Fuel Injection Number 7

[eelley]

Hello all,

Iv'e got a strange one.

I was driving my car to a local shopping mall which is about ten miles from my home. I made it into the parking lot when the car suddenly lost compression, and stumbles about. Pressing the accelerator to floor resulted in the engine blogging down. But was able to get the car parked. Called AAA to have it towed home. Car sat for about one hour, AAA arrived and was able to start the car to limp it to the tow truck (which would not fit under the parking deck)

Upon getting it home, started up and ran fine. Drove it around the block a fews times and parked it. Still fine. The CEL is throwing code 1257 - Fuel Injector 7.

What the heck is going on? Time for new injectors? The car has about 194K on the odometer.

Eric

Repairs I made myself so far: Intake reseal (1 yr ago), Crank Position Sensor (2 yrs ago) Oil on the coils (3 yrs ago)

[MBXB]

What did the injectors look like when you resealed the intake?

[Ross]

If the injector stuck open that would certainly make the car run crappy.
Was there any smoke when it restarted? If so that's probably the case.
I'm not sure if the computer can read such a condition to throw a code.
Clear the code and and check fuel pressure before a cold start, an injector that leaks down will leave you with none. Also check your oil for fuel dilution.
There are lots of places that "refurbish" injectors for about $20 a piece. They flow test, ultra-sonic clean and replace the integral screens in each one. A leaker will usually be junk but at least you don't pay for eight new ones.

[eelley]

What did the injectors look like when you resealed the intake?

They looked like this before resealing and cleaning the intake one year ago (people think it is strange that I photograph all my work):

http://store01.prostores.com/newenglandmicrocomputer/images/WebShared/IntakeSeal23.jpg

Here is what they looked like afterwards. I did not want to mess with the injectors themselves fearing I would srew them up.

http://store01.prostores.com/newenglandmicrocomputer/images/WebShared/IntakeSeal24.jpg


Hope they don't look too bad. Anywho things have changed abit:

I climbed in the car this morning and it turned over - after a few tries. No CEL; so I figured everything was fine. But I did not get to work when the car lost compression again and stalled -- about a mile from my house. Was able to restart it but it would run for about five seconds then stall. Now the car will not start at all. Just cranks. I don't want too crank it too much for fear of ruining the starter. The check engine light is on again -- this time thowing code 1212 -O2 Sensor 2

Eric

[eelley]

If the injector stuck open that would certainly make the car run crappy.
Was there any smoke when it restarted? If so that's probably the case.
I'm not sure if the computer can read such a condition to throw a code.
Clear the code and and check fuel pressure before a cold start, an injector that leaks down will leave you with none. Also check your oil for fuel dilution.
There are lots of places that "refurbish" injectors for about $20 a piece. They flow test, ultra-sonic clean and replace the integral screens in each one. A leaker will usually be junk but at least you don't pay for eight new ones.


How do you clear the codes? I tried depressing the accelerator pedal to the flooor for five seconds but that did not do anything. I would like to clear the codes because the CEL is throwing another code now. Here is what happened this morning:

I climbed in the car this morning and it turned over - after a few tries. No CEL; so I figured everything was fine. But I did not get to work when the car lost compression again and stalled -- about a mile from my house. Was able to restart it but it would run for about five seconds then stall. Now the car will not start at all. Just cranks. I don't want too crank it too much for fear of ruining the starter. The check engine light is on again -- this time thowing code 1212 -O2 Sensor 2

Eric

[Ross]

The simplest way for you would be to disconnect the battery and short the terminals(not the battery)to each other to discharge capacitors.

[bsell]

If the car truly 'lost compression' it would sound very 'flat' and would turn over at an abnormally high speed while the starter was engaged. This condition, a total lack of engine compression, generally does not come and go. It usually just goes through a sever parts breakage.

Do you mean the engine, while running, lost any sense of power-making ability? Something like when you turn the key off?

I wonder if your fuel pump relay or fuel pump itself is dying. How many minutes does your drive take before the car craps out? It seems to be a consistent time to failure from your descriptions.

The O2 code can come from any condition causing a sever air/fuel mixture problem so don't bet the bank on the O2 sensors yet.

Brian

[eelley]

If the car truly 'lost compression' it would sound very 'flat' and would turn over at an abnormally high speed while the starter was engaged. This condition, a total lack of engine compression, generally does not come and go. It usually just goes through a sever parts breakage.

Do you mean the engine, while running, lost any sense of power-making ability? Something like when you turn the key off?

I wonder if your fuel pump relay or fuel pump itself is dying. How many minutes does your drive take before the car craps out? It seems to be a consistent time to failure from your descriptions.

The O2 code can come from any condition causing a sever air/fuel mixture problem so don't bet the bank on the O2 sensors yet.

Brian


Well after conducting some tests, I have determined that the fuel pump bit the dust.

I connected a fuel preasure gauge tester to the fuel supply line via a tee-adapter and had someone start the car. No preasure at all. In fact when I disconnected the supply hose from the rail, I did not get the normal spurt of gas once the hose was disconnected.

Disconnected the fuel relay and connected the jumper wire to turn on the fuel pump - still no fuel pressure.

Removed the hose from the rail and placed the end of it into a glass bottle and briefly bypassed the relay again - no gas.

Measured the voltage at the fuel pump connector in the trunk and it read about 11 volts (the battery was going dead) when the ignition key was turned or when the jumper was applied to the fuel pump relay.

So I ordered the fuel pump and two fuel filters (early model 95 530i uses two of them). Besides draining the fuel from the tank (my tank is 3/4 full of gas), and not smoking while replacing the pump, or providing a source of sparkage, what other things should I watch out for? I will be working on the car outside.

Thanks for your guys, your the best!

Eric

[eelley]

Well after conducting some tests, I have determined that the fuel pump bit the dust.

I connected a fuel preasure gauge tester to the fuel supply line via a tee-adapter and had someone start the car. No preasure at all. In fact when I disconnected the supply hose from the rail, I did not get the normal spurt of gas once the hose was disconnected.

Disconnected the fuel relay and connected the jumper wire to turn on the fuel pump - still no fuel pressure.

Removed the hose from the rail and placed the end of it into a glass bottle and briefly bypassed the relay again - no gas.

Measured the voltage at the fuel pump connector in the trunk and it read about 11 volts (the battery was going dead) when the ignition key was turned or when the jumper was applied to the fuel pump relay.

So I ordered the fuel pump and two fuel filters (early model 95 530i uses two of them). Besides draining the fuel from the tank (my tank is 3/4 full of gas), and not smoking while replacing the pump, or providing a source of sparkage, what other things should I watch out for? I will be working on the car outside.

Thanks for your guys, your the best!

Eric


Another quick question: Is it necessary to drain the tank?

Eric

[Ross]

No, and save your money on the second filter.
Glad you got it figured.

[eelley]

No, and save your money on the second filter.
Glad you got it figured.

Well It was the fuel pump after all. I finished the job earlier today. I did end up draining the fuel tank because you have to reach in and grab the pump by its plastic mounting clips and pull it out. Also for anyone else doing this job, make sure you use plenty of WD-40 or some other rust disolver on the fuel filter bracket bolt or else you will run the risk of shearing the retaining bolt in half and have to tap another hole - like I did.

A quick question for the experts: After filling up the gas tank and driving the car for several miles I noticed that there is a light coating of gas around the sender flange of the gas tank. The gas is not pooling, its not coming from the hoses and if I tighten the flange nuts any tighter, I'm sure I will snap one of the tanks bolts off. I did replace the gasket and it is installed correctly (since I think it only goes on one way.)

Any ideas?

Eric