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1993 854 non-turbo AT 92k - stalling at 40-70 mph[ALL/1998] posted by mark barron on
Monday, 11 August 1997, at 8:28 a.m.
I had every intention of posting a positive message of thanks to Robert,Abe and Mark
thanking them from their imput ( I still do) and tell them how my replacement of the CMP sensor and the small fan at the lower
front of the CU box had fixed all my stalling problems -- Not so. I drove 1,800 miles
to Glacier NP only to stall on the western travelling descent of Logan Pass. Fortunately
there was no opposing traffic at that moment and I pulled off onto the left pull -out.
Although there were codes ( the one for CMP sensor, 314, I think it was) prior to replacing
the CMP sensor,. the stalls are all uncoded now. I had another stall on the way home.
Two weeks after returning home, my wife had two more on the way from shopping -
both stalls seem to be within a couple of miles. I know engine compartments get hot,
but the 850's has always seemed a bit hotter than most.
Facts about the stalls:
There have been approximately 10 stalls; all but one with the
car moving more than 30 mph. perhaps 7 stalls had no code thrown.
Many appear to be in pairs. All stalls have occurred at or about 75-80 degrees F.
The last three or four stalls have requirred a wait of say 30 seconds before it will
restart.(Earlier stalls allowed snap restarts).
I am trying to figure out how I can solve this problem short of buying a second
850 and starting to swap parts.
Questions:
What is the logic controlling the CU box fan, It appears to follow the auxilary
fan for the radiator -- should it run all the time? What direction should the fan
turn - I am wondering if it could be reverse wired.
Below I am pasting a message cut and pasted by a mechanic friend of mine,
Because of all the cutting and pasting , I am not sure if the names included in
the message belong to the messages above them or below them. Hopefully
you will find them interesting , I am interested in what you all think about
the msg regarding the Spike from the Fuel Pump Relay.
Would the Volvo Computer be wired to order a stall at a Spike from the
AMM ? ---- Mark
0000000000000000000000000000000000
On Volvo/Bosch LH fuel injection systems, a bad fuel pump relay can
feed voltage spikes to the air mass meter (AMMI and/or the ECU,
Always replace the fuel pump relay when replacing the AMM and/or
the ECU, If you don't, the new AMM or ECU may die soon after.
Volvo stamps the manufacture date on their fuel pump relays. A good
rule is to replace the fuel pump relay before it's five years old.
Howard Hawks
Volvotech
Renton, Washington
You In The Driver's Seat
For a few bucks, you can check the charging system voltage and AC
ripple from the driver's seat:
· Purchase a DC lighter plug (Radio Shack P/N 270-021 for approximate-
ly $3.49).
· Attach your digital multimeter (DMM) to the cigarette lighter plug.
· Start the engine, then rev it to 2500 rpm. The charging voltage should
be 13.5-15.0 volts on most import vehicles.
· Keep the engine running at high rpm, then turn on the bright head-
lights.
· Switch the DMM over to AC volts, then monitor the reading. More than
0.4 volts AC means a bad alternator diode is allowing AC to leak into the
vehicle's DC electrical system.
Tames Halderman
Sinclair College
Dayton, Ohio
off The Ground I
Off The Ground
New Theory:Re: 1993 854 non-turbo AT 92k - stalling at 40-70 mph[ALL/1998] posted by mark barron on
Tuesday, 19 August 1997, at 1:34 p.m.
Is it possible that the Temperature Sending Unit is not turning
on the Coolant Fan and the Control Unit Box fan soon enough, thus allowing
the engine to get too hot? How would I determine this? What would
the exact name be for what I am talking about?
Many thanks, Mark
Re: New Theory:Re: 1993 854 non-turbo AT 92k - stalling at 40-70 mph[ALL/1998] posted by Mark Klein on
Saturday, 23 August 1997, at 8:50 p.m.
Does the temp gauge indicate the engine is overheating? Do you have any other indications it is running too hot?
Re: New Theory:Re: 1993 854 non-turbo AT 92k - stalling at 40-70 mph[ALL/1998] posted by mark barron on
Tuesday, 26 August 1997, at 11:20 a.m.
Mark, No the temp guage indicates that everythings is fine.
I have noticed that not one of the stalls has taken place when
the ambient temp is below 75 degrees. When I lift the hood after
the car has been running it seems too hot - i realize this
is subjective. The stalls do seem to fall into another pattern.
The stalls seem to occur after the following pattern:
1. drive car until warm.
2. shut off car.
3. restart normally after say 5-30 minutes
4. drive a few miles
5. stalls dead under power.
Re: New Theory:Re: 1993 854 non-turbo AT 92k - stalling at 40-70 mph[ALL/1998] posted by Mark Klein on
Thursday, 28 August 1997, at 9:27 p.m.
This is reaching but try moving the coil wire away from the wire from the air mass meter. Most of 'em are almost touching and you can get some weird electrical interference at times. Also check the wire from the cam position sensor. See if its next to another harness. Move it also.
I just don't think the under hood temperature is getting hot enough to cause your problem.
Rerouting wires:Re: 1993 854 non-turbo AT 92k - stalling at 40-70 mph[ALL/1998] posted by mark barron on
Friday, 29 August 1997, at 11:09 a.m.
Thanks again Mark for your ideas. Nice to know I am not totally alone
with this problem.
I rerouted the coil wire away from the AMM sensor wire, It is maybe
2 inches away now. I replaced the CMP sensor and a routed the cable
as far away as possible from other cables.
A friend and mechanic told me I am going to have to get info
from the cabin when these stalls occur, say that I need to check
1.Fuel pressure
2.Spark
3.Fuel injectors.
1.I think I will check 1 last.
2. I wish I could have a light in cabin that would
work like a timing light. Is there such a thing?
3.I have ordered a noid light for Bosch
that works, i believe from it description,, with the injector
cable detached. I would
like to have one that would allow me to drive with it on an
monitor an injector from the cabin . I can not count on having
a second person in the car when it fails, so I would have no
one to crank it over while I listened to the injectors with
a stethoscope.
What I fear is that this checking will all be useless because
there is something fried in one of the control units and I will
not be able to track it down short of swapping my fuel and ignition
CU's with
another 93-95 (right?) 850 , or would it have to be a 1993
Any thoughts on all this?
Re: Rerouting wires:My cable rerouting was done in May[ALL/1998] posted by mark barron on
Friday, 29 August 1997, at 11:15 a.m.
In my post I neglected to say when I rerouted the Coil wire
away from the Mass Airflow Sensor cable. It was in May
and had no apparent effect on the stalling problem.
Sorry, Mark
Fuel Pump Relay:Found the answer? We'll see[ALL/1998] posted by mark barron on
Friday, 5 September 1997, at 6:55 a.m.
I read a recommendation to replace any fuel pump relay in an 850
that is over 4 years old. I did it 2 weeks ago. The theory is that it can
send a spike to the Air Mass Flow Sensor. My wife has not had a stall
since. Because the stalls appear to strongly correlate
with warm weather, it will probably be June before I might feel
confident on this "solution".
Mark Barron