help!!!! my 1988 jeep cherokee 4.0 runds great for 30 secinds then starts to die?

Question

most of the time it dies the first time sometimes it picks itself back up and then starts it again after 30 seconds starts spiin and spuddering and then dies it will start right back up and then run great for 30 seconds if i play with the gas it stays running but if i put it in reverse and play with the gas it dies but when i put it in drive i can drive it around as long as i keep my foot on the gas when it goes to an idle it runs for 30 seconds and then dies we jsut put the motor in the jeep it never did this with the old motor the new motor is the same thing as i used all the parts off the old one. PLEASE HELP ME!!!!!!!! iv'e check the ics and it sucks air like someone told me to try iv'e taken every conection off and reput them on to make sure it's conected right any sugestions would be great im pulling my hair out.

Answer 1

did all the grounds get bolted back on engine if not do so ,,sounds like fuel pump or injectors not maintaining proper signals to stay operating get a noid light and check for continous pulse,also check sparkand fuel pump for the same thing check fuelpump pressure, fuelfilter, auto shut off relay is it out of time! good luck hope this helps

Answer 2

You have a vacuum leak......
You may need a little help to this.
Have someone start the engine, with the bonnet up grab ahold of the throttle cable,( I am assuming this is a carb and not fuel injection.) give the motor just enough throttle to keep it running. While you are doing this take a can of WD40 and spray slowly, first around the carb, air lines and intake manifold. If it is a small leak the engine will actually speed up on its own when you spray over the area that is leaking, this is because WD40 is flammable.
If it is a large leak it may kill the motor, this is due to changing the air fuel mixture too much.
Connect the directional tube onto the spray button on the WD40, this will allow you to narrow the focus of the spray and pinpoint the leak. Be thorough all around the carb, including the linkage of the butterfly.

Answer 3

in case you have self belief the mild interior the glovebox is on all of the time... take the bulb out and attempt lower back. There might desire to be a battery or alternator indicator mild on the sprint... if the mild comes on; you have a charging circuit fault...if there's no longer then there's a gauge that exhibits charging... a motor vehicle might desire to fee at 14+ volts to maintain 12 volt provider... If the warning signs and warning signs from a gauge (or the absence of a mild) states there's no alternator concern, you will possibly be able to desire to look someplace else. on occasion a gas pump dying will react in a matching way.

Answer 4

I like all the answers vacuum leak is the first to check then fuel pump 88 jeep carborator problem dont adjust use spray to check. also every vehical I have ever owned I also own the book on it.

Answer 5

first thing check your fuel filter sounds like it might be clogged if so replace it with a new one. If that don't do the trick check the fuel pump and make sure you have vacuum lines in the right locations.

Answer 6

It sounds a lot like you have a bad vacuum leak somewhere. You can try using a can of carb cleaner, spray it around the manifold, carb, tbi (whatever), and see if the idle changes dramatically...that may help isolate where it is...

First gues, based on what you describe...

Answer 7

1. Check the fuel pressure 45-50 PSI

2. If fuel pressure low, replace fuel filter(s) & recheck

3. If fuel pressure OK then replace the TPS (Throttle Positioning Sensor)

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Answer 8

Bad fuel filter or fuel pump?

Answer 9

that is the egr valve stuck open here is a link to clean it.also here is a link to the vacum lines

Answer 10

don't forget to check the air hoses for leaks. you may have nicked one without noticing.