1998 Jeep Grand Cherokee Starts runs for second shuts off HELP PLEASE

Joshua Potter

New member
So I am purchasing a 1998 Jeep Grand Cherokee 4.0 staight 6 all stock 150.000. Here is the issue. You turn the key and it starts right up but only runs for a second and shuts off. If I give it gas it reves for a second and shuts off. It does this every time you turn the key in both park and neutral. I was told it is a map sensor . I am only paying 250 for the Jeep. I don't have a lot of money. Seems like a good deal if I can get it running. Am I wrong?
 

Alot of times its the simple things that go wrong, try replacing your fuel filter and see what happens. The MAP sensor is run by vacum lines so check those lines for loose connections also.

I hope this helps.

Mike
 
The fuel filter is on the fuel pump. There is no external fuel filter. I put dry gas in thinking that he got bad gas but that didn't work. He said it was running fine. He went got gas stopped at his parents house. Went out to start it and it did this.
 
I am no mechanic, so please take my comment with a grain of salt... It sounds to me that you have the ingredients for combustion, but something give out soon after starting. If it was me, I would probably start with the fuel aspect, like you did. It sounds like it's being starved, so a partial blockage may be the cause. Once the engine is off a little fuel gets by to get your hopes up at the next go. I would start disconnecting fuel line at different point to insure a flow. BTW: I wouldn't do it near an open flame! ☺️

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I'm no mechanic either but I believe you guys are on the right track .
Although it should not be ruled out , a fuel restriction is less likely than a bad electric fuel pump .
It could not hurt to change the fuel filter . But since the filter on this model is integral with the fuel pump which lives inside the fuel tank , the plan of attack would be to check fuel pressure key on engine off , with and without pressure regulator vacuum line on , and engine cranking.
Problem is , we are talking about a jeep that is a potential purchase and by someone without much money. At the minimum , a fuel pressure test will have to be performed .
 
We tested fuel pressure at the rail, it looked good. I put dry gas in just in case he got bad gas. Going to get a map sensor and see what happens. As I am taking everything off I am going to clean everything up and look at the wiring. Can't do anything for about a week so I will keep everyone informed. The reason I am getting it so cheap is becase the guy was going to junk it because he has another vehicle and doesn't need the jeep. So he selling it to me for what he could get for it from a scrap yard. He is actually working on it with me and we are using his garage. So he wants me to get it running. He said that this is the first time he has had a problem with since he has owned it. He has had it for over 3 years.
 
If your having a vacuum issue and all of your Vac lines are good then you can get an aftermarket alternator for this jeep that has a vacuum pump built into it from orielys.

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So I am purchasing a 1998 Jeep Grand Cherokee 4.0 staight 6 all stock 150.000. Here is the issue. You turn the key and it starts right up but only runs for a second and shuts off. If I give it gas it reves for a second and shuts off. It does this every time you turn the key in both park and neutral. I was told it is a map sensor . I am only paying 250 for the Jeep. I don't have a lot of money. Seems like a good deal if I can get it running. Am I wrong?

Sounds similar to what happened to my 2003 Grand Cherokee. It would just turn off, as if someone removed the key. In our case, it was random. My wife would be driving and the Jeep would just stop. When I got to her to swap cars, I started it up and drove home. No logic at all.

Turns out the "Crank Sensor" was failing. The computer thought the crankshaft had stopped, so it stopped firing the spark plugs and injectors and other stuff it needed to run. This wouldn't show up in the OBD tool, but the dealer could read the computer log in the car and they fixed it pretty quickly.

The total repair from the Jeep dealer was $356.49. The sensor itself was $122.85

Hope this helps.
 
Sounds like a security issue to me... might try resetting the KAM (keep alive memory). Remove both battery cables and touch them together for about 10 seconds to discharge residual voltage and the KAM should be reset. Or, with a scan tool check the pids for the SKIM and SKREEM modules (security modules).
 
I had this problem, it is the crank sensor on the bell housing of the transmission. This tells the computer where the TDC is or Top Dead Center. There is also one for the cam shaft. I would see about changing this out or looking into this. They do go, and it sounds like a lot of other things, but if it fires and dies, you can push in the shraeder (sic) valve on the fuel injector area to see if it has fuel.
[h=3]Operation[/h]In a typical Jeep application, the ignition control module (ICM) is located in engine compartment. It consists of a solid-state ignition circuit, as well as an integrated ignition coil that can be removed and serviced separately. Electronic signals from the ECU to the ICM determine the amount of ignition timing or retard needed to meet engine power requirements. The ECU provides an input signal to the ICM. The ICM has outputs for a tach signal to the tachometer and a high voltage signal from the coil to the distributor. The crankshaft position sensor senses TDC (Top Dead Center) and BDC crankshaft positions, as well as engine rpm. This sensor is secured by special shouldered bolts to flywheel/drive plate housing and is not adjustable.
This is for your 1988 year. Good Luck! I am on my 5th Jeep Grand Cherokee over 27 years! Love me some jeeps..hate the sheet that happens, but then they usually can be fixed easily enough!
 
So I am purchasing a 1998 Jeep Grand Cherokee 4.0 staight 6 all stock 150.000. Here is the issue. You turn the key and it starts right up but only runs for a second and shuts off. If I give it gas it reves for a second and shuts off. It does this every time you turn the key in both park and neutral. I was told it is a map sensor . I am only paying 250 for the Jeep. I don't have a lot of money. Seems like a good deal if I can get it running. Am I wrong?

Look at your fuel pump relay ,they go out all the time.
One my 89 it would start and shut off like that ,the relay was bad ,the reason it starts is that the ignition bypasses the relay when starting.
 

Another issue is possibly security shut off. This happens when it doesn't read the key chip correctly (only in late 98 and newer) or if the security system is not functioning correctly and needs to be reset. Last possibility is fuel filter, pump, or pressure regulator.

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hmmm....it is actually on the transmission bellhousing for my year..anyway sorry that you think otherwise
 

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Does it continue to run if you keep your foot on the gas pedal? If so it is like the IAC on the throttle body. It may need to be cleaned or replaced. At a minimum clean the TB and IAC and be sure it's all plugged in correctly.
20110731_155812_throttlebody-1.gif


Regards,
JPNinPA

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My 98 4.0 says it's in the front by lower (crank) gear inside timing cover. I also have same sensor on the bell housing but in my manual it says it is a tach sensor. May be a typo or something. My 98 has 98 body but 99 engine (and other 99 parts scattered throughout the jeep). The title says "limited se", registration says "laredo se" and when I check the Vin online it says 1998/1999 special edition limited. When I called Chrysler they told me it was a "special order - custom build" unit. I asked what they meant by that and was told "the original owner requested, and paid for in advance, a special build to have specific features that were not available on the standard production model." The actual manufacture date was 11/1998.

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The engine will rev up when I step on the gas pedal and hold it down, but dies the same way and in the same amount of time as if I just turn the key.
 
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