I am having issues with my 98 Jimmy; first it wouldn't start; my son told me to turn the key on and leave it on for like 5 secs then shut it off; do it like 3 or 4 times then try to start it; it did start that time and ran fine for a couple days; now it won't; all i seem to get is start and immediately die; WILL run so long as u spray starting fluid in it but dies immediately once the starting fluid is stopped; he checked the release valve today and gas shot out; don't know what the issue is....if someone could please give me some suggestions; the pump IS running when u turn the key on but my son says it might still be too weak to give it enough pressure; any suggestions would be greatly appreciated; im on disability and can't really afford to sink alot of money into it but i do need to fix it as it's my only transportation right now

 

Starting fluid should not be used on an internal combustion engine. One spark, or a backfire, and POOF, you have an instant flash fire. Very dangerous and can do serious damage to the engine and YOU. Better to use carb cleaner in a spray can but still dangerous.

Sounds like you have a problem with fuel delivery, you have the classic symptoms.

On 1998 and newer S&T series, there is a vacant terminal in the underhood fuse panel, right next to the fuel pump relay. It is the "pump prime" terminal and the circuit runs directly to the fuel pump.



1. Connect the fuel pressure tester to the service port next to the distributor.
2. Connect a fused jumper wire from battery positive to the pump prime terminal.
3. After the fuel pressure stabilizes on the tester, write it down.
4. Remove the jumper wire.
5. Wait 10 minutes and write down the fuel pressure.
6. Post your results.

If it fails one or both of the tests, there is a problem with fuel delivery. You will need to do some "creative plumbing" to the pressure tester so that it will connect directly to the fuel filter outlet. All pressure and fuel flow must end at the tester.
1. Install the jumper wire as you did in the previous test.
2. Write down the pressure.
3. Remove the jumper wire.
4. Wait 10 minutes and write down the pressure.
5. Post the results.

Depending on the results from all of these tests, it will tell where the problem is, and possibly what the problem is.

 

well so far we have changed the fuel pressure regulator, the spider injector (only cause when the guy was takin it off he broke mine so he put another one on it lol); fuel filter AND brand new fuel pump and it is still doing the same thing - it will turn over, start, then instantly die like something is shutting the fuel pump off. Idk what else it could be; any suggestions would be greatly appreciated...thanks

 

Is the security light in the instrument cluster on or flashing when it starts and runs?

Do steps 1 through 6 of the first set of tests in my previous post. Then post the results here.

EDIT: Do step #2 and see if it starts and stays running with the jumper installed.

 

I don't know my husband said he thinks it just comes on when u try to start it; he doesn't think it 'flashes' the vehicle is actually in a friend's garage cause that's where we are workin on it at out of this nasty weather lol; but i will try that jumper wire tomorrow; will post results when i know something.

 

Security light should come on with the key, stay on for a second or two and shut off.

Do steps 1 through 6 of the first set of tests, then post the results here.

While you're doing step #2, see if it starts and stays running with the jumper installed. Post the results for that as well.

 

Well we went over to the garage this morning and tried the jumper wire and it still won't stay running; don't have the money right now to even 'rent' a pressure tester but a mechanic told us today that it could even be the crank position sensor; idk where this is located or how easy it would be to fix; idk; im takin it monday to get it diagnosed; and as far as the security it comes on and it 'flashes' constantly while the key is in the 'on' position; he is sayin it could cost upwards of 3-500 bucks if it is a security issue; any other ideas of what it could be? Idk where else to turn; help!!!!

 

A flashing security light, when the ignition is in the run position, means that the passlock system has detected a theft situation and has disabled the fuel injectors. The system is probably not recognizing the key. It could be a faulty sensor behind the ignition lock cylinder, which is fairly common, but that's just a guess. It needs to be diagnosed using a scan tool that is capable of accessing the Passlock system data. You can try two things: 1. Use a different key. 2. Disconnect the battery, wait 20 minutes, and reconnect it. If neither of those work, you'll need to have it checked out.

 

Yeah I think that is what it is too but of course i don't understand why it just happened all of a sudden lol; but anyways, if it IS the key issue and the sensor needs to be changed, how difficult is it to change? I really wanna start driving this vehicle again I just don't know what else to do...i thank you for ALL your suggestions...if u didn't notice I keep coming here and posting all I've tried, etc. to get some more input from you...keep the advice coming cause i sure can use it lol...thanks

 

If you determine it is the Passlock. There is a Passlock relearn for your truck for keys that DO NOT have the little square black computer chip on the key:

1. Try to start your truck one time, of course from what has already been stated, that probably won't happen, but it is a part of the relearn

2. Once you've tried to crank it, leave the key in the "On" (some refer to it as "Run") position for 10 minutes. Don't cycle the key back at all just try to start it and when you can't leave the key in the "On" position. Leave it in that position for 10 minutes. At the end of the 10 minutes the security light should stop blinking and go off.

3. After that turn the key to the "Start" position for 3 seconds. The truck won't start.

4. Return the to "Off" for a second or two and then cycle it in one motion straight to the "Start" position and start your truck.

That procedure is supposed to sync up the BCM and the Passlock. Apparently it has a pretty good success rate. Good luck!