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DogpawSlim

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Everything posted by DogpawSlim

  1. Thanks Moses. I ordered a used canister as I couldn't find a new one. I will post the outcome when I get it installed.
  2. I'm sure Moses will chime in, but the ground locations should be 1) the dipstick support tube (the negative battery cable should go here, and three or four black wires from the harness) and 2) a braided strap from the driver's side of the head to the firewall.
  3. Good news and bad news. I replaced the computer (found a good deal on a reman), and the solenoid now closes at idle (no vacuum at the output). I am, however, still getting vacuum downstream of the evap canister. You may remember that my canister was not holding vacuum. Are these canisters repairable, or should I just look for a replacement?
  4. I can't find a light to hack up for the light test, but I checked the resistance an continuity of all the ECU wires to a solid engine ground. My results are attached below: 2.5 ECU Pinout.pdf I'm not sure how to interpret this. It looks like the main ECU grounds are functional. The "EGR control" wire at pin 5 seems okay all the way to the solenoid (no resistance). The other side goes to the fuel pump relay, and this wire seems fine as well. I did some further digging into my ECU and found this: I may have to amend my statement that the ECU isn't toast. What do you think? Thanks, Greg
  5. I replaced the TPS, and it is idling smoother, but the EGR is still getting vacuum. I cleaned all the ground locations I could find (dipstick support and firewall to head).. I traced the ECU side of the solenoid back to the ECU with a multimeter, and the connection is solid. I jumpered the solenoid, and the solenoid works as it should (i.e. when the ECU side is grounded, the solenoid closes and vacuum to the EGR is cut off). I think I've narrowed it down to either 1) there is an incomplete ECU ground somewhere, or 2) the ECU is toast. I doubt the ECU is toast because this is my only symptom. Also, the ECU internals look okay (i.e. solid traces and no fried components). Are there any other ground points I should look for? Thanks, Greg
  6. Thanks Moses, I will replace the TPS and do some further testing and will report back this weekend. And the emissions timer is indeed disconnected.
  7. The EGR functions fine: opens when vacuum is applied and closes when removed. I jumpered the original solenoid from the blue wire (ECU to the diagnostic port and EGR solenoid) and the solenoid did not activate (still had vacuum at output). If my procedure was correct, I will jumper the new solenoid and see what happens. I forgot to mention that I tested the TPS, but was unable to get the voltage in spec at WOT. I maxed out at 3.8v, and I believe I should be around 4.6v based on the percentage formula. Could this be a potential cause? Also, should the MAP sensor hold vacuum? The voltages tested within spec, but the sensor leaked vacuum when a hand pump was used. Thanks again for your time. Greg
  8. Instead of considering the solenoid vacuum at idle as the problem, I started thinking of it as a symptom. The MAP sensor tested fine per the FSM procedure, as did the WOT switch. The (new) CTS has 330 ohms resistance at operating temp. The o2 sensor has 17 ohms resistance, which is out of spec per the FSM (5-7 ohms). Is there any other part of the system that could be malfunctioning and tricking the ECU into not engaging the EGR solenoid? Thanks again for your help.
  9. I tested the canister at the purge port a few weeks ago, and it would not hold vacuum. I will try the water trick later today. The solenoid output has vacuum at idle. Assuming this one is good, is there any particular ground wire I should check? Should I pull the ECU and look for burned out parts?
  10. Thanks Moses. I installed a new (used) solenoid, but the problem remains. Do you have any suggestions on where I should go from here?
  11. Back from checking the jeep: the vacuum lines are routed correctly, and the canister is not holding vacuum. Following diagnostic procedures, there is vacuum to the solenoid source at idle and there is vacuum at the solenoid output at idle. Based on the diagnositc procedures, I should "check solenoid/ECU operation with the DRB-ii Service Diagnostic Tester and repair as necessary." I doubt I will be able to find a DRB-ii here in 2014. Is there a workaround? Thanks in advance.
  12. Thanks for your detailed response, Moses. I am away from the jeep until next weekend, but I will run the tests with a pump gauge (instead of my finger) and double check the vacuum lines over the weekend and will post my findings. Thanks again.
  13. This site has been very helpful with my current EGR issue, but I've reached an impasse. My electronics experience is limited, so I'm hoping for some help diagnosing the problem. The jeep is a 1990 YJ, 2.5l. My EGR is getting vacuum at idle, so, it idles rough or stalls out when the vacuum line is connected. The diaphragm appears to be working correctly: if I connect the vacuum source, the EGR valve opens and closes when I remove it. The lower outlet at the EGR solenoid has vacuum at idle, so it does not appear that the vacuum canister is causing the issue. There is no voltage reading across the pins on the solenoid connector at idle. There is battery voltage from the red wire to the negative battery terminal at idle, and battery voltage from the red wire to the positive terminal when the jeep is off. There is connectivity between the blue wire and the negative terminal when the jeep is off. The CTS tested fine, per the FSM. Any help would be greatly appreciated.
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