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Re: 1988 volvo 740
I have an 89 740 GL automatic that will not start or if it does, floods itself out if i try to start it outside when its cold. In the garage it starts because its heated though it still runs very rich. I got 175 km (110 mi) on a tank. I talked to the service manager at the dealer, he suspects oxygen sensor, but im going to spend $50 and have it tested on the computer to be sure. Also, if you touch the gas pedal when you try to start, it WILL flood. If you find the plugs are wet with gas, you can pull all of the the plugs, and clean them. Then pull all the injector connectors off (yellow), and the blue cold start injector plug under the manifold. (You will need 2 flat tip screwdrivers, one to press the spring and one to push the connector off). Pull the coil wire off the distributor, and place that end near something that will allow the spark to go to ground. Now with the injectors disconnected, and plugs out, you can crank the engine and blow out the excess fuel (20 seconds is enough), Then put plugs back in, wires back on, leave injector connectors off. Crank engine again, If it starts or fires a few seconds, that is a good sign. Reconnect all injector connectors including the one underneath the manifold and try to start again, remember DONT touch the gas pedal. If it starts and runs rough with black smoke, then it could be the same problem i have.
If the plugs are dry, check the fuel pumps. The easiest way is to pull the fuel line off the back of the fuel rail, have someone crank the engine, if it shoots fuel, the pumps are probably good. If there is no fuel, check the pumps. The pumps only come on when the engine is cranking and running, but if you have someone crank for you, you might be able to get close to the pumps and hear them running during cranking. The high pressure pump is under the car behind the drivers seat. There is one wire, you can run a jumper wire from the battery positive to the pump, if it comes on, then it works, if it doesnt, it could be a bad pump, or a bad ground on it. The other pump is in the tank, a little harder to get at, but there is a panel in the trunk under the carpet close to the seatback on the drivers seat, 4 x 10mm screws. I think there is 3 wires, the red one powers the pump, black is ground, the other is for the guage. You should be able to hear if the pumps when you connect jumpers. If you can jumper both and they are both working, try starting, if the car starts, then you have a wiring problem, if one or both of the pumps wont work, then they are the problem. Both pumps have to work for the car to run. I believe fuse 1 (25 amp) is for the high pressure pump and fuse 12 (15 amp) is for the tank pump, check these.
Pls Let me know if this helps, or if you now have you car running, tell me what the problem was. My car will be going in the shop friday, ill post the results shortly after that. Good Luck, KGP
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11-20-2007, 10:47 AM
