98 Jimmy cranks, won't start - S-10 Forum
S-10 Forum is the resource on GM S-series trucks, Suspension, engine information, Body Modifications, painting tutorials.  Modifications to suit every need, budget and whim

98 Jimmy cranks, won't start

Go Back   S-10 Forum > Specific Model Forums > 2nd Gen Forums > Blazer / Bravada / Jimmy / Envoy
New User? Register Forgot Password


 
LinkBack Thread Tools
Old 11-08-2010, 03:31 AM   #1
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
98 Jimmy cranks, won't start

1998 Jimmy 4 dr 4wd worked fine. Parked it yesterday. Today it was a little hard to start, then I moved it over a few feet on the driveway. Two hours later it would crank but not start.

Fuel, air and spark... I've read all the posts on here I could find. Here is what I plan to do, but I have questions. If yuo can answer any of the questions, thanks in advance.

1. I will turn the key on and listen for the fuel pump.

2. I will try to start it with some starting fluid. WHERE DO I SPRAY IT IN? If you could refer me to a picture, that's be great.

3. WHERE is the fuel pump fuse, under the hood? Is this the same as the ECM fuses?

4. If I need to check the fuel pump relay, WHERE IS IT, and can I swap it with another one (which one)?

5. One post said to check the fuel pressure, there is a valve stem on the fuel line back by the driver's side of the distributor. Can anyone point me to a PICTURE?

6. Where is the FUEL FILTER?

7. How do I check if the INJECTORS are pulsing?

8. Can I check SPARK by clipping a timing light to a wire? Or can I pull a wire and hold it near a metal engine part while cranking it over?

9. Where is the CRANK SENSOR? Where is the CAM POSITION SENSOR? How do i check them, if needed?

10. If I end up replacing the fuel pump, I'll probably cut the hole in the floor to get to it. Dropping the tank sounds like a disaster. Any PHOTOS or measurements? There's one thread on here that points to some photos, but the poster never followed up with measurements. They listed http://store.getgmparts.com/fuel-pumps.html as having good fuel pump prices, but I don't know what part number.


Any other ideas?


THANK YOU IN ADVANCE!!!
Old 11-08-2010, 06:47 PM   #2
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
98 Jimmy FUEL PUMP

UPDATE

No fuel pump sound (opened gas cap to relieve pressure, key on--nothing).

Zero fuel pressure at fuel valve stem on fuel line going into throttle body.

Engine starts on starting fluid and runs as long as fluid is sprayed in throttle body. When spraying is stopped, engine stops soon after.

Checked the fuel pump fuses and relay by swapping them with others--all good.

I don't think it's the fuel filter, because I have no fueld pump sound at all.

NEW QUESTIONS

How do I check if there is power at the fuel pump? I realize the pump is inside the tank and is accessed through the top of the tank. If I have to replace the pump, I haven't decided yet if I will drop the tank or cut a hole in the floor. I see from the parts diagrams that there is a fuel pump wiring pigtail with a plug on it. Where does this plug sit--on top of the tank, alongside the tank, or...? Am I able to check for power before I drop the tank or cut the hole?

Where should I buy the fuel pump? Prices are all over the map!

THANKS!!
Old 11-08-2010, 07:07 PM   #3
i saw what you did there!
 
fast68chevy's Avatar
 
Age: 36
Join Date: Sep 2002
Posts: 3,571
Location: Lincoln IL
User is: OffLine
Re: 98 Jimmy cranks, won't start

jump orange and gray wires at oil switch plug or relay socket plug

orange wire shoul dbe hot all times


see if 12 volts in gray wire at connector by tank
Old 11-08-2010, 11:03 PM   #4
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

Thanks for the reply, fastr68.

Can I get at the connector by the tank before dropping the tank?

Do I understand the following correctly? The fuel pump relay runs the pump for maybe 3 seconds when the key is turned on. Then when the engine is cranking, the crank sensor tells the same relay to run the pump.

In addition, there is a separate way the fuel pump is run--the oil pressure switch--when there is about 4 psi or more of oil pressure, the oil pressure switch turns on the fuel pump (independent of the fuel pump relay?).

I think the oil pressure switch is behind the distributor. I'm not sure how easy it will be to get back there to jumper the orange and gray wires at the oil switch. It seems it would be easier to remove the relay and jumper the two sockets corresponding to the orange and gray wire there--but how do I know which two sockets those are? There are 4 sockets for the relay.

Since my engine runs on starting fluid, but does not keep running when the starting fluid stops spraying, then the oil switch is not successfully running the fuel pump, right? So this is not a question of the relay or oil switch being bad. It's a question of whether or not power is getting to the pump, or if the pump itself is bad. Correct?

If I have tio replace the pump, should I drop the tank or cut the hole? The truck is 12 years old with 137k miles, midwest winters so plenty of corrosion due to road salt.
Old 11-09-2010, 06:22 PM   #5
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

I looked for the fuel pump test connector, "usually found on the driver's side of the engine compartment (on or near the fender), with a single wire (usually red) leading from the relay to the connector".

I couldn't find it. Should I have one?

I cannot find the oil pressure switch, either. Help!
Old 11-10-2010, 05:59 PM   #6
Registered User
 
Calvin51's Avatar
 
Join Date: Dec 2007
Posts: 269
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

Before you do all of that, do one simple thing. Swap out the coil wire. THe reason I say that is that we were driving up the road and my Jimmy died. It showed all symptoms of a bad fuel pump plus my gas gauge was also non functional. After dropping $350 on a new fuel pump, we took it around the block and it died. The coil wire shorted out on the heater hose. The heater hose was wire reinforced and the coil wire laid on top of it until a very small pinhole developed in the coil wire. A simple check but way cheaper than a fuel pump
Old 11-10-2010, 06:53 PM   #7
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

Thanks for the reply, Calvin51. I looked at the coil wire and don't see any obvious problems. I realize you can't always see that kind of thing. But the engine starts right up and runs if I am spraying starter fluid into the throttle body, so I think the ignition system is OK.
Old 11-14-2010, 09:00 PM   #8
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

Still working on getting access to the top of the fuel tank. Have to siphon out the fuel per my other post. I still have no idea if I'm getting voltage at the fuel pump. I guess the only place to check is the connector at the rear top of the tank? I hope to be able to access that with the spare tire out, before trying to drop the tank, which I don't want to do if it's a wiring problem.
Old 11-17-2010, 11:33 PM   #9
Registered User
 
GreenEnvy's Avatar
 
Age: 34
Join Date: Aug 2010
Posts: 48
Location: Bergen County
User is: OffLine
Re: 98 Jimmy cranks, won't start

To make sure it's not the pump, try this first... kick the bottom of the gas tank or hit it forcefully with a "RUBBER" mallet. Don't try to put a whole in it, but give it a good whack, then try and start her. Every time my fuel pump was the issue (3 times - IMO don't buy anything but dealer for the fuel pump,) I kicked the tank and she started, just enough to get me home.The embarrasing part of my story... a die-hard carb guy told me about this.
Old 11-18-2010, 04:30 AM   #10
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

Thanks, GreenEnvy, after reading a lot of posts about this, I had tried that. I whacked the plastic tank many, many times as hard as I dared with my rubber mallet, on the side, on the bottom right below the pump, all over. No joy. I need to check the ground again to make sure it isn't the problem.
Old 11-22-2010, 01:45 AM   #11
Registered User
 
Join Date: Jan 2009
Posts: 89
Location:
User is: OffLine
Re: 98 Jimmy cranks, won't start

The ground wires in the fuel pump electrical connector are good. Getting 10.6V at the fuel pump contact. Not sure why that isn't 12V+.

Still working at dropping the tank. Fuel line clips are a problem (have a different thread on that). The rusted band hardware is a problem. Would still prefer siphoning the gas out if I can somehow get the fill or vent hose off.
Sponsored Links
Advertisement
 

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the S-10 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 02:21 PM.

Powered by vBulletin® Copyright ©2000 - 2011, Jelsoft Enterprises Ltd. SEO by vBSEO 3.2.0
SEO by vBSEO
vBulletin Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.