hello,
need some help fast, please.

this is my first time taken my "new" 94 944 on the open road--drove a solid 75-85 mph, no problems. now, stuck in dallas at my brother's house.

car ran fine from houston to dallas today.

but car is idling rough now, pulsing rpms from about 700 to 1100 rpms up and down. and sometimes when i start the car, it sometimes idles at 1100 rpms. but almost always, the idles swings, pulses 700-1100 rpm. if i drive it and then stop, the car dies. i have to start it, pump the gas pedal to get above 1500 rpms, move it from neutral to drive, and pump the gas to move forward.

in short, when i'm driving, if i stop at a light, it dies. when i drive from a stop, i have to press the gas pedal many times to keep it going.

i checked the obd codes and it says o2 sensor, but i replace the o2 sensor 2 weeks ago and i certainly cleared the codes. i cleaned out the throttle body some weeks back, too.

fuel filter, fuel pump? i only have my tools with me, not any fuel gauges.

it's a rex/regina.

i did a search in the archives, but i'm sure, the tb switch, iac are working fine, i think.

need some help fast, only have this weekend to fix and get back home monday.

thanks very much for your insites.

regards,
byron golden
86 245
92 245
94 944
92 244 parts car

i swapped out the tb with the switch, but no changes.

the obd codes still say o2 sensor, but the new o2 sensor has only been on the car for only 2 weeks.

again, symptons are
1) can't keep a steady idle, swings 700-1100 rpm as if someone is on the gas pedal.
2) when i run it up to about 1500-2500 rpms, it's missing.
3) when i unplug the tb switch, it idles high about 12-1500 rpms.
4) odb codes show o2 sensor problem, but it's a 2 week old o2.
5) when i gun it higher and then let off the gas, it goes down normally and then dies.

i don't think it would be
1) air temp sensor
2) map sensor
3) cat (new also)

all help very much appreciated.

regards,
byron

I had the same experience a couple of years ago. After much misdiagnosis from the O2 sensor, AMM, vacuum lines, and one incorrectly MAF test, it was indeed the MAF. I bought one used one which also failed, and finally bought a reconditioned one from Volvo for $360. I probably spent $500 replacing everything except the MAF, so hopefully this helps. FWIW, I would not bother with a used one. Bite the bullet and get a rebuilt from Volvo. Good luck and keep us posted.

Byron,
Sounds like the air mass meter.
Unplug it while the car is off, then start the car and
see if it runs any better.

Don't plug or unplug the AMM while the car is on.
Salvage yards don't charge too much for a used one.
Check it on the car before you leave the salvage yard.
Match the part number with yours for accuracy.

Good Luck,
Joseph Segura

hello joseph,
thanks for your reply.

the car is a rex/regina with a air temp sensor and a map, (manifold air pressure). no air mass meter like the 240s.

i found out something. when i unplugged the throttle position switch, the car ran better.

i will try swapping out the tb switch.

thank & regards
byron

The throttle body switch has two positions. If it is misadjusted or not working, you can have similar symptoms. See the FAQ for a simple test and the adjustment procedure:
http://www.brickboard.com/FAQ/700-900/EngineSensors.htm#ThrottlePositionSwitch

--
See the 700/900 FAQ at the drop-down menu above right.

I am glad your narrowing down the problem.
Sorry 'bout my mistake, I was just tryin' to help a fella out.

Joseph Segura