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BladeRunner
04-20-2009, 12:52 AM
Hello, two questions for all the E30 fans out there. I own a '84 318i and the engine is difficult to start when the weather is cold and when the engine is cold (basically when the oil & coolant is cold because she hasn't been started in a while). She does crank and will run once started, just have to give her some gas to get thing purring.

So I've changed the intake bellow, replaced a leaking oil pressure sensor, ensured all clamps were secure on visible engine bay hoses, checked air intake filter, and and now she's running better. But, still not optimal.

The issue I'm experiencing is a surge while accelerating which mostly occurs when going uphill. Furthermore, when in the cabin there is a noticeable but interment ugggh sound coming from beneath the rear passenger seat every 2-5 seconds.

Any thoughts on what's creating the surge and/or ugggh sound?

Thanks in advance!

echo
04-20-2009, 06:21 AM
Fuel pump issue maybe?????

richie_s999
04-20-2009, 10:09 AM
fuel pump is under your rear seat and the only thing that would make noise, Where about are you I have a new one that was never used in the garage.

BladeRunner
04-20-2009, 04:59 PM
richie_s999 I'm located in Atlanta, GA. I had the in-tank fuel pump replaced approximately 5 years ago but the fuel filter and main fuel pump hasn't been replaced since I've been the owner.

So if it is the fuel pump is it normal for someone in the cabin to hear the fuel pump cycling while the vehicle is idling? Also, is there anything else I can try or do before replacing the $200 fuel pump?

The Sly
04-22-2009, 12:05 AM
richie_s999 I'm located in Atlanta, GA. I had the in-tank fuel pump replaced approximately 5 years ago but the fuel filter and main fuel pump hasn't been replaced since I've been the owner.

So if it is the fuel pump is it normal for someone in the cabin to hear the fuel pump cycling while the vehicle is idling? Also, is there anything else I can try or do before replacing the $200 fuel pump?


Yes Yes..On this 318i and other e30's they had issues with the fuel returning into the tank and originally they had a one way valve or trap on the fuel line near the fuel filter.
Sometimes the fuel pump wont keep the pressure in the line,but don't chage it.

BMW sells a kit for this problem for all E30's and it is very cheap. "around $10 to $20
I can't remember what the part number is but this kit is installed right at the fuel pump on top of the tank.
It prevents the fuel to return in the tank and keeps the fuel pressure up in the line so that it start easily even after a very long time.

hope this helps

Sly

richie_s999
04-22-2009, 01:16 AM
I have had my car for 2 years, only time I heard the pump was with the back seat removed(was changing the seat and had it out for a day), you shouldn't be able to hear it with the seat installed.

change the in line fuel filter first, if you have never changed it who knows if the previous owner ever did. they should be change every 48000km(30000miles) it might be restricting flow, and the pumps working harder to get the fuel moving.

BladeRunner
04-24-2009, 03:47 AM
I just ordered some parts I'm going to change the fuel filter and test some of the ignition system electronics this weekend or next week (depends on the weather and free time).

Uhh these cars are a love-hate relationship...you love them when they're working fine...you hate them when they aren't! BMW should be sued for making these damn cars so addictive. :) Anyway, I'll keep you guys posted.

BladeRunner
05-02-2009, 03:10 PM
OK I have not been able to put the new fuel filter in and test fuel pressure. However, using a mechanics stethoscope I was able to determine a few lingering air leaks one was the usually culprit for E30's the idle control valve. Using the stethoscope I also listened to the injectors and valve tones. The injectors and valves sounded normally (to my ear), didn't notices any erratic ticking sounds.

Based on the sound tests performed, that fuel pump sound mentioned before appears to be coming from the fuel pump outside the car located just in front of the LR wheel. Will not know for sure until the rear seat is removed.

I did attempt to remove the rear seat just to check the in tank pump but one of the nuts holding the seat is stripped. Any ideas on how to remove a stripped nut? Also, I haven't checked yet but does the Bentley or Hays manual detail how to test the fuel pressure?

Ceeker
05-02-2009, 04:30 PM
there are no bolts holding the rear seat cushion down. unless that model is different?
there are two hanger type latches which you have to unhook. Push the seat cushion towards the back away from you and pull up. This should release and then do the other side. you don't need to take the seat back off to get to the fuel pump. Now if you are referring to the seat back. Yes there is one bolt holding each down along the side if this is what you mean? Take a vise grip, clamp on and turn as you pull. This bolt goes straight into the body so it's not really anchored to anything. They strip easy.

BladeRunner
05-02-2009, 07:38 PM
On my model there are two bolts where the arrows on this page point http://e30.bmwdiy.info/rear-seat-removal/index.html. I wasn't sure if these bolts were for securing the rear seat bottom but it made since to me.

Ceeker
05-02-2009, 09:50 PM
yes, those are the two I think he was meaning...