update on this for those interested...the fuel pump plastic seal ring was cracked, which was source of fuel leak. New part ordered from jag. The white plastic barb fitting apparently does nothing. Also, evap smoke test revealed cracked purge valve canister. I'm going to see if epoxy will seal that, if not I will buy a new one. Suspecting these two items are reasons for monitors not completing and vac leak causing lean codes. Fingers crossed.

 

Thanks for the update. I am curious - how much does the new plastic seal ring cost?

 

Good find! Just curious about how this didn't show up on the previous smoke tests. Was something done differently this time?

 

May you find inner peace with your S Type

 

shop told me it is $140 from Jag

 

previous smoke test was performed with a large plug inserted into throttle body intake. During this event, a new mechanic I have not met before at this shop told me that would only show intake manifold leaks. He said a proper evap smoke is performed thru that fitting that looks like a tire pressure valve located on the purge canister. He smoked it there to confirm leaks at evap and gas tank

 

Good deal! Thanks for the follow up on this.

 

There is a special type of epoxy made specifically for fuel leaks. We use this stuff in aviation on fuel tanks and I swear by it. We call them Tootsie Rolls.

Strange as it may seem, it barely sticks to dry surfaces. But on a surface already wet with fuel, it adheres like nothing you have ever seen. Somehow, the fuel improves the adhesion. If the surface is already dry, simply dab a little fuel on the surface and work it into the epoxy.

EPOXY-TABS? TYPE "O" | LA-CO




I think Loctite, Permatex, and JB Weld make their own versions of the same stuff. I bet any of these products would work very well to repair the purge valve canister.

 

Thanks.....Another update on this.......The outer plastic clamp ring was severely cracked on the fuel pump seal. That , and the inner ring were both changed. That area is now dry and no leaks even with topped off tank. I put on a new gas cap too for the heck of it. The little evap purge canister (round) was definitely separating at the joint around the bottom of it. I used JB Weld after drying it thoroughly with acetone and I applied the epoxy liberally. I allowed it to cure/harden overnite before restarting the car. It is still hard and appears in good condition, however.........codes...I did a hard reset after both repairs to start fresh. For the first several drives, I was very happy to see no 0174 or 0171 and the fuel trims were behaving as if I had finally fixed the issue. Historically, my stfts are very erratic as monitored with my real time obd reader (Torque app). They seem to respond instantaneously with throttle demand. If I apply throttle, the stfts go up but settle back down at cruise. The ltfts have been problematic. Especially bank 2, which always goes up first and sometimes without bank 1 following it. Bank 2 ltft has habitually gone up to +19.5 at idle after a few minutes and reacts back down to zero with throttle. I know this is classic vacuum leak indicator. Bank 1 will follow the pattern of bank 2 if left alone for a few days. BUT...immediately following the repairs, this pattern of ltft behavior changed. For the first several drive cycles, the ltfts initially repeated the pattern of climbing to +19.5 but then surprisingly, began to fall, even at idle. In fact, the longer I let the car idle in park, th stfts hovered around 0 and the ltfts began to DROP without me doing anything! I was ecstatic, thinking that the computer was relearning after the repair and that I had won. I watched as the ltfts went from +19.5 to +10 and still dropping at idle. So I happily shut off the car, thinking that another real drive cycle might result in ltfts dropping back to 0 and without lean codes or mil, I could smog the car and go about my life. All the monitors have now cleared EXCEPT evap. I can pass smog in California with evap not ready as long as no mil and no hard codes. BUT...LAST NIGHT AFTER STOP AND GO DRIVING ON FREEWAY, THE LTFTS WENT BACK UP TO +19.5 AND THE MIL CAME ON. With that condition, I can not pass smog. The dilemma is that there are no hard codes and if not for the mil being on, I could smog it. But to get the mil off, I have to clear the ecu again, and then the whole process of drive monitors has to repeat. So, I'm still not fixed. Due to the unusual behavior of the fuel trims that at first indicated a likely fix, and then reversal, I am still in trouble. I think I either have lower intake gasket leaks (since I have not done those), or faulty maf, or maybe even a faulty ecu?
I have to ask, even though I know I'm inviting sarcasm and criticism......is there a "trick" to defeat the mil without resetting the ecu and drive monitors? Will anyone admit such a trick?

 

Step back and look at your results. You made two big repairs and all seemed to be good for a while. Then, out of nowhere, the fault returned.

Follow this link, with your credit card at hand:


https://www.funnypartyhats.com/produ...gnifying-glass






Why would the fault come back? From Troubleshooting 101, look at the most recent work when the condition changed, whether for better or worse. What if your recent epoxy repair failed? That was the first thought that came to mind. Or perhaps the fuel tank ring failed again, with some external condition still present (warped surface?) that caused the first one to fail, too.

I'd re-investigate those recent repairs before going into FullPanicMode™.

 

agreed..will do

 

I checked the fuel pump seal and all is good. Nice and dry, no odor. I checked the evap canister epoxy job and it looks solid, no apparent failures. If anyone has thoughts on the fuel trim behavior....now the stats are sitting near 0 and the lifts are again steadily dropping at idle and I presume doing the right thing...
but now a hard fault code 0171 has appeared (bank 1). I took some pics of the obd


readings if it useful

 

Bear in mind a tiny (to a human) leak is a big (to the car) leak.

 

What engine?
Have you tried spraying carb cleaner or propane around the intake while monitoring fuel trims?
.
.
.

 

this is the 3.0. Yes I have tried carb cleaner around all the vac fittings and intake with no change in trims or sound. What does "closed loop,using 02 sensors for fuel trim mean"? That message us on my obd reader all the time . This morning started cold , the afr reading sat high at 18, and the lifts were negative 0 while the stats were maxed at +25. The 02 sensors sat at 0 with no movement. When car warmed, the 02 sensors began fluctuating and the stfts dropped while the ltfts simultaneously climbed to +19.5. All at idle.

 

Put that into a search engine

Then read...

 

More random thoughts:

As previously mentioned, did you confirm your carb cleaner will actually change the trims? Not all types have the required flammable propellant. Induce a known leak by loosening a vacuum line. Spray the carb cleaner in that area and make sure the trims respond. If not, your brand of carb cleaner isn't working for this purpose.

What if the evap system had more than one leak? Remember when mechanic #1 did the smoke test incorrectly and never found the leak. Mechanic #2 tested properly and found the cracked canister, which you repaired. What if there had been a second, smaller leak somewhere else? The smoke would have poured out of the big leak, never even reaching the second leak. If you keep getting the lean codes, it may be worthwhile to repeat the smoke test.

Also previously suggested, have you tried disconnecting/plugging the line to the evap system and going for a test drive? If the lean codes now aren't set, you've found the culprit. With the system disabled, you may get some new evap codes, but ignore them for now. A diagram of the evap system would be very helpful. There may be a check valve (or other restriction) keeping the smoke test from reaching the entire system. You could still have a big vacuum leak being overlooked due to limitations of the smoke test.

 

This means the control system is in normal operating mode. "Closed loop" is when the O2 sensors are warmed up and providing normal feedback, allowing precise control of the air/fuel ratio.

"Open loop" is when the computer is not using the O2 sensors for feedback, and is substituting stored values. Fuel control is much less precise. This can be a normal condition right after a cold start, until the O2 sensors warm up. It can also be an abnormal condition, such as if an O2 sensor output is way out of normal range, so the computer deliberately ignores it. You'd get some kind of code for the latter, though.

 

thank you kr. One thing I'm sure of is that you really are trying to help me.

 

A little depressed today over this vehicle. Maybe she just has too many miles and too many variables to overcome without investing a fortune for a professional game of hide and seek for the lean code culprit(s). The car only notebooks for about $2500 With 200,000 miles. Problem is that it is paid for, wife loves it and doesn't want to give it up, cosmetically it is showroom condition...but I can't smog it. And I can't just go buy another car. I gotta take a day or two off from this problem and recharge. Thanks to all of you for your patience with me.