On my way home with my 740 on the tow truck.

Post by **Southbay850** » 12 Jan 2013, 23:11

Driving home from work this evening in my 740 turbo and with out warning it completely stalls. No warning signs at all. I coasted to the side of the road to see what was wrong. I am stumped. There is plenty of oil, coolant, gas and checked the timing belt they all were good. I tried to start it up again and it just does not want to budge. It seems to me like it is not getting any gas. I just hope its not the electrical gremlins trying to mess with me.

Post by **JDS60R** » 12 Jan 2013, 23:15

Check cam/crank sensors. No rpm signal and she will shut down.

Post by **billofdurham** » 13 Jan 2013, 11:52

If you have a fuel delivery problem it is easy to check. Crank the engine several times and remove a spark plug. If the plug is wet that is not the problem. If the plug is dry check the fuel pump relay by putting your finger on top of it and switching on the ignition. If the relay is OK you will feel a click. If there is no click check the fuel system fuses. Further checks are listening for the two fuel pumps kicking in when you switch on the ignition.

Do these initial checks and let us know if there is a fuel delivery problem.

Bill.

Post by **Southbay850** » 13 Jan 2013, 16:07

Where would I find this relay? Is it behind the stereo where the fuses are?

Post by **Southbay850** » 13 Jan 2013, 16:12

One thing I am noticing is it wants to start with a squirt of starting fluid. I was trying to check the on board fault code tester thing and plugged it to socket #2 the trouble light is lit and i pushed it one second with no results it just stays lit. Seems like its screaming the answer to me but I just dont see.

Post by **billofdurham** » 14 Jan 2013, 12:34

You don't say what year the car is but usually the fuel injection relay is middle row extreme left of the relays in the fuse/relay box.

If the car wants to start with starting fluid I would suspect you have a fuel problem. Things to check are the fuses, the relay in the fuse/relay box, the in-tank and main pumps which you should hear momentarily when you switch on the ignition, after checking the fuses and relay.

As previously advised try starting the car and then pull a spark plug. If the plug is wet with fuel there is no supply problem. However, on the 740 there is another relay in the engine compartment that works on the fuel system. It is called a radio suppression relay but actually supplies power to the injectors. Before that relay was fitted there was a lot of interference on the radio from the injectors. That relay on the non-turbo model can be found attached to the coolant reservoir retaining strap. Depending on the year of the car the radiator cooling fan relay may be mounted alongside this relay and they may be interchangeable allowing you to quickly check the relay.

Bill.

Post by **Southbay850** » 15 Jan 2013, 21:46

I apologize the car is a 1990 740 turbo.

Post by **billofdurham** » 16 Jan 2013, 11:59

No problem. The radio suppression relay is on the other side of the car:

740 radio suppression relay location.pdf: (197.78 KiB) Downloaded 106 times

All other advice holds.

Bill.

Post by **Southbay850** » 03 Feb 2013, 16:15

Got her to kick over today.

As she was starting up getting my hopes up I heard a loud pop (backfire) followed by a small engine fire that was put out instantly. I think the timing is off or something. I am trying to find the correct plugwire to distributor order I have 4-3-1-2 no luck but 4-2-1-3 will fire if I keep the starter engaged for extra second or two.

Post by **billofdurham** » 04 Feb 2013, 11:37

Firing order is 1-3-4-2. Looking at the cap from behind the engine #1 is top left hand

740 firing order.pdf: (157.51 KiB) Downloaded 104 times

Ignition timing is computer controlled and can not be adjusted.

Bill.