Hesitation during acceleration

[Zed Head]

45 minutes ago, DC871F said:

So if the TVS does not pass the insulation test, I'll at least need to replace. Would this cause my issue?

Hard to say.  It just means that one of the contacts is shorted to ground.  It might just be a trail of dirt or a bent contact.  You could probably take the cover off and clean it up and get it back in order.  There's not much to them.

[siteunseen]

Spider's webs too.  They get in the damndest places.  The TVS cover is not as tight or sealed like the AFM cover.  I've read where people washed their engine bay and got the TVS wet, caused problems. 

[rcb280z]

Yep, big mistake to wash down the engine bay equip'd with EFI. Ask me how I know . Many years ago when it was the thing to do, did it and still to this day am regretting it.

It's easier to remove the TVS from the throttle body to access the interior of it, unless it's already been opened. Just mark the throttle body before removing it. Mine had some light corrosion in it. I used the striker area from a book of matches to clean my contacts. Worked well.

Edited January 5, 2018 by rcb280z

[DC871F]

37 minutes ago, siteunseen said:

Spider's webs too.  They get in the damndest places.  The TVS cover is not as tight or sealed like the AFM cover.  I've read where people washed their engine bay and got the TVS wet, caused problems. 

It will be the first place I go this morning, after it warms up a little. Could have got 4 240Z's working in the time this ZX is taking.

[DC871F]

32 minutes ago, rcb280z said:

Yep, big mistake to wash down the engine bay equip'd with EFI. Ask me how I know . Many years ago when it was the thing to do, did it and still to this day am regretting it.

It's easier to remove the TVS from the throttle body to access the interior of it, unless it's already been opened. Just mark the throttle body before removing it. Mine had some light corrosion in it. I used the striker area from a book of matches to clean my contacts. Worked well.

I did that about 25 years ago with a TurboZX, that was a huge mistake. And I was at work when I did it, it was a long herky jerky ride home, LOL.

[DC871F]

TVS clean, no defects I could see. Filed the contacts, cleaned, reinstalled.

Still cant get it to pass the insulator test on p.82, whatever that test means. Maybe theres a short in the 3 prong plug, but it looks intact.

Just for future reference for anybody else. You have to drill the 2 small pop rivets to get the cover off.

Edited January 5, 2018 by DC871F

[Zed Head]

To be sure, can you describe how you did the test or show a picture?  With the TVS off of the engine you'd have to connect one of your leads to the mounting plate, since that would be the path to ground.  With everything installed you can run that test at the ECU connector by placing the negative lead on a good ground point then testing each of the three pins. 

And, to be very sure, you want no reading on your meter, like it's waiting for you to do something, or a very very high one, in ohms.  If you had a test light it wouldn't light, or a test beeper it wouldn't beep.  

[DC871F]

I did the test with it on the car. It just showed an open on all three terminals, not "0", or a large resistance reading. The ground I used was good.

Re-installed TVS, took car out and drove it about 90 miles. There is definitely a "sweet" spot on the accelerator peddle, about 75-80% full throttle to where the car will accelerate smoothly. Also, I think the fuel consumption is way high, but that will have to wait till tomorrow to confirm how much gas it used, it may be the fuel sender lying to me.

I will go out tomorrow and do the insulator test through the ECU plug, since last time I did all 3 tests with the TVS disconnected.

[Zed Head]

35 minutes ago, DC871F said:

I did the test with it on the car. It just showed an open on all three terminals,

I will go out tomorrow and do the insulator test through the ECU plug, since last time I did all 3 tests with the TVS disconnected.

That's a "pass".  Open circuit (infinite resistance) to ground, on all three.  I'm guessing that your ECU connector test is going to be a "pass" also.

The clamp on the return line might not work if the pump is struggling. 

The gauge will tell.  Everything about the EFI electronics revolves around a controlled and predetermined fuel pressure.  The ECU programming is based on it.

[DC871F]

14 hours ago, Zed Head said:

That's a "pass".  Open circuit (infinite resistance) to ground, on all three.  I'm guessing that your ECU connector test is going to be a "pass" also.

The clamp on the return line might not work if the pump is struggling. 

The gauge will tell.  Everything about the EFI electronics revolves around a controlled and predetermined fuel pressure.  The ECU programming is based on it.

Hey you're right. I was stuck in the frame of trying to read ground.

 

[siteunseen]

I have know idea what a  crank angle sensor is or does but is that a possibility for your hesitation?   Bored to death.

 

[DC871F]

Fuel pressure checks ok, Not quite 30 at idle, but a solid 37 at acceleration. I'm a PSI off, but may be the gauge.