jhickman Posted July 4, 2014 Share Posted July 4, 2014 This is a very informative topic and I've been following it with interest because I just bought an 88 but I don't know all of the acronyms that are being used. Is there somewhere on the site that lists the acronyms or could someone give a quick rundown of them.....I know TPS but I'm not sure of the TCU and ECU. Thanks. Hope this helps! http://comancheclub.com/topic/12163-acronyms/ (July 2014 MJOM) Wow, just what I need, thanks for the link! Link to comment Share on other sites More sharing options...
cruiser54 Posted July 4, 2014 Share Posted July 4, 2014 This is a very informative topic and I've been following it with interest because I just bought an 88 but I don't know all of the acronyms that are being used. Is there somewhere on the site that lists the acronyms or could someone give a quick rundown of them.....I know TPS but I'm not sure of the TCU and ECU. Thanks. This should help. Click on the link in my signature and read/perform items 1 through 5. You will become more familiar with acronyms and your Jeep in general.... Link to comment Share on other sites More sharing options...
cruiser54 Posted July 4, 2014 Share Posted July 4, 2014 This is a very informative topic and I've been following it with interest because I just bought an 88 but I don't know all of the acronyms that are being used. Is there somewhere on the site that lists the acronyms or could someone give a quick rundown of them.....I know TPS but I'm not sure of the TCU and ECU. Thanks. This should help. Click on the link in my signature and read/perform items 1 through 5. You will become more familiar with acronyms and your Jeep in general.... Link to comment Share on other sites More sharing options...
jhickman Posted July 4, 2014 Share Posted July 4, 2014 This is a very informative topic and I've been following it with interest because I just bought an 88 but I don't know all of the acronyms that are being used. Is there somewhere on the site that lists the acronyms or could someone give a quick rundown of them.....I know TPS but I'm not sure of the TCU and ECU. Thanks. This should help. Click on the link in my signature and read/perform items 1 through 5. You will become more familiar with acronyms and your Jeep in general.... Will do, thanks. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 8, 2014 Author Share Posted July 8, 2014 Well.... Bad news. New egr is on and I fixed the tps ground issue on the TCU side and still no improvement. I did the egr test again. When i unplug the solenoid connector and all the vacuum hoses are connected the truck makes no change in rom. When i hook up the hose coming from the solenoid directly to the egr valve the truck stalls. Which is good. Idk what to do next! Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 8, 2014 Author Share Posted July 8, 2014 I'm thinking MAP because there could be an internal bad connection or its not getting enough vacuum. So i will get an actual vacuum reading at idle to start off. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 8, 2014 Author Share Posted July 8, 2014 Update: Sprayed the inside of the MAP with eletronic cleaner and made sure all grounds I could find had close to 0 resistance. Double checked TPS again. Tested the MAP and the inital voltage was 4.6 and when running it dropped to ~1.4 V. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted July 9, 2014 Share Posted July 9, 2014 Still running like poop? Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 9, 2014 Author Share Posted July 9, 2014 A few seconds after start up itll vary in idle still quite a bit. The. After warm up the idle will hover around 600 rpm. Still "hunting" for correct idle. So its still not there yet Link to comment Share on other sites More sharing options...
cruiser54 Posted July 9, 2014 Share Posted July 9, 2014 Refresh me about your oxygen sensor. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 9, 2014 Author Share Posted July 9, 2014 Its brand new from autozone and I was getting correct readings (from what you said). You can look back from what the readings actually were i forgot. I also said the heater was working but I am going to double check that. I went back through my manual and it seems that the fuel pump relay has four orange wires going to 87. The o2 sensor has two orange going to 87a and one orange going to 87. I will double check later today. And just to double check my knowledge, 87a and 30 should have 12 V. 87, 85, 86 should have no voltage. Correct? Link to comment Share on other sites More sharing options...
cruiser54 Posted July 9, 2014 Share Posted July 9, 2014 Can't look that up right now, but if the O2 sensor heater doesn't get heated, your O2 sensor doesn't work. I was too lazy to re-read the thread. Sorry. If you click on the link below and scroll through, you'll see not only some nifty Jeep technical photos, but a diagram of the REnix relay center. http://www.cherokeeforum.com/members/cruiser54-42565/albums/jeep-technical-photos/ Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 9, 2014 Author Share Posted July 9, 2014 Yeah thats okay. The voltages were .1V - 4.5V after startup. Link to comment Share on other sites More sharing options...
Dillithium Posted July 9, 2014 Share Posted July 9, 2014 I'm following this thread, too. I have a low idle when cold and it hovers quite a bit, nearly stalls everytime I depress the clutch and then picks itself up. its mysterious for sure. Link to comment Share on other sites More sharing options...
cruiser54 Posted July 9, 2014 Share Posted July 9, 2014 I'm following this thread, too. I have a low idle when cold and it hovers quite a bit, nearly stalls everytime I depress the clutch and then picks itself up. its mysterious for sure. Do the ground refreshing. Post 1 in my Tips. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 9, 2014 Author Share Posted July 9, 2014 Okay and here are the results... with pictures! :brows: with the relay out of the connector: 30, 87a, and 85 all have conductivity 2.1 ohms for resistance of pin 85 85 goes to solenoid (dark blue with white stripe) 30 goes to o2 sensor (orange) 87a goes to connector which goes to sync? (black) 87 goes to another connector which runs somewhere (light green) 86 goes to solenoid with fuseable link with truck running: 30,87, and 87a all had 14 V I had the ground of the multimeter on pin 85 while testing for these voltages I also switched relays from the a/c relay light green wire is 87 black one on the very right is 87a solenoid: bottom left with white stripe wire is 85 top left orange wire is 86 So from my thinking in the picture above...... 30 should always have the 12V power source when 85 and 86 get power from the solenoid then pin 87 will have the 12V power when 85 and 86 are not energized 87a should have the 12V source plus.... it shows that there is a yellow wire and three oranges. which looks like the relay on the opposite end. I used this diagram in your picture cruiser to chose the o2 sensor relay on the very right but it seems like the wrong one to me. :dunno: :doh: :???: :hmm: But when i tested for voltage 87 and 87a both had 12V. Something isnt right. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 10, 2014 Author Share Posted July 10, 2014 In the diagram it looks like the heater should initially be on and then when the ecu goes into closed loop mode the coil engergizes and then the power source coming from 1will then be routed to 4 on the relay. Link to comment Share on other sites More sharing options...
Dillithium Posted July 10, 2014 Share Posted July 10, 2014 I'm following this thread, too. I have a low idle when cold and it hovers quite a bit, nearly stalls everytime I depress the clutch and then picks itself up. its mysterious for sure. Do the ground refreshing. Post 1 in my Tips. Just did this while replacing my rotor, cap and leads. It helped significantly. I also did the contact points on my coil. I should've gone through your list ages ago, but there were so many mechanical issues to tackle first. It still has a low idle, but it doesn't waver nearly as much as it did.. Thanks Cruiser! Link to comment Share on other sites More sharing options...
cruiser54 Posted July 10, 2014 Share Posted July 10, 2014 There's a good possibility that my diagram is correct and the FSM is wrong. You could do a continuity check to verify. I'd appreciate it. You could also unplug the O2 sensor, start the Jeep and check for power between the red and black wires. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 12, 2014 Author Share Posted July 12, 2014 Okay so today I did a lot of wire testing to check for high resistances and for power where there needs to be. The O2 has power going to it. My manual FSM is CORRECT for the 02 heater relay. If standing by the passenger side wheel and looking down at the relay towers, the 02 heater relay is the one on the very left. So cruiser... the picture you have is wrong in my case. I also took the connectors off the ECU and tested various wires/sensors to make sure there is a good connection. To do this a made a simple jumper wire from the target sensor/wire to my driver side door area. This gave me enough length to probe my jumper wire to the ECU connectors. Doing this I tested: TPS wires all grounds air temp input coolant temp input wires coming from relays map sensor B+ Latch relay wires I seem to have good connections everywhere. My thought now is that since connections are good there is a driver/device issue. Sensor or ECU... My O2 and TPS are new and adjusted to be working correctly My MAP values seem to be within spec. voltage drop of 2.2V My air and coolant sensors are close in values 1760 and 1988 respectively The only thing I cannot test is the IAC So I might just replace that and see what happens. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 13, 2014 Author Share Posted July 13, 2014 Replaced my IAC and the idle is still rough :/ Link to comment Share on other sites More sharing options...
cruiser54 Posted July 14, 2014 Share Posted July 14, 2014 Have you done #9? Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 14, 2014 Author Share Posted July 14, 2014 Yes I sprayed both the connectors and the ecu pins with electronic cleaner. Then I carefully bent the female connector recepticles so they contact better. Link to comment Share on other sites More sharing options...
cruiser54 Posted July 14, 2014 Share Posted July 14, 2014 Refresh me. What brand spark plugs are you using? Link to comment Share on other sites More sharing options...
1989 Eliminator Posted July 14, 2014 Author Share Posted July 14, 2014 I recently replaced my plugs with Champion Coppers Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now