Resurrected '84 318i

[Minnesota]

I recently bought a 1984 318i with 80k miles on it. It was stored for a few years and the previous owner was 90% of the way through an engine replacement when I bought the car.

After extensive repairs and some wire and vacuum hose chasing I got the engine running and have been able to drive the car somewhat consistently for the last month or so. There have been some major failures (leaky gas tank, slave cylinder, fuel pump). There have also been minor niggling problems that aren't emergencies, but are annoying nonetheless.

One of these problems is the apparent lack of power from the engine. I realize that the M10 isn't a rocket ship, but 109 hp should get the car around better than it does.

Here are all the things that have been replaced on the engine:

Plug wires
Plugs
Distributor cap
Rotor
Fuel filter (twice)
Injector o-ring kits
#4 Injector
Fuel lines
Aux Fuel pump inside tank
Intake boot
Some of the vacuum lines


The previous owner hacked many of the electrical connectors under the hood. On this list are the:

Vacuum advance solenoid
Air temp sensor
Barometric pressure sensor
Idle control valve (I have since found the connector for this)

I have cobbled together connections for everything except the barometric pressure sensor (BPS). I have the BPS, but it isn't hooked up.

The car runs okay once it warms up, but it doesn't have any oomph when you give it gas to go up a minor hill. It also runs very poorly when it is cold. The mileage is also a bit low, in that it has gotten a max of 22 mpg in 3 or 4 tanks of gas I have run through it.

It also sometimes has a miss at idle.

Any advice? Comments?

[allbmw]

Timing makes a very big difference in the performance of my 318i. I set the timing at 2500 rpm instead of the 2000 recommended by the manufacturer.

[Minnesota]

Originally Posted by allbmw

Timing makes a very big difference in the performance of my 318i. I set the timing at 2500 rpm instead of the 2000 recommended by the manufacturer.

This has been very much on my mind. When we got the car started we had to put the engine at TDC and line the rotor up with the #1 plug wire. Then the car started and we tweaked the timing by ear. We then used a timing light, but it is very hard to see the timing marks on the crank pulley.

I've heard of timing the engine by looking at the flywheel. Any tips on how to do this?

I suspect that the timing is off, since the vacuum advance seems to lose power, rather than adding it.

[allbmw]

There is an opening at the top of the transmission housing just in front of the firewall through which you can see the z ball. It is not easy to get to, but you can with a bit of work get a timing light to shine through the opening. Disconnect the vacuum line to the distributor. You should see the mark move with an increase in engine rpm. It should be steady at a given rpm. If it jumps or seems inconsistent, there is something wrong with your distributor. There was a problem with mine. I put the ball in the center of the opening with the engine at 2500 rpm. The factory says 2000, but I don't think there is as much torque at this rpm. If you advance the distributor much beyond this, your idle will be high.

Try setting the timing and let me know how you do. I think there is a chronic problem with high mileage 318i distributors, but maybe yours will work well. Good luck.

Alan

[Minnesota]

Originally Posted by allbmw

There is an opening at the top of the transmission housing just in front of the firewall through which you can see the z ball. It is not easy to get to, but you can with a bit of work get a timing light to shine through the opening. Disconnect the vacuum line to the distributor. You should see the mark move with an increase in engine rpm. It should be steady at a given rpm. If it jumps or seems inconsistent, there is something wrong with your distributor. There was a problem with mine. I put the ball in the center of the opening with the engine at 2500 rpm. The factory says 2000, but I don't think there is as much torque at this rpm. If you advance the distributor much beyond this, your idle will be high.

Try setting the timing and let me know how you do. I think there is a chronic problem with high mileage 318i distributors, but maybe yours will work well. Good luck.

Alan

Thanks. Now I just have to get my hands on my father-in-law's timing light.