93 850 with 256k stalls and won't start

Post by **Ozark Lee** » 18 Aug 2009, 17:54

I think you have either a bad master fuel system relay or a bad connection to the master fuel system relay. The relay will trigger the IAC valve which will emit a constant buzzing sound just below the throttle body with the key in position II. It also turns on the power to the fuel injectors.

The relay is gray in color an it lives on the US driver's side of the fan shroud. Very carefully inspect the wiring to the relay - that seems to be where the problems occur more than the relay itself.

The sound and the location of the noises that you are hearing is in the vicinity of the IAC valve and it would explain everything.

...Lee

rgtrough · Post by **rgtrough** » 19 Aug 2009, 09:25

Hey guys, this is the exact same problem that my neighbor is experiencing with his high milage 1994 850. What I don't understand is if it is a fuel issue why can't we get it to at least try to start with starting fluid? Yellow spark to plugs coil tests ok.

Post by **Ozark Lee** » 19 Aug 2009, 16:09

What I don't understand is if it is a fuel issue why can't we get it to at least try to start with starting fluid?

If the IAC valve isn't working it can keep it from starting. Do you hear a buzzing sound next to the throttle body when the key is in position II?

Have you pulled the codes from A-2 and A-6?

...Lee

mbarron · Post by **mbarron** » 19 Aug 2009, 17:23

The IAC does buzz. I have ordered a Fuel Injector Main Relay, circa $29, since I don't see anything wrong with the wiring. I am so grateful for your input. I will advise.

Post by **Ozark Lee** » 19 Aug 2009, 17:33

If the IAC valve is buzzing consistently with the key in position II the relay is working.

...Lee

mbarron · Post by **mbarron** » 20 Aug 2009, 12:25

I got my fuel injector main relay delivered in about 30 hrs!
It did not fix the problem. I should have tested the old one before I ordered. I have just now finished testing the old one.
You can see that the relay has four terminals, namely 30,87, 85 and 86.
Visit this site anyone who is unfamiliar with relays.
http://www.classictruckshop.com/clubs/e ... /relay.htm
I used a 9 volt battery on 85 and 86 which caused the relay to
click closed, that is, the resistance 30 - 87 went from infinite to
virtually zero. The signal voltage between 85 and 86 controls the flow of current between 30 and 87. I suppose the relay could be bad by virtue of having
slowed down in its response time. I any case neither new or old
relay produced a start.
A2 has been clear of any codes for several days, I believe there were
zero codes there when I started working on this stall, I am not totally sure of that. A6 had many , many 3-1-4 codes. I have cleared A6 of all codes just now.

Any suggestions welcome. Thanks for you patience.

Post by **confused_al** » 20 Aug 2009, 13:11

If 3-1-4 (Camshaft Position sensor (CMP) signal missing or faulty) keeps coming back, either the sensor itself or the connector/wire is bad. Wouldn't you think?

mbarron · Post by **mbarron** » 20 Aug 2009, 13:41

Al,
I assumed they were old codes, but that is not all all certain.
Thanks. I will crank and pull codes as soon as the trickle charger
permits.

mbarron · Post by **mbarron** » 21 Aug 2009, 08:51

I tried again to start the 850 with a fully charged battery. A2 and A6 were totally empty of codes both before and after the try. The car did turned over well but did not even cough. Half way through the 20 second crank I tried some Starter fluid in intake. Below are the readings I got.

Fuel Injector Main Relay Connector 4-Female
Wires going out below page
____________
/ \
| 87 30 |
| |
| 85 86 |
| |
----------------

87 Thick Green
30 Thick Red
85 Thin Brownish
86 Thick Red

With Ignition Off
-----------------

Wire To Grnd Volt To Grnd Ohms
87 0.0 1590
30 12.6 16 Meg
85 0.0 infinite
86 12.6 16 Meg

With Ignition ON
----------------

87 0.0
30 12.6
85 0.0
86 12.6

Test done later with weak battery at 12.6 Volt

rgtrough · Post by **rgtrough** » 21 Aug 2009, 19:34

Hey guys, tonight we installed a new egr valve on my neighbors 850. Fired right up. The plastic housing was cracked on top and broken more on the bottom. Many people told me that a bad egr valve would not keep it from starting, but we made an executive decision and replaced it anyway. This car has sat for 3 months and we have worked on it off and on. The car never threw a egr code. All I know is that I have learned way too much about volvos. I need to stick to my small block Chevies with their carbs and distributors.
Thanks for being here for guys like me.

peace Bud

93 850 with 256k stalls and won't start

Re: 93 850 with 256k stalls and won't start