PorKen

Could be rich, could be lean, could be ignition related.

Check what the MAF CO screw is set to. Should normally be somewhere around 382 ohms (zero).

Crumpler

hey Ken, thanks for keeping your ears on.

I know I'm running rich on MAF, I had put a wideband with guage in to fill the extra bung on the X pipe so I could look cool...Then noticed all the lean readings on gauge...then jacked up the MAF to 780. Probably a case of the tail wagging the dog.
I will go back down to 380 on the MAF when I get home and see if that does it.
Regards.

PorKen

780 will make it hella rich!

AFRs will wander from 13.5 to 15.5 with the O2 loop active. Unplug the O2 sensor and adjust the MAF CO for high 14's. (No need to unplug the LH, it doesn't learn.)


WOT AFRs should be in the 12-13 range. Check that the WOT switch is working/getting to the LH.

Crumpler

Alright guys, remember I'm a veterinarian and be kind:

So I took the MAF down to 380 Ohms.
Double checked all connections and took her back out.
Performance was good until I got up into second and heading for third when issues started again. Hesitation and stumbles, engine cuts when in idle. Will restart without issue.

I moved on to check WOT.
Both ECU plugs out and battery disconnected for readings.

Plumley speaks of using 18 and 26 on EZK for ohms, but I don't have a female receptor on the plug at 26 on my year...

Then I used my LH-Jet test value book:
To test throttle switch idle it says to use terminal 3 and ground off LH.
I got good numbers: 3.5 Ohm (<10) closed and infinity when open.

For throttle switch full load (which I'm calling WOT), I am using terminal 12 and ground off of LH.
Those results look like garbage...
idle position 46.3 M Ohms (should be inf.)
2/3 of opening travel should get me < 10 Ohms, and I got 51.5 M Ohms.

So I will try and repeat readings directly on throttle switch next.
Short harness is fresh but the TPS is not fresh, PO did it four years ago. If it is TPS, it is my bad for making assumption I was alright, seemed to run fine.

Can the stock chips work around a bad WOT? And would WOT do what I'm experiencing?
Greatly appreciate feedback at this point, thanks.

Dadddio

Could this possbly be a Temp sensor issue?

Crumpler

Thanks Chris, I will look at that as well.

I didn't get much done yesterday.
Did check TPS Ohms at plugs on short harness, which I'm calling an extension of TPS.
I got same results as off the LH: ilde switch ok, full load gets me garbage readings with no Ohm changes working pedal.

If anyone still has any interest in this thread... I did read in one of Wally's guides that stock ECU can compensate for a bad WOT at higher airflow rates.

I'm going to pull fuel rail tonight and replace TPS, I have not put stock chips back in yet.

PorKen

The TPS is often full of oil.

The LH will go open loop at high load, but both stock and S300s chips require the full-load input to activate WOT programming.

S2/S3 LH2.2/EZF pinouts - https://rennlist.com/forums/928-foru...2-pinouts.html

Pfc. Parts

I, for one, am waiting to hear how this thread plays out. I wish I could offer suggestions but it seems you already have the best advisor you can get

I honestly didn't know there was a chip set for the S3 and plan to install them on mine as soon as I can track down the technical details, installation guides and source the parts. Very much looking forward to hearing your experiences after you have the car sorted out.

Thanks for posting on this topic.

Dadddio

Reading Kens chip recommendations on his website says
0 degree cam timing -2/0 cold.
Isn't normal 10 degrees BTDC?
Does this have to be reset?
Just a thought.

SMTCapeCod

Same here, interested, following, rooting for ya, taking notes...

Crumpler

Hey you guys thanks for the support, it does mean a lot.
Unfortunately, I learn a lot more about the car in these situations when I'm forced to.

I spent a couple hours pulling things apart to get to TPS.
The bottom screw was stripped on TPS from PO and became almost blue hose quality frustration.

The arm that extends from throttle body into the TPS was a lot longer then I thought -- there's no room to pull TPS off. I had to move ISV a little and loosen and lift entire throttle up enough to get some clearance.


Just as Ken predicted...pic of oil dripping out of old TPS.
second pic shows old TPS and lack of clearance to pull off.

Attachment 862927

Attachment 862928

SMTCapeCod

oil filled is definitely the norm, I don't think it is attributed to a particular fault, just the status quo.
If it is interfering with the conductivity at the switch and causing your readings, that's interesting. Hope you are able to check the outputs to the new one. Also, since you're in there, some folks have found vacuum leak at the rod that holds the throttle plate, and they replace the o-rings in there. Haven't tackled that myself.

Also, be sure to really scrutinize those hoses that go down to the lower plenum. Easy place for hidden cracks/looseness, and no fun to go back in for. BTDT.

byrdman454

Dave, did you take readings with your meter directly at the TPS without the harness installed? This should tell you if the TPS is a problem or the wiring since your readings at the LH were not within spec.

Crumpler

SMT, can do. Maybe a case of the more I look, the more I find.

Mike, that's what I should have done last night before I pulled the old TPS.
I will say the short harness to TPS is fresh, but still possible there's an issue between TPS and short harness plugs.

I will get readings tonight on the way out at TPS, harness, and LH to make sure they reproduce in spec.

Here's a question:
New TPS has about 2-3 mm rotational play on the arm from the throttle body.
If rotated counter clockwise, you can feel the switch click.
Do I need to tighten screws in the that switched position, or does it matter at all?
Thanks again.

byrdman454

Yes, this is the whole purpose of the TPS and the slotted holes. The TPS needs to be installed and then rotated on the slots until the button is depressed at idle (clicks). This tells the LH to switch maps over to the idle circuit. When the TB butterfly is opened off the idle stop, this TPS should click.