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check gauges light and now no start

52K views 8 replies 5 participants last post by  nlynd1978 
#1 ·
Howdy all,

My ex's 1999 Grand Cherokee has the "check gauges" light on and now it won't start.

It turns but won't kick over. Sounds like no fuel or no spark.

We replaced 2 bulbs in the dash yesterday and she drove it home but this morning it won't start.

Thanks.
 
#2 ·
Howdy all,

My ex's 1999 Grand Cherokee has the "check gauges" light on and now it won't start.

It turns but won't kick over. Sounds like no fuel or no spark.

We replaced 2 bulbs in the dash yesterday and she drove it home but this morning it won't start.

Thanks.
so did this happen after you replaced the 2 dash bulbs? Which bulbs in the dash?

Anyways, if you have a code reader see if there are any pending codes.

Shoot a light spray of throttle body cleaner or starting fluid in the throttle body while turning over to see if you get any kind of firing. If it begins to run then you've got a fuel issue.

Saftey First! Be very careful:
Check for fuel pump pressure by placing a cloth in front of the fuel rail schrader valve on fuel rail. Remove cap & slowly depress the valve pin to release pressure. If no pressure comes out then you may have found your problem.

edit: creepingdeath is correct...low pressure will cause hard starting as well so it would have to be a good spray of pressure coming out to rule out the fuel pump/check valve/filter-regulator. This is only for a quick rough check and as creepingdeath said a guage is the best way to go. Again, this can be very dangerous!
 
#3 ·
In order to check fuel pressure, you will need a gauge from somewhere. While it may come out at the depress of the shraeder valve, it may be low and not enough to fire injectors or something. It is just better to have the gauge to know exactly what pressure you have or you may ed up doing/checking things twice. Motors need only a few things to run...compression, fuel, air, and spark. Spark would probably be easier to determine first. Starting fluid is easy enough to try as well.
 
#4 ·
Thanks for the replies. Really appreciate it.

My ex found a mechanic that seems to know Jeeps pretty well and charges a highly reasonable rate - she used to go to the dealer and get screwed.

Turned out to be the fuel injector sensor.

Thanks again.

Tushy
 
#5 ·
Turned out to be the fuel injector sensor.
Just curious?
What do you mean by sensor? The PCM's injector driver can "sense" when an injector is not working by what the voltage drop is during the pulse. There will be a certain voltage drop when the solenoid is actuated properly. If it doesn't see this it will throw an injector code.
 
#6 ·
No such animal..

Can you get the work order & share the part name? I'm concerned that a made up part name was given because the issue went away for the tech and you may still have it.

And as Rebuilder indicates, it could have been the issue....but it would still start if it were, right?
 
#7 ·
Fuel injector sensor is what my ex told me that the guy told her. He may have dumbed it down for her.

While searching posts on this problem I've seen PCM mentioned but I don't know what that is. I'm a Saab guy not a Jeep guy.

I'll ask her for a more specific name of the part. I doubt the problem fixed itself and he made up a part and charged her but I guess it's not completely out of the question.

Tushy
 
#8 ·
PCM is essentially the computer for the vehicle. They're known for having solders that are weak and after a few hard jolts or just time, they can cause electrical gremlins and complete shutdowns while driving. Power Control Module, I believe... Sometimes also referred to as the ECU - Engine control unit.

For whatever reason, I've observed more 4.0L units with the PCM issue than the 4.7L units.

If it's working now, great but sharing the actual fix and part is what we most appreciate from members...should you get a chance.
 
#9 ·
1. tell your ex to get her jeep back from that mechanic. He doesn't know **** about jeeps. Let alone hes making up a part for your ex to pay for. Injectors don't have sensors. There basically resistors. You apply voltage/amps to the injector, the more power the farther it opens till fully open. Gas flows through. They work or they don't. When they don't your engine light comes on and the vehicle drives for ****. They all don't go bad at the same time usually.

2. Start by taking the vehicle in to a shop that will run a standard diagnostics test on the Jeep. I had a similar issue that turned out to be a PCM. Take a look at my thread in my sig. Basically when my jeep wouldn't start the computer was not communicating due to shorting out. Was pinned down after awhile because the diagnostics machine never could connect to the computer when it wouldn't start.

3. DO NOT TEST A FUEL LINE BY SEEING IF IT SPRAYS. Get the proper tool. Also any one here that can tell me they know the difference of 12psi to 25 psi to 55 psi by sight is full of it. Use a fuel pressure gauge to determine if your fuel system is pushing the proper amount of psi, not the does it spray test. Also getting a flammable all over the engine and your self is not exactly a safe method of testing something.

4. The mother of all problems with the WJ model is the CPS or crank position sensor. There about 50 bucks and depending on if you have a 4.0 or 4.7 easy or painful to change. Good place to start if you want to throw parts at it with out paying for diagnostics. Usually cause's the symptom's your having.

Going into the business, i hate mechanic's like that. They will tell you anything that you want to hear or lie to you to make a extra buck. And more so when its a women. Gives the rest of us a bad name.

On a further note, next time also post the engine and trim package. There is a difference betweent he 4.0 and 4.7 as well as the laredo and limited.

Edit: Missed the post where it said to get a proper gauge to check Fuel Pressure. Also, why do you find it hard to believe some one would lie to a un-knowledgeable woman about her car to make a buck. Its probably the biggest single most irritating thing about this profession. Mechanics for years have gotten bad reputations of being untrustworthy due to the very thing is guy is doing.
 
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