Bullnose Enthusiasts Forum

1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Classic

List

Threaded

67 messages Options

1234

sgauvry

1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Gents -

Am working hard to get my new engine to start. Sounds like it wants to kick over but won't. Used ether and it starts for a moment and then cuts out. Did the same process over and over again with the same results.

I am definitely getting fuel to the rail. I also checked to see if I am getting volts to the injector harness and it appears I am.

Pulled one of the injectors out of its hole in the intake and cranked the engine to see if I would have fuel come out of it. I did not. Also pulled the number 4 plug (easiest for me to get to) and it was dry and has zero fuel smell to it.

Ideas?

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

That's confusing - both fuel and power to the injectors but no fuel from the injectors?

As shown on pages 60 & 61, the injectors are powered by the EEC power relay. But them just having power doesn't mean they are being used. The EEC has to ground them to cause current to flow and the injector to open.

So you need to check the tan and tan/white wires that go from the injectors to the EEC to find out if the EEC is grounding them. You should see voltage readings going crazy as the injectors are grounded and then the ground is removed. If not, you need to figure out why the EEC isn't playing along.

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

85lebaront2

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

Just in case, I think I still have at least one of the 1985.5/86 EECs I scrounged up when Matt was fighting with his. Be sure circuit 349 is connected to pin #56 and is seeing a pulse. That is the PIP (Profile Ignition Pickup) which tells the EEC the engine is turning and after it receives the #1 pulse (short pulse) starts firing the injectors.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

In reply to this post by Gary Lewis

So, voltmeter positive lead to the positive battery terminal, and negative lead to the tan wire?

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

That would work. Or use a test light.

Gary, AKA "Gary fellow": Profile

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Yes. There are two tan wires on the connector that go to the injectors. I am assuming I can use those to check. When probing those, I get very erratic numbers while cranking the engine.

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

Each injector should have two wires - a red for power and either a tan or a tan/white that goes to the EEC and is grounded by it. Red should be the same as battery power when the key is on - within a few tenths of a volt. And the tan or tan/white wires should go from battery voltage to almost ground (.7v) and back very quickly.

The rapid changes will confuse your DVM, which is why a test light is better - it'll flash.

Anyway, if you are seeing the voltage go all over the map then it looks as if the computer is telling the injector to fire. So, if you don't have gas then you must have low/no fuel pressure.

Gary, AKA "Gary fellow": Profile

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Yes. There is power going to the injectors and there is ground. Fuel gauge reads over 60 and I know that fuel is getting through the rail.

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

Strange. I'm lost as it would seem that fuel has to come out if you have power, the negative side is getting grounded, and you have fuel.

Hmmm, what if your "power" isn't good? What if you have 12v when no injector is being told to fire, but that the power goes way down when an injector tries to fire? Can you put your DVM on the power going to the injectors and the other lead to ground, and then crank it? Watch the voltage and see if it stays up fairly high, or if it goes way down. A bad connection somewhere between the EEC relay and the injectors would do that as you'd have 12v when no current was being drawn but much less with current.

Gary, AKA "Gary fellow": Profile

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

In reply to this post by 85lebaront2

So I did a few tests for my TFI module. (1) was for volts, (2) was for ground, (3) was for the ignition coil switching. And since the first three tests were as they should have been, I did not do test 4, which is for the PIP signal.

If I do the PIP signal test while probing the number 1 circuit wire on the TFI, will that suffice as a test for what you are referring to?

Steven A. Gauvry - 1985 F150 5.0 EFI

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

In reply to this post by Gary Lewis

Yes. Voltage starts at 12.4 and when I crank it, drops to 10 and under.

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

10v during cranking isn't too bad. The drop is due to the starter's load, and the injectors should be firing if the other side is taken to ground.

At this point I would probably pull a connector from an injector that's out of the manifold, and carefully put 12v to one side and, with fuel pressure showing, ground the other side of the injector. You should get a shower of gas, which is kinda scary given you are playing with 12v, so do you connection/disconnection to ground well away from the injector. Or, you could connect/disconnect the power instead of ground.

If your fuel pressure stays up after cranking you should be able to do that test w/o turning the key on. But getting power and ground to the pins on the injector w/o them touching each other may be very difficult. However, you need to have the computer disconnected to ensure you don't cause a problem w/it, so the wiring has to be off.

Gary, AKA "Gary fellow": Profile

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Thanks, Gary. I will do this, but it'll have to be tomorrow. I will let you know the results.

Steve

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

Good luck. And you might have to crank the engine before you do it in order to get fuel pressure up.

Gary, AKA "Gary fellow": Profile

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

This post was updated on .

Thanks, Gary -

I was thinking about my injector harness. Page 61 of my EVTM shows one connector (C160) that travels to two splices (S140, S141). Connector C160 is on the drivers side of the vehicle as is S140 and that side of the harness controls injectors 5 - 8, whereas S141 is on the passenger side of the vehicle and that side of the harness controls injectors 1 - 4. As far as S140 and S141 are concerned, I have them placed on the correct sides of the engine.

But what about the individual injectors and their connectors? Is there a precise order in which I must have them connected? If there is, this may be my problem.

When I put the injector harness on, each of the connectors pretty much naturally laid in a certain position and I connected them as such.

It looks like it matters because all T/OD injector wires run to pin 58, and all T/RD injector wires run to pin 59. I think I'd better look at these before I do anything else.

Steve

Steven A. Gauvry - 1985 F150 5.0 EFI

Gary Lewis

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

That's an easy answer - Page 61 shows where each injector goes: 1 - 8. But, in reality there are just two sets of injectors since your engine is "bank fired". One set (1, 4, 5, & 8) has the tan/orange dot wires. The other set (2, 3, 6, & 7) have the tan/red dot wires. So, as long as you have the right color wires going to the right cylinders you are good.

But, even if you put the wrong wires to the right cylinders you'd still be getting gas out of the injectors. And, it is likely the engine would try to run, if not run albeit poorly. So I doubt that's the problem.

Now, your post set me to thinking, and C160 is the easy way to test things. Disconnect it and on the part going to the injectors you can put power to the red wire and then take either the tan/orange dot or tan/red dot wire to ground. And you should have gas out of 4 injectors, although just proving that you get gas out of one of them should be enough.

Gary, AKA "Gary fellow": Profile

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

OK. Thanks!!

Steven A. Gauvry - 1985 F150 5.0 EFI

sgauvry

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

In reply to this post by Gary Lewis

In various diagnostics tests it was shown that I had spark going to all of my cylinders and everything was pointing to a fuel delivery problem. Initially, the pumps were not working but that issue was fixed. Still, no fuel.

In conversation with Vinny it was discovered I had my fuel intake line connected to the fuel return tube on the fuel rail and the fuel return line connected to the fuel intake tube on the fuel rail. That mistake was in part, due to an erroneous diagram I found online, and in part due to my bad memory and lack of understanding regarding this specific fuel rail. Here's the diagram:

In the diagram you'll notice that #6 is listed as the fuel injector supply. That is incorrect and explains why I was not getting any fuel. In fact, the fuel injector supply is on the opposite side of the fuel rail.

I reversed the fuel lines. Now there's plenty of fuel getting through the injectors to the combustion chamber. In fact, too much fuel is getting through to the chambers as it is flooding out and preventing the starting of my vehicle.

In disconnecting my fuel relay, draining fuel from the lines, and adding ether to the throttle openings (about a 3 second squirt into each opening) the engine fires up. With the relay plugged in, the engine will not start. Going through the process of disconnecting the fuel relay switch again, draining the fuel from the lines, and using ether to start the engine, it again fired up. I did this about 8 times with the same results.

At one point, while I had the engine running due to an ether start, I plugged in the fuel relay with it running. I know I shouldn't do this, but under the circumstances I wanted to see what would happen once the engine got fuel. Well, the engine immediately stalled. I then tried to start it with the fuel relay plugged in and it would not start.

With the fuel relay plugged in and when turning the ignition to the on position, the fuel gauge reads at 34. That's about right. The fuel injectors were tested and they are indeed squirting fuel. The plugs smell of fuel and are wet. I can only conclude the engine is flooding out with fuel.

Sometime this week I will pull the injectors, get the model number, and post it for your review. Possibly I have the wrong injectors. Before I buy a new set of 8, I'd like some feedback to determine if the injectors I have are too much for my little 302.

Thanks!!

Steve

Steven A. Gauvry - 1985 F150 5.0 EFI

NotEnoughTrucks

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Steve, I recall a picture somewhere of spiffy new injectors on your engine, but darned if I can find it now?

What size injectors are you using? Are they leaking even without the ground? They should seal off tight when not actuated.

85lebaront2

Re: 1985.5 F150 5.0 EFI - Problem with fuel through injectors?

Administrator

In reply to this post by sgauvry

Steve, two suggestions, with the injectors (I would just do the driver's side) lifted up out of the manifold and the wiring harness unplugged, see if the injectors are spraying with the key on, if not, then you probably do not have an injector problem, if they do, unplug the individual injector connections and try the same test, if they do not, then it is wiring related. Second, same test again with the harness plugged in, if they spray continuously, then you have a wiring problem between the plug and EEC. Disconnect the EEC and repeat, no spray, EEC is kaput, spray, start looking for a ground in the two injector group wires, tan with a red dash and tan with an orange dash. Good luck, these are the kind of things that will drive you nuts.

Your injectors should probably be orange top and are 19#/hr, those are used on 5.0 and 5.8L engines and a lot of the later Mod motors.

Bill AKA "LOBO" Profile

1234