Feed up!

[icemaninlv]

91 NA 5sp 2+2
Running like straight A$$!!! No power under load, high idle, spitting and sputtering
Pulling ZERO codes (55)
I have ECUTALK so TPS is set to .40 with throttle showing closed. and timing set to 15 degrees.

New plugs(correct NGK ones) gapped .040

5of6 injectors ohm'd 12.3, cyl #1 bounced all over! Well i had an extra injector that shot good so now all injectors are good!
All injector wiring ohms good to the ecu

All coils ohm 1.1 and have good continuity to the PTU.

Ohm'd the PTU as per the 94 FSM, good! .504ohms

Reviewed both these links
ptu-subharness-delete-t563983.html

running-out-of-ideas-t564182.html

I don't want to spend 167 via Concept Z for one but if that is going to fix it.

On a good note the AC blows nice and cold

Thinking PTU or CPS

So the big QUESTION is

[nissanfreak12]

Have you done a Boost/vacuum test? When was the last time you changed you timing belt?

[icemaninlv]

All vacuum lines are new, never heard of the test, "newer" engine installed about 20 ago, previous owner. I don't see a timing belt doing This problem, as the reports of stretching are miniscule

[icemaninlv]

http://www.atlanticz.ca/zclub/techtips/vacuum/

Might try this tonight

Nissanfreak12, is this what you were talking about?

[ThisIsSparTTa]

I think this one is a better guide: http://www.thumper300zx.com/z32/boostle ... _guide.htm . Also check your MAF and TPS.

[icemaninlv]

non turbo, on my ECUTALK I believe my Air Flow was 1.57V tps is good.

Something else was the balance test.

When unplugged the #1 and 5 C/P no change in engine, so there is something, how ever both injectors and C/P ohm checked good.

[ThisIsSparTTa]

Doesn't matter if it's turbo or not. There's still tons of air lines running around for your intake and vacuum systems.

If you're not running on 2 cylinders then that's what you need to attack. Move plugs, move coil packs, see if the problem moves. Check your wiring connection between the ECU, ptu and the coil packs and injectors. Check your grounds. Lots of stuff to do.

[nissanfreak12]

Do you have the newer style PTU? Is it all black or does it have silver fins on it?

[icemaninlv]

New style, I followed the 94 fsm, and it ohms good

[Rubyz32]

I'm in the same boat. I think it's internal. I'm ordering a new engine and ecu next month.

[nissanfreak12]

All vacuum lines are new, never heard of the test, "newer" engine installed about 20 ago, previous owner. I don't see a timing belt doing This problem, as the reports of stretching are miniscule

To get back to Timing Belt, I wasn't concerned with stretching, I am more wondering if it jumped a tooth. Yes, a slipped belt could cause what you are describing, especially if it slipped on one side of the engine, like the 1,3,5 intake cam. Just someting to look at.

HOw are your o2 sensors? Are they newer? OEM or not? Non-oem have been known to make the car do odd things. You can check to see if they are doing what they are supposed by switching in mode II or the program you have should tell you. Just let us know.

[icemaninlv]

I guess I could take the cover off and see if everything lines up.

[icemaninlv]

Opened up sprocket covers, all dots line up, maybe a touch on either side if playing to level the other side. Not even close to a tooth off thou. All good there

New of sensors, bosch direct replacement, no codes nor errors

[icemaninlv]

Anyone know about this brand of ptu? Reads .504 where needed and open when needed

[ThisIsSparTTa]

Counting teeth is only real way to know what shape the timing belt is in. When mine was off 1 tooth at the crank, it would idle fine, and accelerate okay until about 50% throttle then start sputtering and puking like crazy. It looked like it was at the right place, but was off by 1 when counted.

Not sure what .504 means, I'm guessing you did continuity mode, better would be ohm mode. I personally wouldn't go with an aftermarket PTU as finnicky as the electricals on this system is, but up to you. See if you can find someone's good PTU to borrow?

[icemaninlv]

That was my question, I pulled this one off the car. Didn't know if it was factory or not.

As for the timing. I didn't pull the harmonic balancer off however I aligned the mark to the 0 mark. and all the cam sprockets were aligned properly.

Additionally my CAS via ECUTALK displays 15 BTDC.

300zx's are slim here in hell....i mean Lawton Oklahoma haha. Concept Z has the kit for 167 that I was going to buy friday.

And it was cyl 2 and 5 not 1 and 5 that had no reaction to the balance test. all wiring is good to the injectors and CPs.

[nissanfreak12]

The marks on the backing plate are ONLY for reference, after getting the timing set, they more than likely will not line up. Spartta said it right, you need to count the cogs as stated in the FSM. Just because ECUTALK says 15 btdc, doesn't mean the belt is aligned. On cam could be off one tooth.

That PTU, definitely could be an issue. Never seen one like that before, looks like an ebay special.

[icemaninlv]

Good and bad


created my own boost leak tester. Good news is not a single leak or air blow off.

did a compression test
Cyl 1 170psi, Cyl 3 140psi, Cyl 5 155psi
Cyl 2 155psi, Cyl 4 160psi, Cyl 6 160psi

Cyl 2 went to 190psi after I added oil, so looks like those rings might be going bad but shouldn't cause a problem I am having, maybe minor power loss nothing like what I have

Another bad was cyl 1 and 5 both had gas on plugs when removed. Looks like 2 bad injectors or bad seals. I'll dive deeper later this week.

[ThisIsSparTTa]

Good on the boost leak test. Low compression won't affect you in this way, you're just losing performance. The gas could just be from dumping fuel in but not starting all these times.

[icemaninlv]

Just bought a new PTU and the new style injector adapter from Concept Z

Then bought some refreb'd 270 JCES new style injectors.

Going to do the 12vdc mod to pin 58 on the ecu from the constant 12vdc from the clock.

should be done this weekend. I will report sunday!

Thanks everyone for their help

[ZL8NING]

Take some pictures for "before and after". Also some pictures as you go along for a mini "how to".

Then post those on your other thread: post6593466.html#p6593466