sounds good

Not trying to overload you.  That one test result, showing wide open throttle, should be causing your engine to run really gassy though.  So you must have another problem, or that result is wrong.  Easy to get the probes in the wrong spot.  Once you have an out-of-spec. result though, then you can focus on what that part of the system controls.

Actually, the wide open part isn't adjustable.  So it might just be dirty or the wires are shorted.  It's a fairly crude mechanism.

and what about the temp sensor, that one is the one that will cause problems during warm up, then drops out of the equation after the engine is hot. Note the Temp sensor is not the Temp gauge sender, that does nothing for the EFI.

I mentioned that in #82 but it's buried in other words.  The OP is probably at that point where he's thinking "maybe I should replace all of this EFI stuff with carbs?"

I assume op means other person which would be me I'm on board with everything you guys are saying and we have gone through a lot of it but I'm in a delicate situation because I don't know a whole lot about this stuff and I don't want to insult him as a mechanic I think he has some pride and I'm just stepping carefully on how much I can tell him to do but for whatever reason he keeps telling me it's not the coolant temp sensor I'm hoping to get him there tomorrow and adjust the TPS and check that  coolant temp sensor, I love the fuel injection to keep the car original.

OP means original poster.  The guy that started the thread.

Yes, the sensitive tech problem.  It shows up occasionally.  People will get on to a forum and announce that they are an ASE certified tech but then realize that they don't know how these old systems work.  Lots of teeth-gnashing and nasty words ensue, typically.

If you want to give him the foundation for the whole system show him the first few pages of the Engine Fuel chapter, and the "fuel enrichment" chart.  It's all about adding fuel to a base injector open time.  Then he can reason things out as he goes.  More satisfying.

Don't forget the off-setting problems theory either.  He might be thinking the coolant sensor isn't involved becuase they usually run rich when that's a problem.  But you seem to be running lean.  He's focused on lean.  A shorted coolant sensor circuit would cause lean.  By the way the sensor is often shortened to CTS.

My CTS was decidedly low ohm for given temp, That's one part that I would def replace if its the original part (40 years old). But that does not mean assume a new is good, must check before install. ALL my thermostat stuff ended up getting replaced as it was all off enough or not working at all. That would be

Temp sender (for gauge) (poor calibration)

Temp sensor (for EFI) (MUCH lower ohms for a given temp than it should have been)

Water temp switch stuck open (EGR on my Cali car, distributor timing on others) EGR was recirc with cold engine.

ThermoTime  switch (cold start injector) stuck open while not a big deal here in FL could be an issue on cold days during winter. I ended up going with a 85f just to make starting a bit easier (think the stock will not fire unless under 70f). I suspect I am just covering for a loss of pressure to the injectors after sitting over night. My fuel pressure holding period is somewhat erratic.

Most of these will not stop the car from running or even be a big deal once it warms up (I do like a working temp gauge to keep an eye on things so I don't overheat), but I am something of a perfectionist on this stuff and figure there are enough things that I maybe missing that I don't have the luxury of ignoring the stuff I KNOW is wrong.

Edited July 6, 20168 yr by Dave WM

2 hours ago, Zed Head said:

Don't forget the off-setting problems theory either.  He might be thinking the coolant sensor isn't involved becuase they usually run rich when that's a problem.  But you seem to be running lean.  He's focused on lean.  A shorted coolant sensor circuit would cause lean.  By the way the sensor is often shortened to CTS.

Mine was just like what Zed says. The potentiometer was to add fuel on mine. It would spit and sputter through the intake and buck like a mad horse until 2,500 rpms then it ran good and pulled hard.

Thats what had me focusing on the TVS.

My mechanic friend clamped the return hose to add more fuel and it ran better. Thats when I did the volume knob from radio shack.

Those sensors in the thermostat housing can be cleaned up. Sandpaper or a bench grinder with a wire wheel. The thermotine connector could be switched around with the CTS connector, check that too.

Sorry for all the post, just got in and scatter brained at the moment.