Hey guys, first off let me apologize if i posted this in the wrong place, not exactly a ford truck but didn't really know where else to ask. I have an 85 Toyota pick up that we put a 302 out of an 89 Mustang gt in. It runs and drives fine EXCEPT any time you "get on it", about 15 seconds later it dies. It will take a couple mins to start back up after that, then its fine again as long as you just casually drive it, but lay in to it again and it does the same thing. I kinda get the feeling that the fuel is not keeping up with it and that's why it dies. It has an electric 4-7 psi fuel pump on it because, since the engine is out of an 89 gt, the cam doesn't have the gear on it to turn a mechanical fuel pump. I've heard that it could be that the floats in the carb aren't adjusted right, so i checked it by pulling the screw out of the fuel bowl and shaking the truck a little and a little fuel trickles out(per troubleshooting forum). It has a Holley 600cfm on it BTW. I just bought a new fuel pump, haven't installed it yet BC i wanna try everything else before i do and cant return it. I dont really know what to do next, been working on this problem for two weeks now. I am open to any and all suggestions. Thanks in advance for any suggestions everyone!

 

"I kinda get the feeling that the fuel is not keeping up with it and that's why it dies."

I think you're right.

Your fuel filter is most likely clogged. When the engine stops, the fuel slowly trickles through the dirty filter until it fills the carb, and the engine can then run until the fuel in the float bowl is used up.

To test, disconnect the fuel line at the carb and direct it into a bottle. Switch on the fuel pump and see how much fuel comes out. It should come out in a good stream. If the filter is clogged, it will just drip out.

If there is a filter in the carb itself, take it out and blow through it to see if it is the culprit.

The other cause could be that the pump is not doing its job, perhaps a piece of teflon tape is blocking an outlet or the pump itself is faulty.

Or a mud dauber wasp plugged up a line while some parts were disconnected.....

 

I don't remember the time limit on this. But there is a rec-neck FP test, you take a 16 oz coke bottle (plastic, of course). You put the hose in it, and crank the beast...in your case you just turn on the pump...if I remember right, you should have to shut er down at 7-10 secs as the bottle will be full.

This would be a "Flow" test versus a "pressure" test.

 

Which Holley 600 is on there ? Is it a single feed or dual feed ? The pump pressure is fine, you do not want any more pressure to feed a carb. And it takes very little flow to feed a carb (or even three carbs in my case) As Beanscoot said, check the filter. If it's a dual feed Holley, there are filters inside the bowl inlets, behind the inlet tube fittings. If someone ran this carb without an inline filter, the filters inside the inlets can become clogged. Now, when you adapted this motor to a carb, did you change the distributor from the EFI unit to one suited for a carb application ?

 

thank a lot for all the responses everyone. I greatly appreciate the help. The carb is a holley 1850 single feed fuel inlet. The fuel line has one filter on it about 6-8 inches before the carb, and the fuel pump is mounted at the rear of the truck roughly 6 inches from the tank. The filter is one of those small mr. gasket clear glass filters. Is that supposed to be full of gas when the engine is running? It always looks about half full. Its pouring down rain here (NC), and my to oldest sons (7 and 6) have wrestling practice tonight. If the weather is a little better when we get home, then i will try the coke bottle test. If not then i am off work tomorrow, so i can do it in the morning. Thanks a lot guys.

Oh any yea, its got an ignition system off a late 70's model ford truck

PS, the transmission we put in the truck is a 3 speed auto out of a 67 fairlane. any suggestions on how to make or find a passing gear cable or rod? I'm going to upgrade to a newer AOD style transmission in a couple months.

 

Make sure the pump is as low on the frame as possible to keep it from having to "lift" fuel. Electric pumps are made to push fuel, not suck it. As long as it's as close to the tank as possible (your location sounds fine) and at or blow the level of the tank bottom, it should work. It doesn't take much flow to keep a carb fed, my 331 with three 2 bbls runs fine with a 35 gal/hr pump, even at WOT. As for your distributor, if you're runnign a Duraspark setup, you need the distributor for an 85 Mustang GT with manual transmission, this was the only application that had a steel gear to match the roller cam. These can be bought as a reman unit at any local parts house for less than $100. As for a passing gear rod, skip it if you're going to replace the transmission soon anyway. What flexplate did you use on it ?

 

It's common for fuel housings to have trapped air in them. If the fuel enters in the higher side or end, the air is never entirely driven out, although the fuel will run through quite fine.

 

The fuel pump is a couple inches above where the gas comes out of the tank, i will move it closer to level first thing tomorrow. I actually have a long block and distributor out of an 85 Gt, so that works out well. The flex plate is part of the reason im upgrading transmissions. Its out of the 67 fairlane. I'm not 100% sure on this, but those are externally balanced and the engine (89 gt) is externally balanced. I think that is contributing to ridiculous amount of vibration the truck has. Beanscoot, we drilled a hole in the bottom and mounted a 90 degree elbow in the gas tank to let gravity help with the fuel delivery. Will doing the "coke bottle" test as mentioned earlier help purge the air out of it? Thanks again everyone!

 

Yep, you've got the wrong flexplate on it. The motor uses a 50 oz/in flexplate and you've got a 28 oz/in flexplate on it. They do make an aftermarket flexplate for this, several companies do. You're looking for a 157 tooth, 50 oz/in flexplate. I You didn't need to install that elbow in the tank, that may be your problem, it could have a piece of trash plugging the el. The stock fuel line would have sufficed, the siphon effect will be enought to keep the pump supplied as long as the pump is at or near the level of the tank bottom.

 

The reason we drilled the hole for the fuel line is i didn't have the original fuel pump assembly in the yota. It had been removed and sold. So i made a cap for the hole and sealed it all off. I can remove the elbow and just make it a straight tube coming out of the bottom. I would like to find some way to make the passing gear work for now because its going to be at least a few months before i can upgrade the transmission. Reason being is my wife likes to inform me that im well over my budget on this project, lol. So i would like to get to drive it around every now and then. I want to upgrade it in the future be a 3 speed just is not enough to drive it comfortably in the area i live in. I just got home from doing some side jobs on my day off, so i'm headed out now to start tinkering with it again, starting with the coke bottle test. Thanks again for the help!

 

Well, it failed the crap out of the coke bottle test. After running the pump for over 30 seconds, the bottle (mountain dew, lol) was only about 1/8 the way full. I guess a carb doesn't need much fuel at all to run at low rpms. I'm amazed it runs at all. I don't have room to put the truck in my garage, and it started raning again. So as soon as it lets up I'm going to go at it again. I think I'm actually going to start with the fuel lines though. They have been cut and pieced together in several places, so I'm going to replace them with a solid flexible line, i guess. The fuel pump on it now is only a couple months old and has very little time on it because I bought it for this truck. I bought another one the other day, but I'm hoping i don't have to use it and can return it. I guess ill know after i do the fuel lines. Thanks guys!

BTW.. i posted a few pics of the truck on the online garage one this forum is anyone wants to see it. Keep in mind, she is still in the building stages

 

You don't need a passing gear, all you need to do is downshift it manually when needed. Check for kinks in the fuel line, had that happen on my 99 SD F250 after installing an inline fuel filer to bypass the intank filter assembly on it.

 

Well I'm glad you're homing in on the problem. Try disconnecting the line right at the fuel pump outlet and see if you get tons of flow then. If still not, then try putting the pump inlet hose into a container of fuel to see if it flows well.

If it flows well now, then the filter sock in the fuel tank might be clogged. It can be cleaned by removing it, drying it of gasoline and then spraying oven cleaner on it and brushing with a toothbrush, rinsing with warm water (I had a fuel tank with weird sludge on the bottom and learnt all about this).

Be very careful of fire hazards when checking pump flow.

 

From his description, there's no sock in the tank. Just the elbow in the tank bottom.

 

Hey guys, just wanted to give an update and let everyone know i didn't just ditch the forum when the problem was fixed (hate when people do that). I actually broke my hand last week and have been very limited since I'm right handed and it was my right hand that I broke, lol. My father in law is coming up this weekend just to work on the truck with me. So hopefully we get it solved, I will be sure to let you all know. Thanks again guys!