Need Help Checking Timing!
 

I'm stumped.

Went to get vehicle smogged for registration (CA rules) and failed because the timing was not within factory range.
My problem: idle not dropping when jumping TE1 and E1 terminals. Because idle did not drop, timing read 32* advanced!

What I have done:

• removed and cleaned throttle body
• removed TPS and cleaned to free motion (snaps back into place like new)
• checked resistance of the TPS in relation to various throttle positions as seen here, resistance values within range

  Throttle Position Tech & Adjustment Procedure - LC Engineering

  www.lcengineering.com/.../pdf/Throttle%20Position%20Sensor%20Adjustment.pdf
  
• replaced TPS with an aftermarket unit
• checked resistance of new TPS in relation to various throttle positions as stated above, resistance values within range

Results: idle still not dropping when terminals are jumped. However, check engine light is flashing.

I feel so defeated! I totally thought the sticky TPS was the culprit, but nope :(
One thing I noticed is when I slightly tap the throttle linkage on the throttle body the idle does not immediately return to normal. It sounds like the throttle is sticking, but moves freely in your hand. However, after a big rev the idle returns to normal. I should also note the engine runs great, decent power, no idle surging while driving. I had no idea there was a problem until I brought it in to get smogged.
Any ideas?
I did not check the ECU as recommended in the 4crawler write up.

Has anyone had anything similar to this?

Do you have the timing properly aligned or at least close to 10 degrees when jumping the terminals? If the timing is too advanced, the engine would still be idling high. Unlock the distributor bolt and rotate it CCW to reduce the advance. That should make the idle drop.

Jumpering TE1 and E1 just shifts to base timing. The difference between sitting-there timing and base timing depends on temperature, etc. There isn't always a difference, so the idle doesn't always drop.

32° is way too advanced to be correct anyway. In fact, it's so far advanced I would suspect you're off a tooth on the distributor drive (about 28° per tooth). Since the base timing is what is causing you to fail smog, address that. Start by just trying to adjust the timing the usual way (you may be all the way at the wrong end). If you can't reach 10° (or whatever your under-hood sticker calls for), you may have to "re-stab" the distributor.

But what if it doesn't run (well) when the timing is set "correctly"? Then it is possible that you have a "spun" harmonic balancer. You can check for real TDC with a chopstick or straw through the #1 plug hole.

(We, at least I, don't know which vehicle you're talking about. Put your make/model/year/engine/trans in your signature and you won't have to repeat it each time.)

Just to clarify. jumping TE1 and E1 just removes the ECU advancing returning timing to "base". Base is given by how you aligned the distributor. If the distributor is off, or the timing belt jumped, it won't go back to factory spec, which should be 10 degrees at 800rpm

I never updated this. I ended up not adjusting the TPS correctly, it is VERY sensitive. Got it back together and passed smog!

Good on you for returning to let us know! So frustrating searching through threads and no one ever posts the fix!

Glad you got it solved, TPS is very sensitive indeed. :safari:

I know what you're saying! Welcome!

I should also add the vehicle is a 1987 4runner 22RE. In case anyone is looking.

The hardest part of the adjustment with the throttle body in the vehicle, was fitting a feeler gauge where the screw stop is. There is no way anyone is putting a feeler gauge in between the throttle body and the screw stop. What I did was use two pieces of solder that I hammed flat to the correct thickness of an equivalent feeler gauge, that I measured with calipers. Redneck tech. Ha!

Take the TB out and adjust on the bench.