My 92z Ls swap
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Car: 92 Z28
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My 92z Ls swap
So I should have done this last year when I was originally putting the car together, but was so busy with school and actually working on the car I never did. So here is my build thread. The car started as a 92 z28 with a 305 tpi. I got a really good deal on the car, it wasn't perfect but not horrible either. The sagging head liner was probably the worst part of it, so again not too bad. It has a little rust on the underside but its all fixable which will be the main project for next winter. But I lucked out and found a really good deal on an complete ls1 for a great price. I didn't rebuild it but did replace all the gaskets and cleaned it up. Then I hunted down a t56 for the transmission, ended up getting one of the packages from tick with the tick master cylinder, standard flywheel and monster stage 3 clutch which is probably a little over kill for the car but I plan on being able to make good power eventually. I did my own harness with the help of pockets threads and a lot of others help from this board. I built the car with the intent of it being a mainly an autocross/street car. So I did all the suspension minus sway bars when I was putting it together, along with 4.10 gears in the 10 bolt. So I went with eibach sport lines along with konis shocks and struts. Founders suspension in the back, I also used the jegs pan hard relocation bracket to level out the pan hard bar, it made a big difference in how it felt. Also tossed a strut tower brace on it along with a wonder bar. For the exhaust I did a 3 inch true dual exhaust which sounds awesome. It took me about 5 months to get it driving. I also had purchased hp tuners, which is probably some of the best money I spent. It drove great didn't really have any big issues, just a bunch of little ones like gauges reading incorrectly or not having something grounded well enough. So fast forward to this year and its time for the sequel. I decided that I would do cam, heads, and headers to squeeze a little more out of it. I started this around memorial day this year. I made it a point to replace everything I could while I had it apart. I ended up going with a set of prc stage 2.5 5.3 heads and howards asa cam along with hookers 1 3/4 swap headers. Got it all back together finally over fathers day weekend and my brand new timing chain decided that it wanted to walk a pin out. Got about 20 miles on it before this happened. Trashed my new heads along with my engine. So now im in the process of waiting to get the motor and heads back from the machine shop. While the engine was out I re-did some little things like re routing the ecm inside the car, notched the k member, and installed polyurethane engine mounts. As far as the rebuild its just a stock rebuild with arp everything and some 1.8 roller rockers to go along with the cam. I also got a wide band so I could fine tune it when I get it put back together. I also got a cowl induction hood that im going to toss on it for a while. I havnt been the biggest fan of cowls on these cars but I surprisingly liked it when I test fitted it. Im keeping the stock z hood just in case though. Hopefully the engine will be back from the machine shop in the next week or so, so that I can get it assembled and get some good miles on this thing. Im sure I have left something out, kind of hard to put everything in 1 post so sorry for the long read. Ill post up some pictures later because I know these threads are boring without them. Defiantly couldn't have done all of this without everyone's help on here.
Last edited by redmaroz; 08-10-2016 at 01:08 PM.
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Car: 92 Z28
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Re: My 92z Ls swap
Here are a few pictures from bringing it home and after it was running. ill post more as i come across them and update the progress.
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Car: 92 Z28
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Re: My 92z Ls swap
Not much to update on but i got the k member notched for this go round. It was a little too close for my liking. I also got my wideband gauge installed. Just spoke with the machine shop today and they are finishing up, so hopefully this time next week ill be posting pictures of assembling the motor.
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Car: 92 Z28
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Re: My 92z Ls swap
Thanks man. Cam specs are 226/236 .525 lift, 110 lsa im also using 1.8 roller rockers. The cam sounds nasty, but isnt all that radical. Im using shorts machine shop, hes local and has done good work for me in the past.
Last edited by redmaroz; 08-22-2016 at 06:10 PM.
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Re: My 92z Ls swap
Still no motor, found out it also spun a rod bearing when the chain went along with a gouge in the #7 cylinder so they are going .005 over on it to clean it up. So if anything else happens to the cylinder down the road its done for unless I get it re sleeved. Which at that point ill get a another block. I got some polly sway bar mounts and end links put on today so hopefully that will tighten it up a little more with rest of my suspension. If not then ill hunt down a 36/24mm set. And i got more parts in to let sit in a box and stare at until the motor is back lol.
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Re: My 92z Ls swap
Couple pics of the taller valve covers for the 1.8 rockers. The last one is a comparison between the stock and the tall covers.
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Car: 92 Z28
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Re: My 92z Ls swap
Well i dont think its going to be running today. Had some unexpected things come up that kept me out of the garage. Im going to close it up today and hopefully get it in this week.
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Re: My 92z Ls swap
Thanks man, I was pretty impressed with them. And I will post up as soon as its running lol, cant wait for it.
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Re: My 92z Ls swap
So we got the engine and tranny in last night...I think when I do this again I am doing it from the bottom. Last time it was done I did it from the top, but the engine and tranny were separated. This time I just put it in all together, and paid hell with my motor mounts. I know it was tricky last time but it was little more rough last night. But o well its in there now I just have to get everything hooked back up. Ill post up some more pictures later tonight. Just out of curiosity how much clearance do you guys have from the back of the heads to firewall? Mine has always been tight. And with the taller valve covers I was having issues with the wiper motor which was to be expected. Just curious how much room everyone has around their engines.
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Re: My 92z Ls swap
So we got the engine and tranny in last night...I think when I do this again I am doing it from the bottom. Last time it was done I did it from the top, but the engine and tranny were separated. This time I just put it in all together, and paid hell with my motor mounts. I know it was tricky last time but it was little more rough last night. But o well its in there now I just have to get everything hooked back up. Ill post up some more pictures later tonight. Just out of curiosity how much clearance do you guys have from the back of the heads to firewall? Mine has always been tight. And with the taller valve covers I was having issues with the wiper motor which was to be expected. Just curious how much room everyone has around their engines.
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Re: My 92z Ls swap
You still have ac correct? I have a heat only box and its on top of it, pretty sure It wouldn't have fit with the ac box on it lol. But its in there so that's all that matters, just a really tight fit. Thanks man.
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Re: My 92z Ls swap
I can fit my hand down the back of the heads on each side... if I remove the harness to do it lol. Wiper motor had to be removed for me to install the engine itself.
Almost there, man!
Almost there, man!
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Re: My 92z Ls swap
Ok so mine isn't as bad as I thought. Yeah Braz mines about the same, I thought I was going to have to get the motor out of the way but some how or another I got it in around it. Im going to try like hell to get it tonight, if not tomorrow for sure. The exhaust shops around here will not touch it unless its a weekend because of no emissions...so this weekend or bust!
Last edited by redmaroz; 09-23-2016 at 11:16 AM.
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Re: My 92z Ls swap
Build looks great so far. I like those valve covers but have a question I am hoping you can help me answer. How deep are the threads tapped into each of the coil posts? I want to buy a set of these but cut off the posts and smooth them down. Just seeing if I will need to tig up any holes that might be there or if there would be solid aluminum underneath. I like the smooth Pro Form covers but they are almost 2X the cost of the Holley's and the OEM's just didn't look right after I smoothed a set.
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Re: My 92z Ls swap
Thanks, yeah i was looking at the proforms but yeah i didnt want to spend that much on valve covers. I dont know off the top of my head, but ill grab a measurement for you later today when im in the garage. Hoping to finish it up tonight so i can the exhaust done and start tuning.
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Re: My 92z Ls swap
Thanks, yeah i was looking at the proforms but yeah i didnt want to spend that much on valve covers. I dont know off the top of my head, but ill grab a measurement for you later today when im in the garage. Hoping to finish it up tonight so i can the exhaust done and start tuning.
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Re: My 92z Ls swap
So it was one of those weekends...I got everything in and was able to start it, but I have a running issue that I have to figure out. It ran fine before the chain went and its the same tune. The issue is I can start it but in order to get it to idle I have to stay on the throttle, second I let off it dies with a little back fire. Ive checked for vacuum leaks, made sure the coils are where they are suppose to be. im not getting any error codes with hptuners. I have 1 wire that might be causing it, but I really think that's grasping at straws. Ive tried tweaking the idle etc but still no go. Cam was installed and degreed correctly so that's not it. Im wondering if my cam or crank sensor somehow got messed up when the chain broke, don't know how it would have, im just trying to figure out what the deal is. So im going to re-run the one wire and see what happens, if that doesn't do it then ill move on to the cam then crank sensor. I triple checked the reluctor wheel before the crank went in and it was fine so I don't think that's the issue either. I also have good fuel pressure, spark, and plugs are good. So long story short I really have no idea what the issue is.
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Re: My 92z Ls swap
Build looks great so far. I like those valve covers but have a question I am hoping you can help me answer. How deep are the threads tapped into each of the coil posts? I want to buy a set of these but cut off the posts and smooth them down. Just seeing if I will need to tig up any holes that might be there or if there would be solid aluminum underneath. I like the smooth Pro Form covers but they are almost 2X the cost of the Holley's and the OEM's just didn't look right after I smoothed a set.
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Re: My 92z Ls swap
Question for the wiring gurus, would a bad solder on b57 which is the battery voltage pin for the ecm, cause a running issue? Its the only thing that I changed from before because I moved my ecm and it was the one wire I had to extend, and when I was looking at it last night I realized that the solder job wasn't too great and didn't look like it was all the way seated...kind of grasping at straws here so any help is appreciated.
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Re: My 92z Ls swap
Question for the wiring gurus, would a bad solder on b57 which is the battery voltage pin for the ecm, cause a running issue? Its the only thing that I changed from before because I moved my ecm and it was the one wire I had to extend, and when I was looking at it last night I realized that the solder job wasn't too great and didn't look like it was all the way seated...kind of grasping at straws here so any help is appreciated.
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Re: My 92z Ls swap
Yeah everything is reading in the scanner, that's part of why im stumped. Its not throwing any codes, that's part of why I was thinking it could be the pin blue 57, like its getting just enough juice to run under throttle but its not flowing well enough to maintain it. That or one of the sensors like tps, iac, cam, or crank sensors are on their way out and just not throwing a code yet.
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Re: My 92z Ls swap
I had similar issues so I'll give you advice off of that. First double check vacuum lines. I forgot the one behind the intake. Next check your battery. I swore my battery was good and that my IAC valve was the issue because I could reset it or unplug it and get it to run. It ended up being my battery even though advanced said it was good. The voltage at startup was enough to mess it up. Replaced the battery and it ran great. I only found one other person online that had the same issue. Also I don't think the car runs without crank sensor. I forgot to hook mine up and got nothing. Idk about the cam. Just my 2 cents.
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Re: My 92z Ls swap
Thanks i double checked the battery and alt both good. Also reran the wire and changed the cam sensor. It will start, idle like ****, back fire then die. Checked the coils and they are good. Im going to try the tps and iac sensors next and see what they do when replaced.
#29
Re: My 92z Ls swap
My IAC would do that. You can remove the iac and pull the plunger out so its extended then reinstall. Leave the harness disconnected. Then start it but I'd start at relearning them first.
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Re: My 92z Ls swap
They mainly adjust the fuel trim, not much to do with starting. If you can see the live data you should be able to look at the readings on all of your sensors and rule stuff out. When O2s go out they usually get "sleepy" where they won't register much reading and then wake up when you hit the fuel. A low reading on one side could also designate a misfire on one cylinder.
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Re: My 92z Ls swap
Ok thanks, yeah they have been reading correctly then. Im just stumped right now. Ive double checked wiring and grounds, even added an extra ground. Ive tried swapping coils on both sides. Im going to mess with the iac motor and see what comes of it. Im just running out of ideas short of pulling the motor out again.
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Re: My 92z Ls swap
Ok so the iac is shot, the plunger shot off it. So i put it back in without the plunger to see what would happen. Well it actually idled on its own for a few then spudderd out with a backfire. So the obvious thing is to replace the iac. Does that sound like something that could cause this issue to you guys, or do you think its more of a coincidence that the iac was just bad and adding to another issue? Thanks again everyone for the help trouble shooting.
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Re: My 92z Ls swap
Without the plunger the idle should be high. Could very well be your issue. Either way you need a new IAC!
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Re: My 92z Ls swap
Haha, paging Mr. Obvious...yeah im going to stop and get one on my way home from work tonight so ill give that a shot.
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Re: My 92z Ls swap
So this kind of goes along with what black18ice was talking about...but if using a distribution block what all wires can be moved off the starter to the block. I know the purple wire from the ignition has to go to the starter along with the wire from the battery. What about the double connector with fusible links in them, do they have to stay on the starter also?
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Re: My 92z Ls swap
Purple wire goes to the solenoid, and you need batt power to the other post on the starter. You can move anything else to a junction block. Stock they used the starter as a junction for batt power. Only think I used it for was to jump over to the alternator for convenience.
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Re: My 92z Ls swap
Ok cool, thanks man. I was sitting here looking at the starter diagrams at work and trying to see if I possibly omitted a wire or have something out of sink. Just looking at anything and everything right now on my way to nutsville.
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Re: My 92z Ls swap
So it for real runs lol....but 4 and 8 are not firing. I moved some wires back to my starter because they were not getting a solid 12v and it helped it out. So now ive got to figure that out why the 2 are not firing.
Last edited by redmaroz; 09-29-2016 at 05:04 AM.
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Re: My 92z Ls swap
Yeah that's next on the list for this evening, im going to try swapping a couple different coils on it but I don't think that's it. Just because it would be extremely random for 2 coils to go bad, but I guess anything is possible. We will see.....
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Re: My 92z Ls swap
Check if those coils on there are firing first. I had issues with some cheap connectors randomly keeping the coils from not firing. Also had one clogged injector. Made for a fun diagnostic.
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Re: My 92z Ls swap
So ive been doing a little digging on tech and some other ls forums. But would a case/crank relearn possibly help? I only ask because some of the postings ive come across have said anytime the crank, rotating mass or sensor has been changed then the relearn needs done. I have also read that all the relearn is for is to clear a code and has nothing to do with how it fires. Also the other part I need to know before I attempt it, and im assuming yes but the engine needs to actually be running in order to do the relearn correct? Im a little hesitant to run it up to full throttle when I haven't been able to really even let it run very long since I got it back and in.
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Re: My 92z Ls swap
Its alive!it ended up being the passenger side coil harness being bad...ill post up some pics and videos tomorrow....gotta go for a spin!
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Re: My 92z Ls swap
Thanks i appreciate it. Still have a lot of tuning to do, but just the little i did over the weekend has made a huge difference.