Rebuilt E30, few issues

[Hick]

I just got finished rebuilding my E30, including rebuilding a tired m20b25. '90 325is

Ive got a few issues, some with the brakes others with the engine.

1, Brakes are a little spongy after bleeding several times. Ive also notice that if you pump the brakes while the car is off, the pedal comes up and is firm. Once the car is started the pedal drops and the brake travel is longer. I think this is a symptom of a bad brake booster. The connections are all look good and the car does not have any vacuum or fluid leaks.

2, The car keeps throwing code 1222, which is the coolant temp sensor... which one is this for? PN?

3, The car will warm up fine an the heat will come out great in the car. However, once you bring the rev's up the heat goes away. Ive bled the system more then once, and this wont go away. Could i have switched the heater core hoses?

4, Hunting idle, think this has something to do with the coolant temp. Hard warm start, also has to do with Mr. 1222

Answer my quesitons and i will reward posters with nekid ladies and beer.

[b*saint]

#1 does sounds like a leaking brake booster. Had the issue in my 88 Sentra.

#3 Is the tstat new?

#4 Ive heard of bad temp sensors causing a hunting idle, except whenever I have had a bad temp sensor in a variety of cars, it usually just high idles but never a seeking idle.

[Hick]

#1 does sounds like a leaking brake booster. Had the issue in my 88 Sentra.

#3 Is the tstat new?

#4 Ive heard of bad temp sensors causing a hunting idle, except whenever I have had a bad temp sensor in a variety of cars, it usually just high idles but never a seeking idle.

tstat is brand new. Its almost instantanious that the heat goes away once the roms are brought up

[jlevie]

Soft brakes are the result of air in the system or a bad master cylinder. What you describe as happening when the engine is running supports that and means that the brake booster is good. With the engine running, vacuum is applied to the booster and thus greater force is applied to the master cylinder. That will magnify any defects in the system. If the booster were bad you'd have stiff brakes when the engine is running.

A DTC of 1222 is a Lambda fault, which indicates either a bad O2 sensor or an upset in the A/F ratio. The life of an O2 sensor is not more than 100k. So it that applies, replace the sensor. The hunting idle and 1222 code suggests the presence of intake leaks or fuel system problems. A smoke test of the intake will tell if there are leaks and the fuel system tests in the Bentley will assess the condition of the fuel system. Injectors are also a possibility and having them cleaned and flow tested is advisable.

If you've bled the cooling system properly (see below) more than once and gotten air out each time, there is a head gasket leak or a crack in the head. That would be consistent with the loss of heat after the engine is brought to higher rpm a time or two.

The hunting idle suggests the presence of intake leaks and/or a sticky ICV.

1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.

2) With the bleed screw open, add coolant until no more air comes out of
the bleed.

3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.

4) Once the engine is at temp bring it up to 2000-2500 for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.

[jaywood]

Your brakes are supposed to do that. There's no vacuum to power the booster when the car is off.

[Danny]

Joe, you switched the hoses.

[KenC]

There is air in the brake lines.

Do some hard stops from 60 to engage the ABS, then rebleed.

[Hick]

Thanks for the info guys.

After i posted this i found the fault codes online. 1222 covers a few parts, but mainly the motor running to lean/rich. I should of mentioned that it has a Mark D chip and 20# injectors. So running rich would not surprise me. Come to think of it, it only happens at idle.

I think im going to try to bleed the system again. Every time i have done it the cap has been on tight, dumb me should of known better. If that dosent work then swap the heater core hoses, i had this problem before but i cannot remember what caused it. Ive also got a newer brake master, this car has 280k+ and i doubt the master has been changed.

Once all this is fixed ill make with tittys

[Hick]

Oh another part to a brake AND engine problem. I also noticed while trying to hunt down the brakes with the gf pumping while the car was running; the idle comes up as you pump up the brakes.

Logic would say as you remove vacuum from the intake, i.e. lower it, then the engine would pull in more air bringing the idle up. Or is this something ive left out?

Yanking the oil cap while running didnt change the idle, but pulling the brake booster line out of the throttle body caused the car to stall.

[jlevie]

The idle rising when you pump the brakes is from more air being dumped into the intake from the booster. The fact that idle didn't change when the oil filler cap was removed indicates that the engine isn't under vacuum, which in turn suggests that there are intake leaks in the engine.

[Hick]

Fun, i just rebuilt this motor. Time to look for leak. It runs great, so i dont know where it could be.

[Sputnik]

before you rule anything out, pump up the brake pedal a couple of times, and hold pressure on the pedal. If it sinks back down to the floor, then your master cylinder has an interal leak.

[Hick]

There are no vacuum leaks. I wonder if the one way valve is bad.

Cooling system had an air pocket, so that is fixed.

[jlevie]

The one-way valve between the booster and intake could be bad, but even if the valve is bad it won't cause the symptoms you described.

If you are saying that there are no intake leaks because you've had a shop run a smoke test at 2-4psi for at least 5 minutes and didn't find a leak, then I'd believe there are no leaks. But what you've described is what happens when there are intake leaks.

[Hick]

Ill keep looking. I rebuilt the motor in my garage, so im pretty sure there are no leaks.

I checked around the intake, hoses, bellows and see no signs of a large vacuum leak. The oil cap has no foamy sludge, and i sprayed the area with starter fluid with no change in rpm.