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The misfire code we were dealing with went away in open loop mode where the engine runs on speed density (I think). After talking to some people, it seems like there still might be an issue with the MAF sensor because we never got a genuine GM part. An AC Delco part is on its way and in the meantime I cleaned the fuel injectors, verified the fuel pressure (steady 60 psi), and replaced a PCV hose because it was kinked. 

Since we are just waiting on a MAF sensor, I made this to show the whole build process: 



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Got the Z tuned today! Made 295 hp and 340 ft/lbs torque at the wheels on 87 octane. The tuner thinks he can get to about 350 hp on 93.    edit: makes 305 on 93 -  I guess the tuner overesti

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For anyone who might be interested, new O2 sensors fixed the random misfire issue. I think they went bad because of a completely blocked PCV system due to a kinked line (at least I hope there isn’t another issue). 


Edit: the issue reappeared within another 25 miles. Found two spark plug wires melted through - replaced with ceramic low clearance wires and now no misfire.

Edited by Whitley_280z_2+2
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  • 3 weeks later...

Got the Z tuned today! Made 295 hp and 340 ft/lbs torque at the wheels on 87 octane. The tuner thinks he can get to about 350 hp on 93. 


edit: makes 305 on 93 -  I guess the tuner overestimated his abilities :) Still, 305 at the wheels is plenty fun!


Edited by Whitley_280z_2+2
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The Z is still running great. After the tune, it pulls much smoother which makes a huge difference in terms of acceleration.

Had a couple issues with the lug nuts loosening especially in the front because the front studs are short relative to the rear ones. We run a 1/4 inch spacer so that makes things worse. Today I put in extended lugs all the way around to fix this issue. 


the rear lugs were easy because we got rid of the drums.


I used a press with equal height sockets to press in the front studs.526253F0-0E53-41C4-A448-B837E386A801.jpeg.2c900af312a3df54675cf20a592e656d.jpeg

should make the car a little less sketchy :) 

Edited by Whitley_280z_2+2
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My Dad was driving the car on the highway and hit a big chuck of tire retread. 28F78657-922D-49BC-AB2F-83E21A8FF416.jpeg.7c8fc991975d1b87365c92ae45eee90c.jpeg

Now it just looks like it’s been track driven really hard lol. Thankfully we have some left over paint should be able to fix her right up. It’s been driven about 1200 miles since completion. Gas mileage hasn’t been great but that’s just driving style 🤘

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Had low oil pressure recently. The engine was just sitting at around 20 PSI at idle and would only get up to about 40 PSI at WOT. Thought it might just be a result of of 100K+ mile engine, but changed the oil recently and found the side plug in the oil pan (plug for some sensor we don't use that was originally in the F-bodies) was not even finger tight. Little loctite action and we're back to 40-60 PSI. 


Also, developed some rear end clunk when shifting. Going to try and find an extra set of axles/diff to rebuild on the side and throw in eventually. The axles in there right now haven't been touched since 1977 so nothing unexpected here. I feel like a sorted OEM diff and axles are perfect for your common 300hp 2+2 LS swapped 280Z so no need to upgrade to something more modern. Does that sound right?

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Been doing lots of little stuff to the car recently so I thought I would give an update. The clunk I thought was in the rear end was just loose driveshaft bolts. I don’t know if I ever mentioned this in this thread but I built this car with my dad mainly during high school and then finished it over breaks during college. When we had it driving I was away at college and then an engineering internship so I never actually drove it. So over Christmas break I’ve been learning to drive stick on this thing and it has been a lot of fun! It’s especially fun racing civics, mustangs, and maximas ; ) 


just recently fixed an AC leak under the dash and while we had the system discharged we put in a low pressure service port in the engine bay instead of only having one under the dash (was a real pain to work with).


We also cleaned up the interior a little by putting in some of the plastic interior pieces. Also, the Tach has never worked so we put in this obd2 gauge called an Ultragauge. I researched these for a while and this was the only one I thought would be any good for under $100 because it’s made in America and they have a lot of information on their website. I’m really satisfied with it and it’s the perfect size. Definitely would recommend for anyone else LS swapping their Z. Also check out them MPG’s!



Also this weekend I took it to a cars and coffee and saw another guy, forgot to get his name, with a VQ swapped Z that was really nicely done! Also saw this Miata that is goals for the LS swap club:


Someone posted this on the cars and coffee page:


Overall it’s been really fun to drive and learn stick on and it’s pretty reliable!!

Edited by Whitley_280z_2+2
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Alright, I want to close out this build thread and I got some pics this morning so here goes. Going on 6K miles and the car is still fun! It spins 1st and 2nd easily and goes around corners effortlessly. Overall it was a great project . . . thanks for the help! Also to anyone reading this in the future and thinking about attempting a similar project, don't think you have to know the right people or know a lot about cars to start. You can learn as you go and take it system by system and still complete the project within a reasonable timeline. Most advanced thing I'd done before this project was clean a lawnmower carburetor, replace brake pads, or something along those lines. A lot of people will say to start with an easy project if you aren't used to working on cars . . . I'm not sure what level I'd put this build at but I think it was a great intro to building cars. 











Some engine bay shots:










I really like these shots:









This one is probably my favorite:



Time to RB swap a K5 Blazer ; ) 

Edited by Whitley_280z_2+2
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