2001 Jeep Grand Cherokee

This problem started out about a month and a half ago. It started missing slightly. Then I noticed my gas was going down very fast. So I started watching it, A five mile trip used a eighth tank of gas. It keeps getting worse. My husband popped the hood and was looking to see if he could spot anything.( Couldn’t smell any gas) He noticed the purge control solenoid wasn’t making the noise it normally does. He took it off, cleaned it and put it back on and it started working again. ( NO CHECK ENGINE LIGHT WAS ON AT ANY TIME ) It did it again. So we called the dealer, made an appointment, took it in, He asked my husband what was wrong, My husband told him what he had done and that it seemed to help for a bit. The dealer service guy said he Scanned for codes PO443 Performed Diagnosis Found EVAP PURGE SOLENOID Sticking Open. He said everything else checked out good. He ordered the part, called said it was in, went back, installed it. Amazingly IT"S STILL NOT WORKING. Now, I Do Not TRUST the dealership. I Can’t afford to shell out that kind of money since I and my husband are on a fixed income, ya know. It Stalls and misses and spits and sputters when it is in park and you give it the gas. There’s times when I am at a parking lot waiting to get out and I start to pull out it trys to die on me. Is there any advise you can give me. Thanks Wanda

Have your husband go out and locate the fuel pressure regulator.

http://www.rockauto.com/catalog/moreinfo.php?pk=1319645&cc=1373666

Have him remove the vacuum hose from the nipple on the regulator shown in the image. If gas leaks out of this connection the regulator is leaking and requires replacement.

Tester

I wouldn’t guess a purge solenoid sticking open would cause a drivability problem. It would cause more air pollution, maybe some extra evap of gas so you might notice some decrease in mpg, but shouldn’t affect how the engine performs. I think that was a red herring. No harm done though, it is something that needed to be fixed, otherwise it would have soon turn on the CEL.

To me this sounds like a lean condition. Either not enough gas or too much air is getting into the cylinder. Good comment by Tester above, that tests the not enough gas part of the equation. You could be getting unmetered air into the engine too. W/a 2001 this wouldn’t be an unusual thing, as most any rubber component in the engine compartment could be leaking at this age.

I’d start with suspecting the brake booster. You could get lucky. You don’t need a dealership. Ask for recommendation for a good local inde shop, preferably one that specializes in Jeep products.

Thanks, Will certainly give the advise a try !

The people at the dealership should know this, but a P0443 does not mean that your purge solenoid /control valve is no good. It means that there is a problem in the circuit. The solenoid itself is only one part of the circuit. The PCM operates the solenoid (usually by grounding it). So the whole circuit has the PCM at one end, and then all of the wiring, and then the solenoid. Perhaps a small wiring problem has caused the solenoid to get a constant ground and thus remain open. (So, i.e., the solenoid itself is just doing what it’s “told”).

If your valve is truly stuck open, it can act like a vacuum leak. The vacuum leak with lean out the fuel/air mix and the PCM will be pumping in more fuel to deal with the lean condition. Thus your car might run a little funny and use too much gasoline.

My first thought was actually the same as Tester’s - to check the fuel pressure regulator and then move on to other things that result in the engine running too rich. As he describes, checking the FPR is as simple as pulling the vacuum line to check for fuel.

Here’s a simple way to temporarily take the evap solenoid out of the picture. Just follow the vacuum line away from the solenoid to where it connects to the intake (this is often on the throttle body). Pull the line off of the intake/throttle body, and cap the port. (Anything air tight would do, but cheap vacuum cap assortments can be had at any auto parts store). You can drive that way for a while to see what happens. You cannot keep driving that way, however. If it makes no difference at all (a distinct possibility) go back to looking at things making it run too rich.

+1 to Cig’s post.

The evap system allows the entry of additional air post-MAF, and if it’s stuck open it will act like a vacuum leak. Change that… it will BE a vacuum leak.

NOTE: if your engine runs great with the port capped, that does not mean you can just drive it that way. Your CEL would remain illuminated in perpetuity, and you’d miss a crucial warning of another, perhaps destructive, fault in the future should one occur.

To tack one more “warning” onto mountainbike’s, the vacuum line from the solenoid will also be a fairly constant source of fuel vapors venting under the hood. That’s never a good idea. And if you just cap it, your gas tank will perpetually over-pressurize and cause more problems. That’s all in addition to having it cover up other problems that might emerge.

You guys are great ! My husband is oldtime repair guy. I have a seal leaking in the rear something and he said he needs to fix that so he knows a little I guess. DIDO to the DEALER HE LOST MY TRUST ! I’m not sure where to go, but I printed off your comments and will take them with me !!! Perhaps this will teach someone how to fix my Jeep. Thank you All SO Much Forever Grateful Wanda

@the same mountainbike: The only problem with that is that I think all Chrysler vehicles in that year range use a MAP sensor system, not a MAF.

The basics first: How long has it been since the vehicle has had a basic tune up with new spark plugs, fuel and air filters, etc?

My 99 Grand Cherokee started popping on start and running terribly. The check engine light code said evap system something or other. I put new plugs in and replaced a small rubber hose that connects to the gas filler tube only because it looked dry rot. Voila. Once these Jeeps start getting a little age on them, the rubber hoses that route the evap system fail. I had to replace another that led to the gas tank when the check engine light came on again at the most inopportune time.

Doggon cars they’re all alike. I threatened to shoot mine. It’s been good since.

Old Jeeps, a mechanic’s best friend.

The basic tune up was last spring. My husband checked the gaps of the spark plugs and one was off 10 He reset that one. But have not done anymore to it since Oblivion stated that year of vehichle used a MAP sensor system instead of the MAF Not sure what these things are??? Waiting now on further instructions from you guys. Thanks Wanda

Did you try capping the intake (or throttle body) port where the evap hose connects? This is simple and won’t cost anything and would take about 30 seconds (once you know where it is).

I’ll go out there and try to find it myself. My husband is down with his back, but hey , I should be able to follow a hose RIGHT? Thanks

Right - if you know where the purge solenoid is you should just have to follow from there toward the engine.

Of course, this whole thread might have gotten distracted by a code that isn’t the issue.

As was asked before, how old are the spark plugs and wires and filters and stuff?

All the wires spark plugs and filters were changed this past spring. NOW DO I CAP THE HOSE “OR” THE PART I PULL THE HOSE FROM ?

Cap the part you pulled it from - on engine’s intake or throttle body. But I’d also cap the hose so it doesn’t get gunk in it. The problem, of course, is that the whole system builds up pressure, so you don’t want to leave it this way for long. You’re just trying to find out if it runs any better.

I did notice a small crack in one of the hoses around the area of the solenoid stuff It seemed to be all the way down it but it’s just a short one . About 3 or 4 inches long maybe

Replace it. That stuff is cheap at any auto parts store.

WILL DO THANKS A BUNCH WILL LET YOU KNOW