uggghhhhh....I just finished typing my post and it said I wasn't logged on, but I know for sure that I was, and I lost all my text and have to do it all over again
Just a reminder my car is a 1988 190e 2.3 8v
From the beginning....I took off the air filter assembly to expose the fuel system. I cleaned the entire area with a cleaner from Liqui Moly's Professional Line called " Intake System Purge" and noticed some oil around some of those shaped hoses and so I took the spacing element out from between the hoses and cleaned it well, since it was very dirty/blocked (oil). Afterwards, I took out and cleaned the fuel pressure regulator, cold start valve, and the throttle valve housing, inside and out. Next, I removed the injectors and cleaned all around there and installed new Bosch injectors and seals.
Now it was time to do a fuel sytem pressure test. I used the one made by MAC. First, I checked the fuel pump relay with this equipment and it is working just fine. Next, I did the pressure test and the gauge read 84 psi. I did the test 3 times to be sure.
Haynes manual says it should be 76.8 - 79.7 psi. Bottom line is that there was a lot of pressure. Whew, what a relief, saved me from buying that costly fuel pressure regulator.
Moving along, it was time for a compression test. Here are the results:
Test done without oil
Cyl. 1 150 psi
Cyl. 2 165 psi
Cyl. 3 165 psi
Cyl. 4 165 psi
Test done with oil
Cyl. 1 200 psi
Cyl. 2 200 psi ( maybe 198 psi )
Cyl. 3 200 psi
Cyl. 4 200 psi
Compression pressure should be 145 - 174 psi
Minimum acceptable compression pressure 123 psi
Maximum compression difference between cylinders 21 psi
I did both tests because I was told that there is a way to diagnose an engine by doing this. My concern comes from the fact that I have noise coming from the engine that sounds like lifters or valves. I'm not sure and I'm hoping one of you guys may have an idea about this
.....I changed the spark plugs too. The electrodes were quite black, probably carbon deposits.
Last but not least for the day, after noticing that there was oil in the throttle valve housing which lead into the air filter body and the filter itself, I took out the filter and cleaned the entire air filter body and related parts and reinstalled without the air filter. Instead, I put a K&N air filter. Here is a pic...
I know I said that I check the 02 sensor, but I ran out of time...that's next.
Oh yeah, I adjusted the idle too. The car is much smoother now, idles better, more throttle response...overall a good day