3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
BimmerWerkz.com is the premier BMW Forum on the internet. Registered Users do not see the above ads.
I recently purchased a 1984 318i to replace my other 84 318. I was asking the woman I bought it from what work she had done to it. She said all she had done was replaced the in-line fuel pump.
Here is my problem. The car is hard to start if it has been sitting for over 4 hours. It takes approx 6-7 cranks before it will start. Subsequent starts within a short time will be normal. Another symptom is when the car is on and running a pulsing buzzing and a swooshing sound from the area of the in-line pump can be heard, almost as if there is air circulating around in the line.
I have done the following to attempt and rectify the problem:
Replaced fuel filter.
Replaced in-line fuel pump.
Primed the fuel system by disconnecting the hose from the fuel rail and running the pump till fuel ran.
I have tested the pump relay.
The only system I have not checked is the in-tank pump. Could it be drawing some air somehow?
After the car starts, it runs perfectly fine, no loss of power at any RPM. The only symptoms are the line noise around the pump, and the hard starting.
Have you had a chance to totally clean out the fuel tank? If there's enough sediment, there's no telling how many filter changes you could go through.
Yeah, my next step is to take out the in-tank pump assembly and check that out, while I'm in there ill take a look at the condition of the tank. I was reading online and a noisy main pump is sometimes a sign of a malfunctioning pre-pump.
When i got mine, i changed the gas tank and the in tank pump/sender unit due to the same probelms but i was having hesitation startin at 2200rpm. i also noticed over the last couple of months that if i run anything less than chevron gas the car is harder to start (i guess its the gasahol) That ethanol crap is not good for the old electric fuel injection systems thats the only other solution that comes to mind. goodluck and if you have any other problems or if you need parts i have a bunch of stuff layin around
When i got mine, i changed the gas tank and the in tank pump/sender unit due to the same probelms but i was having hesitation startin at 2200rpm. i also noticed over the last couple of months that if i run anything less than chevron gas the car is harder to start (i guess its the gasahol) That ethanol crap is not good for the old electric fuel injection systems thats the only other solution that comes to mind. goodluck and if you have any other problems or if you need parts i have a bunch of stuff layin around
Yeah the in-tank pump is the last thing I have to check. Do you know an easy way to test that particular pump? Im gonna remove it from the tank and take a look at its overall condition, maybe run some voltage through it to see if it powers up. Thanks for your help!
For the hard starting problem, I'd say it might be the 1 way valve in your fuel line. It only lets fuel go through the line going towards the engine, if it isn't working the fuel wont be held in the fuel rail it will run back into the tank. So that time where you're waiting for it to start(6-7 cranks) your just waiting for the fuel to get from the tank to the fuel rail.
try turning the ignition to the ON position and waiting a while for the pressure to build up. If it starts no problem after that it's the check valve. I forget the proper name for it.
For the hard starting problem, I'd say it might be the 1 way valve in your fuel line. It only lets fuel go through the line going towards the engine, if it isn't working the fuel wont be held in the fuel rail it will run back into the tank. So that time where you're waiting for it to start(6-7 cranks) your just waiting for the fuel to get from the tank to the fuel rail.
try turning the ignition to the ON position and waiting a while for the pressure to build up. If it starts no problem after that it's the check valve. I forget the proper name for it.
If I do what you said and let the system pressurize for a few minutes, the car will start normally. Where is this check valve. There are about 5 or 6 little devices on various locations of the fuel line. I'm not sure which one to look for.
If I do what you said and let the system pressurize for a few minutes, the car will start normally. Where is this check valve. There are about 5 or 6 little devices on various locations of the fuel line. I'm not sure which one to look for.
I don't know where it is, but I'm fairly sure it's in the tank.
if you don't want to fix it then just wait and let it pressurize everytime you start your car, but it's there for a reason...
Ok, I just got back from working on the car. I took out the in-tank transfer pump. I hooked it to 12 volts. The pump clicks, but no whirring or anything that would indicate that it works. I believe I have found my problem. Futhermore, disconnecting the power lead from the transfer pump, it reduces the sounds coming from the main pump. Almost as if when the transfer pump was powered it was blocking flow. I shall source a replacement from the junk yard seeing as to order new would cost over $140. Thanks for the help everyone!
Good job man glad i could help sorry it took so long for me to get back to you also i have used a pump off a 97 chevy 1500 with a V-6 (some assembly required but its the right psi and gpm so that would be an easier pump to find again some assembly required interchange is Some 94 chevy-gmc up to 99 i believe has to be a V-6 though also S-10's with the 4.3 v-6 good luck and if you need anything else pm me or send me an email at FatKidRacing01@gmail.com
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Linear Mode
