Messages

1

Engine + Driveline / Fuel Pressure?

« on: February 15, 2010, 08:45:31 AM »

Thanks for the replies. I was measuring between the tank and the engine, just before the fuel filter (which i replaced recently). These measurements were all taken with the car out of gear. Sounds like I might be looking at getting a new fuel pump?

2

Engine + Driveline / Fuel Pressure?

« on: February 13, 2010, 03:02:39 PM »

Where should my fuel pressure be at on my 93' 318i? I checked it today (car in neutral) and it was around 40-41psi, then when under acceleration is was 38-40psi, what should it be at?

3

Engine + Driveline / Pressure regulator or fuel pump failing?

« on: August 08, 2009, 08:17:09 PM »

So heres what I'm thinking. As I approach WOT, the vacuum should be decreasing. So, if my fuel pressure regulator is working correctly I should see a steady increase in fuel pressure as the vacuum decreases?

After writing that out, it seems like my idea won't produce any conclusive results because it could still either be a fuel pump or fuel pressure regulator issue if the fuel pressure isn't increasing when the vacuum is dropping...Anyone have any thoughts?

4

Engine + Driveline / Pressure regulator or fuel pump failing?

« on: August 07, 2009, 08:42:09 PM »

Is there a port where I can get a vacuum gauge to measure the manifold vacuum pressure without screwing with the fuel pressure regulator? Then I could test to see what happens to the fuel pressure as the vacuum drops or rises.

5

Engine + Driveline / Pressure regulator or fuel pump failing?

« on: August 06, 2009, 03:14:43 PM »

I'm driving a '93 318is.

What is a good way to test whether my lean condition is caused by a faulty fuel pressure regulator or my fuel pump?

Unplug the pressure regulator's vacuum line and test to see if the car drives differently?

6

Engine + Driveline / Rough idle/take off

« on: May 31, 2009, 06:05:10 PM »

I tested the TPS again. I got 3.81k ohms with the key off and the throttle closed (idle position). When I move the throttle the ohms stay steady all the way to WOT. The ohms never move off of 3.81k...seems to be the throttle closed reading is slightly low and the throttle test definetely failed.

7

Engine + Driveline / Rough idle/take off

« on: May 27, 2009, 08:38:07 AM »

I wouldn't condemn the FPR right away, I'd test pressure and flow.  Might be a bad pump, could be a different vacuum leak.  Does Advance Auto rent fuel pressure testers?  I've used them a lot of times for things like spring compressors & brake tools.  Maybe pick up a cheap vacuum gauge too, run some tests.
Does this rough running happen all the time, or only when the engine is warm/cold?  The computer should raise the idle for A/C.

It generally runs rough all the time, although the car does much better if its been sitting for a day or two. I have a fuel pressure guage, when i have time I'll run some tests at idle, around 3k and then what happens when I bring it back down.

the idle does not pick up when I turn on AC. The car idles around 6-7 hundred all the time, it gets worse when it cycles through those rough spots while sitting at idle.

8

Engine + Driveline / Rough idle/take off

« on: May 27, 2009, 12:29:22 AM »

Update:

The car drives exactly the same as before. Its gets VERY rough when I run the AC, which is esentially a must with a black on black car in AZ. Leads me to believe the fuel regulator is bad if it doesn't make a difference with the vacuum tube on or off. Thoughts?

9

Engine + Driveline / Rough idle/take off

« on: May 25, 2009, 09:53:48 AM »

Alright guys. I'm slightly embarrassed that I didn't notice this before, but the vacuum tube leading form the fuel pressure regulator was badly damaged and on top of that didn't fit tightly at either end. It was kind of hidden under the TPS so I didn't notice it before. I haven't been able to fully test it to see if I've fixed it.

What is the function of this vacuum line?

10

Engine + Driveline / Rough idle/take off

« on: May 24, 2009, 06:44:12 PM »

Whats the best way to check for vacuum leaks? I forgot to mention that I've cleaned my ICV before as well. I just looked at any visible tubes for cracks and I replaced one skeptical one.

11

Engine + Driveline / Rough idle/take off

« on: May 23, 2009, 02:37:20 PM »

I've got a rough idle problem with my '93 318i that has me a bit stumped. I've checked the vacuum hoses, TPS, coil packs and fuel pressure. Installed new O2 sensor, new crank/cam sensors and plugs and I've cleaned the MAF.

Its tripping the CEL, 1222 (Lambda) code.

Here are my symptoms:

- Rough, choppy idle that persists until engine RPM's get up around 3k. If I really slip the clutch/keep RPMs up the car won't stumble.

- on take off it feels like it wants to die but never does (If I don't really slip the clutch/keep rpm's up out of the hole)

- when idling the problem comes and goes in a cycling manner. If I listen to the exhaust I can hear a "put, put" noise when the idle gets rough, leads me to believe its missing on a cylinder.

- Problem is not noticeable if the car has sat for a few days; however it will return after 20-30 minutes or drive time.

- The problem gets much worse if I have my AC on.

- Exhaust does not smell rich

12

Engine + Driveline / Crankshaft sensor going bad?

« on: March 23, 2009, 03:43:45 PM »

Bump. How can I test the TPS?

13

Engine + Driveline / Crankshaft sensor going bad?

« on: March 20, 2009, 08:21:48 AM »

tried testing the TPS???   or checking/moving if the connections are good in the black box under the intake manifold?

How can I test the tps?

I had all the connections off to do the head gasket. I reconnected them during reassembly and it ran the same afterward, minus the overheating part.

14

Engine + Driveline / Crankshaft sensor going bad?

« on: March 19, 2009, 06:25:52 PM »

You have the same exact symptoms that I experienced when my CPS was going bad. Its probably a break in the cable somewhere and the signal becomes intermittent explaining the bucking and poor running. A working used CPS fixed my problem, I would look into it. Good luck.

I was sure that was causing the problem. I replaced both the camshaft sensor and the crankshaft sensor and I still have the same problems. I might try the O2 sensor as mentioned above. Will my 93 have a 3 or 4 wire 02 sensor? I'm hoping I can use the 89 mustang sensor trick...

My sensor was brand new...so maybe I should try to track down one I know is for sure working.

15

Engine + Driveline / Crankshaft sensor going bad?

« on: March 19, 2009, 10:16:56 AM »

Well I initially did the stomp test and got the "no error" code. a few days later I do it again and get the Lambda control error. I had already ordered the crank/cam sensor since I had suspected that was the problem. I installed the two sensors yesterday and it didn't change anything. I'm starting to wonder if I should just part it out, I've got no idea what it could be and I've spent a ton of time on this thing. It misses like crazy when first starting out from a stop, bucks/jerks while driving and is consuming more fuel than usual. It runs better when I start it up and the engine is cold...