Plain Jane OEM nothing to see here rebuild

[vrracing]

Sorry, Jeff. ISC is Initial Set Connector. I believe that is the standard term. It is the single green plug near the battery/main fuses you ground whenever setting the idle. We had it on and off so much when doing the swap I made a wire with a male spade and a ring terminal. But even though it was attached to a cleaned bolt holding the main fuses to the shock tower it wasnt delivering a good signal to the ECU.

The fast idle adjustment needs to be set so that when the engine (well the wax) is cold the green topped drum is aligned with one of the marks on the cam and when hot (the piston rises) the green topped drum is aligned with the other mark on the cam.

Good luck. It gets better!

[JustJeff]

Got the wideband wired up and calibrated. Other than pulling the downpipe and having a friend weld the bung and doing the wiring the engine hasn't been started since I last set the idle and TPS a day or two ago.

Idle was set at around 750-800rpm. TPS was at 1V and ranged nicely up to 4.75V. Full range is still off by about .2something-.3V but it ranges even with no deadspots. I verified at both the TPS harness as well as the ECU.

I finish the wideband install and start up the engine and it's back to just barely being above 0rpm. I let it warm up and no change. At idle the afr was 11.7ish. I drive the car around maybe a 1 mile loop get back and idling afr was at 10.8.

I used the simulated narrow output and tapped that in right at the ECU.

Here's a video of it after taking the drive. I was taking it up to about 3000rpm and the wideband would go to open air 22.4 and then come back down to 10.8.

http://www.youtube.com/watch?v=LtDPndOIeaQ&feature=youtu.be
I tried having it displayed directly in the thread but couldn't figure out how to do it.

[RETed]

Originally Posted by JustJeff

-Ted

[JustJeff]

^ hehe how did you do that??? I know I've posted vids before but couldn't figure out how it's done?

The gauge will eventually move to my A pillar but I've got a situation where the screws holding the convertible top attachment were seized on (locktite at the factory?). I tried impacting them with a hammer on screwdriver and that did nothing. After stripping them I've started drilling them out. Short story long, I need to get my A-pillar off in order to change my single gauge holder to my double and add the wideband there.

I may go play with the idle again and wideband more...though I"m a little frustrated and may step away from it for a day.

One very curious thing the wideband was doing while I was driving was sporadically going to open air. Every so often it would go to 22.4 hold a second or two and then return. My ground may not be the best (under the shifter bracket). Gonna try regrounding in a better spot.

With the idle it seems like I set it, come back and it's not where I set it anymore.

[RETed]

Originally Posted by JustJeff

^ hehe how did you do that??? I know I've posted vids before but couldn't figure out how it's done?

You need to grab the YouTube unique "name" for the vid and dump it between the "YOUTUBE" brackets...
You can't just cut&paste the entire URL, i.e. "http://..." - that just rewards you with a nice black square on the screen. :P

Basically, you cut&paste the random letters and numbers after the "watch=" string in the URL.
So the entire URL you pasted was: "http://www.youtube.com/watch?v=LtDPndOIeaQ&feature=youtu.be"
All you need is this part: "LtDPndOIeaQ"
If you click <QUOTE> on my reply and stare at it, you'll figure it out.


-Ted

[JustJeff]

^I tried doing that with my post but on preview it showed a blank box, so I assumed it was a dead video

Getting back to the car. Can my full range TPS being off by .3 or so V be enough to cause my problems? The narrow range seems to be dead on. This coming week I"m going to talk to an electrical instructor about borrowing an osciloscope to test the TPS.

I'll at least pull the CEL codes today, see if they tell me anything.

[RETed]

Wish I could help you out with those questions...

Mines is an S4, and I haven't messed around with an S5 with the E-OMP to get enough info for you.
I vaguely remember the full-range TPS doesn't matter so long as it's linear...?


-Ted

[JustJeff]

Originally Posted by RETed

Wish I could help you out with those questions...

Mines is an S4, and I haven't messed around with an S5 with the E-OMP to get enough info for you.
I vaguely remember the full-range TPS doesn't matter so long as it's linear...?


-Ted

Yeah, it's linear...no drops in the range on either full or narrow. I've heard an osciliscope is a better test and if it's as easy as borrowing the tool and hooking it up I'll test it that way.

[Pete_89T2]

Originally Posted by JustJeff

Yeah, it's linear...no drops in the range on either full or narrow. I've heard an osciliscope is a better test and if it's as easy as borrowing the tool and hooking it up I'll test it that way.

As long as it's linear, with no drop outs its should be fine. Referring to '89 FSM, page F2-81 cites a resistance measurement spec for the TPS, full & narrow ranges. To test, disconnect the TPS connector, and measure resistance across the TPS connector terminals it references at closed & wide open throttle conditions. Do this with the engine at operating temp OR you can use a screwdriver to lift the fast idle mechanism off the thermo-wax plunger so the TB is not sitting at a high idle for the closed throttle measurements.

Full range TPS @ wide open throttle should be 3.4 - 5.1 K-ohms; at closed throttle it should be 600~900 ohms. The narrow range is 0.8~1.2K ohms closed, and 4.0~6.0K ohms WOT.

[JustJeff]

^ that is a good point, I've done both resistance and voltage tests on this TPS. I'm told that testing for voltage is more reliable because it tests the TPS under load. But I can cross-reference voltage test with resistance test and they should both be good. If one is good you'd assume the other is. If they aren't the same then something is amiss.

[JustJeff]

I've opened up my FSM to look over the checklist for rough idle. I'll go down the line and test all those.

One question related. The water thermosensor:
I'm curious if it would work to test the water thermosensor for resistance but at the ECU pin rather than the sensor itself?

Reason being, to test per FSM means removing it, draining coolant, etc. Is there any reason why I can't start with a cold engine to test resistance at the ECU and let the engine warm up while testing?

[Pete_89T2]

Originally Posted by JustJeff

One question related. The water thermosensor:
I'm curious if it would work to test the water thermosensor for resistance but at the ECU pin rather than the sensor itself?

Reason being, to test per FSM means removing it, draining coolant, etc. Is there any reason why I can't start with a cold engine to test resistance at the ECU and let the engine warm up while testing?

The problem with doing it that way is your DVM/ohmmeter puts some voltage across the terminals you're trying to measure a resistance across. If it's still connected to the ECU with power applied you could potentially harm the ECU. Also, unless you have a good aftermarket temp gauge, how will you know the water temp when you're taking the resistance measurement?

Assuming you do have a temp gauge, one option would be to run the car until warmed up, then jot down the water temp off the gauge and shut it down. Disconnect the battery. Then disconnect the ECU connectors, and do your resistance measurement across the two ECU harness connector pins that connect to the water temp sensor. That will only get you one test sample though, so you still won't know if the temp sensor works across its full range. IIRC, the FSM gives 3~4 temp points to measure resistance on that temp sensor.

[JL1RX7]

Originally Posted by Pete_89T2

The problem with doing it that way is your DVM/ohmmeter puts some voltage across the terminals you're trying to measure a resistance across. If it's still connected to the ECU with power applied you could potentially harm the ECU. Also, unless you have a good aftermarket temp gauge, how will you know the water temp when you're taking the resistance measurement?

Assuming you do have a temp gauge, one option would be to run the car until warmed up, then jot down the water temp off the gauge and shut it down. Disconnect the battery. Then disconnect the ECU connectors, and do your resistance measurement across the two ECU harness connector pins that connect to the water temp sensor. That will only get you one test sample though, so you still won't know if the temp sensor works across its full range. IIRC, the FSM gives 3~4 temp points to measure resistance on that temp sensor.

If its a RTD or resistance temp device it should have table somewhere about the resistance readings. So say 1k ohm means 72 degrees. Wouldn't really matter if you got multiple readings as long as you get a good resistance reading.

Also resistance will determine your voltage. So if your TPS has a "dead spot" it won't matter if you're reading voltage or resistance. One you when off, the when on.

[JustJeff]

Originally Posted by Pete_89T2

The problem with doing it that way is your DVM/ohmmeter puts some voltage across the terminals you're trying to measure a resistance across. If it's still connected to the ECU with power applied you could potentially harm the ECU. Also, unless you have a good aftermarket temp gauge, how will you know the water temp when you're taking the resistance measurement?

Assuming you do have a temp gauge, one option would be to run the car until warmed up, then jot down the water temp off the gauge and shut it down. Disconnect the battery. Then disconnect the ECU connectors, and do your resistance measurement across the two ECU harness connector pins that connect to the water temp sensor. That will only get you one test sample though, so you still won't know if the temp sensor works across its full range. IIRC, the FSM gives 3~4 temp points to measure resistance on that temp sensor.

Yes I have an aftermarket temp gauge, a Prosport, which isn't name brand, but it' seems to be about dead on. The sender for the temp gauge is tapped into the front of the water pump housing and is taking a reading at the same spot the OEM thermosensor is.

I also have a temp gun I could point at the water pump housing, radiator, hose, etc.

I was thinking the same thing about taking multiple readings, per FSM. I could test as the engine is warming up. Turn off the engine at each temp test and continue to the next....ugh but that means taking the UIM off each time to get to the thermosensor harness.

Originally Posted by vrracing

Our RTek 2 shows the temperature reading from the ECU on the Palm. Does the 1.7 not have that capability?

No logging on Rtek till you get to 2

Originally Posted by JL1RX7

If its a RTD or resistance temp device it should have table somewhere about the resistance readings. So say 1k ohm means 72 degrees. Wouldn't really matter if you got multiple readings as long as you get a good resistance reading.

Also resistance will determine your voltage. So if your TPS has a "dead spot" it won't matter if you're reading voltage or resistance. One you when off, the when on.

The FSM has 3 temps to take resistances at and what the corresponding resistance should be, but not really a full scale that I know of. I suppose I could take resistance readings when they are at the resistances for a specific temp (per FSM) check the temp of the coolant to see if they line up.

With the TPS, yes we are kinda saying the same thing...I was more round about. But laws of electricity say that if there is a dead spot in voltage test there will be one for resistance also. I meant something is amiss, as in it wasn't tested correctly..not probed correctly and such.

[Pete_89T2]

Originally Posted by JustJeff

Yes I have an aftermarket temp gauge, a Prosport, which isn't name brand, but it' seems to be about dead on. The sender for the temp gauge is tapped into the front of the water pump housing and is taking a reading at the same spot the OEM thermosensor is.

I also have a temp gun I could point at the water pump housing, radiator, hose, etc.

I was thinking the same thing about taking multiple readings, per FSM. I could test as the engine is warming up. Turn off the engine at each temp test and continue to the next....ugh but that means taking the UIM off each time to get to the thermosensor harness.

Don't need to take the UIM off... What I was suggesting in my previous post is you take your readings off of the 2 water temp sensor pins on the ECU connector, after disconnecting it from the ECU. BTW, the resistance reading you'll get this way will be a little higher than what the FSM states for the temp sensor, but it shouldn't be by much more than a few ohms. This is because you're also measuring harness cable losses to the sensor.