Mass Air Meter or O2 Sensor?

[eladsinned]

94 celica w/ 2.2 engine 190K, problem with acceleration; after engine warms up power drops out & rpms fade when opening throttle. Goes into crawl mode, putting along at about 10mph.
Jumpering diagnosis box shows only normal code. Has a single wire O2 sensor mounted on exhaust manifold. Still haven't found MAM or how to test it.

[toyomoho]

The MAP sensor may be bolted to the firewall and connected to the throttle body via a vacuum hose. If you need to know what it looks like try www.rockauto.com and find the part, they typically have photos.

Other possibilities include the throttle position sensor and low fuel pressure/flow.

Suggest a Haynes manual or similar If in Seattle, King County library may have OEM service manuals at the referance desk or aftermarket Celica manuals for check out, or try Seattle public library. Call first or go online to save a trip.

[keving85]

Originally Posted by eladsinned

94 celica w/ 2.2 engine 190K, problem with acceleration; after engine warms up power drops out & rpms fade when opening throttle. Goes into crawl mode, putting along at about 10mph.
Jumpering diagnosis box shows only normal code. Has a single wire O2 sensor mounted on exhaust manifold. Still haven't found MAM or how to test it.

quick test you can do is disconnect the MAF or MAP sensor.... not sure which setup the 2.2 has, a MAP or MAF..... when you disconnect them the car goes into a sorta open loop mode like what newer cars do....
if you disconnect it and it drives alot better as it should, then you have a good bet that its that sensor.... for metering the air.....
(this is an option if not able to diagnose with proper equipment)

kev

[eladsinned]

Thanks for the help. MAP sensor so far checks out at 4.9 volts (test range 4.5 to 5.5)

[eladsinned]

Turns out it was the distributor

[eladsinned]

Having problems installing a new distributor; engine will not fire with new dist. installed. Inspecting inside cap I discovered the rotor is 180 degrees out. Can't turn the rotor around, and can't install with the coupling turned 180 deg. out--this is odd, because I can't see how the coupling is made for one position install--it appears and measures out perfectly symmetrical. So, with the dist. installed per manual at TDC, the rotor is backasswards, and there's no fix for it. It's an ebay part. Somebody please tell me I'm stupid and missing something.

[Pineapple]

The end piece that fit into the cam is not symmetrical. If the last owner(s) took it apart and assemble it wrong, that'll be why. Nothing to do with the rotor. Its the piece on the other end of the shaft. You'll need to press the pin out to fix it. If you gonna do that, order a seal kit from kbox.ca and install it. All 5S dissy will leak at some time. Fix it now while you have the thing apart.

[eladsinned]

"Nothing to do with the rotor" au contraire, it has everything to do with the rotor. I seem to have confused you with too much info. That "thing at the other end" which I correctly identified as a coupling is reversed, thus the rotor is reversed. It is a remanufactured part bought from a parts wholesaler. And what's this "seal kit" business? I got a new dist and new seal. My head hurts.

I dropped the dist off with a mechanic with instructions to turn the coupling around

[eladsinned]

Success. But new problems, alas.