need help

[Ecomike]

i just put i new map sensor and it will start as soon as you give it gas it will die

OK, sounds like you had more than one problem, one being the MAP sensor. In my experience the TPS is the next culprit, but you might want to test this first as the O2 sensor or CPS (CKP) can do it too. The TPS can be tested in several ways with an analog volt meter. I would disconnect the wire harness from the O2 sensor next, and see if the problem goes away with it dying as you give it gas. That will tell you if the O2 sensor is causing the dying.

Also, a hair dryer to heat up the CPS, and an ohm meter to test the CPS would be next.

If you don't have an analog (needle indicator, not digital) volt/ohm multi meter, you should buy one (about 15 to $20). It is the best tool around for troubleshooting the 87-90 jeeps.

There are many threads here on testing these parts with a volt meter.

Just out of curiosity, did this jeep get wet under the hood, like water or coolant on the TPS, MAP, O2 sensor?

 

[90jeepfullofmud]

the last time i want offroading it did that was 3 week ago

 

[Ecomike]

the last time i want offroading it did that was 3 week ago

It did what three weeks ago?

The TPS usually dies permanently when it gets wet. O2 sensor dies when exposed to engine coolant.

 

[90jeepfullofmud]

it get wet 3 week ago. if you unpluggingthe 02 sensor id dies

 

[Ecomike]

it get wet 3 week ago. if you unpluggingthe 02 sensor id dies

Will it start and run with the O2 sensor disconnected?

 

[90jeepfullofmud]

no as soon as i disconnected it dies

 

[Ecomike]

no as soon as i disconnected it dies

It can't die, if it is already off!

Listen closely, once again, disconnect the O2 sensor. Then try and start the jeep. It should start with out the O2 sensor connected. If it starts, see if it will run normally.

 

[90jeepfullofmud]

if i disconnect the O2 sensor it will start it take like 20 sec to start if you give it gas it dies

 

[Ecomike]

if i disconnect the O2 sensor it will start it take like 20 sec to start if you give it gas it dies

Ok, for now leave the O2 sensor disconnected (reconnect it later once we fix the problem). It now sounds like the TPS is bad. It can be checked with a multi meter, volt-ohm meter. If you don't have one, go buy one for about $15, but get an analog style meter, it has a needle indicator, not a digital scale. Then test the TPS.

There are details on testing the TPS in a number of threads here, including this one:

http://www.naxja.org/forum/showthread.php?t=905849&highlight=renx+files

or here:

http://www.naxja.org/forum/showpost.php?p=243533340&postcount=119

 

[Ecomike]

Are you unhooking the vacumn line to the MAP or the electrical connector? I think you need to verify that the fuel pressure is good. Some stores like Autozone will loan you a fuel pressure guage.

I am thinking he needs to look at this issue again, fuel supply. Maybe it is getting enough fuel just to idle, but no more, and so runs out of fuel to meet demand when he opens the throttle.

 

[90jeepfullofmud]

iam going to get multi meter and test it i think it the tps to i just did i fuel pump last moday

 

[lawsoncl]

i just did i fuel pump last moday

Did you get it from the dealer, or it is a cheap brand? Just asking because the el cheapos have a tendency to fail. It really is worth the money to get a quality pump just to avoid the possibility of having to do it again. I think you really need to check the fuel pressure.

 

[90jeepfullofmud]

it is from autozone it cost me 83$

 

[whalebus]

I just bought one from auto zone and it lasted 1 wheeling trip.about 5 hours.I will be buying one frome the dealer

 

[90jeepfullofmud]

i fixed the jeep i was the fuel pump thank you for all your help