I've got a 91 non-turbo. Check engine light is on. When short the test connector the CEL flashed 9 times which I have found to be the water thermo sensor. I've only got a Hayne's manual and it barley mentions this part.

I want to make sure what I'm doing before I do it. Is this the green thing on the back of the water pump? If so how does it actually come off?

 

It is on the back of the filler neck/water pump. Your best bet is to take off the alternator to get at it. It has a hex shape built into the base, so just slip a wrench on it, and take it off like any other nut.

 

I replaced the sensor and I still get the CEL.

I'm pretty lost now :-/

 

Did you reset the ECU?&nbsp The codes are flashed PROM'd, so you'll need to reset the ECU by disconnecting power to it for a few minutes...



-Ted

 

Yeah. I verified that by pulling the harness for the oil squirter and when the key was on it flashed the code for that too.

 

I think if I had that car, I'd go to the ECU and put a meter on pin 2E(here's hoping its the same as a 89), with the connector hooked up, and start the engine and watch the meter. It should start out at 2-3v and decline to about .5v, give or take .1 or so volts. If you have no reading at all, then wring out the wiring b/t the ECU and the water thermo sensor and also check to see if there is 12v on the other wire on the sensor.

 

I actually got it mostly fixed. The first time I couldn't figure it out. Both sensors that I had on hand were fine resistance was exactly in spec. When I check for voltage on the pins of the connecter I got .5v.

Well... last night I had no voltage at the connector. Then I moved and had voltage. Then I moved and it was gone again. Then I saw a break in the insulation.... and a break in one of the wires :-/

Needless to say a quick electrical tape job will work until I get a replacement connector.

 

HAYNES-HAZY MANUAL DON'T WAIST YOUR TIME OR MONEY. go to iluvmyrx7 and down load the maunal for your car. great site PEACE. ex...

 

I would always recommend you get both the FSM and the Haynes. Sure the Haynes doesn't have half the info the FSM does, but it has two things the FSM doesn't: lots of clear photos (as opposed to simple sketches) and clearly worded step-by-step descriptions of how to do things. This is relly useful for the backyard mechanic.
Also, you'll need to go to www.fc3s.com for a FSM suitable for a 91, iluvmyrx7 doesn't have it (only 86-88).

 

I looked at both of those sites. I did get the resistance range from one of them. The haynes manual does skip over some stuff but it's been pretty decent so far.

The pictures REALLY help. I'm just in a way glad that it was the fault of the guy that swapped the engine (which is a story i don't want to get into right now).

The 7 is running great now. 800 miles on a rebuild with ALL the sensors finally working and the throttle cable and idle set properly (more of the story...).

Thanks for steeping in with help though.