Starting problems and cutting out

[Aragorn]

86 2.9:
My 2.9 recently has been hard to start. It cranks fine and sounds like it always has when you turn the key, but once you let go, it dies. It usually takes between 2 and 4 cranks and then it just decides to work.
The scary part is, on occasion the engine will suddenly cut out. It has happened 3 times, each one the second I hit a big bump or pot hole.
It has absolutely no problems accelerating, idling, or just keeping speed. Only starting and when it hits a large bump.

The starter is new (but that obviously isn't causing the cutting out).
The canister fuel filter is about a year old.

My prediction is a fuel delivery problem, which could be completely wrong. It seems to me like it can't get enough gas when starting, and it may be having the flow interrupted when I take a major bump. If this is the case, I don't know what to look into (fuel pump, filter, injectors, etc.).
Thank you guys so much for any help you can offer.

Nick

 

[martin]

If it dies suddenly the problem is more than likely an electrical connection somewhere. While its running try shaking the wires to try to narrow down the area.

 

[kunar]

check the fuel inertia shutoff switch. it is on the floor under the pass. side dash and seems to like to cause problems. check it by jumping the connection but dont leave it as a permanent fix if that works, always fix it right because it is, after all, safety equipment

 

[Aragorn]

ok, i've checked the inertia switch and much of the electrical. I think I'm going to try the fuel pump relay I read about as a common cause of this problem on another thread.
Question is, there are two relays that look exactly the same next to each other, one with five wires, one with four. Does anyone know which is the fuel pump and what the other is?

 

[Natedog]

Dont remember what the other solenoid is for at the moment. My factory manual says what they are, but I don't have it handy. Unplug one at a time and then turn the key to 'run'...don't crank the engine, and listen for the fuel pump running and pressurizing the system. Whichever one is unplugged when the pump doesn't run during this test is the fuel pump solenoid (relay).

 

[rickcdewitt]

did you try pulling codes?

 

[Aragorn]

I was messing around under the hood again today. With the engine running, i tapped on the relay I presume to be for the fuel pump. The engine began to sputter and hesitate.
BINGO! ...i thought.
I replaced the relay, which is the dark one, not the green one. Started the engine, and it ran on the first try. I thought I was golden. Went to drive it again tonight, and it took about 3 or 4 tries.
I'm confused as to how replacing the part causing the engine to sputter didn't help the problem.

No, I haven't pulled codes. Don't know how to go about that. Thanks for your help and replies

 

[Aragorn]

Geez, doing 50 on a 6 lane road and hit uneven pavement. Truck died. This is so frustrating. I've been talking to some people and a few think it's electrical, and some fuel. Do parts stores generally pull codes for free?

 

[Psychopete]

I replaced the relay, which is the dark one, not the green one.

For some reason I recall the fuel pump relay being the green one, and the PCM relay being the brown...

No, I haven't pulled codes.

http://www.troublecodes.net/Ford

You will need to follow the volt meter method, as the '86 lacks a CEL.

I had a similar problem, except is was the coil positive wire. It had corrded out, I imagine you might be having the same wiring issues. Say the engine is just idling, running okay, what happens when you drop the hood or shut the passenger door pretty good? To me, it kind of sounds more like it's more electrical than fuel. If you can get the problem to happen again, you might get a fuel pressure tester and see what's happening there to rule that out at least.

Pete

 

[kunar]

For some reason I recall the fuel pump relay being the green one, and the PCM relay being the brown...

pretty sure you are right (had similar problmes on mine about a year ago) and im pretty sure the replacement that autozone sells you will work in either situation. pull the new one out and put the original back, then use the new one for the fuel pump and see what you get

also would be a good idea to check fuel pressure...even if you dont have a gauge, see if you have any pressure at all. if the pump isnt working than there wont be any pressure

 

[AllanD]

Also check the ground connection next to the PCM behind the passenger side kick panel.

a loose ground to EITHER the EEC power relay or the fuel pump relay will cause an identical problem.
Ever REAL ranger enthusiast should have the words "check the grounds first!" tatooed on their forearm

AD

 

[alllw88]

Found this info on an intermittent Ranger...... maybe your problem too?

http://www.asashop.org/autoinc/dec2002/techtotech.htm

 

[Aragorn]

For some reason I recall the fuel pump relay being the green one, and the PCM relay being the brown...

That very well may be true. The reason I changed out the brown, not the green, is because the brown was the one that, when tapped, stalled the engine. Maybe I should do both of them?

also would be a good idea to check fuel pressure...even if you dont have a gauge, see if you have any pressure at all. if the pump isnt working than there wont be any pressure

Now how to I do this?

Also check the ground connection next to the PCM behind the passenger side kick panel.

Will it just be a black wire bolted to the body? I should know since I've had the kick panel off a dozen times.

Thanks for your replies!

 

[96stroker]

I had the same symptoms as you with it taking 3 - 4 times to start the truck and have it stay running. I fought with this for better than six months! I thought it was because I had a hole in my gas tank(and I'm sure that was part of it) but when I had the tank down the pump in the tank turned out to be bad. After I replaced that($50 at Autozone) the thing runs great. Somehow these trucks can run off just the pump on the frame rail. One way to check the pump in the tank is to have someone turn on the key while you have your ear close to the tank. You should be able to hear the pump kick on for about 2 seconds then shut off. Hope this helps

 

[IMenriched]

I had the same symptoms as you with it taking 3 - 4 times to start the truck and have it stay running. I fought with this for better than six months! I thought it was because I had a hole in my gas tank(and I'm sure that was part of it) but when I had the tank down the pump in the tank turned out to be bad. After I replaced that($50 at Autozone) the thing runs great. Somehow these trucks can run off just the pump on the frame rail. One way to check the pump in the tank is to have someone turn on the key while you have your ear close to the tank. You should be able to hear the pump kick on for about 2 seconds then shut off. Hope this helps

Agreed! another thread also ran to this issue (Starving For Fuel? ) where they thought that the fuel filter was the issue...but ended up with lots of foamy fuel in the injector rail/manifold. hence the pick up pump was bad...(in the tank)

IS your fuel gage screwy??? read pretty normally till 3/4's of a tank then drops off to E quick, then come back up??