Fuel injectors

  • Thread starter Thread starter liag
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liag

Hello forks, I have a 1997 Volvo 940 tubro charge that won't start because
fuel injectors not opening, can anyone tell me the cause of this or how to
fix it? I need help.
 
liag said:
Hello forks, I have a 1997 Volvo 940 tubro charge that won't start because
fuel injectors not opening, can anyone tell me the cause of this or how to
fix it? I need help.
Click to expand...

Where do we start on this one men?!

Tim..
 
Tim (remove obvious) said:
Where do we start on this one men?!

Tim..
Click to expand...

I didn't even know there were 1997 Volvo 940 turbos!!! Did they sell these
in Canada?
 
How do you know the injectors won't "open"?

If that is established, then;

if you have fuel, and you have spark, and you have turn-over, then;

Test the harness leads at each plug for signal, either with a tester or that
nifty expensive Bosch kit.

Is there fuel in the rail?

Can you hear the fuel pump working?

Check fuses. Pull #1 and 11 while the car is running to reset the fuel pump.

that's a start.

RS
 
liag said:
Hello forks, I have a 1997 Volvo 940 tubro charge that won't start because
fuel injectors not opening, can anyone tell me the cause of this or how to
fix it? I need help.
Click to expand...

Look at the tach when you crank the engine - it should kick about once a
second... more or less. If it doesn't kick the ECU isn't getting impulses
from the crank position sender (which means the spark is also missing).

If the tach is kicking or you know you have spark, I believe the injectors
are opening but you have no fuel pressure. Unless your fuel rail is a lot
different then the one in my '85 760T there is no place to readily hook up a
pressure guage. I had to improvise. But you can check for *some* pressure by
unfastening the nut that connects the fuel line to the back of the fuel rail
after trying to start the engine. Fuel should try to squirt out well before
the nut comes loose, and if you unfasten the fitting completely it should
release about an ounce of fuel altogether. If it hisses when you loosen it
the main pump is running but picking up air from the tank, while if it gives
little sign of life the main pump isn't running.

Something to check, fairly rare but it happened to me and a couple of
others, is that the wiring at the battery positive post hasn't corroded in
two. In my 760, the 10 ga wire that provides power to the ECU and therefore
the fuel pump had corroded completely and fell aprat when I moved it.

Mike
 
The injectors are fed from a resistor block. The power comes from battery
plus via relay contact of the Radio Interference Suppression relay. The Grey
wire at pin 2 of the resistor assembly feeds current via four resistors (one
for each injector). The injectors are ground switched via the ECU pin 18.
The RIS relay contact also feeds the coil (Blue wire on the 15 terminal of
the coil). The coil drive signal and the Tachometer pulse feed come from the
Ignition Amplifier pin 1, the Amplifier being switched by the ICU pin 16, on
pin 5. On turbo equipped cars the RIS relay should be permanently "on" but
on non-turbo cars it is switched by the ECU pin 21. Pin 21 switches the
Fuel Pump relay on turbo cars. On 1995 onwards cars there appears to be only
one fuel pump even with LH2.4 system.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).
 
Hey Mike, we are testing to see if your idea works, thanks alot, will laet u
know.
 
Hello Peter
Where is the Radio Interference Suppression relay is located in the 1997 940
turbos?
The injectors are fed from a resistor block. The power comes from battery
plus via relay contact of the Radio Interference Suppression relay. The Grey
wire at pin 2 of the resistor assembly feeds current via four resistors (one
for each injector). The injectors are ground switched via the ECU pin 18.
The RIS relay contact also feeds the coil (Blue wire on the 15 terminal of
the coil). The coil drive signal and the Tachometer pulse feed come from the
Ignition Amplifier pin 1, the Amplifier being switched by the ICU pin 16, on
pin 5. On turbo equipped cars the RIS relay should be permanently "on" but
on non-turbo cars it is switched by the ECU pin 21. Pin 21 switches the
Fuel Pump relay on turbo cars. On 1995 onwards cars there appears to be only
one fuel pump even with LH2.4 system.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).
[quoted text clipped - 5 lines]
Tim..
Click to expand...
Click to expand...
 
Should be fixed at side of one of the strut towers (right hand tower on UK
models).

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

liag via CarKB.com said:
Hello Peter
Where is the Radio Interference Suppression relay is located in the 1997
940
turbos?
The injectors are fed from a resistor block. The power comes from battery
plus via relay contact of the Radio Interference Suppression relay. The
Grey
wire at pin 2 of the resistor assembly feeds current via four resistors
(one
for each injector). The injectors are ground switched via the ECU pin 18.
The RIS relay contact also feeds the coil (Blue wire on the 15 terminal of
the coil). The coil drive signal and the Tachometer pulse feed come from
the
Ignition Amplifier pin 1, the Amplifier being switched by the ICU pin 16,
on
pin 5. On turbo equipped cars the RIS relay should be permanently "on" but
on non-turbo cars it is switched by the ECU pin 21. Pin 21 switches the
Fuel Pump relay on turbo cars. On 1995 onwards cars there appears to be
only
one fuel pump even with LH2.4 system.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).
Hello forks, I have a 1997 Volvo 940 tubro charge that won't start
because
Click to expand...
[quoted text clipped - 5 lines]
Tim..
Click to expand...
Click to expand...
Click to expand...
 
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