Crank no start with ignition key, with ignition key on and jumping the starter relay truck starts

[MJGenay]

So my '91 is being a little funky. I resurrected an old thread looking for advice when I misdiagnosed the issue and will include that original post down below. Here is what is going on. If I turn the key, let the glow plugs warm, and then crank it just cranks and cranks and doesn't catch at all. I'm getting power to the FSS on the IP. The FSS seems to be working correctly as it clicks if I unplug or plug in the connector. If I jump the starter relay the engine cranks and cranks but doesn't catch. If I turn the key to on and jump the starter relay the engine catches and starts immediately.

Here is my post in another thread where I misdiagnosed this.

Figure I'm better resurrecting this thread than starting a new topic. Trucks been sitting for a few days as the brake booster went out, replaced that yesterday. Went to start it today and it turns over real well but doesn't catch at all. I found the plug (plastic protector broke off) for the fast idle solenoid was sitting on the IP housing. I'm wondering if that could've shorted out my fuel shutoff solenoid? With the key in the on position I am getting power to the FSS. No noticeable clicking or anything except from the glow plug relay. Attempted to call up a few Stanadyne dealers but it's the 23rd and no-one is around. I get fuel spitting out of the Schrader valve when I crank it.

I'm looking at this one: https://www.amazon.com/Injection-Solenoid-26214-Stanadyne-Master/dp/B07KQQ3BTG/ref=sr_1_3?crid=3BVSMS4SVSOWR&keywords=fuel+shutoff+solenoid+stanadyne&qid=1671819603&s=automotive&sprefix=fuel+shutoff+solenoid+stanadyne,automotive,175&sr=1-3&ufe=app_do:amzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc

Anyone have any experience with these?

EDIT: I take that back. The FSS clicks when I unplug it or plug it, I'm just going deaf I guess. I'm going to try to get a friend over to crank the engine when I crack the injector lines.

 

[captain720]

So the truck only starts with key on fender solonoid jump? But the key to “crank” will turn it over but it can’t start? When you are cranking it over with the key does it crank slower or intermittently relative to when you crank it from the fender?

 

[tradergem]

You might want to check the ignition switch that is mounted down on the steering column. They have a nasty habit of partially separating the top half from the bottom half which then causes intermittant connections and starting problems.
If your truck is like my 90 you will have to take the switch out to find the problem.

 

[MJGenay]

So the truck only starts with key on fender solonoid jump? But the key to “crank” will turn it over but it can’t start? When you are cranking it over with the key does it crank slower or intermittently relative to when you crank it from the fender?

Correct that it only starts with key on fender solenoid jump. Correct that turning the key to crank means it cranks well and fast but doesn't catch at all.

When cranking with the key there are no intermittent or slow cranking issues.

 

[IDIBRONCO]

Correct that it only starts with key on fender solenoid jump.

This is how it's supposed to work. If the key isn't on, there's no power to the FSS so the engine will never start. Many people will disagree with me, but in the situation that you're describing, I would use a starter push button. That way, the key will need to be on, but you don't have to turn it to the start position. It should start every time because you're always jumping the solenoid (in a sense).

 

[MJGenay]

This is how it's supposed to work. If the key isn't on, there's no power to the FSS so the engine will never start. Many people will disagree with me, but in the situation that you're describing, I would use a starter push button. That way, the key will need to be on, but you don't have to turn it to the start position. It should start every time because you're always jumping the solenoid (in a sense).

Okay, thanks for the advice. Naturally I'm hoping I can avoid that by fixing the issue but if push comes to shove that is what I will do. By using the starter push button what am I bypassing? I ask as I wonder if that may be my issue.

The neutral safety switch and the clutch safety switch have been bypassed from what I remember seeing. At any rate I can crank the engine over with the clutch out and the truck in gear if I want to.

As I understand it this truck only needs two things to start on the electrical side; power to the fuel shutoff solenoid and to energize the starter. Am I correct in that train of thought?

 

[hacked89]

X2 bronco and to your question the key switch and slider piece that ford changed to plastic is messed up on every brick nose I have. 3 for 3 on the trucks. I push button every one.

 

[hacked89]

Positive side I have enough switches and sequencing that no one besides someone that owns an idi and knows how they function would ever be able to even start it

 

[MJGenay]

You're referring to the that lever inside the steering column?

 

[IDIBRONCO]

By using the starter push button what am I bypassing? I ask as I wonder if that may be my issue.

You're bypassing the actuator lever (as Ford called it) inside the steering column. They have a habit of breaking when it's cold outside. When they break, usually, you won't be able to engage the starter with the key. There's nothing wrong with a starter push button. A lot of people use one. It also adds one more inexpensive theft prevention device, especially if it's fairly hidden and not labeled as "starter" or something similar. That's just one reason why I like to have my glow plugs on a manual control.

The neutral safety switch

Neutral safety switches are only found on automatic transmissions.

As I understand it this truck only needs two things to start on the electrical side; power to the fuel shutoff solenoid and to energize the starter. Am I correct in that train of thought?

Correct.

You're referring to the that lever inside the steering column?

Yes.

 

[MJGenay]

Okay, that all makes sense except the engine is turning over just fine with the key. I don't understand how installing a push button start, to turn the engine over, fixes this. What am I not understanding here?

 

[IDIBRONCO]

Correct that turning the key to crank means it cranks well and fast but doesn't catch at all.

orrect that it only starts with key on fender solenoid jump.

Okay, that all makes sense except the engine is turning over just fine with the key.

What am I not understanding here?

Well according to what you've said here, even though I missed a c on the word correct, your starter works just fine by using the key, but the engine won't start. If you jump the solenoid on the fender, with the key "on", the engine will start. That is what the push button is supposed to help with.

 

[hacked89]

The only slim chance difference is if for some reason the FSS is losing 12v when you turn the key to start vs on. You know the FSS gets 12v and jumper starts the truck. The difference is the start switch circuit.

 

[MJGenay]

Well according to what you've said here, even though I missed a c on the word correct, your starter works just fine by using the key, but the engine won't start. If you jump the solenoid on the fender, with the key "on", the engine will start. That is what the push button is supposed to help with.

Look, I'm just trying to learn here. If you don't mind telling me, I do not understand what is "broken" here. How is that push button any different than what I already have? I have power to the FSS and I am causing the engine to reliably crank when I turn the key? In my mind the key is doing what it is supposed to do (provide power to the FSS and engage the starter). The only thing I can think is when I crank the engine with the key, it cuts power to the FSS for some reason - I haven't had the ability to check this as I need a second set of hands - one to turn the key to "start" and one to measure voltage on the FSS connector.

Are y'all hinting that the "slider" or "actuator" is cutting power to the FSS when I turn the key to start?

I appreciate you telling me that the push button is supposed to help with starting the truck but I do not understand "why", without that "why" I can't fix this.

 

[MJGenay]

The only slim chance difference is if for some reason the FSS is losing 12v when you turn the key to start vs on. You know the FSS gets 12v and jumper starts the truck. The difference is the start switch circuit.

Yeah. That is the conclusion I have come to I just need an extra set of hands to test it.