"92 740 quit running

TomC · Post by **TomC** » 22 Apr 2009, 08:52

My '92 740wagon(Non turbo) stalled on me the other day.

I was driving up a fairly steep hill when it suddenly lost power.
I was able to coax it home, but the car wouldn't go over 10mph and stalled repeatedly.

Now it's very hard to start and dies out almost immediately.

I'm thinking fuel pump?

Any advice will be greately appreciated.

Thanks

Post by **billofdurham** » 22 Apr 2009, 11:43

It could well be. Can you hear the pumps when you first switch on the ignition? The main pump is easier to hear if you have someone else switch on whilst you lie down beside the pump. Removing the filler cap can help you to hear the in-tank pump.

Check for fault codes using the On-Board Diagnostic (OBD) in the engine compartment. Then progress to the fuel pressure, coolant temperature sensor, engine speed sensor, throttle switch and connector and ignition and coil circuit.

Before you do replace the fuel pump(s) do a search for fuel pump with author Kmaniac in California USA. Chris has a comprehensive write up after his problems with fuel pumps.

Bill.

TomC · Post by **TomC** » 07 May 2009, 18:23

Still haven't fixed the car yet, been sick(ear surgery).

Today, I changed the plugs, cap and wires.

Still no start.

getting a diagonestic code: 1-2-2 from the #2 socket on the "B" side of the Diagonestic Unit. Any idea what this indictes?

Thanks

Post by **JDS60R** » 07 May 2009, 19:23

Tom,
Where are you located?

Post by **JDS60R** » 07 May 2009, 21:59

Found some info from other sources

1.there are two diagnostic boxes in the engine compartment - A & B.Socket B2 is used to check for fault codes in the cruise system.

Code 1-2-2 is Speed below minimum/no signal.

When checking for fault codes on B2 it should be done after a road test which must exceed 22mph otherwise code 1-2-2 will always be stored. The test must be done before the engine is switched off otherwise 1-2-2 will be stored and the road test will have to be repeated.

2.The code 1-2-2 is erased as soon as the ignition is turned off. Have the owner, or yourself, check for fuel system codes using A2 and ignition system codes using A6. Something other than the cruise control is setting the CEL.

3.Code 122 for the fuel system is Intake air temp sensor missing or faulty.
Might be a bad Mass Flow sensor.

TomC · Post by **TomC** » 09 May 2009, 18:20

thanks everyone for your input.

The car starts now, but idles very rough and hesitates when starting to accelerate till about 10 or 15 mph.

That's the bad news, but I've discovered a problem with Cruise Control System I thin may be related.

while the car was idleing, I discovered a disconnected vacuum line going to the Cruise Control -control unit. I plugged it in and the car died. If I unplug it the car idles, but roughly, If I connect the vacuum on the cruse control unit the car will not idle and I can't get it above 2000rpm.

I am also getting the fault code 3-1-1(Speedometer signal absent)

Could a bad Cruise Control - control unit be causing my problems?

Btw, so far I've changed bothe fuel filters, plugs, cap and rotor, wires. The fuel pumps seem ok.

Thanks and I'm in Chicago