duowing

Hey guys! I finally came back. I lost interest in the Z for a while, mainly not having anywhere to work on it, other issues, etc. Now I'm back at it. I'll get you guys some pics soon.

I've got it running! It still has some issues with cold start, that might be helped once I get my O2 sensor hooked up. I've got it running an 88 Z31 N/A ECU that I installed a NIStune board into so I can use the larger Zirconia O2 sensor.

I've got my Tokico Illumina 5-ways installed, Tokico springs, Energy Suspension bushings all around, 4-piston Toyota front brake calipers, new tie rod ends, new ball joints, etc. The fuel tank was removed, cleaned, and coated. I have my Walbro fuel pump installed.

I have an older not sure what year 5-speed that I refilled with Redline synthetic, along with the Diff. I'm running a Fidanza lightweight flywheel, 240mm ACT Street Performance Clutch.

Replaced the P90a head with a P90, running a N/A cam, removed the extra row from the crank pulley. Have a shaved and polished N42 egr-less intake manifold. 2.5" MSA downpipe on the turbo, currently no exhaust other than that.

I've totally removed the front and rear bumpers and the support struts, the A/C system was all removed before I bought it. The entire interior is currently stripped.

Now that it seems to be running, I bolted the driver's seat back in. I'm hoping to bring it home soon from where it's stored and clean/finish up the wiring. Finish painting the interior, get the interior panels cleaned up, painted, and reinstalled. Then get the car ready for body work.

I'm just hoping that the O2 sensor and cleaning up the wiring takes care of the remaining starting issues. Once I've got the car started initially I can turn it off after like a minute or so and it'll keep restarting no problem.

I'm really looking forward to getting this back in gear and going. I'm hoping to be able to get it ready to be sent off for body work during the winter.

NismoPick

Yay! Welcome back!!!

duowing

Alright, I have a few more things to try and get taken care of before I take it out on the road. Got all my taillights, headlights, dash lights, etc working except for the license plate lights. I brought the little bulb holder/sub harness home with me to play with and test out, but now I can't find my multimeter...

Anyway can anyone give me an easy explanation on how to adjust the clutch pedal? I have the FSM and I see it says loosen the pedal stopper locknut and adjust the pedal to this height, then loosen the pushrod locknut and adjust the pedal so it has x free play and x free travel. I'm not sure what the difference between free play and free travel are. I would think I would just adjust it so that the pedal barely moves when I just push on it, and almost immediately starts to engage the clutch.

Still haven't worked out why it has such a hard time on that initial cold start. I'm wondering if it's because when I'm done I unplug the ECU and take it with me. Maybe initially that first startup the ECU is trying to relearn everything. Once I got the car started I waited maybe 20 seconds, 30 max. Then turned it off to try again and it immediately started.

NismoPick

Adjusting the clutch pedal is easy once you get upside down under there w/ a light. As you push the pedal, the plunger won't move for a bit if there is too much play. You'll need to pull the cross pin, then you can loosen the nut and adjust the plunger distance. I did that w/ my 280zt brake pedal upon installing the 280zxt brake booster.

As for the cold idle problem, did you remove all the tubing for the AAC? You still running an air regulator?

duowing

Not sure where the cross pin is. I know in the FSM it doesn't mention pulling any pin. It just says about loosening the locknut for the pedal stopper, adjusting the pedal height, then tightening that. Then loosen locknut for the pushrod and then adjust it.

As for AAC that's long gone. I wasn't running the AAC even on my 280ZXT. I made a block-off plate for it and just took out all that tubing and just ran hose from the J-pipe to the air regulator. I am still running the air regulator. If I wasn't running that it would make quite a difference.

Car gave me a bit of a scare yesterday. I was sitting there messing with it, and I'll continuously keep messing around to try and restart it. I had it in first and didn't realize it. Went to crank the car it jumped forward, I backed off the key and the thing started and just kept going forward. I was just sitting sideways in the seat with the door open. I quickly swung around to hit the clutch and brake. So lucky there wasn't anything right in front of me.

NismoPick

There's a pin that links the pedal arm to the plunger hook. IIRC there's also a cotter pin to pull first. Now that I think about it, I imagine the plunger can rotate in place, so once you loosen the lock nut, spin the plunger till it's tight & check again. Here are two pics of the booster (From my swap thread)... same basic items:

duowing

Thanks for the info.

I may have to upgrade to the 280ZX brake master at some point.
Oh, also when you did your wiring for your 280Z how did you connect the tach? I see I could run the wiring from the harness out to the coil and connect it to the old blue tach wire, but I was trying to locate that under dash resistor and just disconnect it and hook it directly to my 280ZXT harness inside the car under the dash, rather than running a bunch of extra wire out into the engine bay.

Well I put the ECU in the car, got it started, turned it off, started it a few times to get it to the point where it would just fire right up. Then I left the ECU in there and the battery connected and left for a while. Came back about an hour or so later when I figured it should be cool since I didn't even run the car for a total of a minute. Did the same thing with the cold start. I was looking around the engine bay, shaking wires, etc. Found that for some reason my one wire going to fuel pump relay that I had fixed once before was getting hot again. I think I need to just remove the inline fuse holder and go to straight wire. The fuel pump relay was warm, but so was the EFI relay. Also the one black fusible link was getting hot as well. I wonder if that has anything to do with the fuel pump relay wire. I was going through and checking wires for any other hot ones, all I found was another part where I had spliced in a male and female crimp connector for the fuel pump power wire. I think I'm going to cut these out and just solder the wires here as well. See if that makes any change.

NismoPick

There is no tach resistor on the S30... it's on the L28ET ecu harness (blue wire on the coil sub harness). You attach it to the blue wire with white single female spade connector. See pics:

duowing

Thanks for that pic. I had no idea what I was looking for. I think I was thinking there was some resistor on the old tach from something I read and going through the wiring diagrams and there was a connector or some box where the wire went into and then came out of. In that first pic of the ZXT harness is that the Fuel Pump Modulator in the upper right corner? I don't have that hooked up in my car. I was wondering if I should see if I can find it and hook it up or if it even makes any difference. I thought you didn't need it with the Z31 ECU, but I still had it hooked up when I was using the Z31 ECU in my 280ZXT.

Did you completely remove the old 280Z coil wiring and that little 3 pronged box that sat near the coil? I still have those in the car by where my current coil is hooked up. They aren't connected to anything, but it looks like they run a good ways through the harness so I just have them hanging there for the time being.

NismoPick

Yeah, that's the FPM, but it should not be connected when running the Z31T ecu (I only had it connected for taking pictures while the harness was on the ground). The Z31 ecu controls the ground signal to the fuel pump relay.

As for the stock 280z coil wiring... yes, also I left the 3wire bracket in place for the same reason you said. I didn't want to chase them clear into the harness, then find out I shouldn't have cut it.

How about some current project pics?

duowing

Well I keep forgetting to bring my camera anytime I go with me. I'll try and make sure to grab pics when I go back tomorrow. I start working on it, then stop for a while. The car's not just in easy access to work on. Anyway I've done a few things. I did the maxi-fuse upgrade, cleaned up a little more of the wiring, removed some crap from the engine bay, made a bracket for my fuel pressure regulator, changed the 12+ battery connection for the FPR from going directly to the battery to another wire inside the car so it's on the maxifuse circuit, and connected the tach. Anyway I'm still having starting issues. Today the car was giving me a heck of a time. Just starting it several times it would die as soon as I would hit the throttle. I'm wondering if it's a fuel issue or what. Although I did find the wire I forgot to cut and solder(just left it with crimp connectors) that is the power wire coming from the FPR and going to the fuel pump was getting really hot. It also felt like I was getting poked, almost like I was getting zapped by it. I'm really hoping that this is the issue. I'm gonna go back tomorrow, cut out those crimp connectors and solder the wires together. It seems like after the car kinda got warmed up a bit it was doing better, but I don't know why. I just can't seem to figure this out. It's driving me nuts.

duowing

Well I've learned how to adjust the valves. I realize how easy it is. Anyway I pulled my plugs and all of them were terrible. They were just fuel soaked and black. It's a wonder the car was really running with them looking like that. I fixed the last of my wiring for my fuel pump relay which seemed to help. The wire was no longer getting hot. Nice and cool now. I'm gonna make up some new battery cables as well and clean up grounds and stuff to make sure. I haven't tried running it since I adjusted the valves. I only did a cold adjustment for now, but my valve adjustment was all over the place. The mechanic I know said it was fine because he didn't really hear them making any noise. Anyway I had at cold valve lash on the intake all over the place. The lowest being .005in on cylinder 2 and almost .013 on cylinder 6 along with everywhere in between. The last on my exhaust valves were split. Half were .008 and half were .012.

I'm hoping that with a new set of plugs and now the valve lash at least adjusted properly that will fix some of my issues. I also need to check my timing. I know I set it a while back, but I may have set it when I had forgotten to plug my CHTS in. I noticed that if I disconnect the CHTS idle speed goes up and it sounded like everything advanced a bunch. So for all I know the timing may be a bit retarded aiding in making it run so rich and giving it a hard time.

One other weird thing that I noticed is my fuel pressure regulator. It would not seem to hold pressure once the pump would shut off. Now I looked at it even after 2 days of not running and it was showing that it was still holding about 15psi. Not much, but just odd that it's suddenly holding pressure now.

duowing

Alright, put a tighter vacuum line on my fuel pressure regulator and manifold as the one I had on there was a bit big and was causing a slight vacuum leak. Put the old plugs back in there. Cleaned them a bit, but didn't want to dirty up a set of new plugs yet. Anyway put everything back together, put a tee in my vacuum line and connected a vacuum gauge in there. The car managed to start up a little better this time, but not too much, but it definitely smoothed out way quicker and right off the bat was responding better to throttle. Throttle response, and revving were alot smoother. Idle was better to. Overall just sounded better. Fuel pressure is sitting around 35psi at idle, should I adjust my regulator down to 30psi like the Haynes shows you should have at idle?

Anyway vacuum was at 17inHG. Seems a little low, but the gauge wasn't really fluctuating too wildly. Timing was only advanced by like 4 degrees. I'll have to reset that back to normal as I can advance the timing through Nistune and keep everything more baseline. Idle was reading 1000 on the Tach, a little over 800 on Nistune. In Nistune's maps the idle is set to be at 700rpm.

Anyway this was still bothering me and I started spraying carb cleaner or starter fluid. I forget which all around the place hoping to find a vacuum leak. Was finding nothing. Finally I found right by the throttle body gasket, blockoff plate for where the cold start injector goes, and that connector to throttle body for the air regulator, there must have been a leak. When I'd load it up with the spray the car would start bogging real bad. I made sure to really go wild all over the place and that was the only spot I was finding that was causing any noticeable change in the idle. So now I need to remove these items and replace the gaskets. What do you guys do for new gaskets? I can't seem to find where you can buy a throttle body gasket for these cars.

I really hope that I've about finally figured this thing out.

NismoPick

I keep my fuel psi @ 35psi unless I feel the need for more power.

As for the gaskets, Autozone / any parts store has "make it yourself" gasket sheets. You can get the thin cardboard paper or go cork. Just cut it to fit. I use a paper hole punch to make the holes for bolts / studs.

duowing

Now when you say 35psi, that's your idle fuel pressure right? I wonder if the higher idle fuel pressure is what is helping the car to run a bit better despite the vacuum leak?

Thanks for the info on the gaskets. I'll have to go pick some of that up now.

duowing

Alright got the new throttle body gasket installed, cleaned up the ground connections and and made sure they were nice and tight. Tried starting the car and nothing. Realized my MAF came unplugged so I plugged that back in and tried and the car started right up. Not sure if that was a coincidence as the car had been cranking a bit and things would already be starting to warm up? I'll go back tomorrow and try from a dead cold start. Vacuum was still about 17-18inHG and it wavers a bit. Still seems a little low, need to adjust the timing back a bit, but I didn't have anything to put on the timing plate to mark it. The timing mark on the pulley though looks dead steady and isn't jumping around where it is. Fuel pressure I noticed is sitting at a steady 30psi at idle now. Another thing I noticed was that back before I fixed my wiring my fuel pressure gauge would be vibrating like crazy, now it holds nice and steady and for some reason it seems like my aftermarket FPR keeps holding more and more pressure the more I run it.

I was spraying all around looking for vacuum leaks and to check if I fixed them and I couldn't seem to find anything so that's a good sign. Every so often it seems like the idle will become kind of unsmooth. At one point the engine randomly stalled and I was having a hard time getting it going again. I'm thinking this is something with the wiring. I just can't seem to pinpoint it. Still running my old black plugs so maybe a new set of clean plugs will help make a difference as well.

duowing

Well went to try and mess with it today and it seemed to be doing still the same thing. Although it was acting like my MAF was bad, after I unplugged it and plugged it back in it seemed fine. So either my wiring is bad or my MAF is dieing. Also I was playing around with the injectors again and it seemed like number 5 is doing nothing. I need to get a noid light to make sure it's firing, but when I'd unplug injector number 5 it didn't seem like there was much if any change in the idle. All the other injectors seemed to make a noticeable difference. The car seemed to rev and idle just the same with number 5 plugged-in/unplugged. I also then started messing with spark plug wires. I pulled 1 wire off at a time to double check every cylinder made a difference except 5 or if it was making a difference almost non-noticeable. I had continuity from the ECU plug to the injector plug so it seems like that should be fine.

I went to O'reilly's and borrowed a compression gauge as mine is junk and gave me 95psi for all cylinders. Anyway at least what I got with the rented gauge was:

1 - 135
2 - 130
3 - 135
4 - 135
5 - 135
6 - 130

This kind of annoys me, but at the same time time at least the engine seems to be wearing relatively evenly. I squirted oil in cylinder 1 and the compression went up to 140. I squirted oil in cylinder 2 and the compression went up to 135. I didn't bother squirting oil in the others to test. I don't know if that oil will sit in there because after I got done doing the rest I came back and checked number 2 again just to see and it was still showing 135.

Still reading like 16-maybe 17inHG of vaccum at idle. Maybe it would go up if 2 was doing more?

Unplugged the injectors to do a test and while cranking I was holding a steady 400RPM and holding a steady 3inHG of vacuum.

This car is really getting on my nerves. I'm wondering if maybe the injectors got clogged from sitting around so long. I'll have to pull the rail up and check. I can't seem to find anything wrong with my wiring. I keep shaking stuff and sometimes it seems like the engine will change, but I can never get it to repeat and it just seems to be a coincidence.

duowing

Well I'm about at a loss here. I'm thinking it's gotta be a vacuum leak I've failed to find, or something with my wiring. I pulled the rail up today and hooked up the old 280Z pump to it, left the pressure regulator connected along with the return line to the tank. I stuck the feed for the pump in a fresh tank of gas and connected it to the battery. Pump pressurized the rail up to 40psi which is the max my regulator is set at without vacuum on it. Used an old coffee can and a cut fuel injector connector from the 280Z harness and hooked that up to the battery. Went one by one connecting the different injectors. They were all spraying in kind of a cone pattern. Should it be in a straight line, but either way the spray looked all pretty much the same amongst all 6 injectors. They didn't spray intermittent or anything.

So the injectors check out, there's not a head/headgasket/valve issue as far as I can tell. At least judging by the compression tests. The fuel pump seems to be fine as the rail pressure seems to hold steady. Spraying starter fluid all over the place hasn't seemed to reveal any other problems. I've got spark at all the plug wires at least when hot and running I do. The only codes the Z31 ECU is giving me is Fuel Pump, Fuel Temp Sensor, and Knock sensor. These were codes I'd get when running my 280ZXT. Maybe I'll have to pull the stock unmodified 87T ECU out of my Z31 and see if that makes a difference. I know the car pretty much won't start with the MAF unplugged and even if it does it won't rev past 2000 or 2500RPM I forget which, but revs fine when plugged in. I'll have to try starting it with the CHTS unplugged next. I guess I'll just have to get out the multimeter and just start testing things.

Any other suggestions? I just can't figure out why it seems to run fine once warm.