My 348 Stalls when in Neutral any Ideas

This is basically what I am saying but when you block off the idle motors, you will have to turn the screws out probably about 2 turns each to get it to even idle enough to start syncronizing the banks.

[And those clogged expansive valves are fun. Especially on the TR. I try to change out those receiver/dryers about every 5 to 8 years.]

 

Anything special involved in "blocking off the idle motors" on a 348?

 

When I had to reset the synchroniation of my throttle bodies on my 348 I used the mechanical adjustment of the throttle plates as the primary adjustment and the air screws just to fine tune the balance. I first set the throttle plate opening distance at .05 mm(measured between plate and the wall of the body) with air screws opened only about a one turn and blocked the off the air motors and reset the potentiometers at, IIRC, at 520mV or somewhere in that area(when I opened the throttle plates the meters were out) then started the car, after it warmed up the idle settled out at about 800 rpm. To get the idle to around 950 or so I opened the gap on the throttle plates(balancing the 2) and then opened the air screws just a touch to get 1050 rpm(balancing the 2).
My point of my discusion here is that I noticed quite a bit better throttle response which I thought was do to using the throttle plates as the primary adjustment of the idle instead of the bleed screws. IIRC the bleed screws before were set at 3 or so turns out and the throttle plates were almost closed tight(I was surprised they were closed so much). What do you guys think all in my head on the throttle response or what? Regards, Vern

 

ND, I used round rubber stops that you can buy at the hardware store and insert into the hose connected to the valve.

 

Oh, that's good. So you left the hose connected to the intake plenum, but disconnected that hose at the plastic valve side and placed the rubber stops there?

Nice tip, thanks.

 

If the 348 idle air bypass screws are analogous to the idle air bypass screws on my old Corvette (old, ha, ha...it was a '95), then it makes sense to me that you would get more precise throttle control/response with less air going through the bypass and more air going through the butterfly throttle body opening...since that's the part that the throttle is controlling.

If the 348 idle air bypass screws work differently, then I have no idea.

 

Remove the hose at the air cleaner side ie; inlet side to the valve and insert the stopper there. Don't unplug the connector that will turn on the CEL not that it will make any difference but there just no need to disconnect it.

 

Nice tip, thanks.

 

Yeah, it should run fine on either 95 octane or 98 octane. Certain fuel at certain servos can be contaminated - you've no doubt read about some unscrupulous servo operators in the Sydney area using unauthorised additives in their fuels such as ethanol !!!

 

So, the turning of the screws worked for you too>?

 

No problems since (about a year now).
BT

 

I have a battery disconnect switch in the front of my 348 which I utilise when the car is dormant (I'm paranoid about electrical fires in vehicles as well as electrical drains) - are you guys saying that it's wrong to disconnect the battery when the car is not in use. My vehicle also has an on-board battery charger which I just plug into to the mains and trickle charge as and when required.

 

Uh huh. You're pretty well screwed.

 

Don't mind Husker; he's just being funny in his own way.

 

Ummm - can you elaborate on that comment?
I was trying to be serious. I still drive the car when the battery 'is' connected you know !

 

The thing about disconnecting the battery is that if you then just hook it up and drive off without re-initializing, the Motronic ECU's may lose their baseline settings and give you running problems or unstable idle. I don't think you can damage anything in this way, you just have to take a few minutes to set it up again. Real easy. I wouldn't make any adjustments on the other settings until I had performed the re-initializing. I haven't unhooked my battery in about three years, and my 348 has never stalled at idle (not that I can remember).

 

Thanx for the above advice. I've turned the cut-off (isolation switch - black knob) switch off and on, then driven my vehicle without any problems so far (6 months ownership). Does this mean I've been lucky or is disconnecting at the battery itself the cause of the unstably running/idling problems?

 

Reinitializing A/F ECUs: Disconnect your battery for 15 minutes (this can be done by turning your battery disconnect switch). Hook it back up, start your car, and let your 348 idle for 10 minutes. Do not touch the accelerator (before or during). Your ECU's are now "re-initialized." It's not that tough!

NOTE: Re-Initializing your ECUs is required whenever you change ECU chips or any major air or fuel or timing engine component. This process is also useful for solving some minor electrical gremlins.

 

Your car must be an earlier model than mine (mine is 12/93 compliance). My battery is located under the passenger side (RHD vehicle) front fender adjacent to the wheel arch. Above the battery and located in the square hole with two pins to hold down the lid, is a factory fitted battery isolation switch with a black knob attached. I'm not sure what the situation is with batteries located in the 348 engine bay. Maybe the brotherhood can assist you there.

 

Thanks for explaining the ECU reinitialization process - much appreciated advice. This probably explains why I haven't experienced problems so far with idling/stalling (after reconnecting the battery isolation switch) as I generally warm my vehicle up in the garage for 10 min or so, prior to takeoff.