Gear selector silly question

[Dariusz Salomon]

Hi guys(99 Tahoe)-I read somewhere(someone mentioned) that if the selector is not properly in P(due to malfunction/wear) the truck will not start. What is causing it-is there a switch of some sort,connector,that has to close the circuit or what?
And if it's electrical,then what are the symptoms-what does it affect-a pump or ecm or what? Is it,that there's no crank at all or crank no start-what exactly is happening in such situation?
I'm trying to better understand the truck. Thanks in advance.

 

[stutaeng]

The park neutral safety switch maybe? I you remove that switch to drop your transmission and get it clocked off a bit on re-install(or damage it) the truck won't start because the ECU thinks the gear is R.

 

[Dariusz Salomon]

The park neutral safety switch maybe? I you remove that switch to drop your transmission and get it clocked off a bit on re-install(or damage it) the truck won't start because the ECU thinks the gear is R.

Yeah-that's probably what I mean-so what will be the symptom of it? No crank at all?

 

[HotWheelsBurban]

Yes, the system is set up to only allow cranking in Park or Neutral. The linkage in the steering column gets a little slop in it too,after 20+ years....
The indicator often doesn't show the right gear, so we know it's in OD when the shifter handle is at 3 o'clock. And count clicks for all gears....

 

[someotherguy]

Yeah-that's probably what I mean-so what will be the symptom of it? No crank at all?

Maybe ask from the opposite direction - what exact symptom is your truck having?

Richard

 

[Dariusz Salomon]

Pump not priming sometimes-old story. It gotten more serious recently. Result is crank not start. I'm trying to understand all ways affecting that kind of fault and eliminate one by one before I tear into the pump and pigtail. But also I'd like to know more.

 

[454cid]

That sounds like a fuel pump issue....or the electrical circuit for it.

 

[Ed Hardy]

I can say is not the neutral safety switch what can I say that is rewarding? She fired for the first time in over a year without pouring fuel Down her throat! If I could just keep it up that would be even better news wouldn't it? The problem is that she blows the fuse every time she does it. But, I think it's a step in the right direction. What did I do? what did you do ? what everybody what did he do ? well I'll tell you, take it easy.
-I ran a ground wire from the battery to the blue wire of the injectors-
So there's your answer to are the fuses getting grounded? what happens? Shock to me too! I know! NOW, I have to state this: this was not how I was told to do it this was just something I just pulled out of my own……er, hat. It was that “are your fuses getting grounded” just kept bouncing around inside my skull and I could make sense of it I've always found them to pop every time I'm grounded one out but I figured everybody was screaming at me and pointing the right direction. hell I'll give it a shot. I know what you're saying, I was a little literal answering the question, but i got this amazing feat to happen, it's amazing to me anyway to hear it run again. NOW how do I keep it running and not blow fuses , I guess would be the next question in line. So how do I do it? I was looking and researching and found something on YouTube, I know, but, code 42. I took a picture of the screen of the chart that he had and a shot of the description of it. Ive printed them out and I just read them over and over and over trying to make sense of it but it just seems like it fits the bill. The guys description of his ailments kinda fit the bill but not entirely. Again I don't have scanner, I have that GM/amazon OBD I tester that only spits out 12s. And I've never seen it spit out a 42 just to be clear. Honestly it's been a dust collector in one of the drawers of my toolbox ever since I read the book, useless. (you got a fix it befor your use it?) Place all responses, remarks and insults below. If I knew getting insulted would fix my truck I would've been chastising people long ago! Sorry Shirley, you did help me. The unfortunate thing for me is I didn't piss off the right people until the other night, I do that on a regular basis. (I have a knack) I should've started with Shirley first He at least knew how to fix my truck. HA!

 

[stutaeng]

Hook up a fuel pressure gauge and check for pressure when it cranks, but not fire up.

 

[Pinger]

My 1999 'Burb won't crank if in anything other than P or N.
Cranking but no start is unlikely to be selector IMO.

Pump not priming sometimes-old story. It gotten more serious recently. Result is crank not start. I'm trying to understand all ways affecting that kind of fault and eliminate one by one before I tear into the pump and pigtail. But also I'd like to know more.

What are you basing your 'pump not priming' diagnosis on - lack of sound (where you can normally hear it - unlike my 'Burb where the tank is so far back)? If so, thoroughly check the wiring. On mine, the pump had been replaced and the pigtail was connected poorly with crimps. From memory, your Tahoe has the tank forward of the axle - but the same could have happened.

The other thing that caused me no-starts was a stuck fuel pressure regulator. When we run on LPG the FPR will be wide open returning all the petrol to the tank. That I think makes them prone to sticking wide open and negating the pump's ability to hold pressure for starting (though it'd be useful to know if the prime is stopped after X amount of time or when pressure has built). You can check this by turning the key to prime then depressing the pintle in the pressure test port. If there's a dribble there then the pump took fuel up from the tank. Repeat to check.

NB a healthy pump and FPR will squirt fuel from there and it will land on the dizzy - do not attempt with a hot engine or attempt a start if this happens.
No fuel whatsoever - not even a dribble - says pump not engaging.