July 10, 20205 yr 17 hours ago, idosubaru said: Fuel coming out of that hose is not a common symptom. I’ve never heard of it happening and no one has yet mentioned what causes that so I’m assuming they haven’t either. Hooking up the wrong hose does it OP tells us
July 10, 20205 yr 9 hours ago, DaveT said: Get the engine up to operating temp. Shut down. Disconnect the connector. Connect an ohmmeter to the sensor leads [it has 2 wires]. Watch the ohms. take note of the hot, and look every 10 minutes or so. And for a while every so often. What you want to see is a slow rate of change, not jumping around crazyness. Somewhere on this forum I have posted some typical numbers and temps. The exact values are not super critical, but the general slope and smooth change is. I think some of us need a bank of DMM on dash to read from CTS, O2 and a few other sensors just so we know what things do when all is running fine I would love a fuel pressure gauge
July 10, 20205 yr 8 hours ago, G3.Spiffy said: Just to clarify, the CTS is the two wire one with the green connector that’s by the thermostat correct? The one wire one by it is the signal for the temp gauge and the one on the rad is for the fan relay? Yep two wires, green connector on my turbo EFI stuff, Different manifold design but should be in a water jacket, and not too far from single wire temp gauge sender
July 10, 20205 yr There was a time I was seriously considering building a gauge and simulation panel that would plug in between the ECU and the harness.
July 10, 20205 yr Author 4 hours ago, Step-a-toe said: Yep two wires, green connector on my turbo EFI stuff, Different manifold design but should be in a water jacket, and not too far from single wire temp gauge sender 2 hours ago, DaveT said: Yes, this is correct. Thanks, on to the testing portion 4 hours ago, Step-a-toe said: I think some of us need a bank of DMM on dash to read from CTS, O2 and a few other sensors just so we know what things do when all is running fine I would love a fuel pressure gauge 2 hours ago, DaveT said: There was a time I was seriously considering building a gauge and simulation panel that would plug in between the ECU and the harness. I’d love to have a better view of what’s going on at any given time as well, but the trouble with that for me is where to put aftermarket gauges... I’m too in love with the OEM styling of the car so would need to make a portable one for diagnostic purposes. Willingness to modify the car beyond stock is a hard one for me
July 10, 20205 yr Mine was exactly that, a diagnostic panel. No way to put that many gauges and indicators on the dash. Plus it would be crazy making when just driving around normally.
July 10, 20205 yr Author Nice! It would definitely be a useful (although highly specific) tool to have at your disposal
July 10, 20205 yr Author 17 hours ago, DaveT said: Get the engine up to operating temp. Shut down. Disconnect the connector. Connect an ohmmeter to the sensor leads [it has 2 wires]. Watch the ohms. take note of the hot, and look every 10 minutes or so. And for a while every so often. What you want to see is a slow rate of change, not jumping around crazyness. Somewhere on this forum I have posted some typical numbers and temps. The exact values are not super critical, but the general slope and smooth change is. So, I just finished my CTS testing. I was unable to find where you previously posted “normal” values for this specific test, but based on the numbers I got I think my CTS is fine. Results are as follows: Tested resistance before starting the car, totally cold, just to cross-reference the value with the FSM value for 68°F, which is about the temp it is out in the morning. Value was 2.454 kOhms, which is dead center of the FSM range. Ran the car until warm, turned it off and immediately tested resistance: 320.85 Ohms 10min: 0.401 kOhms 20min: 0.498 kOhms 30min: 0.584 kOhms 40min: 0.671 kOhms 50min: 0.762 kOhms 60min: 0.849 kOhms Probably could’ve stopped here, but wanted to be absolutely sure 70min: 0.934 kOhms 80min: 1.013 kOhms 90min: 1.134 kOhms Assuming these values are normal (as previously stated, I can’t locate the thread with proper values posted in it), would the next logical thing to test be my fuel pressure under different conditions (upon startup, warm up, driving, asking a lot of the car, going up an incline, etc)?
July 10, 20205 yr Yeah, since the 2 known temps were in range, and the drift while it cools was normal, I'd say it's ok. I found it, searched for ohms - CTS Test - put the sensor in a pan with some water, on a stove top. Use a thermometer and an ohm meter. It took a while, looking through my FSMs and finding my old notes - Water temp sensor ohms 14F 7000 - 11500 68F 2000-3000 122F 700-1000 Above are from the FSM. Below are actual measurements. Done at 2 different times, compiled here. The 1990 unit was in a good running engine. The new dealer unit was bought locally, and I made the measurements before installing it to get the extra reference points. measured ohms temp 1990 used new dealer unit 77F 2390 122F 1154 1098 185F 400 190F 454
July 10, 20205 yr Author Awesome! I have complete sets of both the 1986 and 1990 FSMs, so I have their “ideal” values, but real world data is exponentially more useful imo!! Glad to have this for future reference
July 11, 20205 yr Honestly at the age of these electronics and with their inability to deliver real time diagnostic data...... if you really want to run that hot garbage I would just wire up a stand-alone to it. A LINK Monsoon would run that no problem and make diagnostics much easier. Not to mention you can just re-calibrate for any sensor drift issues, etc: https://dealers.linkecu.com/G4X-MonsoonX-ECU Also the CTS, etc testing should be done at the ECU connector, not at the sensor. Need to do both but it's what the ECU see's at the other end of the wires that's important. GD Edited July 11, 20205 yr by GeneralDisorder
July 11, 20205 yr Author 9 minutes ago, GeneralDisorder said: Honestly at the age of these electronics and with their inability to deliver real time diagnostic data...... if you really want to run that hot garbage I would just wire up a stand-alone to it. A LINK Monsoon would run that no problem and make diagnostics much easier. Not to mention you can just re-calibrate for any sensor drift issues, etc: https://dealers.linkecu.com/G4X-MonsoonX-ECU Also the CTS, etc testing should be done at the ECU connector, not at the sensor. Need to do both but it's what the ECU see's at the other end of the wires that's important. GD At this point in my build I don’t think that would be practical for me, especially considering I have zero experience in tuning or with stand-alone systems Once I have a better understanding of those systems I can see how it would be very beneficial, and will keep it in mind for the future!
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