Hello all,
740 won't start. I have a spark to all 4 cylinders. I have turned engine over trying to start. Pulled spark plugs and they are dry. I assume I am not getting fuel. But I can put a bottle on fuel return line on FPR and crank and fuel is flowing. In tank fuel pump is new. Fuel relay clicks when I turn key. I have power to injectors. Ignition module is new. Tach jumps when I turn key so I assume it is not hall sensor. I can spray starting fluid into intake and car will run for half a second then die. Anybody have suggestions on what my problem is? Thnx.

I don't know if your problem is resolved. But I had this problem in March 2005, and It was Mostly my RSR relay, I resoldered it. You can probably switch the fan relay next to it to verify. I say probably because both of my relays were needed to be resoldered, and it has cranked like a champ ever since.

I also, replaced my damaged RPM Sensor ($45 aftermarket).

I bet that's it.

1990 740 GL REX 201K

That sounds like a radio suppresion relay - but you said that you were getting power to the relays.

Hmmmmmm?
--
"Be blessed in your quest'' 89 764 (110K), '94 940T (180K) , '92 745T (totaled 2-10-05 RIP)

Hi there,
It sounds like a fule problem to me. If the engine runs for a sec with starter fluid your igniton systems hould be ok. I would change the fuel pressure regulator with a good one ...and then fule pump relay.. try to start the engine with a starter fluid and let one of your friends listent he main fule pump and the in tank fuel pump.. If they run? It could be stupid question but have you checked the fuse for the fuel pump?
Hope this helps
Sammy

Sounds like the injectors are not opening. How about a year model on the car? You need an injector noid light to put in place of the injector and see if it is opening and closing, the noid light will flash when it gets power adn ground. You can try using a long screwdriver like a stethoscope and see if you can hear them clicking as they open and close. I use either the noid or a real mechanics stethoscope and it will let you know everytime. Have you checked to see that the pumps do buzz for a second when you bump the key? Pumps typically don't kind of wind down they are working or not. Check those things next.

mark