About 2 years ago I purchased my 280z for 300$. It was a rusted sad looking car that was stripped. I brought it home where I didn’t have a garage and just started stripping it. I got laid off that winter so I took it down to bare chassis. I took all of the suspension pieces and brought them to bare metal and painted them all. I put the car back come spring time then stripped the engine bay and interior following with a coat of paint. For a while I was gonna go with the 280zx turbo motor but then i changed. I ordered a 1JZ-GTE non VVTI and grabbed a trans from a Pontiac solstice. I taught myself how to weld when patching the sheet metal then took classes and actually got a job as a welder making decent money. I funded the z, grabbed a dash with gauges, interior pieces, wiring harness, front fenders and more. I welded up engine mounts and trans mounts, a driveshaft, and I even made brackets and mounted s13 calipers on the back! Now I wired the old to the new motor harness and I’ve had it running after welding in brackets and mounting my fuel cell. I can drive the car down the block but it runs rich as a pig and brakes up on any throttle. I’ve literally replaced about every single sensor on the motor and the ecu and igniter. Heck I hooked up an e manage ultimate to try and get it tuned out but nothing. I’m gonna try hooking up a fuel pressure regulator to see if that helps since I’m running a Bosch 044. I’ll keep posting for this build since I’ve since gotten a house with a big garage! I’m hoping to get it street ready by the time I’m 22! (April) thanks!!

Here are some ideas I found in a quick Googling:

You weren't joking when you said it's running rich. Standard injectors?

Bad fpr?

What are you're A/F readings (I don't understand the A/F reading lean.........)

If you have a signal or ground problem with the sensor, the ECU is seeing lean, and that's why it's dumping more fuel.

 

Well, if both sensors are giving a lean signal, you have a problem that is most likely electrical.

And like I said, your ECU is seeing this signal, just like your meter is, and over compensating by dumping more fuel.

 

You need to find out why your getting a low voltage signal from your 02 sensors.

Bad ground, bad wiring, bad something.

There should be 2 grounds also.

Sensor ground, which should go to the ECU ground pin, 100.

and heater ground, that should go to the chassis ground point, like 22,23,94.

The heater lead should go to a switched 12VDC source, 69 looks correct.

And of course the sensor signal should go to what ever pin the ECU is looking for the low voltage A/F from (57).

Got it fixed. The iacv and vsv needed a 12 volt switched source. Runs perfect now. No more miss and pop. Thanks for all the advice guys. More than helpful as always

I’ll trace my wiring! I bought an aftermarket 02 since that was my first try but recently went with a new oem one since the signals could be different. I have checked the ground pins for the ecu but not the 02 sensor yet. And I’m running about 10 afr it’s just how much fuel is coming out of the exhaust, if it just sees a lot of oxygen and not as much consumed fuel it will go higher in the 15’s and up. I want mine at least around 13 and it’s just not happening. I’ll give that a shot and may even add extra grounds. Thank you! 

Look at the pids on your tuning software and check for voltages out of range, go from there. Does it always run in the 10s? Or only during cruising, idle, part throttle, wot, etc. If it starts off in the 10s on a cold start then it’s probably not your o2 sensor unless it’s wired incorrectly and is backfeeding the wrong circuit into the computer. Your ecm starts off in open loop during warm up and doesn’t pay attention to the o2 sensor until it goes into closed loop once the coolant temp reaches whatever the calibrated temp is (typically around 160*). 

Other factors for rich condition off the top of my head that aren’t Ecm related: mechanical timing, ignition timing, fuel quality, restricted exhaust, restricted intake system, wrong injectors, too much fuel pressure (but that’d have to be way off to run as rich as you are). 

Edited December 2, 20186 yr by zeeboost

Ah okay I gotcha! When it first turns over it’s good for about 5 seconds then it drops to 10 haha. I’ve put a new belt on it since I had to do the water pump and it was my third time doing timing. I gotcha, hmm I welded up my own exhaust and there shouldn’t be any restriction it’s straight piped to a through muffler with 2.5 piping. I have the tuner off just to try and eliminate everything and get it to the basics. I’m about to go to the store and get some extra line to put my regulator in now. As far as I know the injectors are stock because I tried tuning it saying it has big injectors and It didn’t help too much. I was thinking maybe with the fuel pump and the 12v mod could maybe do it especially if my stock regulator is kinda bad 

Btw if you haven’t checked it out yet, go to www.hybridz.org

 

That site is dedicated to z car engine swaps. There is a Toyota 6 cyl help section you could go digging through over there. You may find some help here but it’s more of a site for all original or lightly modified Zs. I like this site but I come here to get my purist fix on, see how inferior my Z is based on some letters and numbers stamped into the metal 50 years ago, how many speakers and modulations my radio caters to, along with all the other little hidden Easter eggs.

Verify your timing marks with some pictures on google if you haven’t yet.

I gotcha and your car is beautiful if it’s your profile pic! I’ll give that a shot thanks! Haha that’s funny! I might of went pretty stock if I had a better starting point haha. I like making the car how you choose!

1 hour ago, 1j280z said:

I gotcha and your car is beautiful if it’s your profile pic! I’ll give that a shot thanks! Haha that’s funny! I might of went pretty stock if I had a better starting point haha. I like making the car how you choose!

I have you verified your fuel pressure at idle with a reliable gauge?

3 hours ago, 1j280z said:

 I was gonna go with the 280zx turbo motor

a 1JZ-GTE non VVTI

wired the old to the new motor harness

replaced about every single sensor on the motor and the ecu and igniter.

e manage ultimate

hooking up a fuel pressure regulator to see if that helps since I’m running a Bosch 044.

2 hours ago, 1j280z said:

 aftermarket 02 since that was my first try but recently went with a new oem one since the signals could be different.

checked the ground pins for the ecu but not the 02 sensor

running about 10 afr 

 

I cobbled together your basic facts.  It's not really clear what you're using for engine management, the ECU and harness.  Also looks like you're just connecting things up then seeing what happens.  Not a great idea, especially with a turbo engine.  Most modern engine management systems have a fail-safe or limp mode to protect the engine when things aren't right.  Timing is retarded, and/or cylinders are shut off.

Also looks like you're not 100% on the O2 sensors and how they work, and the different types.  You need to get the right ones, guessing and getting lucky is iffy.

I'd get the pinout for your ECU and wiring harness and spend some time checking every circuit.  Adding extra grounds is kind of pointless.  There's no magic, just get the right parts connected the right way.

Good luck.  Looks like it will be a lot of fun when it's running.  Be careful too, you'll have enough to be spinning in circles before you know what happened.

7 minutes ago, Patcon said:

I have you verified your fuel pressure at idle with a reliable gauge?

I second this also.  The 044 is a high volume pump.  Known for overpowering fuel lines.  The ECU/PCM works on an assumed base fuel pressure.  It can only adjust so much.

Edited December 2, 20186 yr by Zed Head

Thanks for the replies everybody! And okay to sum it up.. it’s a stock ecu for the motor because I took out the e manage until it’s running correctly. I know about the 02’s I just didn’t realize the one I had purchased used voltage to measure instead of ohms. My afr gauge is not hooked up to anything just for readings to help me, although it did feed information to the e manage. I’ve checks some of the pins but I can’t really check continuity because my leads aren’t long enough to reach. I was replacing sensors based on the problems they could cause when they go bad since my cel doesn’t work. I’m in the process of hooking up and altering the fuel pressure now (if it’s too high) ! ?

Good luck.  

They all produce a voltage.

https://www.fixdapp.com/blog/oxygen-sensor