j9fd3s

iTrader: (3)

i don't know why people bother with the haynes, its like a playboy without pictures.... the FSM has a page with the TPS adjustment. i like the two light method, as its the output from the ecu, everyone else seems to set the resistance of the tps, which is the input, and discounts the harness, ymmv, the certainty is that the TPS is out of adjustment

re the brake adjust, i checked the master to booster clearance on mine and it was way out. the pedal to booster clearance was close to right. haven't driven my car yet, as its midway through a series of treatments, but 1mm at the master/booster, is like 5mm at the pedal... i expect a big difference in feel, or the brakes to lock on.

spectre6000

iTrader: (1)

I know the Haynes sucks, and I usually don't bother with them, but it came with the car and I haven't printed off the FSM yet... I don't want to take my laptop out there to sit in the sun. It's on the edge of existence right now anyway, and I make my living with it, so best not to tempt any demons.

I started with the clutch switch test. Either mine doesn't work or it didn't exist in '86.

The spec I wrote down said the TPS should measure out at ~1KΩ with the engine off at operating temperature, and 4-6KΩ at WOT. I adjusted it to within a 10Ω (1/100th of a K) of 1KΩ, cycled it a few times, and verified. Then I checked the WOT reading, and either my switch is bad, or the spec I read/wrote was off by an order of magnitude... It was between 500-600Ω toward the high side... Hopefully that's how it's supposed to read. It cycled smoothly upward from 1KΩ, then dropped straight to the 5XXΩ reading.

I turned it back on, and it still stumbled around a bit. I cycled the throttle a few times, and it leveled out back to about where it was before messing with the TPS. I attempted to adjust the idle up a bit (since it's on the low side), and the screw was very non-responsive. I used the screw at the very top of the intake manifold, but maybe there's another one somewhere... The way it topped/bottomed out across such a short range and didn't really do anything makes me think I might be missing something.

Assuming the spec was off, I proceeded to check timing. It was a skosh advanced, so I put it back to happy.

Since it's still stumbling, the TPS is (I think) properly adjusted, and the idle set screw did just about nothing, I think I have a vacuum leak. I sprayed some PB'laster around on the vacuum lines/caps hoping to find a leak, but didn't. I may have to take the manifold off again this coming weekend to track it down... What a PITA.

If my TPS specs are way off, please let me know so I can save some time. I don't really want to spend a ton of money on the thing, but it would save a ton of time.

clokker

iTrader: (2)

There are two clutch switches, neither of which affects the way the car runs, so which one are you checking and why?
Did you have the initial set grounded as you adjusted the TPS?

spectre6000

iTrader: (1)

The clutch switch is simply supposed to prevent it from starting if the clutch is not depressed. It was one of the initial checks in the Haynes manual, and it is tested by literally just turning the key without depressing the clutch when you start it. Max time investment of 1 second.

I did not, but the manual did not say to do so. The resistance test of the switch itself shouldn't care, and the other doesn't seem to want it.

j9fd3s

iTrader: (3)

the clutch switch that effects the starting was introduced mid 87, and only in the US, because we have trouble starting our cars without going through the garage door.

spectre6000

iTrader: (1)

https://www.rx7club.com/2nd-generati...eeded-1081090/

That is the majority of what I just went through. I could use some help there.

Additionally, and on a slightly different subject, between my checks I started the engine up again to make sure it was fully at operating temperature. When I shut it off (hot), I noticed the fan kept going. Mayhap I'm looking at either a fan clutch (seems to be NLA) or an electric fan setup soon too... The bastard just keeps fighting!

spectre6000

iTrader: (1)

Good news. I guess it passed the test after all!

lduley

iTrader: (1)

When it comes to your idle, i'd go through the idle relearn adjustment thats in the FSM, you have to jump the check connector, adjust the screw on the top of the manifold, then the variable resistor IIRC, i had to do it twice in one summer once

spectre6000

iTrader: (1)

Can you either elaborate on that or point me to a specific page in a specific manual?

j9fd3s

iTrader: (3)

http://foxed.ca/rx7manual/manuals/Tr...ing_System.pdf page 3-8.

fan isn't locked up until 90c, which would be like half way up the gauge

spectre6000

iTrader: (1)

So, the "variable resistor" is the little R/L potentiometer between the air box and the strut tower. That's the functional equivalent of the idle mixture screw on a carb (now it's in terms I understand).

What does the check connector actually do? It's one of the green plugs at the DSF corner just behind the light. I stick wires in it (which makes my brain hurt), and it...

Once I do that, I check the resistance of the switch again? And then?

clokker

iTrader: (2)

Just to keep my pedantry polished, I'll point out that the thermoclutch never locks up nor does it ever freewheel. It runs between about 20-80% of engagement all the time.

I have a spare efan you may be able to utilize, spectre.

spectre6000

iTrader: (1)

Alight, Iduley... I went and gave it a shot. I even broke down and took my laptop out there so I would have the manual handy.

As per the manual (p. 4A-77) I went and did the TPS tests (back to p. 4A-50). I warmed it up, turned it off, turned the key back on, and adjusted the TPS set screw so that the one lead on the test plugs gets voltage (10.5V). Then I shut the key off, fully unplugged the TPS itself, and tested the resistance as per the manual (p. 4A-50). The spec should be 1KΩ in the idle position (which should be set according to the first test), and 5KΩ ±1KΩ at WOT across two leads, and 5KΩ ±1KΩ at idle AND WOT on the other two. What I got instead in the former scenario was 1.276KΩ in the idle position and infinite resistance at WOT. In the latter scenario I got infinite resistance at idle and 521Ω at WOT... Not even a loose approximation of spec. From there, I can't actually set the idle mixture, because I can't get it to set and hold an idle...

The Volts/no Volts state at the test plug could conceivably be affected by whether or not the initial set coupler is jumpered. Who knows, it's a black box. Testing the switch itself is 100% agnostic to the state of the initial set coupler, and that thing is not reading right. Is there something I'm missing?

lduley

iTrader: (1)

Theres voltage at the plug whether or not the check connector is jumped or not, jumping the connector pretty much just tells the computer "hey, ***** changin"

So....your getting 10 volts at the G/B wire with the red probe of your multimeter in that wire and black to ground? With the plug still connected?

spectre6000

iTrader: (1)

At the test plug between the air box and the shock tower, not at the TPS. I haven't measured voltage at the TPS yet. Going to do that here in a bit hopefully.

lduley

iTrader: (1)

That isn't the check connector, the plug you jumper is drivers side, behind the battery and is green, only has 2 wires

clokker

iTrader: (2)

One of those wires is orange and the other just goes to ground.

spectre6000

iTrader: (1)

Right. The manual indicates the green three lead test plug between the air cleaner box and the PS shock tower. That's the one I tested for voltage. The jumper is an entirely separate affair, and is not specified in the manual as part of the test.

I'm about to go out there, drive around a little bit to get it up to operating temperature, then I'll change into my grubbies, and start poking and prodding... I have a fresh battery on my phone. Maybe I'll take a video. There seems to be a wealth of miscommunication going on, and I imagine it has a lot to do with my poor grasp of the vernacular.

spectre6000

iTrader: (1)

Video attempt failed due to ancient technology being ancient...

I did manage to set the TPS via voltage at the sensor plug. 1.00V sweeping cleanly and smoothly to 4.60V. I did this with the battery side jumpered plug jumpered. Then I went and started it back up. There was a decent delay due to my videography attempts and technological fumblings, and by the time I went to restart it, it had cooled down somewhat. Once started, it would rev to something a bit higher than idle, then just die. I was able to feather the throttle to keep it turning while it warmed up back to operating temperature, then attempted to manipulate the idle adjust screw. It did nothing. I wasn't able to adjust the idle mixture as a result.

I'm working on solving my phone issues, and will hopefully have video shortly. I'm hoping that someone with more educated eyes and ears will be able to see what's going on and point me in the right direction.

lduley

iTrader: (1)

When you started it back up did you remove the jumper? When you have it jumped and running the motor will run like crap until you unhook it

spectre6000

iTrader: (1)

I don't know that I did initially, but I certainly have since. It runs like crap at the moment. I solved the tech issues and took some video, but now I have a new tech issue that makes my phone forget how YouTube works, so I'm having to upload it with my laptop, which is somehow even slower... I'm having serious issues today...

spectre6000

iTrader: (1)

Helped out a friend up in Boulder, and got to drive the car around quite a bit today. The idle is now MUCH smoother, but it's still backfiring in the exhaust a good bit and wanders probably about 10 RPM in a fairly consistent fashion. Before I left, I tested out the BAC and the MAF temp sensor. The BAC seems to be OK, but the MAF temp sensor is pretty dead. It reads to spec for a split second, then looses conductivity. If I tap it again with the probe, it'll read slightly lower, then no conductivity, and repeat. Lower readings equate to higher perceived temperatures, so essentially it's burned out. It looks like I could probably replace just the temp sensor if I could find a good one, but the MAFs only seem to come as (expensive) units. Clokker said something this past weekend about the myriad options for replacing it with better things, so I'll have to look into that when I find a little time.

I think my idle issue at this point is pretty much just the temp sender there sending a false (non) reading. If I get that sorted, I can probably do a better LBI tune and make it happy. In order to get it happy as it sits, I think it's ended up pretty pig rich... I can smell it in a way I hate smelling on other people's (typically carbureted and tuned for sea level) cars.

Extrapolating a bit, I imagine the non-reading on the MAF temp sensor probably causes the ECU to retard the timing and richen the mixture in a safe mode of sorts. It may even be wandering around as a result of the conflicting readings it's getting from the myriad other sensors that don't think it's really cold assuming non-conductivity is perceived by the ECU as high resistance, which the sensor puts out in response to colder temperatures. I don't know if it's that smart, but that's what I would do if I were an ECU seeing that reading...

clokker

iTrader: (2)

To be clear, the only option I presented was the S5 AFM.
I had seen a crossover/swap diagram to wire a S5 meter to a S4 ECU and have a spare unit already configured to test (we tried it on the Z).
I have no idea how this swap actually works but do have the parts handy to try.
If you think your current unit is bad and have no replacement, there's not much to lose.

(Just search the forum for S4 to S5 AFM swap- or something like that- and you'll find the diagram.)

spectre6000

iTrader: (1)

I thought you said something about having seen people using a Ford part (the type that hangs down in the air flow) or something like that. I'll be looking into it in the near to now term for sure. If you're offering that S5 unit, and you already know how to hook it up though, I don't think I'd hesitate to take you up on it.

clokker

iTrader: (2)

That discussion was about the Z with a Megasquirt...options abound for sensors with that setup.