The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

poor running, ideas appreciated, recap 200 1991

posted by  runwld2 on  Sat Oct 1 12:39 CST 2016
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Tue Sep 30 13:11 CST 2014
[RELATED]

Thanks for the thorough reply. I long ago removed the preheat hoses from my Volvos, and usually tho' not sure on this car, remove the thermostat in the air box and block the flap to the cold air position.
I an pretty convinced it is not the AMM, although I could try the one from my '93 245 to be sure.
I checked the fuel pressure yesterday, 38psi, bumps up when opening the throttle, so the FPR seems to be OK. Stays up on engine shut down.

To be clear, the car starts fine, but within a few minutes, runs awful. Not just, need a tuneup awful, but stumbling, will not respond to the throttle, may even stall awful. Then, like a switch is thrown, will run fine, normal acceleration, nice idle (for a 200K mile engine), then it could instantly, go back to awful. It can switch back and forth in seconds, or run good or bad for many minutes.

I have changed the white pump/system relay, new one installed. Whacked it a few times, but does not seem to be it or the wiring nearby.
Changed the ECU, no difference. It has a .....951.

Pulled 2 of the plugs. both had tan at the tips, but also some soot around the bases. At that time the car was running OK. But it makes me think it is running too rich when it is acting up, although that seems incongruous with its penchant to stall.

All together, I think it must be an electrical connection problem with the way it comes and goes so fast. But I can't get a handle on what exactly is making the engine run so bad. The ECU us fine, (the O2 sensor is old, and I think one of the codes is for O2 sensor, but it makes no difference whether it is connected or not, and from my past experience, it has very little effect on engine performance or idle). it's not the AMM (unless it's the connector, will check that). May have to hook a scope to the injectors and look at the length of injector pulses. Is the ECU getting erroneous inputs, or ??

I hope I can fix this, it will make my day.
Now back to the brakes on the daughters S40....
--
93 245 Classic, M47, IPD, 91 245SE AW70, 89 745, M46, IPD, Dependents-00 S/V 40s






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.