No Throttle After 15 Minutes

treblig · #1 (**permalink**) 02-10-2011, 03:01 PM

I am out of deals on my 302, please help!!

I have stock 5.0 with less then 2000 miles on the motor. I took off almost all the sensors that I could to keep the car to run correctly. I have the O2’s, ACT, BAP, no EGR, I am on a three pulley system, no power steering, AC, or air pump, no WOT or BAT (?). I have 3/8 fuel coming out of tank to a -6 fuel filter (Summit 10 micron) to a Holly fuel pump then to the 5/16’s stock 5.0 fuel line then to the injections. Inside the tank I have a 1969 Camaro tank with a 69 sending unit, pick up tube is 5/16. The tank has been coated with POR 15 tank coating.

Here’s my problem:
When I start out the car runs great, jump on the gas and the tires break loose, engine temp is 0 to 100 degrees. After driving the car for 20 to 30 minutes, engine temp is 180 and the oil temp is 190, outside temp is 34 degrees. When I go to give it gas the car just dies, you let up on the gas and the car runs but you have to give the gas very easily. After 30 minute you really have to play with the gas and baby the pedal to make it back to the barn. The first time this happen I dropped the tank and coated the inside thinking of rust and corrosion. That’s done, drove it again same thing. So I dropped the tank and found out that the pickup tube has a screen and there is a crease right where the tube ends so I thought that the tube was sucking up the screen so last night I cut the screen off. Put the car back together and went down to the DMV today (they were closed due to the weather) to get my license tabs. On the way back the same thing, car dies until you let up on the gas and baby it.

The fuel pump is an old Holly inline, when they first were doing the 5.0 conversions, 1993. Also the pump is pretty quite at first; 15 minutes later you can really hear the pump (at a stop light) next thing the car is dying.

Before I go out and spend 250 for a new pump, I wanted to see what you guys think. I want to think it’s the pump however I am thinking it might be electrical, stock coil and distributor, motor gets to temp and you heat expansion could cause gaps in solder joints I know if it’s electrical I could be chasing this for weeks and drain my savings account for my paint job. I am so close.

FWB · #2 (**permalink**) 02-10-2011, 03:08 PM

Quote:

Originally Posted by treblig

I am out of deals on my 302, please help!!

I have stock 5.0 with less then 2000 miles on the motor. I took off almost all the sensors that I could to keep the car to run correctly. I have the O2’s, ACT, BAP, no EGR, I am on a three pulley system, no power steering, AC, or air pump, no WOT or BAT (?). I have 3/8 fuel coming out of tank to a -6 fuel filter (Summit 10 micron) to a Holly fuel pump then to the 5/16’s stock 5.0 fuel line then to the injections. Inside the tank I have a 1969 Camaro tank with a 69 sending unit, pick up tube is 5/16. The tank has been coated with POR 15 tank coating.

Here’s my problem:
When I start out the car runs great, jump on the gas and the tires break loose, engine temp is 0 to 100 degrees. After driving the car for 20 to 30 minutes, engine temp is 180 and the oil temp is 190, outside temp is 34 degrees. When I go to give it gas the car just dies, you let up on the gas and the car runs but you have to give the gas very easily. After 30 minute you really have to play with the gas and baby the pedal to make it back to the barn. The first time this happen I dropped the tank and coated the inside thinking of rust and corrosion. That’s done, drove it again same thing. So I dropped the tank and found out that the pickup tube has a screen and there is a crease right where the tube ends so I thought that the tube was sucking up the screen so last night I cut the screen off. Put the car back together and went down to the DMV today (they were closed due to the weather) to get my license tabs. On the way back the same thing, car dies until you let up on the gas and baby it.

The fuel pump is an old Holly inline, when they first were doing the 5.0 conversions, 1993. Also the pump is pretty quite at first; 15 minutes later you can really hear the pump (at a stop light) next thing the car is dying.

Before I go out and spend 250 for a new pump, I wanted to see what you guys think. I want to think it’s the pump however I am thinking it might be electrical, stock coil and distributor, motor gets to temp and you heat expansion could cause gaps in solder joints I know if it’s electrical I could be chasing this for weeks and drain my savings account for my paint job. I am so close.

had similar issues with a race car the tank was getting a vacuum to it by all the fuel getting sucked out and no air going back in to replace it. i could see the tank imploding as the fuel was being used.

try running without a gas cap to see if problem goes away, i think vented caps just vent one way and won't suck in air as you pull fuel out of the tank

jdean · #3 (**permalink**) 02-10-2011, 03:09 PM

Do you have a way to see a fuel pressure gauge while inside the car?

treblig · #4 (**permalink**) 02-10-2011, 04:05 PM

No fuel presure gauge. I could install one but that would be all new task.
Thanks for the reply I have white board in the garage and will make this one of my action items if nothing else works.

treblig · #5 (**permalink**) 02-10-2011, 04:11 PM

FWB
So it sounds like you think the engine is not getting fuel which is what I think. I'll pull the cap off and go for a spin tomorrow. I don't have a vent tube on my tank. Everything when I fill the tank gas shoots out the top. I think that is caused by fuel taking up the air space in the tank. So that is one of my must do's.

Jeff

Jerry Clayton · #6 (**permalink**) 02-10-2011, 05:04 PM

If you are having what might be a fuel problem---a fuel pressure guage is a must have--

Lets see----no vent
after running awhile pump gets noisy
so we'll try another pump and put the pressure guage on a to do list??????

treblig · #7 (**permalink**) 02-10-2011, 05:10 PM

Jerry,
You just talked me into it. That's why I use this web site

Dwight · #8 (**permalink**) 02-10-2011, 06:30 PM

Jeff has a 5.0 EFI

What is the year model of the motor?

Fuel filter to small or clogged?

What is the fuel pressure? 38 psi? You will need a fuel test pressure gauge. Parts store $18 to $45.
Did you leave the fitting on the fuel rail behind the alternator?

The vaccum on the gas tank sounds like your problem.

book you need;
How To Understand, Service and Modify Ford Fuel Injection & Electronic Engine Control by Charles O. Probst, SAE 1988-1993 cars
ISBN 978-8376-0301-8 $34.95

Dwight

FWB · #9 (**permalink**) 02-10-2011, 07:28 PM

jeff,
is your pump even rated for EFI? you said a holley inline pump, like the above post the fuel pressure has to be high enough or the injectors will just dribble. also i remember the ford EFI in stock trim used a return line to keep the tank from being reverse pressurized.

i had the reverse going on, i was using a tank from an EFI car but using a carb. the pump would get noisy half way down the track and fall flat on its face from running out of fuel. as the pump sucked the fuel out it required more and more pressure to get the volume because i wasn't replacing the volume of fuel removed with air. in essence i was collapsing the tank, or trying to, with the fuel pump

treblig · #10 (**permalink**) 02-11-2011, 04:37 AM

Thanks FWD,
I did some research last night on installing a fuel pressure gauge. Also I am going to take one more trip to the DMV today here in Huntsville. I am going to remove my gas cap to see if it is a venting issue. If it is I will tap into my filler tube and vent down through the floor of the trunk to the outside. I have 3/8's ID fuel line which I am going to use. Do I need a larger ID tube?

Still going to install a fuel pressure gauge because next year I am thinking on buying a Ford create 351 motor and for sure will need a gauge. I just thought that it's a stock motor, no need to install gauge.

Will it you know if I got my plates or not

Jeff

zrayr · #11 (**permalink**) 02-11-2011, 09:04 AM

by any chance are you using a msd ignition system? all the wires exiting the msd box must be separated from each other as much as possible, i.e. don't run them all thru the same grommets, etc.

I had exactly the same symptoms as you list & the cause was the wiring.

Z.

treblig · #12 (**permalink**) 02-11-2011, 04:43 PM

Crap!!

So the feedback I got was a vapor lock.

So I took off my gas cap and tried to make another trip to the DMV. I got half way there and the car just about died.

As I gave it gas the engine just shut down but would not stall totally.

I floored it and it was like everything shutting down no voltage. The fuel pump went quite. Motor went quite like turning the key off. It seemed that the motor would stall but it would catch and leap forward then go into a stall mode then jerk and leap forward again. I tried to kill the motor by pushing on the throttle, no luck. Put the clutch in and it would not rev up.. Got a lot of lookie luies. Waited 5 to 8 minutes started it up and it ran OK still could not jump on the gas so I limped it back home.

History,
A. I took a stock harness and reworked it to fit my setup, maybe I have something not right but when I checked my volt gauge there was no draw. Always read 12 to 14 volts.

B. I had a guy dyno my car in October (450 bucks), he installed a chip. After the chip was installed he placed duct tape over the exposed end of the chip. Tried to start the car but would not start, we pulled off the tape and it started. I put the car on the trailer and went home. I placed a small piece of plastic over the chip for protection, no problems. While in the church parking lot I pulled off the plastic and let my EEC hang from the plug, it got my home. I will call this guy this weekend.

I am open for any ideas, I don’t think it’s a vapor lock, fuel pressure gauge will not tell me anything because the pump died down like the motor. I can take it to a school parking lot wait till it starts acting up and just play with it. I am thinking about pulling out the chip just to see what the motor will do. I think the motor will go into survival mode (default) when the chip is removed. I’ve been at this for 20 years on this car, it’s a long story. Now I am focused and I want to finish it.

Jerry Clayton · #13 (**permalink**) 02-11-2011, 05:21 PM

Sounds like(no fuel pump sound, no fuel pressure, no fuel injection)

I'll try to be nice---an internal combustion engine needs fuel air and electric to run---Air is a given---now-is it fuel or electric or no fuel and spark because of electric??? You need a fuel pressure guage and a volt meter---

Take some starting fluid, brake clean, hair spray--anything flamable---and spray into the intake when it don't want to run---

Get a extra spark plug and put it on the coil wire to see if you have a good spark--

And just why did you remove all those sensors???

FWB · #14 (**permalink**) 02-11-2011, 05:40 PM

jeff,

jerry has a valid point to his post.......you are just making guesses at this point . based on the new info in your last post jeff, you have a multitude of possible issues. without the proper test equipment you are going to end up in the funny farm.......if the ford computer is being used get a EEC breakout box get some codes and find out what the hell the computer is getting. then the volt meter and a fuel pressure gauge to troubleshoot from there.
the fact of having a butchered up harness won't make it any easier.

i know this may send you over the edge, but sometimes starting over is the path of least resistance with the harness. you really don't even know if the chip was done correctly either. i would question anyone using duct tape for a reflashing of your chip....maybe send the chip out to another place and have it checked....

Jerry Clayton · #15 (**permalink**) 02-11-2011, 07:58 PM

Duct tape to secure those chips in those computors is pretty standard--

However---the modified harness and removing sensors---

My son took in a task for me to do--a couple guys had put a Lincoln Continental sideways 4.6 dohc engine and trans package into a Taurus-- one was a 99, the other 2000. Now in addition to other issues, the fuel supply was changed from a return system to a non return but modulated pump module----I probably had 40 pages of wiring diagrams before I was done with that one---It made some feature story in some magazine but I never read it---

Even mixing dash guages will screw up one of those deals, but they will run on starting fluid---

Dwight · #16 (**permalink**) 02-11-2011, 08:10 PM

Why did a stock 5.0 EFI need a chip?

I drove my Cobra for six years without a chip. I had non stock heads, cam, injectors, Mass air, TB, etc and lots of sensor removed, harness chopped up. Then I changed everything for more non stock mis-matched parts. At that time I had to have the car dyno'ed and a chip burned.

Dwight

treblig · #17 (**permalink**) 02-12-2011, 07:17 AM

Sorry if I sound a little stupid here but hell I was ready to put the car in the paint shop this week, ending this 20 year project. I put the post out here hoping it could be a very sample fix like venting, very cool, however not that lucky.

I am by no means a motor head; my niche is suspension design and fabrication. But what I can say is I totally built that harness, solder and shrink rap all splices and preformed a test on each system to verify volts and continuity. I can tell you off the top of my head what the ford factory wire color codes are and there function, I have a desk full of research papers, diagrams and so forth. However it could be just one bad joint which could cause me to put the car on blocks again and buy another Harley, not going there going to solve this issue.

I really appreciate yours and Jerry’s input, you guys are totally correct. I need to settle down and start running some tests.

What I can rule out for now, coil, distributor, air mass, TPS, O2’s, going to remove the chip and drive the car, car will run rich but if the stumbling stops then I need to make a phone call.

Problem persists, install the chip, I know a guy here in town who has an extra after market harness for my setup. I was going to buy it this year for next years winter project. I want a stroke 351 with a new EFI system which will come with a harness, fuel pump and so on. So I’ll pull that trigger now, install the harness. Found out this morning one of the club guys has an extra fuel pump so I might visit him today or tomorrow. I have a fuel pressure tester system coming I ordered it yesterday, it’s a dash mounted. I will post my findings.

If I see y’all in town, I’ll buy the first round, thanks for the communication.

Jerry Clayton · #18 (**permalink**) 02-12-2011, 08:01 AM

whats the pressure range???

Another area to look---the Ford computers are proooooon to bent pins

Dwight · #19 (**permalink**) 02-12-2011, 06:53 PM

Jeff
I have a Holley fuel pump for my EFI system.

It is a pusher pump. It needs to be close to the tank and as low as you can mount it to the bottom of the tank.

Maybe it's the location of the pump????? Something to check.

You can hook a hose to the outlet of the pump and pump the gas back into the gas tank. By doing this you could run the pump for 20 minutes to see if it stops.
Keep the faith, we can fix it.

Dwight

treblig · #20 (**permalink**) 03-18-2011, 07:50 PM

I finally got the new harness installed, added two fan relays, and a self test check. Found out that Holly recommends a 40 micron filter in front of the fuel pump and a 100 micron between the tank and the fuel pump. Install a tank vent system, short throw shifter, valve covers and a expansion tank system. The cars runs great, I’ve been driving it all day, what a rush found out that I need sun screen. Went down to the court house and got my license plates so now I'm legal. Car ran at 190 consistently and oil temp stayed at 195 that’s at the heads and not the radiator.

I still have a few more bugs to work out. Starter hangs for 3 seconds after engine has started, it’s to tight between ring gear and bendix, got a rear end leak need to chase it down, I got 84 corvette calipers in front and wildwood dyilite rear. I think I need to change my fronts to be more compatible with the rears. My bias bar is adjusted out the way all, afraid to go anymore due to binding. Thanks FWB and Jerry for the support, found out today I need MORE POWER!!