First of all, I'd like to offer my thanx to RETed for advice on my oil pressure. Hooked up a manual pressure gauge and all was well, so I cleaned some contacts on the original sensor and seems to be working much better. Thanx, man.

On to other things:

I suspect I'm running rich. When I'm getting on the throttle and let off to shift, I get a nice loud "POP" outta the mufflers. Also, the idle's a bit on the lumpy side, making the engine shake pretty bad. Adjusting the L-R screw by the boost sensor helped a little, but still not to my satisfaction. Also, if I disconnect the vacuum line going to the boost sensor from the engine, the car idles much better, but at a little higher RPM.

Now here's my questions:

To hook up an a/f gauge, one wire to O2 sensor and other to ground? Also, having never seen an a/f gauge before, what setting should I be aiming for to get correct a/f mixture?

If I find I am running rich, will a replacement O2 sensor fix the problem or is there another sensor somewhere that could be the culprit? Boost sensor perhaps? Will any O2 sensor from the parts store work or will I need to order one from an Rx-7 shop?

Thanks for any advice and feedback..

- JB

 

What kinda exhaust are you running?&nbsp Stock?

Possible that your TPS is out of adjustment?

There should typically be three wires.&nbsp One goes to turn on or +12VDC switched on.&nbsp One goes to ground.&nbsp The last one should be the signal lead from O2 sensor which is just spliced into the O2 sensor wire on the stock wiring harness.

Let's narrow the problem down before you going buying part unnecessarily.&nbsp If you can confirm the TPS is adjusted correctly, then you can try and replace the O2 sensor...



-Ted

 

What kinda exhaust are you running?&nbsp Stock?

Possible that your TPS is out of adjustment?

There should typically be three wires.&nbsp One goes to turn on or +12VDC switched on.&nbsp One goes to ground.&nbsp The last one should be the signal lead from O2 sensor which is just spliced into the O2 sensor wire on the stock wiring harness.

Let's narrow the problem down before you going buying part unnecessarily.&nbsp If you can confirm the TPS is adjusted correctly, then you can try and replace the O2 sensor...



-Ted

 

Exhaust is Bonez superflo to RP 50mm catback. I've had the bonez on with stock Y pipe and mufflers and still get the poping on letting off high RPM.

I'll check the TPS. I'm reading up on that from my manual now..

Thanx for the writeup on connecting the a/f gauge..

I'll post the results of the TPS adjustment and go from there.. Thanx, RETed...

- JB

 

o.k. I'm looking on your site about TPS adjustment and I have questions:

I want to use the DMM for better adjustment (I've heard bad things about using lights - i.e. blown ECU).

I realize your site describes a TII. Mine is an 87 n/a so:

Do I use the same wires of the TPS? Black and Green?

Do I leave the TPS unplugged or do the adjustment plugged in?

Engine running at idle or off with key on during adjustment?

 

bump

 

For an NA, it's a bit easier since the TPS is easily accessible.
Now, I'm assuming the throttle body hasn't been messed with - this means you'll need to warm the engine up so the fast idle kicks off, and it's running at (relatively) normal idle.

Kill the engine and unplug the TPS and measure the resistance.&nbsp The wire color codes should be the same.



-Ted

 

You assume correctly, except the fast idle at warm-up is not working..at startup the motor sputters pretty bad and I have to blip the throttle a few times to get it to idle. Another reason I wanna do this.

I'll post results tomorrow...

Thank you, once again.

- JB

 

o.k. I checked the TPS. It was out of adjustment - way out of adjustment ("holy ****!" was the first thing I said.).

It now reads 1.003 - 1.008 @idle and about .624 at WOT.

A couple of test drives (including a 110MPH run down the freeway showed smoother power, and the popping between gears has been greatly reduced (from a .45 pistol to a toy cap gun).

I'm gonna try to find an a/f gauge around here today and hook it up to see what I get while driving around town and on the highway.

BTW, the engine still shakes like a m/f. I'm starting to think weak motor mounts might be the issue. I have a RB torque brace coming next week.

- JB

 

Grab the engine and shake it as hard as you can side-to-side.&nbsp If the engine mounts are bad, you'll here them clanking...

Congrads on the TPS!



-Ted

 

I know that I don't know much but when my gxl started the exhaust backfires I found that I had a leaky exhaust. The leak was right before the main cat. Hope this helps you in some way.

 

I appreciate all opinons, turbotwista... You never know when someone throws out something that makes you think, "Hmm.. .I never checked that".

I have fairly new exhaust (in my sig), and I looked at that on your suggestion. No leaks, and since I've opened it up quite a bit, I expect some backfiring.

Ted:

I did as you suggested.. it's tight - no clanking. So hmmm... (I'll throw out some ideas):

Maybe uneven compression? God, I don't even wanna think that. Regular oil changes, no leaks, no smoke.. that CAN'T be it.

Timing off? It's been about a year since I've had it checked...

Once again, Ted, you earn my gratitude and admiration..... if there's any way I can return the favor for all the help, feel free to PM me.

- JB

 

Have you checked timing?
Also, you might want to confirm that your spark plugs are all firing.&nbsp Easiest way to do this is to pull all the spark plugs out and look at their "color".&nbsp The trailings are going to be a bit "blacker" than the leadings, but the leadings should look the same, and both trailings should look the same.&nbsp If there's a weak spark, it'll cause a shaking motor...


-Ted