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help! jimmy wont start!!!


black_trucks bump
10-15-2006, 08:42 PM
:banghead: hey i just bought a 1992 jimmy s15 4x4 wit the 4.3 l v6 vortec when i bought it it dident run. just rebuilt the fuel pump and it seems to be working fine i can stick a pen in the pressure testing port and fuel comes out i cant afford to buy a pressure tester and know nobody with one. the spark plugs get spark but its kinda weak and it wont fire up even with starting fluid ive been reading forums for days and its helped me a littel bit but not as much as i need my buddy came over and looked at it and said that the first thing he would do is replace the ignition module (the truck has lik 125000 miles or so) bottom line is ignition module, pressure regulator, polsator, or what what do i do i cant afford to buy anything i dont need somone please help!!! i know theres alot of post on this and iv been reading the shyt out of them and i just cant find nothing that relates to my problem exactly plz help

jammyjim
10-15-2006, 11:23 PM
AutoZone has a lend a tool program. YOu can check their website for a list of tools.

wb8yjf
10-15-2006, 11:37 PM
Bypass that POS pulsator on the pump! Use a piece of fuel line! New pumps usually come with a piece of hose to do just that. Believe me, I just went through this & the new pulsator was the culprit to all of my problems! Borrow a feul pressure (or rent) and hook it to the shrader valve. There is a LOT of info on this site to help you out. Good luck!

black_trucks bump
10-16-2006, 10:44 AM
the problem with that is i dont know what the pulsator looks like thers three metal lines comin from the tank , two of them got a piece of rubber hose inbetween the metal line for like 3 inches or so looks lik a professional job then the third metal line looks like the person before me just swaped out the rubber hose with another and clamped it down on each side, (the metal line going to the fuel filter still has the original rubber hose you know the kind wit nut like things built int to each sid of the hose is this the pulsator?) and it dosent even fire up on me with starter fluid so dosent it have to be somthing wit the ignition system?

JoulesWinfield
10-16-2006, 10:55 AM
When you say the spark is week, have you tried new plugs?
Check under the cap, make sure everything is clean.
When is the last time this thing had a tune up?

I would say the first thing to check though is the fuel pressure. You may have fuel but if its not enough youll never get it to fire.

black_trucks bump
10-16-2006, 11:24 AM
yes, i understand that but even if im not getting right psi it should still fire up at least for a second with starter fluid shouldent it? and it dosent

jammyjim
10-16-2006, 11:58 AM
You really need to check your fuel pressure before you move on. IF your pressure is good, then you move on to ignition. If your getting spark and fuel, you need to check compression. Buy a Chiltons or Haynes or some similar manuel. It will be better than blindly fiddling and will help you to visualize the advice you get here.

BlazerLT
10-16-2006, 03:24 PM
Fuel pressure needs to be checked before anything at all is done. You can get them on loan from some parts stores.

Do you have the TBI engine or the Vortec name plate on top of your engine.

black_trucks bump
10-16-2006, 03:41 PM
i cant find a store that loans one, i just cant get ahold of the tester i just replaced my igniton module and still not fireing , but i just pulled a spark plug and its wet so do this mean im getting fuel to the cylinders? my coil and spark plug wires are all nasty rusted and coreoded inside so could this be the reason for a real weaak spark? oh ya its vortec vin w cpi 4.3 l

JoulesWinfield
10-16-2006, 03:42 PM
yes, i understand that but even if im not getting right psi it should still fire up at least for a second with starter fluid shouldent it? and it dosent
Not necessarily. Your turning the engine over which means any fuel that is in the chamber will get pumped out when the exhaust valve opens up.

[This is just a metaphor, please do not attempt!]
Imagine putting an eye dopper full of gas into a 55 gallon drum. Slim chance its gonna ignite with a little spark. Pour a 5 gallon bucket of gas in there and you better not stand over the top of it.

jammyjim
10-16-2006, 05:27 PM
i cant find a store that loans one, i just cant get ahold of the tester i just replaced my igniton module and still not fireing , but i just pulled a spark plug and its wet so do this mean im getting fuel to the cylinders? my coil and spark plug wires are all nasty rusted and coreoded inside so could this be the reason for a real weaak spark? oh ya its vortec vin w cpi 4.3 l

If your plugs are fouled, It could be weak spark or poor atomization from the injectors. I would replace your coil and plug wires weather or not it is the problem. Rust is bad, umkay.:iceslolan

Edit: Also, low fuel pressure=poor atomization=fouled plugs.

BlazerLT
10-16-2006, 09:06 PM
low fuel pressure = injectors will not spray = no start.

Get the pressure checked and stop assuming what the truck should be doing with low fuel pressure.

Also don't start thowing your money away by throwing parts at the truck hoping it will solve the problem.

black_trucks bump
10-17-2006, 07:37 PM
ok , i thought id update , today i replaced spark plugs,wires,& coil pack all this cost me 42.50 witchis the same price as a pressure tester (so i feel like a dumb ass seing how this did not fix problem ) and it was the last of my money for a couple days.but i dont feel that bad seeing as how i plan on sellin trucik when i get it started and i kept receipts and it will help and as how i bought the truck for $50 from my freind and its in fairly good condition (ecept for the fact that it dont start) so i guess im just gonna wait till i can get ahold of tester. i might pop off the plenum though and chek for washing.

black_trucks bump
10-17-2006, 08:58 PM
ok the 92 jimmy 4.3 l vortec i bought from a freind vin w
4x4 still had this security thingy on it from a second hand dealer ship that dosent car to start if payment is not made welll the car broke down and he made his final payment but never got it in to get the system removed it was tied into the igintion wires under the steering wheel so i ripped it out, well im wondering now if the car still has somthing else they did that i cant see cause it wont get a fire off starter fluid and i just replaced ignition module , coil pack, wires , spark plugs and its just not fireing so what i need is a good wireing diagram so i can check and make sure everything is fine caus the one in chiltons sucks please if ne1 has a ignition wireing dagram post it plzzz help!

JoulesWinfield
10-18-2006, 07:33 AM
Ouch!

Well I wont say it.

What I will say is check the fuel pressure.

JoulesWinfield
10-18-2006, 02:57 PM
Isnt this the same problem from your previous thread here (http://www.automotiveforums.com/vbulletin/showthread.php?t=632282)?

BlazerLT
10-18-2006, 03:36 PM
Does the engine have the Vortec name plate on top of the engine?

black_trucks bump
10-18-2006, 05:32 PM
yes it dose say vortec on top of engine in bright orange and it is cpi, i just pulled off the intake manifold because i figured i would eventually and its not washed at all, all the tubes coming from injector are fine but theres a mix of- looks like oil and fuel sitting at the bottom of the plenum not much but its there. and also that thingy that is on top of the top plenum that seems to be some sort of valve that gos insid the top plenum wont budge is this normal? and the plenum gasket was in three peices - and i still dont know why it wouldnt fire with starter fluid

and yes its kinda the same thing ecpept i want a wireing diagram so i can make sure everythings wired right so i can eleminate that as a reason that it wont run

JoulesWinfield
10-19-2006, 06:08 AM
Well if no one else comes up with one you can try This web site (autorepairmanualcd.com). I bought mine from them and its full of great information as well as schematics. Mine was $25.
But before you spend any money on a new manual, go get a tester for your fuel pressure.

BlazerLT
10-19-2006, 04:07 PM
That valve on the top doesn't control the starting.

You need to check your fuel pressure before doing anything.

wb8yjf
10-19-2006, 08:33 PM
ok the 92 jimmy 4.3 l vortec i bought from a freind vin w
4x4 still had this security thingy on it from a second hand dealer ship that dosent car to start if payment is not made welll the car broke down and he made his final payment but never got it in to get the system removed it was tied into the igintion wires under the steering wheel so i ripped it out, well im wondering now if the car still has somthing else they did that i cant see cause it wont get a fire off starter fluid and i just replaced ignition module , coil pack, wires , spark plugs and its just not fireing so what i need is a good wireing diagram so i can check and make sure everything is fine caus the one in chiltons sucks please if ne1 has a ignition wireing dagram post it plzzz help!
WHOA! Never heard of that thing before! When you ripped it out, how did you get all the wires back where they should be?? Are you getting voltage to the coil pack? BTW, the pulsator is located inside the tank, between the top of the pump & the outlet line. It is a kind of oval looking gizmo. They sell these at Advanced auto parts for about $20 or so. BUT, I replaced mine with a new one & I had a LOT of headaches later. Ended up bypassing that POS with a piece of fuel line & now mine is running. You really need to get a fuel pressure guage and see what kind of pressure you are getting at the schrader valve (located behind the intake manifold on the drivers side). Like was mentioned before, no pressure = no go. I'm really wondering about the gizmo you ripped out though and the resulting wiring....

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