88mjblue Posted April 30, 2015 Posted April 30, 2015 Back by the firewall. CPS is connected. Coolant temp for gauge is connected Intake temp is connected. What else is back there?
JeepsOLot Posted April 30, 2015 Posted April 30, 2015 Manual or auto? If a manual, it could be for a sensor for an auto that there's nothing for it to plug into. Jerry
88mjblue Posted April 30, 2015 Author Posted April 30, 2015 Manual. What other sensor is there for auto? I already removed the unplugged TPS thing for auto that is by the throttle body.
mjeff87 Posted April 30, 2015 Posted April 30, 2015 I can't see the picture, but the O2 sensor connector is back there as well. Is it a flat 3-pin connector?
88mjblue Posted April 30, 2015 Author Posted April 30, 2015 There's only 1 O2 sensor, correct? The O2 sensor that goes into the bung around the collector is plugged in and is wired underneath the intake/exhaust manifolds.
mjeff87 Posted April 30, 2015 Posted April 30, 2015 yep, only one. If yours is plugged in, that's not it. edit: I can see your pic on my iPad but not on my desktop (weird....). Definitely looks like the CPS connector to me, but yours is plugged in, so......I dunno :) Jeff
88whitemanche Posted April 30, 2015 Posted April 30, 2015 What color wires? Because it can be the wires to the auto trans
88mjblue Posted April 30, 2015 Author Posted April 30, 2015 Here's a better picture. Hard to tell color because of fading due to heat/age. But it looks like yellow w/tracer and pink w/tracer. Also has C B A on it.
87MJTIM Posted May 1, 2015 Posted May 1, 2015 Engine speed sensor? Connector C224, Violet w/ trace (A) and White w/trace (B ). It is about the right location - injector harness, back by the firewall. His wire colors are diff, thou. (Although, I see in the background purple and white wires. Should those plug together?)
cruiser54 Posted May 1, 2015 Posted May 1, 2015 Here's what probably happened. Your Jeep had the CPS bypass done at the dealer. The tech was supposed to clip off the original harness connector for the CPS and tape it back. He didn't.
88mjblue Posted May 1, 2015 Author Posted May 1, 2015 Engine speed sensor? Connector C224, Violet w/ trace (A) and White w/trace (B ). It is about the right location - injector harness, back by the firewall. His wire colors are diff, thou. (Although, I see in the background purple and white wires. Should those plug together?) Do you mean the CPS? (crankshaft position sensor) Because that is what you see in the background - that's the connector that goes to the cps.
88mjblue Posted May 1, 2015 Author Posted May 1, 2015 Here's what probably happened. Your Jeep had the CPS bypass done at the dealer. The tech was supposed to clip off the original harness connector for the CPS and tape it back. He didn't. You are exactly right! I went through my fairly detailed maintenance history and it does show a "flywheel sensor" done in March of 1989 from a Jeep dealership. I'm assuming that's the CPS? What would be the reasoning for a CPS bypass?
cruiser54 Posted May 1, 2015 Posted May 1, 2015 The CPS didn't generate a strong enough signal for the ECU. 1) The CPS was too far from the flywheel. The sensor in the bypass kit had a slotted upper hole. See my Tip 7. 2) There was too mush resistance in the stock harness and especially the C101 connector which reduced the signal the ECU got from the CPS. See my Tips 2 and 27.
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