Hi all! I think it would be best to start from the beginning: A few weeks back we purchased a 1985 XJ6. Drove the car home from the dealership (approximately 1.5 hour drive) without any problems (well, some vibration from the front, turns out to be weak tie rods, but I digress...). The car is finally at the house and we start going through it to see what type of work it will need. We did some of the minor things such as changing light bulbs, cleaning out the terminals in the fuse box, and unfreezing and greasing the emergency brake line. She ended up sitting for a bit while this work was being done, coupled with stormy weather and work schedule which made it difficult to work on right away. While checking out the car we ended up hitting the switch to change the gas tanks. That's where the problem first started, which ironically led to the car not starting.

I started to address this problem by cleaning the drain holes under both filler caps; drained both gas tanks (by having my son crank the engine and using the pump to drain the tanks, lot of small particles coming from at least one tank - added gas and re-drained until it ran clear), added fresh gas with some sea foam, and replaced the fuel filter. She would start, but would not stay running.

I then disconnected the air filter and held the flap open on the air flow meter. The engine would start and finally stay running. When I let go of the flap the engine would again stall. I removed the air flow meter from the engine (disconnecting the plug and pulling it out entirely), and the car again ran even longer without stalling - though it would stall again when put into drive or reverse.

Obviously I'm thinking there's an issue with the air flow meter, but I remove the black cover from the meter and everything appears to be fine. The contact for pins 36 and 35 close properly when the flap is open, there does not appear to be any wearing on the resistance track, and there appears to be proper voltage coming out of pins 6-9 (although slightly low on pin 8 by approximately 1v). After reading about a modification made on either this forum or jagbits, I even advanced the main gear in the air flow meter by a couple notches. I re-connected the air flow meter, and she would start but stall within a few seconds. I removed the air flow meter (at this time noticing some gas in the afm, kept the electrical connected, and it did the same: start but stall. I then disconnected the electrical again and it started and ran until put under power when it finally stalled again.

Before I shell out the money for a new air flow meter, I'm just curious if anyone else has any thoughts as to this dilemma - including if there's something else I'm missing inside the afm (which by-the-by has not been modified). I'm thinking about (1) pulling the fuel injectors to clean [which I was planning on doing just not this soon], and (2) replacing the vacuum lines as the fact that she was sitting under snow, driven approximately 2 hours, and than sat again in the cold may have cracked a line or two. I'm just not sure if there could be another gremlin at play that I'm over looking. Any thoughts would be greatly appreciated, thanks!

 

So here's an update - checked fuel pressure throughout the entire system - everything within normal limits. Removed temperature sensor and bypassed with paperclip. Car started with the air flow meter disconnected. For the heck of it decided to connect the air flow meter, but kept the air filter off - started and ran properly. Turned it off and connected the air filter. Yep, initially started then stalled, and ultimately would not start at all.

I think the only thing I can do at this time is buy another air flow meter and hope it fixes the problem.

 

Mmmmm, my S3 knowledge is quite limited but here goes.

On top of the airflow meter, just toward the engine of the black cover is large vertical hole, and down inside that hole is a large screw slot. Using a large blade screwdriver, turn that screw all the way down, then back it out about 4 turns. This is an air bleed screw, and does have a greater effect than most realize.

I also remember a TSB about a resistor fitment to 2 terminals inside the rubber plug of the airflow meter, and this was to do with overfueling, I think??.

Hopefully Doug will appear, and his S3 knowledge is awesome.

The fact it goes hissy when the air filter is attached, is that filter clean???.

 

Thanks Grant, I'm going to try that tonight and see if it has any positive effects. I read about the TSB which called for installing a resistor between between the two terminals, and it seemed like the jury was out on the impact it made in performance. Since I already have the cap off I'm going to stop by Radio Shack, buy the resistor, and solder it in place to see if it will have any impact.

I believe there are multiple gremlins at play here, most of which I believe involve the need for re-wiring. There was one day when I had the AFM disconnected, and the car was running - however, the heater blower motor would not work, and the car would not move (even a foot) when placed in gear (it would immediately stall). Two days ago, after checking the fuel pressure and again disconnecting the AFM - the car was running, the heater blower motor worked, and I was able to drive the car down the street (though it would stall under great pressure as mentioned above - going up a hill).

By-the-by: The air filter, though a bit dirty, did not appear to be in any condition where it would have been over restricting to the air flow. I'm going to put in a new air filter regardless.

 

You mention several things about testing AFM. I'm curious where to find info on all the goings of the AFM. Thanks

 

hi ive got a 82 series 3 with it looks like the same problem, have you solved it and if so what was the problem?

 

hi before you change afm put cog back to original position as you have probably gone too far if refitting air filter stalls it. temperature sensor may well have an issue but usually substitute with resistor not paper clip. i would check and clean idle valve and vacuum lines too. check that pump keeps running with afm connected. be gentle if moving afm flap by hand as quite fragile, adjustment screw on afm unlikely to be problem as too sudden a fault, should be allen key but be very gentle adjusting that as easily overtightened.corrosion or damp to wiring connectors are favourite after driving fine for hour and half or still muck in fuel line or distributor cap

 

Any updates on this? I have a similar issue

 

hi to all of you suffering running faults on your series 3.s i hope you have found the info you needed. just remember similar is not exactly the same and tests should be done in order and as accurately as possible or you can waste hours following the wrong path. good luck and a happy new year to you all from simon

 

i found when i took the injectors out and removed the rubber hose they where clogged with rusty sludge ive had them sonicly clean and now see runs like a dream.

 

I have found the cure - it involved parting out the darn thing, and putting more focus on my XJ-S Interestingly enough - even with 75,000 miles, in very good condition, I could not give this cat away even for $900. Although part-wise we're approaching the $2,000 mark which doesn't even inlcude the transmission or rear end.

 

Hahhahaha

Still have the afm you want to sell?

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