High folks,

Got a good one for you.

I'm a certified mechanic and can't figure this one out and neither can the dodge dealer.

I have an 02 neon that eats Leak Detection Pumps for breakast. Seems that every 2 weeks this car eats a leak detection pump from Chrysler. Hook up smoke machine and only leak is at at the LDP. Put a new one on. Smoke again and no leaks. Then a week or two later the car is back again.

We run ethonal gas here and I have checked to make sure that there is no fuel sitting in the lines that connect the charcoal canister to the LDP. No vacuum leak between intake and diaphram on LDP on vacuum line.

I'm stumped and so is everyone of the other techs here and at the Dodge Dealer.

Has anyone ran into this??????????

AJCASPER

 

Any other codes that aren't leak codes?

 

Just P0455 large EVAP leak detected. Only code everytime. LDP Purge vent smokes like crazy when pressurized smoke at 0.5psi is applied to EVAP system through service port next to brake booster.

 

When you say you run ethanol gas I'm assuming you mean 10%?


Have you checked the filters on the system?

 

Um... there is a vent line that is suppose to leak. you have to pinch it off to test the system. Vent valve in chrysler product is a Check valve, air goes from Evap to Atmosphere, and seals atmosphere to Gas tank. It is called a Vent for a reason.


you pinch the Vent line, pressure test it to see that there IS a leak or not. If there is a leak, you then hook up smoke machine and smoke it.
If there is no leak to be found with VENT line pinched off, test purge solenoid.

 

ok. understandble to pinch off vent line. I see on the Chrysler mini vans having to pinch of cap off a line between the charcoal canister and the old where it leaks. Never had to do that on a neon. When I put a new LDP in this neon it doesn't smoke at all.

Just to clarify the part that I am seeing smoke from is a cylindrical black cannister (filter of some sort) that is attached directly to LDP by a short rubber hose, called LDP filter in all diagrams I Found. Seems to be this way on all Chrysler minivans and this neon. I wish I had thought to add a picture but forgot.

If it is supossed to smoke out of this LDP filter please let me know because every other Chrysler where I have seen smoke out of there I replace the LDP and the problems go away.

AJCASPER