95 E320 codes 4 and 18

Ok all, I finally took the time to read the codes after reading the many posts in the archives on how to do it and I came up with a code 4 and 18. According to the PM CD-ROM a code 4 is the MAF sensor (open circuit) and a code 18 is the #5 injector (open/short to ground).

Does anyone have any hints on how to test the MAF sensor using a digital ohm meter or how to test the #5 injector? I quickly removed the connectors to the #5 and #3 injectors and read the resistance @ the injector and both read 14ohms, so I'm guessing it isn't the actual injector but maybe the wiring to it.

Any ideas all?

Just FYI, I have 149k miles on the car and what prompted me to do the read out, using the built in LED, was for the last several weeks the car has been hesitating big time at full and 3/4 throttle. It will hesitate for about 2 seconds than it will go back to normal power than hesitate again, all the way to redline. It's acts like the timing is being retarded than advanced.

I replaced the fuel filter and have now replaced all of the plugs and wires. This didn't fix it but after this many miles I figured it was due anyhow. So today is the first time that I attempted to read the codes and get down to the real reason on what's been wrong with it.

Thanks all in advance for your time and suggestions,

Dale

[Arthur Dalton]

You are quoting codes for the HFM-SFI module, but you are also saying that you obtained these from the built-in led.
The led/sw only accesses the Emmission monitoring module and the codes for that are :
4- AIR malfunction.
18 - camshaft adjustment solinoid

To get to HFM module, you must go to pin 14 with a seperate test led.......

Thanks Arthur, I knew you would set me straight.... Your knowledge of these cars has been a big help to me in the past and continues to be now. Now what in the heck is the AIR you mention for code 4? Also the cam solenoid (18) is that the one that is attached on the front of the head? If that cam solenoid was bad, would that account for the feeling of the car running advanced than retarded?

Thanks Arthur, you the MAN!!

Dale

[Arthur Dalton]

Air is just the AIR pump system. Only works when first started
[ cold emission related ]

The cam solinoid is where to check as that is what moves the valve timing. Definately start looking around there....

As you have the PM CD with all the OBD-1 codes, be aware that you can get to them through the other pins on your diagnostic socket. As you can now see from the CD , this system is quite sophisticated for pre OBD=2.

Make a led/sw for $5 and go code hunting......

[Arthur Dalton]

Dale.
Now that you have the CD , go to TSBs and scroll down to
"Oil Fill / dip tube" modification...
Un-related to your problem, but good info for any 104 engine owners to know. May even be part of the cause on these infamous oil leakers....

Arthur,

I looked at the cam advance solenoid and the connector clips just fell apart. I'm guessing from heat and everything else in that area that the plastic just deteriorated. So I hooked it back and secured it for now. I will see if this takes care of the problem but I believe you nailed it on the head.

Thanks Arthur, also I found the codes you mentioned on the PM CD, I was looking under the wrong section.

Dale

[Arthur Dalton]

Cool...
Thanks for the Thanks !!!

[engatwork]

You probably need to "rod out" the line from the air pump to the intake manifold. It is covered somewhere in the archives. Use an old speedometer cable. You may need to modify it to get around the 90 degree bends. I have had to do this on my E320 a couple times.

[Arthur Dalton]

As Jim says, the EGR is also infamous on these ... both the valve and the clogged pipe..
But there you are looking for a code #5...

I cleaned the connector going to the cam advance solenoid and reattached it, it was no help so I ordered a new solenoid that I will be picking up tomorrow. I will look at cleaning out the air pump line as well.

Thanks all,

Dale

[engatwork]

If you need any pictures let me know.

Thanks Jim, I'll let you know once I dig into it.

Dale

After getting a code 5 on my 95 E320 for the third time (and cleaning our the EGR intake tube twice) I decided to look over the rest of the EGR system and discovered a broken vac hose near the front of the engine.

This is a follow up to my original question on the codes.

I replaced the cam advance solenoid today and it made all the difference in the world on how the car runs now. My guess is that it has been failing for a while now because ever since the warmer weather hit here in Atlanta the car has been lethargic after it got hot with little to no mid-range power. Now it feels like it used to with lots of power at all RPM's regardless of temperature.

Thanks Arthur for setting me straight in the beginning of my post on how to read the codes correctly. You saved me from buying a mass air flow sensor that I thought it was reading out.

Again, your expertise and this wonderful site has helped me keep my car running great.

Thanks to all,

Dale