83 245 stalls at idle

My 83 240 turbo wagon with 740 in tank, new in line and 15g and 90+ mani has a big idle dip when I come to a stop that sometimes stalls the car. It's got good fuel pressure out of the filter, I haven't checked anything else. Should I suspect the fuel distributor? It's inconsistent with being either very rich or lean when this happens, but I notice it's going very lean most of the time. It also goes very rich on decel, not sure if that's normal or not for k jet. I have the fuel pressure tester to check the WUR and FD pressures, but I'm not sure what to look for or if there is any adjustment other than just replacing parts.

Don't forget 240T K-Jet also has a separate CIS module to regulate idle control. You may need to check the micro switch and/or butterfly plate setting, or do the CIS diagnostic to function test the idle motor, etc...

I had to move the idle switch when I put on the b230 intake, but it still more or less clicks when I crack the throttle. Maybe I'll play with the adjustment there and see if theres any change. I wonder how hard it is to put the new style switch on.

adamdrives said:

I had to move the idle switch when I put on the b230 intake, but it still more or less clicks when I crack the throttle. Maybe I'll play with the adjustment there and see if theres any change. I wonder how hard it is to put the new style switch on.

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The standard LH2.2/2.4 TPS should work in place of the old microswitch - since it's just open/closed contact, not resistance.

From what I recall if you try to use the switch that is the LH2.2/2.4 type throttle switch. You have to move a wire internally so it works the same as the kjet switch. Basically so normally open and normally closed are the same as the kjet switch.

Wiring layout for CIS ...

Ok awesome, that should be a piece of cake. Thanks for the diagram dad

The other thing you might have to do is adjust the throttle stop screw, since the plate may be slamming closed, causing the car to dip in idle. I've had a couple 240s (my original '82 242T and my blue 245Ti that I'm getting ready to purge) that would do that... Adjusted the base idle, and it was better. Strangely enough, both cars also had their timing well advanced (around 15-16 deg BTDC). Air/fuel mixture should be between 42 and 48 degrees dwell with the sensor disconnected, dropping to 41-44 degrees when the sensor is reconnected. CO content between .7 and 1.3% at 900 rpm.

dl242gt said:

From what I recall if you try to use the switch that is the LH2.2/2.4 type throttle switch. You have to move a wire internally so it works the same as the kjet switch. Basically so normally open and normally closed are the same as the kjet switch.

Click to expand...

^^^ Yes, the K-Jet idle switch is the opposite of the EFI idle switch -- K-Jet is Opened when at idle; EFI is Closed at idle. I'm sure that swapping throttle bodies without changing the switch connections will confuse K-Jet.

I've never opened up the TPS black box on an EFI TB, so I don't know if you can swap a wire on the switch between open and closed closed contacts. You could always add an external relay to convert the TBI idle switch to K-Jet compatible.

Once the switch is sorted out, section 242 (K-Jet CIS) in Bentley is your friend. You may also find the brickboard FI FAQ useful for adjusting the TB:
https://brickboard.com/FAQ/700-900/EngineFuelinjection.htm#EngineFuelInjection

^ I actually have that guide printed out at work as a reminder on how to set throttle switches. Very handy info.

Welp, I did get the correct b230 tb installed today to compliment the manifold, but that was not the source of my issues. Turns out, k-jet does not like BOVs. Live and learn. After I got the tb in and set the throttle switch, I was snapping throttle with the hood open and watching the bov open and close as the car struggled to keep running. Disconnected the vac line and no more issues. This also solved my rich in decel/stinking exhaust problem I made another thread about. Im not happy to admit how long I've been having this issue, but at least its fixed.

Since the throttle signal is reversed in CIS, it's not just a simple matter of moving wires at the switch. I'm not actually sure what the iac is doing, and im too tired to think about it, but the car runs and idles fine with the ground and power hooked up how it would be with lh. I'll have to figure out how to wire that so that the computer can control the iac as it would in CIS.