I have a 1989 Cherokee 4.0L Manual.
When it is cold and I start it up, it idles around 600-700. Watching the tachometer, I can watch the RPM's slowly rise, in unison as the temperature. Idle will reach 1000-ish this way. After driving it normally around town, and highway etc, it'll idle at 1200-1300. I've set the TPS to 0.837 volts, and devided that by the input volts to make around 17% (what one of me Renix manuals says). So that's perfect.
Checked grounds, they all seem ok. Can someone give me detailed pictures of every single ground? I did notice that, with the positive lead of the voltmeter in terminal C (the top one) of the TPS, and the negative lead grounded on the block, it registered a higher voltage than when the negative lead was in terminal B of the TPS. Ground issue? How would I resolve this?
At the idle speed of 1000 (not driving it, but letting it warm up to it's top idle speed), I disconnected the TPS, and IAC, to no effect. Once when I got it to 1300 RPM by revving it and letting it drop, I turned off the engine, cycled it, then let it start up again. Idle was 950. TPS? I tried revving it and such again, but idle remained at 950.
I have tightened my valve cover, and all of my top intake-manifold bolts are tight (can't get to bottom ones, there's a heat shield in the way). Cleaned and checked my throttle body for tightness - it was tight. Here's the thing:
If I put my finger or a plate over the IAC intake hole, absolutely nothing changes in the engine speed. I noticed that the plunger was pretty visible also, almost fully extended? I put a book over the entire throttle body, and the engine went way down in RPM's, but it still idled. Obviously a vacuum leak? I would also like some diagrams of which vacuum lines I can pull and such. IE I don't know if I can pull the one for the fuel return line.
Frusteraaating.
When it is cold and I start it up, it idles around 600-700. Watching the tachometer, I can watch the RPM's slowly rise, in unison as the temperature. Idle will reach 1000-ish this way. After driving it normally around town, and highway etc, it'll idle at 1200-1300. I've set the TPS to 0.837 volts, and devided that by the input volts to make around 17% (what one of me Renix manuals says). So that's perfect.
Checked grounds, they all seem ok. Can someone give me detailed pictures of every single ground? I did notice that, with the positive lead of the voltmeter in terminal C (the top one) of the TPS, and the negative lead grounded on the block, it registered a higher voltage than when the negative lead was in terminal B of the TPS. Ground issue? How would I resolve this?
At the idle speed of 1000 (not driving it, but letting it warm up to it's top idle speed), I disconnected the TPS, and IAC, to no effect. Once when I got it to 1300 RPM by revving it and letting it drop, I turned off the engine, cycled it, then let it start up again. Idle was 950. TPS? I tried revving it and such again, but idle remained at 950.
I have tightened my valve cover, and all of my top intake-manifold bolts are tight (can't get to bottom ones, there's a heat shield in the way). Cleaned and checked my throttle body for tightness - it was tight. Here's the thing:
If I put my finger or a plate over the IAC intake hole, absolutely nothing changes in the engine speed. I noticed that the plunger was pretty visible also, almost fully extended? I put a book over the entire throttle body, and the engine went way down in RPM's, but it still idled. Obviously a vacuum leak? I would also like some diagrams of which vacuum lines I can pull and such. IE I don't know if I can pull the one for the fuel return line.
Frusteraaating.
