994 F350, I'm desperate! Just got through with a simular problem on a '90 Econoline chassis. I too shotgunned the ignition, but it turned out to be fuel system related. Changed both the low pressure pump in tank and high pressure pump on the frame rail, replaced the reservoir filter (on frame rail) and new fuel filter. All is well and I'm not getting towed in anymore. Hope yours is cheaper to fix, but think it's fuel system related. Good luck, Fred

07-15-2007, 03:46 PM	#5
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,315 Likes: 25 Liked 544 Times in 213 Posts	Re: Need Help Troubleshooting a 1994 F350, I'm desperate! My '96 GMC 454 had a somewhat similar series of problems a few years ago. Engine was stunbling and shutting off and wouldn't start and other times would run fine. I had it towed in one morning, changed the fuel filter and it was good for a few days. Engine quit again a few days later and I could restart it and go a few blocks...luckily I was near work. Pulled the fuel tank and changed the pump but bought a parts store model and had to swap some parts from the OEM unit to the parts store model. Ran ok for a day or two....than same deal. Towed in again! Put a fuel pressure gauge on it and drove it around......it was losing fuel pressure when it started to run bad. Replaced the fuel pressure regulator...no easy task on a Votec 454......didn't move 20 feet before it stalled and ran like crap again........pulled the tank again and spotted the problem!! Dirt and crap in the bottom of the fuel tank and the fuel pump filter sock had a lot of fine silt/rust type material on it causing the sock to suck closed. My old eyes never saw it the first time I pulled the tank as I put a rag over the tank opening and never really looked closey at the sock/filter. I bought a new GM pump that comes complete, cleaned out the tank and never had a problem again. Porbably got a load of dirt from a gas station that had bad pump filters. Some low priced station that's staffed by Taliban gas pumpers got me ! I change my fuel filter often after that experience...........Check your fuel pressure ! __________________ Rich Biebel S/C 1479 Stock 147R

07-15-2007, 05:24 PM	#6
Real Racer Member Join Date: Jan 2002 Posts: 99 Likes: 0 Liked 0 Times in 0 Posts	Re: Need Help Troubleshooting a 1994 F350, I'm desperate! Check Tfi Module Connector. They Have A Propencity For Loosening Up And When Not Fitting Well Will Cause Your Type Of Issues. Heat Gun On The Connector While Pushing On It Then Tape It Tight.