Start problem Model 740 Year 1989

  • Thread starter Thread starter Ulf Berghman
  • Start date Start date
U

Ulf Berghman

My 1989 Volvo Model 740 just stopped, (230'000 Km). For the last weeks the
engine has worked uneven when in Idle. Yesterday when starting, the engine
suddenly only ignited on one cylinder. After a couple of tries (I had to get
the car off the street) it died totally. The fuel pump rely was replaced for
about 3 years ago, (so it should be okay). The check box is blinking 1-1-1,
which indicated that everything should be fine. I have checked all cables
and cleaned connectors etc.. Still the engine won't start. Can anybody come
up with some ideas about what is wrong?
 
Check the radio supressor relay at the right front wheel well. But if it was
running on one cylinder sounds more like the ECU is bad.
 
Have you checked for codes on all checkbox (OBD) pins? IIRC There are at least
two pins to check on your model (2 & 6).

Cheers, Peter.



: My 1989 Volvo Model 740 just stopped, (230'000 Km). For the last weeks the
: engine has worked uneven when in Idle. Yesterday when starting, the engine
: suddenly only ignited on one cylinder. After a couple of tries (I had to get
: the car off the street) it died totally. The fuel pump rely was replaced for
: about 3 years ago, (so it should be okay). The check box is blinking 1-1-1,
: which indicated that everything should be fine. I have checked all cables
: and cleaned connectors etc.. Still the engine won't start. Can anybody come
: up with some ideas about what is wrong?
:
:
 
I did not know about the "pin 2" option. Anyhow, I checked and the error
code is following:
3-1-2
2-3-1
1-1-3
Do you know what the codes indicated and where (generally) are the codes
listed?
The "pin 6" codes remains all three (3); 1-1-1
thanks - Ulf
 
I checked and found the relay "hanging" on its cables loose by the front
weel weel. The bracket/holder seems to be lost. How should it look like? I
will purchase a "new" relay tomorrow by Volvo. The realy is most likely bad
after vibrations etc.. How can I find out? Short circuit, so the fuel pump
gets power?
However, I checked the ECU error codes with pin 2 connection and found
following:
3-1-2
2-3-1
1-1-3
The pin 6 showes: 1-1-1. do you know anything about the codes?
Thanks - Ulf
 
Pin 6 showing 1-1-1 means there is no ignition system fault. Pin 2 showing 3-1-2
means no knock sensor output, 2-3-1 means fuel supply too rich or too weak in
part-load stage and 1-1-3 means fuel supply too rich/weak. This latter code
backs up the previous code the main fault being the lack of signal from the
knock sensor. This is to be found about halfway along the left hand side of the
engine just below the head-block joint. It has a screened cable to feed it's
signal to the ECU which may have become detatched from it's connector to the
wiring loom. Make sure that the connector is OK and in good contact then reset
the OBD codes The codes are found in the Haynes 940 manual sections 4A (Fuel)
and 5B (Ignition), as is the reset information. The relevant information is also
to be found in the Chilton manuals C72300 and C72302, both available from Haynes
publishing on http://www.haynes.co.uk where they do mail order.

Cheers, Peter.

: I checked and found the relay "hanging" on its cables loose by the front
: weel weel. The bracket/holder seems to be lost. How should it look like? I
: will purchase a "new" relay tomorrow by Volvo. The realy is most likely bad
: after vibrations etc.. How can I find out? Short circuit, so the fuel pump
: gets power?
: However, I checked the ECU error codes with pin 2 connection and found
: following:
: 3-1-2
: 2-3-1
: 1-1-3
: The pin 6 showes: 1-1-1. do you know anything about the codes?
: Thanks - Ulf
:
:
: : > Check the radio supressor relay at the right front wheel well. But if it
: was
: > running on one cylinder sounds more like the ECU is bad.
: >
: > : > > My 1989 Volvo Model 740 just stopped, (230'000 Km). For the last weeks
: the
: > > engine has worked uneven when in Idle. Yesterday when starting, the
: engine
: > > suddenly only ignited on one cylinder. After a couple of tries (I had to
: > get
: > > the car off the street) it died totally. The fuel pump rely was replaced
: > for
: > > about 3 years ago, (so it should be okay). The check box is blinking
: > 1-1-1,
: > > which indicated that everything should be fine. I have checked all
: cables
: > > and cleaned connectors etc.. Still the engine won't start. Can anybody
: > come
: > > up with some ideas about what is wrong?
: > >
: > >
: >
: >
:
:
 
Thank you for your information. Today is Monday and I was this morning in
contact with Volvo here in Luxembourg. They claim the engine should start
even if the "knock sensor" is malfunctioning. It must be something else. I
have done following today (and yesterday):

1 - take the "radio relay" apart and checked, (very clean inside) works
fine.

2 - take the "fuel injection relay" apart and checked, (very clean inside),
works fine.

3 - checked the cable connector to the "knock sensor" and cleaned.

4 – Total “power off” (disconnected the battery).



Next I checked the error codes:

pin 6: 1-1-1 (3 times)

pin 2: 1-1-1 (3 times)



I attempted to start the engine. Still did not ignite. Note: I could smell
gasoline (so the pump etc. appears to functioning).

Again I checked the error code:

pin 6: 1-1-1 (3 times)

pin 2: 3-1-2 (3 times)



Volvo does not have any parts in stock. They have to order from U.K. and I
should have a new “knock sensor” tomorrow. But I need the car today and as
said the “knock sensor” should not make the car refuse to start.

Anybody have an idea what is going on?
 
Now the problem is solved. A neighbour told me he basically have had the
same problem last year. Squirrels are during the night eating the cables. I
checked the ignition cables and they had a lot of tooth marks. After taking
away the plugs and clean out a "wet" engine, replacing two cables (to the
radio relay and the ignition coil) looking "suspicious" (plus the ignition
cables), the car started up fine. Next week when I am back from Germany, I
will check the "knock sensor" etc..
 
So now the "knock sensor" has been exchanged and no error message. Also, I
have installed an ultra sonic device recommended by my neighbour (giving a
12 KHz/85 dB sound), to keep the Squirrels away (and rats). However, more
problems, when in Germany, I recognized that the fuel consumption was much
higher then previously. I checked for error codes and got following:

2-2-1: Fuel trim (lambda control) too lean at part load; Lean; air leak; low
fuel pressure; bad AMM

1-1-3: Fuel trim (lambda control) too lean or rich; Mixture incorrect; O2S
wiring fault

2-1-3: Throttle switch full load setting faulty or grounding short; Wiring
fault to TPS or TPS failure

I will check the AMM and the O2 (Oxygen Sensor) as well as the TPS. BUT why
do I get all these sensor errors?
 
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