1989 Eliminator

I also bought this setup of fittings. A 1/4" female flare to 1/8" NPT Female straight and a 1/8" NPT Female x 1/8" NPT Male Elbow. I did this since I can look at the guage better this way. I got these off of McMaster Carr. Around $12 total. Part#: 6432T117 http://www.mcmaster.com/#catalog/120/195/=su11cn (Update... Bought the flare fitting and the threads are not deep enough to catch the threads on the fuel rail.) Part#: 4452K471 http://www.mcmaster.com/#catalog/120/4/=su11ql

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.

Replaced my IAC and the idle is still rough :/

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.

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.

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.

Yeah thats okay. The voltages were .1V - 4.5V after startup.

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?

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

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.

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.

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!

Cruiser, I cleaned those plugs with contact cleaner and applied di-electric grease. Somewhere else in the wire is the issue. Jhickman, TCU is Transmission Control Unit. Sometimes people call it TCM which stands for Transmission control module. ECU is Engine Control Unit. It also can be called ECM.

Yes I have. I checked all my sensors but when I checked the TPS i only did the ECU side. From the diagram in the manual the tps grounds to the dipstick/engine and a separate wire coming from the TCU (which is apart of one of the trans connectors) also grounds there. So my guess is that somewhere in the wire harness there is a broken wire or something.

Yup! I totally know how important that is. I already made my own grounds for other sensors. Its just weird about that one ground with that high resistance. Ill have an update sunday.

Right. Thats what i was going to do directly. Because as of right now it comes from the TPS-across the firewall-then splices. But i didnt have enough time. I was doing continuity tests from the TPS connector to different wires to find the reason for the high resistance. I have my FSM electronic manual and ive been following that. I am making sure the TCU also has a good ground.

Yeah I also did that and everything checked out okay. But I did check the resistance of the ground on the transmission side of the TPS (4 prong connector) and it was well over 2000 ohms. So, I plan on just making my own ground straight to the engine block ground. This would work correct?

The EGR will be in saturday but I did some more thread searching and found this one...: http://www.naxja.org/forum/showthread.php?t=905849&highlight=Renx+files&page=8 This is a very long thread but around page 8 is where he figured his problem out. He said it was his TPS but mine is new like his was and he said it was bad out of the box. I did the same ohm test as he did and my values concurred with his. So I at least know my TPS is okay. As far as if the TCU and ECU are getting those same readings is a different story. BTW...my truck recently has a new symptom of mis-shifting between 3th gear and 4th. The truck will be going around 45 mph and then not shift. The rpms will reach 2500 around 65 mph and when i step on the gas the truck shifts up and the rpms go down but only for a short span of time. ????????? :dunno: :wall:

Yeah... A plate and plug for the exhaust manifold. But its illegal technically. And I'm not sure how the truck would run without it. During acceleration and high rpms the ecu tells the egr solenoid to open which then opens the egr valve. And if its not there then I'm not sure what will happen. So i just ordered a new one

Update on my progress. I ordered a new egr valve. Reason being is one time i took off the vacuum hose from the transducer to the egr valve and water came out. A bad egr could be causing my issue. So I'm trying this

Hm okay. I'm still stuck of what to check next

Yes thats the voltages after the truck is warmed up a few minutes after startup.

So the that voltage difference is good? It was switching every second. Like its supposed to. I do not know what to check next. I'm at a stand still!

Okay call me crazy. But why wouldnt this work... If i made a rod made out of metal or wood the same diameter of the iac hole, couldnt i just take the iac out but still connected and place the rod in the throttle body so i can manually adjust the amount of air. And since the iac is out i could then observe if its moving at all

So what brand should I get for a new IAC. $70 autozone $140 Mopar