93 1.0L MAP sensor code?

[metro_nut]

I have a '93 1.0L, 5-speed. I recently replaced the rotor, cap, wires, and plugs. The car still had acceleration issues, and terrible idle in cold
weather, as well as dying on me on two occasions, when taking off from
a stop (in very cold temps). I replaced the fuel filter, which smoothed my idle and helped me take the hills in 5th gear. I took the car out the next day, in 5 degree temperatures. It ran flawlessly for 25 miles or more of mixed highway and stop-and-go driving. Then, trying to accelerate from 35 to 45 in 4th gear, the car hesitated, did some surging, but never died. I managed to downshift to 3rd, coax the RPMs up, and get out of town. I got home and checked for a code, but there were none stored. The next evening, at zero degrees, it took 4 attempts to get the car to start and stay running. Once it stayed running, it was smooth. It stored a code 32 -MAP sensor. Can other problems cause the MAP to send a bad (or what appears to be bad) signal to the ECU? I tested the MAP according to Chilton's, and it appeared ok. Could it be ice in the vacuum line? If the MAP was only $25 I'd replace it today, but at $200+, I'd like some opinions on this. By the way, the car has 101k on it, and I found a used MAP sensor in the glovebox.....

[DOCTORBILL]

Originally Posted by metro_nut

I have a '93 1.0L, 5-speed. I recently replaced the rotor, cap, wires, and plugs. The car still had acceleration issues, and terrible idle in cold
weather, as well as dying on me on two occasions, when taking off from
a stop (in very cold temps). I replaced the fuel filter, which smoothed my idle and helped me take the hills in 5th gear. I took the car out the next day, in 5 degree temperatures. It ran flawlessly for 25 miles or more of mixed highway and stop-and-go driving. Then, trying to accelerate from 35 to 45 in 4th gear, the car hesitated, did some surging, but never died. I managed to downshift to 3rd, coax the RPMs up, and get out of town. I got home and checked for a code, but there were none stored. The next evening, at zero degrees, it took 4 attempts to get the car to start and stay running. Once it stayed running, it was smooth. It stored a code 32 -MAP sensor. Can other problems cause the MAP to send a bad (or what appears to be bad) signal to the ECU? I tested the MAP according to Chilton's, and it appeared ok. Could it be ice in the vacuum line? If the MAP was only $25 I'd replace it today, but at $200+, I'd like some opinions on this. By the way, the car has 101k on it, and I found a used MAP sensor in the glovebox.....

I have EXACTLY the same Geo Metro as you do - made in Canada.

Read the Thread titled:

"How can you test continuity with an ECM and O2 Sensor?"

It is all about MAP Sensor problems.....

You can find used MAP Sensors all over the place.

Call all the wrecking yards around your location.
Get on E-Bay - cars & parts section.

Used MAP Sensors are anywhere from $7 to $50 from old wrecked
Metros. GOD - don't pay $240 !!!!

A MAP Sensor from 1989 to 1994 3 cyl 1.0 L Metros should work
in your vehicle. Look at the first number on it.

Extreme low temp outside (Spokane, WA) seems to have zapped
my MAP Sensor. I plan to obtain a couple if not three of them
over the next summer in anticipation of next winter's cold.

Hey! Try the used MAP Sensor in the glove box - Couldn't hurt...

DieInterim (Blake) has helped me quite a lot with this problem.

DoctorBill

[metro_nut]

Thanks for the reply, DR.Bill. I read your other thread, about MAP sensor testing, and did measure 1.4V at idle. This, however, was in a 30 degree garage. I will go scrounging for a used one...

[DOCTORBILL]

Originally Posted by metro_nut

Thanks for the reply, DR.Bill. I read your other thread,
about MAP sensor testing, and did measure 1.4V at idle. This,
however, was in a 30 degree garage. I will go scrounging for a used
one...

I would not doubt that some glass tube with a silicone plug and a
quartz transducer all rolled up in one device would possibly get screwed
up by numerous and rapid 30 - 40 ° temperature shifts.

Any device that relies on mechanical movement would be a
superman device to withstand such excursions in
expansion / contraction like that.

I wonder if the more modern (1993 is 12 years ago!) MAP Sensors
are non-mechanical devices.... It would be worthwhile to develop
something transistor-like and less "Tube-like". The anology of the
old tube radios versus transistor radios.

Anyway - for God's Sake, don't spend $240 (Schuck's price for a new
one in Spokane!) on one of these things! There were hundred's of
thousands of these Metros made and as they expire, there is a MAP
Sensor ready for 'transplantation' as it were.

Blake (DieInterim) said he'd send me one soon. I sure hope that that
solves my problem.

DoctorBill

[metro_nut]

Originally Posted by DieInterim

Hmmm. 1- 1.5V is specified as correct during idle, vacuum connected. Disconnect the hose and it should rise to 4-5V.

Thank you, O Great One. I will do some further testing next week. I have various Christmas celebrations the next three days. I'll let you know the results.....

[metro_nut]

Originally Posted by metro_nut

Thank you, O Great One. I will do some further testing next week. I have various Christmas celebrations the next three days. I'll let you know the results.....

I'm back at it. With vacuum disconnected, the voltage on the signal
line only reached 3.6V. I guess I'm on the hunt for a MAP sensor...