jkube

The readings you describe on the coolant sensor indicates that its "making" and "breaking" connection. The 255 value is when there is no connection. Could be that you have a bad joint somwhere, it could be at the sensor itself. Especially if its the original 280 unit. Check for corroded terminals there. Work on this first, you need to get a stable value first before you can continue.

I used the stock 280z sensor and used easytherm to recalibrate the MS settings. No problem to date If anyone wants the values, just send me a PM

Yea Z-tard is correct about the lump for the cat. shouldnt be a problem though if its not rotted around that area. Just cut the pans to fit around it. As for selling off the early model pans to fit the 280. If your OK with not having the absolute correct frame rails visually, AND can fit the frame rails to match the engine bay rails, you should be OK to go. If you're at all unsure about doing the extra work to fit them, then yes sell the ones you have and buy the correct year pans and rails. At least this way you can 100% sure about the fit and finish. And you wont be sick to your stomach every time you look under the car and see the wrong parts there knowing you could have made it better. (Dont ask me how I know this!!!)

Hi, I've installed both types. The major differences in the profile down the centers where the rail runs along. Early model floor pans have a "Hump" running front to back and the floor rail flanges are both the same depth. Later 280z model pans dont have the "hump" and the frame rail has differing depth on the flanges on each side. If you have only the floor pans and not the rails, the floors could be interchanged. But it would mean you'd have to make some adjustments when fabricating floor rails.

Yes you can use the stock resistors. You will have to rewire them slightly because they are wired in together on one end, and for Megasquirt they have to be seperated out.

Do you have the EGO still activated? I have mine set to activate at 6000RPM. It seemed that MS became more stabile during tuning for me when it wasnt affecting the fuel. In fact I still have it set that way and both cars start well all the time. Give this a try

Thumper, With 1.5 at 170f and all the other settings at 0 I'm surprized the car would even start. What can you tell us about the TPS. Is there any possibilty that the throttle is being activated when starting? I know that if I even touch my throttle during startup the car will flood.

How about the pulsewidths at -40 and at 170 F. You should be able to affect the fuel amount with these numbers. Try lowering the number for the 170f setting. As reference I have the following on the NA car at -40 - 9.0 at 170 - 4.0 For the turbo car at -40 - 8.0 at 170 - 3.0 Both cars start well both hot and cold

One other thing to look at. I occasionally have a problem with MS on the 240z N/A car on startup, where MS is energizing the injectors fully on startup and flooding the engine. I suspect either I may have a short through the FETS to the casing, and the body or there is fault in the TPS (dont ask why I think that the TPS is a fault, its just a hunch). My suspicion is that one of the mylar insulators for the FET drivers is cracked. I have plenty of heat sink paste on it, but I noticed that one of them had been bent over and cracked I watch the injector LED to see if its fullly on when I start the car. I just engage the ignition key and watch the LED If its fully lit, I disconnect the switched 12 volt. and hit the starter a bit. After that I reconnect the 12 volt switched power and all is well for a few days.

Dont know if anyone is still interested, but I found the GM number for the GM sensor I"m using. #12160244 Here is a link to a pix of it. http://album.hybridz.org/data/500/medium/000_2414.JPG I'm going to take Mobythevans advice and give move the IAT back to intake of the TB just after the Intercooler. I should have time this weekend to retune MS. I'll post my air temp readings after I'm done

Sorry 73turbo240z, I cant find the package that the sensor came in, and there is no part number on the sensor itself. As for using easytherm, I did this because I didnt really know if the resistances were the same as encoded into MS. I didnt want to take a chance. So I measured the resistance settings at 3 different temperatures. First in the ice box (35F), then in room ambient(77F) and then in the oven (200F). I used a room thermometer to record the temps, and a multimeter to measure resistances. The way I knew the numbers would be accurate. Now, on this problem with location. I really dont thnk putting the IAT in the intake to the turbo is all that bad. Heres why, this spring I put a turbo into my son's B13 Sentra, and it uses the MAF to read incoming air temps. It's located in the turbo intake side. The ECU seems to handle these readings with out a problem. All these type of tuner cars seem to use the same setup, and the cars run very well. I took my car for a hard run this weekend and there is no signs of problems with the current setup. Maybe I just lucked out on this one.

I agree with you guys on the location (just before the TB). It makes sense to me too, and thats how I had it set at the beginning of my tuning sessions. I read the manual and located between the intercooler and TB. I moved it because of the trouble during tuning, to see if it would fix my inconsistant cold weather operation and it seemed to. I know the coolant sensor adjusts the fuel flow in cold weather, but I cant seem to find anohter explanation as to why it works. What can I say. Maybe I've tuned around it somehow??? I also routed my piping to go from the turbo outlet..across the rad.. into intercooler on the passenger side .. and then out and around to the TB. I did this because I didnt want the cooled air to be reheated again by the rad. http://www.execulink.com/~jkube/Brians280z/000_2393.JPG The IAT I've used is a GM sensor used on the LT1 corvette. Its an open sensor unit surrounded by a plastic cage and is mounted in a rubber bushing to isolate it from vibration. I used Easytherm to adjust the temps/resistance values table. Maybe this is why the car starts so well in the cold weather now??

I've put my IAT in the air inlet to the turbo. Seems to work well. I can setup the car to start and run well during warmup in colder weather, without a cold air valve. When I had it located after the intercooler just before the TB the air temp seemed to be "off" all the time. I also had trouble getting a consistant fuel setting, I think it was because the different ambient temps under the hood had a big affect in the higher temp ranges depending on how I drove the car. http://www.execulink.com/~jkube/Brians280z/280turbopage%201.html

I bought the air dam used form a racer up here about 10 years ago, but I have seen it on the web at this location: http://www.showcars-bodyparts.com/240z.html Its an air dam meant for a 280z , and I think it had a sticker on it that said American racing.

Nice job !! Well done I did 2 zcars last year in the same manner. I see you managed to find a full quarter for the passenger side and an aftermartket one for the drivers. These items are bcoming very rare. Does anybody know where more of these full quarters exist??? I can only seem to find the small section around the wheel lip http://www.execulink.com/~jkube/Mainpage_lethalzs.html

I've finally finished my Uncle's 76 280z turbo install/restoration. Car turned out quite nicely and runs very strong without any sign of predetonation. I mention this because I decided to try using a stock 240z distributor with a Crane cams XR3000 conversion kit to control spark and Megasquirt to control fuel. I've disconnected the vacum advance of the distributor and only set timing at idle. I dont expect any advance or retard to ocurr at revs (correct me on this if you think I am wrong). I havent read about anybody else doing this sort of setup, and thought you guys would be interested to hear how its working. Other parts in the car: Stock 280zxt motor and turbo 370CC injectors Aluminum Fuel rail Walbro 255 pump Begi RRFPR FMI, with piping from the intercooler routed so that it doesnt run along the rad. 3" exhaust We're currently running about 10PSI boost, but have had it up to 21PSI ( 5th gear) without any carnage. (I'm glad it was Brian that was beihind the wheel). Luckily I had the megasquirt set to dump way too much fuel at WOT for that run. I've since scaled back the fuel for 10PSI and the car runs strong up to about 6000 rpms. Here is my site with some pictures, and I'll be uploadng some more in the next few days. http://www.execulink.com/~jkube/Mainpage_lethalzs.html

I dont beleive a sensor would fit. If I remember correctly the EGR fitting is quite a bit larger. You may have to install a bung further down the exhaust or "Weld-in" a bung onto the EGR fitting.