Manager Forum

How bout a can of gas and a handfull of matches? Im batting 1.000 on this rig

Yea ya would!

Scheduled for teardown on Monday when the left is available. Will keep ya all posted on what i find.

It sorta does have a return line, just lives in the tank as part of the module.

Air in there is bad, as is the pressure drop. Pull the tank and module. Inspect. Might even run the pump in small container to visualize what's happening.

Sounds like a bad module. I think you're closing in on it! Good detective work so far!

I am thinking that the pick up on the bottom of fuel pump might be messed up causing it not to be fully submerged unless the tank is that full, that is the only thing I can think of that would cause air in the fuel, a leak in the plastic line coming out of the pump would cause a loss of pressure, not air in the fuel.....

to my dismay. I replaced the entire fuel pump module and filter. What a nightmare - oh well. Keep in mind, this is a convertible and the rear seat has to come out to access the wiring harness to the fuel pump. However, the problem remains although I now have much better fuel pressure and consistent pressure that does not drop. Actually, the problem is bad enough now that I couldn't hardly back it out of the shop. It runs so bad. No codes now, no misfire numbers - nothing.

Vacuum gauge shows 15 inches of vacuum. Purge solenoid at 10% - is that normal for idle? Spark advance is 24degrees at idle. And, again, I am wondering if that is normal. TPS at idle is .84volt. ECT began at 70 and in a few minutes was at 194. IAT began at 70 and rose to 90 after a few minutes. Short term fuel trim is at -9%. Long term fuel trim is at -14%.

I AM FRUSTRATED!!!!!!!!! It's Friday and I wanna get this job outa here.

Unplug the air flow sensor or both fron 02's and throw it into limp. see what happens. Sounds like the symptoms i would get from bad map sensors from Chrystlers of old.

A shop previous to mine installed a new MAP sensor with no change to the symptoms. No MAF on this one.

i never assume work from other shops is correct, been done, or has used quality parts. I've replaced many "already been replaced parts before" in the years i've been in business.

steven kiser wrote:i never assume work from other shops is correct, been done, or has used quality parts. I've replaced many "already been replaced parts before" in the years i've been in business.

I agree with you and do the same, however by installing a mechanical vacuum gauge and comparing values, the numbers are the same. At idle with the AC on the vacuum is 14.5 inches, with the AC off, the vacuum rises to 16 Inches. Not exactly good but doable.

Does anyone know if there are any monitors and or tests that run for the first few minutes when a cold engine is started up? This problem only occurs after a cold soak - setting like overnight. Once the engine is warmed up in the morning the car can be driven all day stopping and starting with no problems until it is started the next morning.

The EVAP monitor usually runs after a cold soak, but usually after it warms up. If it has air injection, most of those run right at startup.

ricmorin wrote:The EVAP monitor usually runs after a cold soak, but usually after it warms up. If it has air injection, most of those run right at startup.

And for how long does it run? 10 minutes?

Also, how long does the heater on the O2 Sensor run? Is there any way to know that?

That information is not provided by the OEM to my knowledge. Based on experience, the air monitor runs only for 20 or so seconds. EVAP is anyones guess; could be 10 or 20 minutes depending on the strategy. O2 heaters depends on the strategy used. GM's know within a minute if there is a problem because they monitor current. I don't think Chrysler does. Probably no more than 10 minutes on heaters would be my guess.

ricmorin wrote:That information is not provided by the OEM to my knowledge. Based on experience, the air monitor runs only for 20 or so seconds. EVAP is anyones guess; could be 10 or 20 minutes depending on the strategy. O2 heaters depends on the strategy used. GM's know within a minute if there is a problem because they monitor current. I don't think Chrysler does. Probably no more than 10 minutes on heaters would be my guess.

Ric, yer latest post is somewhat along the same line of thinking i have. I am somewhat concluding that the issue may lie with one of these tests the PCM runs because, as I stated earlier, the engine runs bad for about 10 minutes in the AM, upon initial startup of the cold engine. After that, the engine runs perfect all day. Now I am faced with the process of how to prove it one way or another........... Oh boy.


Are we having fun yet???????/

Something cutting through the fog here. I seem to recall something along these lines in this or another forum. Had to do with the vac lines being screwed up at the evap canister or something like that. The vehicle ran rich because the crossed vac lines was somehow feeding raw fuel into the intake. The p.c.m ran open vac during warmup like it should to keep system shut down and after a pre determined time would allow it to open. When p.c.m. shut vac off the vehicle would operate fine. I believe it was caught when the tech watched the scanner to see what switched right before it started running fine. My Snappy scanner will take a snap shot of what's going on so i can actually print out the monitor information and compare. Take a snap shot and print while it's running like crap and then when it's running well. See what's flipped and start working back from there.

Here is an update on this beastie. The customer came an got the car cause they needed it. Haven't heard from them since however, this morning, the owner called an said he needs an inspection on it so I am getting another shot at it. Owner says it still has the original problem. Anybody wanna take a shot at what I should be checking when it gets here?

Your fuel trims indicate the car is rich when malfunctioning. Our previous conversations might point to fuel being drawn into the intake via the purge. A quick check would be to start it up cold and confirm the poor running, then remove the purge line and see if there is raw fuel there. It's a long-shot, but at least you can eliminate the possibility.

Only place it can be picking up air in inside the tank. You may find the pump floating inside the tank.

New fuel pump module has been installed for that possibility with no change

Tim Martin wrote:New fuel pump module has been installed for that possibility with no change

No change in symptom? or are there still bubbles in the fuel?