DTC woes after exhaust work
04-03-2010, 09:17 PM
#1
DTC woes after exhaust work DTC codes:
36; High Resolution Pulse Circuit (Check Opti pigtail)
42; Ignition Control Ground Circuit (check ICM wiring)
Ok, I had my EGR fitting removed/ welded over by my exhaust guy (minor leak). This turned out to be the first bad trip to him because he didn't get to it until the next morning after I told him I was going to my tuner the next morning. I made arrangements last Thursday to leave it with him all day on Monday. I get there Tuesday morning after having been assured he'd have it ready to roll by 10:00 so I could still make my appt. with my tuner for the last tweak after addressing a few minor mechanical odds and ends. I get there and his kid is working on it. Ok, that's ok, he must be pretty good learning from the master, right? I leave for the tuner an hour behind schedule, but it's ok. I took both days off to deal with all this.
Tune goes great, totally happy with everything and then... about a block from the house the car cuts off, I restart it, SES light is on, running like ****. I roll into the driveway, cut it off and look under the hood for clues.
O2 extention on the right side didn't get tied back away from the header and it's crispy. I wait long enough for it to cool off and pull the extension off to see how bad it is. the corrugated sheath is gone, but the 4 wires inside appear to be intact, insulation ok. I crawl under and tie it back.
Today I borrow a scanner and retrieve the codes and clear them, hoping the O2 harness just shorted and freaked out the PCM. This evening, SES light is back on, will borrow the scanner again in the morning and find out which code(s) stuck.
Car was perfect and now it's a huge ******* hassle. No time to deal with it Wednesday, no answer at the exhaust shop Thursday or Friday. Now I have to go over everything with a fine-toothed comb to look for **** the kid may have damaged in my ******* engine harness by pulling **** around to R&R the right side header.
Anybody have history with a ~harness shorting on header~ problem like this? Should I be looking for a PCM just in case?
fukk fukk fukk...
36; High Resolution Pulse Circuit (Check Opti pigtail)
42; Ignition Control Ground Circuit (check ICM wiring)
Ok, I had my EGR fitting removed/ welded over by my exhaust guy (minor leak). This turned out to be the first bad trip to him because he didn't get to it until the next morning after I told him I was going to my tuner the next morning. I made arrangements last Thursday to leave it with him all day on Monday. I get there Tuesday morning after having been assured he'd have it ready to roll by 10:00 so I could still make my appt. with my tuner for the last tweak after addressing a few minor mechanical odds and ends. I get there and his kid is working on it. Ok, that's ok, he must be pretty good learning from the master, right? I leave for the tuner an hour behind schedule, but it's ok. I took both days off to deal with all this.
Tune goes great, totally happy with everything and then... about a block from the house the car cuts off, I restart it, SES light is on, running like ****. I roll into the driveway, cut it off and look under the hood for clues.
O2 extention on the right side didn't get tied back away from the header and it's crispy. I wait long enough for it to cool off and pull the extension off to see how bad it is. the corrugated sheath is gone, but the 4 wires inside appear to be intact, insulation ok. I crawl under and tie it back.
Today I borrow a scanner and retrieve the codes and clear them, hoping the O2 harness just shorted and freaked out the PCM. This evening, SES light is back on, will borrow the scanner again in the morning and find out which code(s) stuck.
Car was perfect and now it's a huge ******* hassle. No time to deal with it Wednesday, no answer at the exhaust shop Thursday or Friday. Now I have to go over everything with a fine-toothed comb to look for **** the kid may have damaged in my ******* engine harness by pulling **** around to R&R the right side header.
Anybody have history with a ~harness shorting on header~ problem like this? Should I be looking for a PCM just in case?
fukk fukk fukk...
04-06-2010, 06:27 PM
#2
Just had a chance to recheck codes today, code 36 was the only one that stuck in the interim. I did check the ICM vs. the previous code 42, 11.9V at A and D to ground, good V~ at B during cranking (see "Opti and Spark Test" at http://shbox.com/1/4th_gen_tech2.html#opti_test).
I pulled the Opti pigtail, it looks fine on both ends, no crud or corrosion. Plugged it back in. Over the weekend while waiting to use my buddy's scanner again I did have a chance to get it in the air and look for misplaced wires, damaged/ loose grounds, etc. and found nothing out of order.
Cleared the code after inspecting & reinstalling the Opti pigtail. We'll see what happens over the next couple of days...
Scenario is occasional hard starting when warm, after a stop for a few minutes (fueling, pack of smokes, etc.) and then start with SES light on. Runs fine, does not miss at all in lower or upper RPM ranges. SES light goes out when engine is turned off and does not come back on until bad starting behavior repeats (2x now).
This is the original Opti and was cleaned (was in very good shape at 69k miles) and had an MSD vented cap/rotor kit 8481 mated to it in December (yes, with red loc-tite on the rotor screws). 1300 trouble free miles until last Tuesday. Maybe coincidence and I went the wrong way with the Opti and should have visited the thepartsladi... maybe my PCM got killed... maybe a bad Opti pigtail. If I run out of troubleshooting steps, I'll buy $20.00 pigtail, then a used PCM, then a new Opti.
I pulled the Opti pigtail, it looks fine on both ends, no crud or corrosion. Plugged it back in. Over the weekend while waiting to use my buddy's scanner again I did have a chance to get it in the air and look for misplaced wires, damaged/ loose grounds, etc. and found nothing out of order.
Cleared the code after inspecting & reinstalling the Opti pigtail. We'll see what happens over the next couple of days...
Scenario is occasional hard starting when warm, after a stop for a few minutes (fueling, pack of smokes, etc.) and then start with SES light on. Runs fine, does not miss at all in lower or upper RPM ranges. SES light goes out when engine is turned off and does not come back on until bad starting behavior repeats (2x now).
This is the original Opti and was cleaned (was in very good shape at 69k miles) and had an MSD vented cap/rotor kit 8481 mated to it in December (yes, with red loc-tite on the rotor screws). 1300 trouble free miles until last Tuesday. Maybe coincidence and I went the wrong way with the Opti and should have visited the thepartsladi... maybe my PCM got killed... maybe a bad Opti pigtail. If I run out of troubleshooting steps, I'll buy $20.00 pigtail, then a used PCM, then a new Opti.
04-20-2010, 10:37 AM
#3
Final results: Was able to rule out the secondary ignition wiring and PCM through troubleshooting. Consistent code 36 returning after engine is warm and then turned off. Restarting is hard, spins 7-8 seconds, catches and throws code 36. Before it happens it runs great.
Mitsubishi optical encoder in the original Opti (71k miles), 15.5 year old part, slowly simmering since November 1994. Anyone want to invent the "Opti cooling mod?"
So my exhaust guy is exonerated, though he did cause me some hassle. I ordered the Delphi CZ20009 Opti from thepartsladi on Sunday. I'll be putting the MSD 8481 cap & rotor on it since they're a little stouter and only have 1300 miles on them.
Mitsubishi optical encoder in the original Opti (71k miles), 15.5 year old part, slowly simmering since November 1994. Anyone want to invent the "Opti cooling mod?"
So my exhaust guy is exonerated, though he did cause me some hassle. I ordered the Delphi CZ20009 Opti from thepartsladi on Sunday. I'll be putting the MSD 8481 cap & rotor on it since they're a little stouter and only have 1300 miles on them.
04-28-2010, 02:33 PM
#4
Interesting update: I replaced the Opti yesterday and got a look inside the old one. The bearing came apart, littering the inside with shiny chunks of bearing. The encoder wheel had enough wobble that FRICTION between it and the encoder was causing enough heat to result in weak hi res signal.
Shouldn't have reused that Opti during the build. Pennywise, pound foolish. Funny, the only thing I went cheap on and I should have known better.
Shouldn't have reused that Opti during the build. Pennywise, pound foolish. Funny, the only thing I went cheap on and I should have known better.
