chadz34 Posted September 26, 2006 Report Share Posted September 26, 2006 First of all, my idling and starting is to do with my PCM ''acting slow''. A GM mechanic told me it is common on these cars. He also fixed a 4 inch long vaccum leak so it runs better. But still needs just a bit of work. What I want to know is where is the PCM and will one from a 3.1 Lumina work? And does it have to be the exact same year as mine or just OBD-II? Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 26, 2006 Author Report Share Posted September 26, 2006 BUMP Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted September 26, 2006 Report Share Posted September 26, 2006 Wait, did you just bump a thread that is 30 mins old at the slowest time of the night? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted September 26, 2006 Report Share Posted September 26, 2006 Yes he did, lol The computer is near the passenger side wheel well under the hood. Should be behind the coolant resevoir. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted September 26, 2006 Report Share Posted September 26, 2006 not sure if the OBDII computers have a memcal like the older OBDI computers do, so i can't say on that. but i'd take the time to get a real 3.4 computer, esp since the later 3.4s have that second cam and crank sensor. first off did you ever get that SES light diagnosed that you mentioned awhile back. as far as years that work, 96 and 97 would be the only years that would work since thats the 2 years a 3.4 could be had with OBDII Quote Link to comment Share on other sites More sharing options...
slick Posted September 26, 2006 Report Share Posted September 26, 2006 not sure if the OBDII computers have a memcal like the older OBDI computers do, so i can't say on that. but i'd take the time to get a real 3.4 computer, esp since the later 3.4s have that second cam and crank sensor. first off did you ever get that SES light diagnosed that you mentioned awhile back. as far as years that work, 96 and 97 would be the only years that would work since thats the 2 years a 3.4 could be had with OBDII Nope, has to be from a 96-97 3.4 eqiupped cars. The 91-95 DOHC cars had removeable memcal's, and were obd1-obd1-.5. A 3100 computer from the 96-97 era may work, but I wouldn't count on it. Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 26, 2006 Author Report Share Posted September 26, 2006 All my SES lights are off and were fixed, minor things. I just need a new PCM. Should I try and find a 3.4 DOHC Lumina PCM? they will be hard to find though.......as a 3100 Lumina will be found in 30 seconds. Quote Link to comment Share on other sites More sharing options...
slick Posted September 27, 2006 Report Share Posted September 27, 2006 All my SES lights are off and were fixed, minor things. I just need a new PCM. Should I try and find a 3.4 DOHC Lumina PCM? they will be hard to find though.......as a 3100 Lumina will be found in 30 seconds. IMO, get one from a 3.4 car. There are differences in a 3100 computer compared to a 3.4 computer. I mean, it will run on it, but it will run pretty crappy. Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 27, 2006 Author Report Share Posted September 27, 2006 All my SES lights are off and were fixed, minor things. I just need a new PCM. Should I try and find a 3.4 DOHC Lumina PCM? they will be hard to find though.......as a 3100 Lumina will be found in 30 seconds. IMO, get one from a 3.4 car. There are differences in a 3100 computer compared to a 3.4 computer. I mean, it will run on it, but it will run pretty crappy. Ok, next question, you said ''3.4 car'' does that mean I could get one off say a 1996 GTP? Because it has a 3.4 and is the same year? Or is this something that is LUMINA specific? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted September 27, 2006 Report Share Posted September 27, 2006 All my SES lights are off and were fixed, minor things. I just need a new PCM. Should I try and find a 3.4 DOHC Lumina PCM? they will be hard to find though.......as a 3100 Lumina will be found in 30 seconds. IMO, get one from a 3.4 car. There are differences in a 3100 computer compared to a 3.4 computer. I mean, it will run on it, but it will run pretty crappy. Ok, next question, you said ''3.4 car'' does that mean I could get one off say a 1996 GTP? Because it has a 3.4 and is the same year? Or is this something that is LUMINA specific? Any 96-97 DOHC equipped W will work. Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 27, 2006 Author Report Share Posted September 27, 2006 All my SES lights are off and were fixed, minor things. I just need a new PCM. Should I try and find a 3.4 DOHC Lumina PCM? they will be hard to find though.......as a 3100 Lumina will be found in 30 seconds. IMO, get one from a 3.4 car. There are differences in a 3100 computer compared to a 3.4 computer. I mean, it will run on it, but it will run pretty crappy. Ok, next question, you said ''3.4 car'' does that mean I could get one off say a 1996 GTP? Because it has a 3.4 and is the same year? Or is this something that is LUMINA specific? Any 96-97 DOHC equipped W will work. Awesome thanks, so I just need this..... Quote Link to comment Share on other sites More sharing options...
cutlassdude96 Posted September 27, 2006 Report Share Posted September 27, 2006 you need whats under the fuse block Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 27, 2006 Author Report Share Posted September 27, 2006 you need whats under the fuse block FUCK....so I have to take that off just to get to the PCM? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted September 27, 2006 Report Share Posted September 27, 2006 you need what's under that. That's the fuse block. You don't want that. It'll have 4 big connectors attached to it. I can't find a good picture anywhere, maybe someone will chime in with one. You can probably get to the ECM without removing that fuse block. Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 27, 2006 Author Report Share Posted September 27, 2006 you need what's under that. That's the fuse block. You don't want that. It'll have 4 big connectors attached to it. I can't find a good picture anywhere, maybe someone will chime in with one. You can probably get to the ECM without removing that fuse block. Jeez, I hope so, I am liable to ruin the fuse block getting it off..... so, could someone post a picture of what it is I need please? I am confused and just want my new friggen PCM. Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted September 27, 2006 Report Share Posted September 27, 2006 Here is a pic of the ECM still attached to the primary engine harness and removed from the car: Here is the ECM itself up close: Here is a pic of where the ECM is mounted inside the car with eveything removed. Keep in mind this is a 92' Lumina but the gen 1.5's are almost identical. I don't know if the gen 1.5 had the newer looking ECM's but in the pic the ECM has a black steel case, I believe the OBDII ECM have a cast aluminum case with what can only be described as cooling fins cast into the case. It is the same size and shape. In the 3rd picture I highlighted where the ECM mounts, there is a plastic bracket bolts to the strut tower and the ECM bolts into it. As you can see in pic #1, the fuse box is only like 6" from the ECM on the same main harness. The ECM can be removed in less than 10 minutes on a gen 1 with only 3 or 4 hand tools. Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 27, 2006 Author Report Share Posted September 27, 2006 Here is a pic of the ECM still attached to the primary engine harness and removed from the car: Here is the ECM itself up close: Here is a pic of where the ECM is mounted inside the car with eveything removed. Keep in mind this is a 92' Lumina but the gen 1.5's are almost identical. I don't know if the gen 1.5 had the newer looking ECM's but in the pic the ECM has a black steel case, I believe the OBDII ECM have a cast aluminum case with what can only be described as cooling fins cast into the case. It is the same size and shape. In the 3rd picture I highlighted where the ECM mounts, there is a plastic bracket bolts to the strut tower and the ECM bolts into it. As you can see in pic #1, the fuse box is only like 6" from the ECM on the same main harness. The ECM can be removed in less than 10 minutes on a gen 1 with only 3 or 4 hand tools. Is the ECM the same as the PCM? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted September 27, 2006 Report Share Posted September 27, 2006 yeah, ECM = PCM. Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 27, 2006 Report Share Posted September 27, 2006 will your dealership flash a PCM for you? Then just grab one of a 3100 car and have the 3.4 parameters installed into it. Ask them if they do it and at what cost. BTW I don't buy that "slow PCM" excuse, I've never heard of that being a problem. Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted September 27, 2006 Report Share Posted September 27, 2006 will your dealership flash a PCM for you? Then just grab one of a 3100 car and have the 3.4 parameters installed into it. Ask them if they do it and at what cost. BTW I don't buy that "slow PCM" excuse, I've never heard of that being a problem. I agree... usually an ECM/PCM either works or it doesn't. I have seen PCM's lose control of certain functions, like the cooling fan, but the engine still runs. I haven't heard of a "slow" PCM before either. As a matter of fact.... I don't think I've ever seen a W with a bad PCM... not to say it isn't possible. It kinda sounds like the mechanic didn't know what was wrong so he gave you the old PCM/ECM excuse. Do you know anyone with the same car? Possibly you could use their PCM for testing purposes? Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 28, 2006 Author Report Share Posted September 28, 2006 Thanks guys for all the help, I am gonna see if I can find one out of a GTP or something, hopefully cheap, because I don't want to be out money I shouldn't be out of. Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 29, 2006 Author Report Share Posted September 29, 2006 I'm just curious, but could the PCM be responsible for my hard starts? Just wondering if that could be possible? Quote Link to comment Share on other sites More sharing options...
slick Posted September 29, 2006 Report Share Posted September 29, 2006 Most likely, no. Did you ever replace the starter like I said you should do countless times. Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 29, 2006 Report Share Posted September 29, 2006 what kind of hard starts? like cranking but not firing? or a slow cranking speed? Quote Link to comment Share on other sites More sharing options...
chadz34 Posted September 29, 2006 Author Report Share Posted September 29, 2006 what kind of hard starts? like cranking but not firing? or a slow cranking speed? It cranks fine, but it just won't start the odd time, like it's not everytime.....it's just random times I need to hold the key for an extended amount.......usually after it's warmed up. As slick said about my starter...I don't see how it could be the starter, especially if it's cranking.....the fuel pump comes on, and I have new plugs wires and coil packs....so what's left that could be wrong? I think it's the PCM? Or could it be? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.