wheelman Posted May 18, 2005 Share Posted May 18, 2005 Well I finally got to hear the LT1 run in the Z tonight. Ahhh the sound of open headers, music to my ears!!! Now I can't hear very well but it was worth it. It's been almost 2 years since I started this project and I fired her tonight. Still a ways to go before I can drive it but this is a real milestone for me. The engine fired right away but has the run for a few seconds problem that Bartman reported with his, at least I think it was Bartman. I know it's not the fuel pump because I could hear it continue to run the whole time, at least I thought I could, it is very loud. In fact the pump even continued to run after I turned off the ignition at one point so I'm going to need to trace out the fuel pump circuit to make sure I wired it correctly. Anyway I still need to build the exhaust system so there are no O2 sensors connected right now and I was running it without the radiator just to see if it would fire, so once I get the radiator and electric fan installed I'll spend more time messing with it. I need to move it out of the garage though, it is loud!!! Doin the Happy Dance!!!!! :D:D:D Editted to correct spelling errors. Wheelman Quote Link to comment Share on other sites More sharing options...
Guest FasterbyFosta Posted May 18, 2005 Share Posted May 18, 2005 Well I finally got to here the LT1 run in the Z tonight. Ahhh the sound of open headers' date=' music to my ears!!! Now I can't hear very well but it was worth it. It's been almost 2 years since I started this project and I fired her tonight. Still a ways to go before I can drive it but this is a real milestone for me. The engine fired right away but has the run for a few seconds problem that Bartman reported with his, at least I think it was Bartman. I know it's not the fuel pump because I could hear it continue to run the whole time, at least I thought I could, it is very loud. In fact the pump even continued to run after I turned off the ignition at one point so I'm going to need to trace out the fuel pump circuit to make sure I wired it correctly. Anyway I still need to build the exhaust system so there are no O2 sensors connected right now and I was running it without the radiator just to see if it would fire, so once I get the radiator and electric fan installed I'll spend more time messing with it. I need to move it out of the garage though, it is loud!!! Doin the Happy Dance!!!!! :D:D:D Wheelman[/quote'] If the engine is starting and stopping after a second or so, its generally caused by the VATS module not being bypassed... Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 18, 2005 Author Share Posted May 18, 2005 FasterByFosta, This engine came from a Caprice cop car so there is no VATS module. I'm going to do a search to try and find the thread where someone else mentioned this same problem. I can't remember if the solution was posted but I do remember the thread. Wheelman Quote Link to comment Share on other sites More sharing options...
Guest FasterbyFosta Posted May 18, 2005 Share Posted May 18, 2005 FasterByFosta' date='This engine came from a Caprice cop car so there is no VATS module. I'm going to do a search to try and find the thread where someone else mentioned this same problem. I can't remember if the solution was posted but I do remember the thread. Wheelman[/quote'] Interesting, sorry, didnt know bout that.... Quote Link to comment Share on other sites More sharing options...
Guest 305240 Posted May 18, 2005 Share Posted May 18, 2005 You scared me there for a second Wheelman. I thought it read fried. Then I read the post and realized you fired it, not fried it. Good feeling isn't it? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 18, 2005 Share Posted May 18, 2005 Make sure that all the open vacuum ports are plugged on the intake. As a test, unplug the MAF and see if it runs longer. If it does, then find your vac leak. With the MAF unplugged, it defaults to speed density so it can take the extra air into account. Tim Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 18, 2005 Author Share Posted May 18, 2005 Make sure that all the open vacuum ports are plugged on the intake. As a test' date=' unplug the MAF and see if it runs longer. If it does, then find your vac leak. With the MAF unplugged, it defaults to speed density so it can take the extra air into account.Tim[/quote'] Tim, Thanks for the pointer, I'll give that a try today. I think I have a can of starter fluid I can use to test for leaks assuming I can keep it running long enough. I do need to replace the MAP connector so maybe thats part of my problem. 305240, Yes, it's a very good feeling especially after going through the process of rebuilding the LT1 harness and integrating it into the Z wiring. My worst fear was that I would be able to crank it over but not have it start. Now at least I know the basic wiring is good and I get fuel and spark so I feel very good about getting this far. Next thing to do is get the radiator and fan installed and then either have an exhaust system built or do it myself. Wheelman Quote Link to comment Share on other sites More sharing options...
V8ZRACER260Z Posted May 18, 2005 Share Posted May 18, 2005 sweet Quote Link to comment Share on other sites More sharing options...
Bartman Posted May 18, 2005 Share Posted May 18, 2005 Great news:rockon: ! I remember the feeling, as it wasn't too long ago that I fired mine up for the first time as well. I think my neighbors are starting to get a little unhappy with me running my open headers and burning out on my cul-de-sac. My LS1 tank should get here tomorrow, and once that's installed I will be able to properly install the complete exhaust. Definitely check your vacuum lines. Once I forgot to reconnect my vacuum line to the brake booster after mucking with the brakes, and it would only run for a couple of seconds. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 18, 2005 Author Share Posted May 18, 2005 I'm going to try plugging the power brake booster line, it's a new booster so it shouldn't leak but it will eliminate it from the equation. Post some pictures of your LS1 tank install. After reading the other threads about this I'm thinking I'll want to do it myself in the future. I welded a sump on my stock tank, which was kind of a pain due to pin hole leaks, but I don't like how low it is and the exposed fuel lines in the back. As Tim put it the "Tampon string". Wheelman Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 18, 2005 Share Posted May 18, 2005 Just unplug your MAF. If it runs with that unplugged, you know its a vac leak.....diagnose before repairing..... Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 19, 2005 Author Share Posted May 19, 2005 Well it does the same thing with or without the MAF. My son helped me verify that the fuel pump is indeed running after the key is released so fuel is not the problem and it appears there are no vacuum leaks, we sprayed all the vacuum ports I plugged with starter fluid with no reaction. I've removed all the emissions stuff (air pump, egr, vapor canister, etc.) but the PCM has not been reprogrammed yet, could that be causing this problem?? I hope this is it as it will be a fairly easy fix. If not then I must've wired one or more of the sensors wrong which is the last thing I want to find. Anyway keep the ideas coming and I'll keep this thread updated with things I check and the results. Wheelman Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 19, 2005 Share Posted May 19, 2005 U haven't removed the VATS? Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 19, 2005 Author Share Posted May 19, 2005 Tim, I haven't done anything to the PCM other than mount it and I thought that because this LT1 came from a Caprice cop car it didn't have a VATS, do you have any info on this? I do need to have the PCM reprogrammed so maybe I should just do that and then try to track down any problems that might remain, what do you think? BTW: Thanks for the help, sometimes it takes someone outside the situation to ask the right questions to solve a problem. Wheelman Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 19, 2005 Share Posted May 19, 2005 Don't pay someone to edit the PCM. Buy TunerCat, and get a cable from Andrew @ AKMelectronics.com. I you want me to edit the PCM, just pay the $20 for the definition file from TunerCat, send me the PCM and I will program it for free..... Tim Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 19, 2005 Author Share Posted May 19, 2005 Tim, I might take you up on that but I gotta warn you my setup has a twist, my T5 tranny doesn't have a VSS and I've not been able to determine which to use so I was going to try going without one. I emailed the guys at PCMforLess and they said the PCM can be programmed to work without a VSS. Can you set it up this way? I'm thinking the only thing that will be affected is idle speed on coast down which I think is the IAC. Any thoughts? Any ideas on a VSS that would work for me? I know they are available that hook into the speedo cable but can the PCM be changed to use a different pulse pattern than the VSS in the T56 or 4L60E? If so can you make that change? If you'd feel comfortable progamming my PCM with this twist then PM me your address and I'll ship it down to you. Let me know how you would want me to provide the definition file for you, a disk in the package with the PCM or $20.00 and you download it on your end. BTW: I'm a software engineer so don't be afraid to use technical computer lingo with me. Wheelman Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 19, 2005 Share Posted May 19, 2005 Why don't you buy the software and cable and do your own programming and tuning......it is definitely worth the cost (~$70 for software, and ~$90 for cable). You are gonna end up spending that just in shipping back and forth everytime you need a change..... Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 19, 2005 Author Share Posted May 19, 2005 Tim, My intention is to buy the software and cable but I was thinking I'd have someone who knows more than I do create a baseline for me that I could then tweak. I'm speaking out my ignorance concerning how TunerCat works but is it possible for me to extract the data from my PCM send it you via email, you make the first changes and then I can upload it to the PCM and tweak from there? Wheelman Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 19, 2005 Share Posted May 19, 2005 Yes, You can read the PCM, save the file and email it to me and I can open it and edit it and send it back to you.....no charge for electronic shipping Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 19, 2005 Share Posted May 19, 2005 Here is a screen print of the speed calibration screen:(this was from the drivetrain that was in my Z from a 94 Z28 ) Quote Link to comment Share on other sites More sharing options...
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