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Car developed a weird symptom over the holidays - stalling when I came to a stop - but only during the warm-up cycle ..once she warmed up, ran relatively smooth. No codes BTW.
After the stall, wouldn't re-start immediately so I opened the hood and did a bunch of re-plugging of the MAF, temp sensor and swapped the relays around a/c compressor with O2 heater relay. Got back in the car and she fired up normally.
I thought I'd nailed the problem, thought it was possibly o2 heater relay/socket related but the next day same thing happened and crank as I might she wouldn't start so I did the replug routine again and she fired right up.
A friend suggested that if it happened again, don't get out and do the replugging, just wait for about a minute and see if she starts. He was right, after about a minute I cranked again and she started.
My instinct told me the timing of the fault was definitely warm-up related, both times the stall occurred about 5 minutes into running from cold with the temp gauge on the dash about 1/2 way between C and N - to my mind, probably the switch over point from open to closed loop operation. Once she was on "N", she appeared to run normally.
Because I got no codes, I swapped out the CPS with the spare from Jim's Redd but the next day she did the same thing and stalled at the same time, halfway to warm.
Today I used some contact cleaner on the connections for pretty much all the sensors incl. the o2 sensor and didn't notice a stall (I took a different route and didn't pull up at the same light) however I did notice the idle stumble a bit down to around the 400's momentarily. Anyway, on the way home after about a 5-6 mile run I got the CEL and it gave me FF44.
When I got back to my place I cleared the code, checked all the connections again and replaced the plug wires, distributor cap and rotor. On the test drive, the CEL illuminated again and we're back to the FF44
I'm leaning toward the o2 sensor wiring, when I replaced the exhaust manifold gaskets last fall the exhaust slipped from where I had it supported and was left hanging by the three wires ..it was quite a bit of weight and may have messed up the wires esp the heater wire ..using more gas than usual over the last few tankfuls too.
Sorry to hear of issues Larry,try backprobing the o2 sensor wire,and read the voltage on the 1v scale.The voltage should swing around quit a bit.
Slow voltage means a bad sensor.Higher voltage is a rich condition,and lower,leaner.
Years ago,we had a similar symptom on a vehicle,it turned out the coolant temp. sensor would tell the ECU,cold,warmer,a little warmer,and BOOM= -40 below!FULL fuel.sputter,stall,1 min. later,all is good.Hope you get it sorted soon,Cheers,Jim.
Sorry to hear of issues Larry,try backprobing the o2 sensor wire,and read the voltage on the 1v scale.The voltage should swing around quit a bit.
Slow voltage means a bad sensor.Higher voltage is a rich condition,and lower,leaner.
Years ago,we had a similar symptom on a vehicle,it turned out the coolant temp. sensor would tell the ECU,cold,warmer,a little warmer,and BOOM= -40 below!FULL fuel.sputter,stall,1 min. later,all is good.Hope you get it sorted soon,Cheers,Jim.
Well Jim thanks for the tip, I've got a spare temp sensor so may as well fit that, easy job, not so much the o2 sensor, bit of a struggle that.
Last time (about 3 yrs ago) did it from the engine compartment, lots long extensions and the old "special" socket of course - first wrought socket I bought was too "springy" and kept opening up and slipping - useless piece of s--t, ended up with a cast crowsfoot, worked properly although slow going.
Not looking forward to swapping it if it's hooped. Too bleedin cold working out in my carport in January
Only good news is I have a new o2 sensor on the way from rockauto, direct fit 3 wire and clearance priced at US$27, shipping included! Sure beats US$333 for OEM!!!
I'm pretty sure the three-wire O2 sensors rely on a ground path through the exhaust, so it's a good idea to use a battery terminal brush and some contact cleaner spray to clean the threads in the downpipe before you install the new sensor.
Hey Larry,I ground and bent a box end wrench just to do that annoying job,still a bear to do tho...
Feel free anytime...
Cheers,Jim
Jim, how's about a pic of that there ground out wrench (or at least the dimensions), I don't think there's enough room down there to swing my ratchet - doing it from the top really needs two people, one to do the work and another underneath, lifting off the socket and repositioning it every 1/4 turn.
Great fun job working alone!
I'm pretty sure the three-wire O2 sensors rely on a ground path through the exhaust, so it's a good idea to use a battery terminal brush and some contact cleaner spray to clean the threads in the downpipe before you install the new sensor.
Cheers,
Don
Thanks Don, I'm going to have a look at all the grounds first thing tomorrow!
Looks like the sensor will be coming by wagon train so I'll have lots of time to check stuff in the meantime ..really should do an intake muck-out and throttle body cleanup too - just wish it was spring and not winter ...brrrrr!
I don't know if these will help, but below are links to photos showing how I replaced the O2 sensor by myself with a cast/forged slotted socket. I worked the socket onto the sensor from below, then used some long extensions to turn the sensor out from above. I just let the wiring harness wrap around the socket and extension. If you clean the threads in the exhaust as we discussed, you'll probably be able to thread the new sensor in nearly all the way by hand, so you only have to torque it from above, requiring very little rotation:
Hey,Larry,here is the wrench I made up,just to do that job,7/8 el-cheapo,you can bend it by taping the thing to a BIG sledgehammer,walk over to the curb,and start wailing away until results are had.
Use another wrench as a snipe,It's a bi#@& to do but it works.
The manual indicates that a stuck-open purge valve can cause FF44, but not one that is stuck shut. However, if the ECM triggers the purge valve to open, it may also shorten injector on time or pulse duration to adjust for the fuel vapors that will enter from the carbon canister. If the injector pulse duration is reduced but no fuel vapors are drawn into the intake manifold, that could theoretically lead to a momentary lean condition, maybe???
On our '93, problems with the purge valve wiring circuit have typically triggered FF89:
The manual indicates that a stuck-open purge valve can cause FF44, but not one that is stuck shut. However, if the ECM triggers the purge valve to open, it may also shorten injector on time or pulse duration to adjust for the fuel vapors that will enter from the carbon canister. If the injector pulse duration is reduced but no fuel vapors are drawn into the intake manifold, that could theoretically lead to a momentary lean condition, maybe???
On our '93, problems with the purge valve wiring circuit have typically triggered FF89:
Hey Don, on the diagnostic notes for FF44, it shows the test procedure for the valve, and as I read it and as it tested, it failed and needs to be replaced anyway!!
I agree the thing may not have triggered the FF44 but I just picked up a spare from Jim so tomorrow I'll replace mine. After it's all back together, I'm going to re and re all the engine bay grounds and test the o2 sensor.
I have a sneaky feeling the closed (stuck) valve has been contributing to my overall slightly rich running/poor gas mileage. It was also a possible symptom for FF23 also, and I had that quite a bit a few years ago (same purge valve as then btw)
I replaced the whole ball o'wax today, all the evap stuff up under the drivers side wheel arch.
Yesterday I got the entire assembly, purge valve, vacuum valve and carbon canister from Jim's "Redd" car. Thought I might as well swap it all as my carbon canister could very well be saturated after all these years of "non-purging".
Don's link was very helpful because with all the hoses off, I couldn't remember which hose went to the purge valve and which one went to the vacuum fitting!
Anyway, did a clean up on the grounds as well as a re-clean and snug up on the o2 sensor connection and reset the code.
Started the car and took her for a 3-4 mile test drive - she warmed up normally and drove smoothly and didn't throw any codes so I thought I'd corrected the fault -BUT- when I got back home and I put her in park, she started surging from about 500 to 1000 rpm!
I opened the hood and started checking connections and vacuum lines and all seemed normal - I could hear a "new" sound too - the clicking on and off of the purge valve (for the first time ever!)
Removing a vac line at the manifold tee did affect the surging a bit but it wasn't until I unplugged the IACV that the idle stabilized.
It was getting pretty dark out there and as I'd forgotten how to set up the IACV I called it a day, I'll have a go at it again tomorrow.
My thoughts are that the extra volume of "whatever" now coming from the purge valve has affected the idle setting and probably the running mixture as well.
Although the car idled OK prior to this purge valve swap, I never REALLY felt satisfied with the IACV setup and certainly not with the idle bleed screw adjustment which I recall didn't seem to do anything.
I'll dig out the IACV adjustment procedure and have at it again tomorrow. Hopefully I'm on the right track!!
Idle seems to have settled down but FF44 has returned.
I just backprobed the o2 sensor and got a steady reading of approx 0.15v - engine was warm.
When I revved the engine I did get some movement on the meter, but certainly not anything remotely connected to the fast switching or fluctuating that I've read about.
The jag e-book suggests this low steady voltage reading could be caused by lean running, i.e. vacuum leak or fuel restriction.
My brian is too tired to think this through, but I presume that a steady reading of about 150 mV could mean the O2S is stuck or your meter cannot react quickly enough to the rate of change of the sensor.
The EMS Diagnostic Manual says the O2 sensor raw voltage signal to the ECM should swing 6-10 times per minute between 200 mV (lean) to 800 mV (rich), and its feedback voltage typically swings between 1 and 4V when fueling is normal. I can't remember which voltage you are measuring at the O2S connector - I assume you were measuring from the signal wire to ground?
I've got to get to bed due to an early meeting in the morning, but I would recommend studying the pages on O2S operation as well as the pages for the DTCs associated with the O2S. I think that may shed light on your measurement.
01-06-2016, 07:57 PM
Stalling occasionally now it's FF44 time!
so I did the replug routine again and she fired right up. 
Update
-BUT- when I got back home and I put her in park, she started surging from about 500 to 1000 rpm!
