Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 It drops from 40 PSI to 0 PSI within about 5 seconds. As far as a leaky injector, I replaced all 8 last weekend. I think this is normal, when you turn your key on the pressure should quickly jump up, correct? Have you done a compression test? When did you replace your ignition wires? I would test each wire for continuity with an ohm meter, sometimes the clip pulls away from the carbon conductor, or the carbon conductor burns out like a cancer. How old are the plugs? Look inside the distributor cap for cracks and tracking, look at the contacts inside the cap for corrosion. I have seen distributors where the upper bearing allowed an elliptical orbit of the dist rotor causing a misfire. If you see uneven wear on the contacts that is a clue. Has the distributor been out? Do you realize that the CAM sensor is part of the distributor? The distributor has a very specific orientation when installed correctly. Check all vacuum hoses for cracks Consider doing a power balance test I think you mentioned that you could not isolate what cylinder causes the problem, if not carefully check the coil, center carbon bit. Do you have a vacuum guage?, if yes connect it and report your findings and how the needle moves. Does your parking brake pop off quickly? How are your brakes, are they hard? A leaky vacuum booster can cause a vacuum leak enough to mess up the engine With the engine running spray water at the seam where the intake manifold meets the head and see if the miss changes. Check the throttle body bolts for proper torque and make sure the TB gasket is good. Consider that your PCM is screwy, its under the dash on the passenger side, take it down and tap on it as described in my above post from borg warner. Don't give up, you will find it, its important to be methodical now, write down everything you have done, and everything you do. Link to comment Share on other sites More sharing options...
tommyjack Posted September 24, 2005 Author Report Share Posted September 24, 2005 I'll check the ECM next. Where is it located? Link to comment Share on other sites More sharing options...
Bruce Nunnally Posted September 24, 2005 Report Share Posted September 24, 2005 on the 92 STS the PCM is behind the glove box. You can remove the kick panel on the passenger side, then unscrew and remove the glove box liner, and see the PCM held by a single bolt on the firewall. reach through the glove box opening to unbolt, and it will slide down into the passenger foot space. Bruce 2023 Cadillac CT4-V Blackwing Follow me on: Twitter Instagram Youtube Link to comment Share on other sites More sharing options...
Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 I'll check the ECM next. Where is it located? I noted where the PCM is in my prior post at the bottom, good luck, I'll be back later off to pump some iron... Link to comment Share on other sites More sharing options...
tommyjack Posted September 24, 2005 Author Report Share Posted September 24, 2005 Do I tap on it with the car running, key on, ect... What is suppossed to happen or not happen. I should be pumping iron but got a bad casse of tendinititis in left arm. Sucks too cause I was getting as strong and big as I have ever been. Link to comment Share on other sites More sharing options...
Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 Do I tap on it with the car running, key on, ect... What is suppossed to happen or not happen. I should be pumping iron but got a bad casse of tendinititis in left arm. Sucks too cause I was getting as strong and big as I have ever been. With the engine idling tap on it and see if you can induce any engine idle changes. I had surgery about 6 years ago on my shoulder because I could not lift any more and started gaining weight. I go through lots of shoulder pain. Drink lots of water and try Glucosamine/Chondroitin http://www.gnc.com/productDetails.aspx?&MS...=275012〈=en Link to comment Share on other sites More sharing options...
tommyjack Posted September 24, 2005 Author Report Share Posted September 24, 2005 I go check my ECM in just a minute. Will post abck this afternoon. I can't do much arm work now (going to rehab) so I'm trying to do legs and abs in the short term. I hate getting old! Link to comment Share on other sites More sharing options...
Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 I hate getting old! I do too, but its better than the alternative! Link to comment Share on other sites More sharing options...
tommyjack Posted September 24, 2005 Author Report Share Posted September 24, 2005 OK!!! Maybe we are on to something here! Pulled the covers to access the ECM. Didn't really get all it the way out (looked like a pain in the arss). But did undo the top bolt holding it in (left the bottm bolt intac) and tappped it pretty good with an extension. Then wiggled the input terminals a little. Engine sounded like it ran smoother. Test drive confirmed it!!!! It ran like it should. Test drive was completed with everything still laying in the floor, glove box not put in yet, etc... Went back to my shop. Put everything back to gether except the top bolt. Tried not to disturbe anything unles I had too. Any way with everything back together, I started it up and you guessed it! The miss was back. Soooo, is it the ECM or maybe the connections? Link to comment Share on other sites More sharing options...
Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 You got me, I would have to be there to figure that one out. Why don't you pull it out, buy some electrical contact cleaner auto parts shops have it, disconnect the connections spray up the connections blow them out with compressed air even the computer type to make sure its dry and hook it up again, and see if that helps. Maybe you will find some green corroded connections. If that does not do the trick I would lean toward the PCM... but I would not buy one until I was sure it wasn't the connectors. By the way look for grounds in the area of the PCM and clean and tighten them. Here are the grounds for the 92....focus on G301 and G305 to be safe.. DISCONNECT the BATTERY before playing with the PCM connections to be safe I told you not to give up! Link to comment Share on other sites More sharing options...
tommyjack Posted September 24, 2005 Author Report Share Posted September 24, 2005 I'll have to try that tomorrow. If it is the computer, what years will work on it? Link to comment Share on other sites More sharing options...
Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 I'll have to try that tomorrow. If it is the computer, what years will work on it? You can buy a new one for about $100 if I am not mistaken. After a search, the AC DELCO, is $105.79 here: https://www.rockauto.com They have cheaper PCMs by Standard and A1 Cardone, but you know the drill... Have fun Link to comment Share on other sites More sharing options...
tommyjack Posted September 24, 2005 Author Report Share Posted September 24, 2005 Thanks!! I really appreicate all your help. I'll update post when I get new computer in, if cleaning the terminals doesn't work. Have a good weekend. Time to go do some leg work. Link to comment Share on other sites More sharing options...
Scotty Posted September 24, 2005 Report Share Posted September 24, 2005 Thanks!! I really appreicate all your help. I'll update post when I get new computer in, if cleaning the terminals doesn't work. Have a good weekend. Time to go do some leg work. You are welcome, relax and enjoy Link to comment Share on other sites More sharing options...
Ranger Posted September 27, 2005 Report Share Posted September 27, 2005 It drops from 40 PSI to 0 PSI within about 5 seconds. As far as a leaky injector, I replaced all 8 last weekend. Has anyone considered a leaky check valve at the fuel pump? It should hold pressure after the key it turned off. Link to comment Share on other sites More sharing options...
jhall Posted September 27, 2005 Report Share Posted September 27, 2005 tommyjack, It sounds like there is a bad connector at the ECM or possibly a bad solder joint on the ECM board. When you remount the ECM, it stresses the connection and increases the resistance of the circuit. Check the cable connectors and the ECM connections. Try to clean them with some contact cleaner. LPS makes some good contact cleaner, but keep it off the interior finishes and ventilate the car when you use it. If this does not solve it, you'll need to open the ECM and look for bad solder joints. They'll have a dull finish as opposed to the shiny look of a good solder joint. If electronics is not your game, replace the ECM. There are plenty of places that sell repaired ECM units for low cost. Good luck! Link to comment Share on other sites More sharing options...
Logan Posted September 27, 2005 Report Share Posted September 27, 2005 Technically..... We mention maybe a ECM issue a while back. Anyway, its possible, that simply unplugging and the replugging the computer might fix it. The ECM pins can form a oxide cover on the pins, if that makes sense. Simply unplugging the replugging can wipe the pins clean. These connections do pretty good, but after 12-13 years things can get goofy.... It should also be noted, in that general time frame at GM there were some TSBs about the harness having a slightly wrong harness connectors sizes at the ECM pins. My bet is its really a bad ECM. Go with the Delco. Delco will not accept aftermarket ECMs as cores. Maybe $100-150US. You will have to swap the PROM over. Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
tommyjack Posted September 29, 2005 Author Report Share Posted September 29, 2005 OK! Got the new ECM in today. Ran like you know what until I did the Idle Relearn. Had to do it a few times though, don't understand that one. Some where in the process I got a EO30 code (ISC RPM out of range). What does that mean? Thanks to everyone (especially Scotty) for your input on this problem I hope this fixes it once and for all. Link to comment Share on other sites More sharing options...
Scotty Posted September 29, 2005 Report Share Posted September 29, 2005 OK! Got the new ECM in today. Ran like you know what until I did the Idle Relearn. Had to do it a few times though, don't understand that one. Some where in the process I got a EO30 code (ISC RPM out of range). What does that mean? Thanks to everyone (especially Scotty) for your input on this problem I hope this fixes it once and for all. You have done so much the the system needed to go through a relearn procedure, the PCM probaby defaults to default mode and your ISC motor probably looked wacked out to your PCM. You cleaned the TB also if I recall. You are not getting that code anymore are you? How does it feel, miss gone, more power, start better? I am thrilled you nailed this, Mike I told you not to give up! Link to comment Share on other sites More sharing options...
tommyjack Posted September 29, 2005 Author Report Share Posted September 29, 2005 No more codes! runs like a bat out of you know where now. Thanks, TJ Link to comment Share on other sites More sharing options...
tommyjack Posted September 30, 2005 Author Report Share Posted September 30, 2005 Scotty, You're not gonna believe this. I have to reset my idle learn just about every time I drive and some times I have to stop on a trip to reset it. Some times it works and some times it doesn't. Car is now running very rough, idles up and down, so rich it makes your eyes water and kills no telling how many brain cells, like I have any to spare (LOL). And mileage is out the door. TPS maybe? This thing doesn't have a MAP sensor does it? Link to comment Share on other sites More sharing options...
Scotty Posted September 30, 2005 Report Share Posted September 30, 2005 Explain what you mean by "reset my idle learn" for me. Link to comment Share on other sites More sharing options...
tommyjack Posted September 30, 2005 Author Report Share Posted September 30, 2005 It's the procedure listed on this site under FAQ. Let car idle for 13 min, turn on diagnostic, then turn car off for 20 seconds, turn key on run diagnostic, turn key off for 20 seconds, do this one more time, start car place in drive for one minute, then turn on AC for one minute, then turn car off. Link to comment Share on other sites More sharing options...
Scotty Posted September 30, 2005 Report Share Posted September 30, 2005 What causes you to have to do the idle learn? A high idle? Its odd that it was running OK and now its not. Have you tried disconnecting the battery? Make sure cables are clean. Explain it makes your eyes water, gas smell? strong black exhaust? Where is the problem coming from? You say you mileage is bad. It sounds fuel related like you have a leaky injector or bad FPR.. A bad TPS will give a code, you have not commented on codes. You may need to adjust the TPS and ISC motor. Did you have the TB, ISC motor or TPS off? Link to comment Share on other sites More sharing options...
tommyjack Posted September 30, 2005 Author Report Share Posted September 30, 2005 No codes. Smell is from the fumes-rich. No smoke. Did not have the TB, ISC or TPS off. It will run fine for a while then start acting up again. Some times when I come to a stop, or just going down the road. Checked the FPR, no fuel coming from it. I've replaced just about everything on this car. What is the procedure for replacing the TPS. For some reason I can't use the search now and google isn't any help. Do I just unhook the batt and replace the TPS? Link to comment Share on other sites More sharing options...
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