my 99 wont start, i hear the fuel pump when i turn the key...

The wierd thing is when i crank my jeep over and pump the gas (like it had a carb) it will fire up and run.....

It just wont run without me pumping the gas. As soon as i take my foot off the gas it will die.

Please help me, i thought it was a simple fuel pump...but its working



(thats how i feel)

 

No idea man I had a dodge avenger just like this. Doesn't idle at,all? I felt the same way when I gaff that car

 

nope wont idle unless i push the gas to 1k rpm or so....

as soon as i take my foot off...it just dies....

no check engine lights...nothing

 

Sounds like a air line to a sensor. For instance I changed a motor mount on my 98 Camry and when I lifted the engine my air line to the map sensor came off did the same thing.

Check all lines, plug wires, distributor on tight. Pressure test that pump maybe. That's where I wild start anyway...

 

ok...i checked the coil wire...all plug wires last night with no sign of improvement

whats really wierd about this...it started right for me sunday for church...i came back from church and washed it...

after washing it i drove it up to the house and left it sit outside b/c it was nice out. It sat on level ground for about 6 hours...went to move it inside and nothing

and when i washed it I DID NOT spray anything in the motor compartment.

from what i gather...its either a crankshaft position sensor, coil, or no fuel pressure at the rail

 

Hmm what happens when you rev it higher than 1k like 2 3 or higher? Have you drive it around put it under a load? Drive it around the block smash the pedal. Does it start to sputter cut out and sound like crap?

 

I'm thinking pressure also btw lol

 

found the problem

it turned out to be a varnished over throttle body

I had it soaked in parts cleaner, scrubbed it down good, blew it out with a air compressor...

Installed and jeep is up and running again

nice part is the idle is way smoother....and i should notice a nice increase in mpg and drive-ability

now this weekend i want to clean the egr valve...anybody had a pic of location of it and how to remove it...im sure thats just as dirty

 

There is no EGR valve on your 1999 4.0 engine.

Last year for EGR was 1990.

 

well then my job is done!

i have a hard time thinking that throttle body could be that dirty, but i do drive like a old old lady, and the guy said that usually is ok, but i should clean it out some times. And by clean it out he meant beat on it

I always used quality fuel...mobil, shell or bp only....no off brand gas ever

 

No matter how you drive, eventually your throttle body will need cleaning.

Did you clean your "idle air control" when you cleaned the TB? If your throttle body was carboned up, your IAC is also assuredly carboned up.

The "how-to" is below.
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The Idle Air Control (IAC) is mounted on the back of the throttle body. (front for 87-90) The valve controls the idle speed of the engine by controlling the amount of air flowing through the air control passage. It consists of a stepper motor that moves a pintle shaped plunger in and out of the air control passage. When the valve plunger is moved in, the air control passage flows more air which raises the idle speed. When the valve plunger is moved out, the air control passage flows less air which lowers the idle speed. Over time and miles, the IAC can get carboned up which can have an adverse affect on idle quality. Cleaning the IAC may restore proper function and is an easy procedure to perform and good preventive maintenance so it is never a bad idea.

CLEANING THE JEEP 4.0 IDLE AIR CONTROL

Remove the air filter cover, associated hoses and the rubber boot that goes from the air filter cover to the throttle body. Remove the IAC with a torx driver (2 bolts; one can be kind of hard to get to)

“Gently” wiggle out the IAC from the throttle body. Gasket on the IAC can be re-used if it is not damaged

Clean the IAC with a spray can of throttle body cleaner; inexpensive and available at any place that sells auto parts. Throttle body cleaner is recommended rather than carburetor cleaner as it is less harsh, safe for throttle body coatings and is best for this task. Use cleaner, a rag and a toothbrush and or Q-Tips. Be gentle; don’t twist or pull on the pintle that protrudes from the IAC as it is fragile and you could damage it.

Thoroughly spray clean and flush where the IAC seats in the throttle body with the same spray cleaner

It is also a good idea to clean the entire throttle body itself, the butterfly valve inside of the throttle body and all associated linkage as long as you have things disassembled

Reinstall IAC and check idle quality

 

what would be the symptoms of a dirty iac?
my idle is way better than before...about 100 rpms lower and smooth..before it jumped around from 500 maybe to 700

i would assume they cleaned it but i dont know...they just said throttle body but if its attached im sure they did