ckuske Posted March 8, 2023 Author Share Posted March 8, 2023 Yep, that’s the plan tomorrow! In the Fuel section of the parts catalog, my truck is either Calibration 376 or 409 (not sure which, the label on the valve cover is long gone) Well I cracked it open, there was a little bit of leaves, sticks, etc in there. Just a couple pieces of junk. No loose components, no leaking caps, I don't see any burnt traces on the PCB. But I am not an expert. Ok, time to buzz out the ECU connector. Link to comment Share on other sites More sharing options...
ckuske Posted March 8, 2023 Author Share Posted March 8, 2023 Well I cracked it open, there was a little bit of leaves, sticks, etc in there. Just a couple pieces of junk. No loose components, no leaking caps, I don't see any burnt traces on the PCB. But I am not an expert. Ok, time to buzz out the ECU connector. I can't find the link now, but I just buzzed out those pin combinations (27/40, and 46/60) on the ECU connector. There is no continuity between those pairs of pins. I'm not sure if the EVP sensor connector is supposed be disconnected or not during this test. Also, I found this pinpoint test, but the wording is a little confusing to me. Am I supposed to plug the ECU back in for the last bullet in the test, or leave it disconnected? Its not clear to me how the readings could be ok checking continuity of EVP to SIGRTN and EVP to battery ground. Oh, ok, wait. We are checking for a short. I will check it... The ECU connector looks ok, but there is some yellowish grease in some of the pins - not sure if this is dielectric grease or what. Link to comment Share on other sites More sharing options...
ckuske Posted March 8, 2023 Author Share Posted March 8, 2023 I can't find the link now, but I just buzzed out those pin combinations (27/40, and 46/60) on the ECU connector. There is no continuity between those pairs of pins. I'm not sure if the EVP sensor connector is supposed be disconnected or not during this test. Also, I found this pinpoint test, but the wording is a little confusing to me. Am I supposed to plug the ECU back in for the last bullet in the test, or leave it disconnected? Its not clear to me how the readings could be ok checking continuity of EVP to SIGRTN and EVP to battery ground. Oh, ok, wait. We are checking for a short. I will check it... The ECU connector looks ok, but there is some yellowish grease in some of the pins - not sure if this is dielectric grease or what. Ok, I just ran those two tests.. Ohming out EVP to SIGRET was "0L" which means infinite resistance. EVP to the battery was 6.7 MOhms. This means I need a new processor, right? (The processor is disconnected, as that is what the instructions say to do. I'm still not 100% on that for some reason...) Link to comment Share on other sites More sharing options...
delco1946 Posted March 11, 2023 Share Posted March 11, 2023 Ok, I pulled it. It basically looks brand new still. I pulled vacuum on it and the valve seems to move freely as well. I did notice that the EGR cooler should have a gasket on both sides. I didn't remove it off the manifold yet, but if there is a gasket there, I sure didn't see it. Either it's fallen apart or isn't there. That would be a red flag (I think). If you slide the cooler on the bolts and try to mate it against the manifold, there's a small "clank". You would think if a gasket was there, it wouldn't do that... It looks like the same gasket should be on both sides of the cooler in the drawing below. I felt inside the cooler with my finger and got some carbon out. I guess I'll pull that next (how deep is this onion?). Before I go down that rabbit hole I suppose I should measure the EVP voltage to make sure that isn't throwing the ECU off... I’m no mechanic but If you replaced the Egr a couple years ago, I’m concerned with the amount of metal etching that I think I’m seeing on yours, left hand side. Pulled mine off and I dont think I had that and it’s prolly 4 years old - makes me think your engine internals are under a high acid environment. Are you driving short drives, not letting your engine warm up? Maybe it’s not coming to temp either if you are driving longer enough due to radiator/ cooling issue ( valve stuck open?). Also makes me think to check you pcv valve. They’re 3 bucks so I’d say replace it, it helped my idle and emissions (which can also lead to acidic internals). Mine was all gummed up, best 3 bucks ever spent đŸ˜†. Link to comment Share on other sites More sharing options...
ckuske Posted March 12, 2023 Author Share Posted March 12, 2023 I’m no mechanic but If you replaced the Egr a couple years ago, I’m concerned with the amount of metal etching that I think I’m seeing on yours, left hand side. Pulled mine off and I dont think I had that and it’s prolly 4 years old - makes me think your engine internals are under a high acid environment. Are you driving short drives, not letting your engine warm up? Maybe it’s not coming to temp either if you are driving longer enough due to radiator/ cooling issue ( valve stuck open?). Also makes me think to check you pcv valve. They’re 3 bucks so I’d say replace it, it helped my idle and emissions (which can also lead to acidic internals). Mine was all gummed up, best 3 bucks ever spent đŸ˜†. Neither am I, which I why I appreciate everyone's comments and support while helping me through figuring this stuff out! If its the picture I am thinking of, what you are referring to is a deposit of coating from the old gasket that was on the EGR, it is not etched. I should have cleaned if off before posting the picture. You are right about not letting the engine run long enough. I am trying to run it longer these days, and I hope to fix this problem and get in on the road more often. I can drive it as-is, but I want it to be solid for my son who's just learning to drive. I ordered a ECU, it will be here tomorrow. The plan is to plug it in and run a KOEO test first, and just see if the same codes are reported or things are "OK" then go from there. I've run the wiring tests for the EVP and everything seems to be passing, so hopefully the ECU is the problem and things run right! (No hesitation from an ECU fault in EVP circuit, and miss gone at high RPM) Link to comment Share on other sites More sharing options...
ckuske Posted March 14, 2023 Author Share Posted March 14, 2023 Neither am I, which I why I appreciate everyone's comments and support while helping me through figuring this stuff out! If its the picture I am thinking of, what you are referring to is a deposit of coating from the old gasket that was on the EGR, it is not etched. I should have cleaned if off before posting the picture. You are right about not letting the engine run long enough. I am trying to run it longer these days, and I hope to fix this problem and get in on the road more often. I can drive it as-is, but I want it to be solid for my son who's just learning to drive. I ordered a ECU, it will be here tomorrow. The plan is to plug it in and run a KOEO test first, and just see if the same codes are reported or things are "OK" then go from there. I've run the wiring tests for the EVP and everything seems to be passing, so hopefully the ECU is the problem and things run right! (No hesitation from an ECU fault in EVP circuit, and miss gone at high RPM) Ok, hopefully I am not speaking too soon. I had to leave home for a bit before I was able to finish things, but: The new ECU came in today. I installed it, and I ran a KOEO. NO CODES I then started the truck up, and it went to high idle. No misses or stumbles at all. I then gave it a quick punch of the gas and it stalled. BUT, I did change the accelerator pump throw in desperation move. I am going to change it back to the middle position it was in before later today, then hopefully take a test drive. Two of the three issues are fixed just by starting/testing in the garage. Hopefully the stumble at acceleration is fixed as well! I am guessing it will be, as the EGR/EVP is now getting processed properly by the system. I’ll check back in later, stay tuned… Link to comment Share on other sites More sharing options...
ckuske Posted March 14, 2023 Author Share Posted March 14, 2023 Ok, hopefully I am not speaking too soon. I had to leave home for a bit before I was able to finish things, but: The new ECU came in today. I installed it, and I ran a KOEO. NO CODES I then started the truck up, and it went to high idle. No misses or stumbles at all. I then gave it a quick punch of the gas and it stalled. BUT, I did change the accelerator pump throw in desperation move. I am going to change it back to the middle position it was in before later today, then hopefully take a test drive. Two of the three issues are fixed just by starting/testing in the garage. Hopefully the stumble at acceleration is fixed as well! I am guessing it will be, as the EGR/EVP is now getting processed properly by the system. I’ll check back in later, stay tuned… I have to leave again (kids are keeping me busy!) but I just ran a KOER and got 35 (EVP again!?!? - but a little different) and 45 (thermactor solenoids maybe?) as running codes. I'll fire up Google, but any suggestions are appreciated. My idle is low, so I’ll bump that up and see if it clears Code 35. Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 15, 2023 Share Posted March 15, 2023 I have to leave again (kids are keeping me busy!) but I just ran a KOER and got 35 (EVP again!?!? - but a little different) and 45 (thermactor solenoids maybe?) as running codes. I'll fire up Google, but any suggestions are appreciated. My idle is low, so I’ll bump that up and see if it clears Code 35. You are making progress, and I guess it is possible that the idle speed could make a difference. That will increase the vacuum, which might do it. PROGRESS!!!! Link to comment Share on other sites More sharing options...
ckuske Posted March 15, 2023 Author Share Posted March 15, 2023 You are making progress, and I guess it is possible that the idle speed could make a difference. That will increase the vacuum, which might do it. PROGRESS!!!! Thanks, progress is something I have not had in some time! The Internet is well.. the Internet, but looking at multiple sources a KOEO of 35 means EVP signal problems. A KOER of 35 seems to mean the idle RPM is too low to test the EGR, and this is something that I have noted as being a little low. So, I'll bump it up and see if it helps code 35. It may mean I need to adjust the AOD rod though... (if it increases more than 50 RPM) Then, I'll chase the code 45 (bad TAB/TAD solenoid?) Link to comment Share on other sites More sharing options...
Gary Lewis Posted March 15, 2023 Share Posted March 15, 2023 Thanks, progress is something I have not had in some time! The Internet is well.. the Internet, but looking at multiple sources a KOEO of 35 means EVP signal problems. A KOER of 35 seems to mean the idle RPM is too low to test the EGR, and this is something that I have noted as being a little low. So, I'll bump it up and see if it helps code 35. It may mean I need to adjust the AOD rod though... (if it increases more than 50 RPM) Then, I'll chase the code 45 (bad TAB/TAD solenoid?) Yep, peeling the onion, one layer at a time. Link to comment Share on other sites More sharing options...
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