TR fuel system problems

Um, to throw my 2 cents worth in here, but on 328 (K-lambda) the CSI only fires for 2 seconds or so (cold engine) until TTS cuts the signal. This can be verified with test bulb on blue input connector. Unless the KE behaves substantially differently, I would expect this to be true for TRs also? Now the FI temp switch (on coolant reservoir tank for 328) signals the FI system to go from "open" to "closed" loop. As I recall, I measured three distinct FV duty cycles (65%/72%/75-76%) as car went from cold to warm.

Hope I'm not throwing fuel on anything here...(cheesy pun intended)!

Carl

Oh BTW Jeff, I've lent it out currently but offer to send along the Gastester open if it would help you...!

Carl

Hank...yes the a/f ratio swings on both banks. I have all new gaskets on the intakes, which I carefully assembled. Can't imagine a vacuum leak. I will check the various hoses going to the intake plenums, disconnect each one and plug the hole and see if the a/f ratio is affected. But deep down I believe it's like you said, the differential pressure actuator is fluctuating. This change should be caused by the fuel ECU signal...this is why I'm considering disconnected the ECU plugs from the fuel distributors to see what happens. I would think with the O2's disconnected the fuel ECUs would go to a "lean stop" position or at least be stable with little variation.

Carl....Thanks for the information, very good to know. I will have access to a gas tester at a local auto shop soon, for a small fee, when they have an open bay on a Saturday to "play around". Thank You againf for your generous offer, I will consider "renting" if from you if things don't work out. Such a great bunch of guys here!

Great Mr. Green!

Now one other thing to look at (very strange, turned out to be my problem): resistance from battery cable to chassis was zero with ignition off but increased to 300-400ohms with key on; this was sufficient to play havoc with FI components and fuel pressure, etc.

I *always* get the strange stuff...(sigh)

Carl

That battery cable resistance is wierd...I replaced the factory coupler at the frame rail with a really high quality sealed connector that uses allen screws to secure the cables. I'll take a look there and elswhere anyway...you never know. Why would the resistance increase with voltage? Is this physically possible?

Tinkered around more with the fuel mixture last night. With the O2's unhooked, at 1100 idle, I have both banks at around 13.5 - 14.0:1 ratio. When I increase the rpms even slightly, it goes leaner...and does not change even if the increased idle rpm's are held constant. I thought it was supposed to a linear situation where the fuel mixture is constant no matter what rpms? I understand that acceleration, deceleration will be rich/lean, but steady rpm's should be steady mixture? Also does anyone have an actual vacuum (psi) reading from their TR? I'm getting around 14psi at idle both banks at 1100 rpm. Increasing idle speed by opening the bypass screws results in leaner mixtures. If I compensate for this, then when rpm's are back to 1100 it will be rich. This seems to contradict the Bosch manual which states the air flow and mixture are linear......hmmmmm. I know that the air diffuser funnel shape affects mixture also, the steeper the funnel makes for a richer mixture and visa-versa. Does the throttle micro-switch figure into this somehow? Mine "clicks" when the throttle is moved just off it's stop, which I think is correct. Just full of questions aren't I?