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1985 f150 running issue while driving

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Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

I agree with you, Jim. But does he really have all of those problems or just one major problem, like the ECM going bad? We need to somehow diagnose this a bit better before he starts throwing money at it - like a new fuel pump.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

I saw you say that in post 5, but I don't know if he has a noid light, or can diagnose a pip signal.

The struggle continues...

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

kyleroth48625

Re: 1985 f150 running issue while driving

In reply to this post by ArdWrknTrk

To unhook the computer I took the 10mm bolt out the center and pulled the whole plug off it. And wire collor is just strait brown

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

kyleroth48625

Re: 1985 f150 running issue while driving

Would a noid light work on the coil power we always used them on efi injectors

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

It would show the ground pulsing, yes.

Why don't you just get an HEI style one wire Dizzy?
Cheap & simple.

How are the fuel pumps running without a computer?

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

kyleroth48625

Re: 1985 f150 running issue while driving

I've never seen a one wire DISTRIBUTOR for a 300 6 and it has a on the frame aftermarket replacement for the mechanical pump that would be on the block. Runs on ignition hot from an oil pressure switch. The computer only controls the timing and something on the carb

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

All you need is compression, fuel and a consistent spark with advance, right?

https://swperformanceparts.com/HEI028BK/

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

In reply to this post by kyleroth48625

I'd guess you need two wires if you have a tach.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

kyleroth48625

Re: 1985 f150 running issue while driving

In reply to this post by ArdWrknTrk

So I took a gamble and threw a fuel pump at her local auto value had a Holley pump for 50 bucks. It started a heck of a lot better made it down the road 50 feet and it blew the fuse found that the choke heater must be shorted out because they share the same power source unhooked that and she has power now up to 4000 so fuel was my problem the old airtex pump was 8 years old must have been giving up on me or the choke short was giving it greif gonna hold on to the old pp for a spare. So now on to the ignition of there is a diagram for the ignition and what all the wires go to in the splices it would be much appreciated.

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Yippee! Progress!

As for the wiring diagram, you need to learn how to use the menu to the hidden gems on the website.

If you go to Electrical/EVTM/1985 EVTM you'll see the contents of the 1985 Electrical & Vacuum Troubleshooting Manual, which has all of the wiring diagrams for the 1985 trucks. If you click on Start & Ignition (Gasoline Engines) you'll find the ignition diagrams, including this one:

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

This post was updated on .

In reply to this post by kyleroth48625

Glad to hear you've figured it out!

And that it was just a cheap replacement.

Your ignition curve is controlled by a bunch of sensors, and the lookup table is in the EEC.
Short of a working computer, options are limited.

So once again you're looking at either a DSII conversion, or a one wire Dizzy
Both of these use mechanical + vacuum advance.

***I see a non-feedback YF in your future.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

kyleroth48625

Re: 1985 f150 running issue while driving

So found part of my problem again the old girl started running like crapp and stalling. Found small leak in gas tank under strap while trying to find the problem dropped the tank and it had a mystery white sludge looking material floating through the gas not sure what it was but pretty sure it was vandalism so ended up using a new tank I had for a 95 but the carbed pick up would not work with it had to gut the efi pump to hooked the pickup to the straw where the efi pump was now having a prime problem with the pump keeps getting louder and truck dies does anyone know how those pums worked

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

kyleroth48625

Re: 1985 f150 running issue while driving

In reply to this post by ArdWrknTrk

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

kyleroth48625 wrote

So found part of my problem again the old girl started running like crapp and stalling. Found small leak in gas tank under strap while trying to find the problem dropped the tank and it had a mystery white sludge looking material floating through the gas not sure what it was but pretty sure it was vandalism so ended up using a new tank I had for a 95 but the carbed pick up would not work with it had to gut the efi pump to hooked the pickup to the straw where the efi pump was now having a prime problem with the pump keeps getting louder and truck dies does anyone know how those pums worked

I'm sorry, but I can't make heads or tails of your post. I think I understand that you found "stuff" in the tank so you used another tank you had for a '95. But then the fuel pickup for the 300, which has a carb, would not work with the '95 tank - because the opening in the '95 tank was too large for the 85's sending unit?

So you gutted the sending unit/pump combo that was for the '95, presumably by removing the pump. And about there I get lost. You say you "hooked the pickup to the straw". Do you mean you hooked the fuel hose going to the engine-mounted fuel pump to the tube sticking out of the 95's sending unit?

And then the pump "keeps getting louder and the truck dies". Is that the engine-mounted pump?

I hate to ask all of those questions, but what you typed does not make sense to me and I don't want to start problem solving until I understand what the problem really is.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

I think he means he put the 'sock' on in place of the EFI pump.
But this means he has a four pin connector on top of the tank where he needs a two pin for just the sender, and the resistance OF the sender would be all wrong for '85 .

Maybe there is an air leak and the pump can't get prime?
Running dry will cause it to be loud.
I don't know if his Holley pump is impeller or check valve style.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Wouldn't he have an engine-mounted mechanical pump?

And if the sock went in place of the EFI pump, wouldn't it be too high?

As for he sender, I wasn't going to worry 'bout the gauge - yet. Yes, it'll be upside down and backwards.

Gary, AKA "Gary fellow": Profile

kyleroth48625

Re: 1985 f150 running issue while driving

I hooked the fuel line to the original pressure line port on top I plugged the return line to keep debris or watter out sealed that part good. Inside I took the pump out and broke the plastic so I could get at the bottom of the pressure line hooked that to the pipe inside the unit that goes down to a sqaur box on top of the sock where the sock meets the bottom the pipe was originally on the side by the pump I assume it's a pick up for the pump when the bowl is dry so it should have good suction but like I said it runs a few minutes and looses prime I have a Holley diaphragm pump that ticks when there dry silent when full

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

Gary Lewis

Re: 1985 f150 running issue while driving

Administrator

Well, there's probably the problem - you can't pump for long from a sealed container. And by plugging the return you have a sealed container. The pump pulls some fuel out, which creates a vacuum, and no more fuel comes out.

Pull the gas cap and try running it with the cap off. If that fixes it then you've found the problem.

Gary, AKA "Gary fellow": Profile

kyleroth48625

Re: 1985 f150 running issue while driving

The vent in the top of the tank is open and working also the cap is off I'm wondering if the opening in the straw is to small it looks bout the same as a 5/16 line or if it doesn't go all the way to the bottom of the pump housing. Going to try adding gas this afternoon I put four gallons in from a dry tank. And I wired the sender into the factory harness the four wire is a solid conectors not removable gauge works as it should shows just over e

My trucks are a 1985 f150 with a 300 6 4 wheel drive I also have an 84 f150 with a 351w not really working on that one right now mostly the 85

ArdWrknTrk

Re: 1985 f150 running issue while driving

Administrator

The gauge shouldn't be able to work unless you swapped senders.

Bullnose to later trucks have completely different scales and read in reverse as well.

Supply should be 3/8", return 5/16.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

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