Car starts then dies (please help)

[buck1115]

I humbly come before you gentlemen hoping you can shed some light on my problems.

I have a 1984 318 with an M10, I was getting onto an off ramp when the car started to steadily lose power. I blipped the throttle to no avail and pulled to the side of the highway. Once stopped I tried repeatedly to start the car, it would turn over no problem but not start.

Fast forward to yesterday when I replaced the Rotor, cap, wires, plugs etc.

Now the car will start for a few seconds then fall flat on its face. I had quite a few issues before this happened, but at least the car ran... Some of the problems were high idle, low power, sluggish revving, and the occasional stall.

Any help would be greatly appreciated!


Oh, and is there a distributor ground on these cars?

[Hey_You]

Check your fuel pump...both of them
Mine did the same thing, with both pumps.
Also, if you have the spare $30 or so, replace your coolant temperature sensor for peace of mind if you haven't already replaced it

[buck1115]

Pumps? I was under the impression there is only one on these cars... I will look into that. To "check" the pump I would use a volt meter to make sure I am getting power to the pump correct?

I took off the fuel pump door, and I can hear the pump when I star the car... But I forgot to add then when the car starts and then dies, it wont start again until it sits for a few minutes. Is this a sign of pump failure?




Thank you for your help, this gives me some avenues to check out!

[Hey_You]

Well, the m10 engine is VERY unhappy if it's fuel pressure isn't in the right neighborhood (IIRC around 48psi?). If you have a pressure gauge, check it. There is an in-tank pump, and if the 84 is like my 85, there is an inline pump located driver side under the car. I had a nightmare tracking mine because it would work for months, then not, then it skipped to weeks, then it would start acting up pretty much on an every-other day sort of schedule. If you have/rent/borrow a pressure gauge, check it at each pump (find specs for them, or if I can remember tomorrow at work, I can see if I can find them on Mitchell1) and also at the FPR. Disconnect the FPR (fuel pressure regulator) vacuum line and if you do, the RPM's should jump up, and NO fuel should be coming from where you unplugged the line. If fuel comes out from the little vacuum port, then it means the diaphragm in your FPR is bad, and the part needs to be replaced. But from the symptoms, it seems like you are losing fuel.

[buck1115]

I bought a pressure gauge today, and I am gonna test that out when I get home... The pressure should be 48psi leading up the the FPR? Or post FPR?

Where do I hook the gauge up to on the pump to get a pressure reading?

Oh and thank you SO MUCH for your help!

[401e30]

There is one in tank fuel pump, and one inline fuel filter. If your fuel pressure is bellow specification I would start with a fuel volume test pre and post fuel filter. Any type of restriction in the fuel lines would result in an abnormal pressure reading. Or, if you're feeling ambitious, use a multi-meter to test amperage at the pump when operating.

I'm not sure if 48 psi is correct for 318 engines. According to my Bentley Manual, the 325, 325e, and 325es look for about 36.3 psi where the 325i likes 43.5 psi. I haven't come across a 318 spec yet.

P