TOPIC: 1990 420SEL Mercedes

This is my first attempt to install the Gadgetman Groove.

The car is a 1990 420SEL Mercedes.

I attached a MS Word file that has pictures and text.


The throttle body is located under the fuel injection system, which had to be removed. So this installation took several days.

The aluminum on the throttle body is not very thick so the grove cut into a vacuum chamber and made a hole. I filled it with J-B Weld epoxy and re cut the groove.


Question:

I don't know if I blocked off the correct vacuum line? I point to it in the pictures.


Next thing is to:
- put some miles on the car and see if the gas mileage improves
- and get another smog text and check the emission numbers.

Hi David, I just looked your post over, Thank You! I just got a little Education about this Mercedes!

Fair amount of work on this one, Eh? Anyway I would definitely get a shop manual for this car/engine to figure out the PCV system. I can't tell for sure if that is the PCV line/hose you blocked. However in the left rear valve cover area it looks like might be the fresh air breather hose, does that hose connect to an air cleaner?

Your Groove looks pretty good to me, if you held the bit flush w/ the throttle blade then cut down (as it appears by bit rash on throttle blade) that's the original technique taught by Ron. If you read around on the site here on many posts and in Documents section, the bit angle has been revised for an improvement in results. The original technique works well, dont worry about pulling you TB off again, I suggest you look over the engine for vacuum leaks, any found must be fixed.

On emissions report the HC looks high, how many miles this car, keep the oil changed, how long since last tune up? What about O2 (Lambda) sensor(s)--how old? Are you using stock Mercedes cap/rotor/ plug wires? The Groove is not a panacea for existing problems, BUT if things are in top condition to at least decent shape it can/does perform!

The whole PCV re-route thing is to eliminate a major Vacuum Leak, please have a good look around the site about that. ANY vacuum Leak will reduce the Groove's effect, we are trying to enhance manifold vacuum and massively increase it during the Intake Stroke...

So my Hat's Off to you, David, this was a challenging car for your first Groove:cheer:!! And Thanks for the Pics, they help a lot, please keep us posted, and, again, Welcome!!

TracyG Gadgetman Reno

Hia everyone. I found this article,

There is no PCV valve on these engines. There are two hoses on the cam covers, one on the rear going to the underside of the air cleaner. There is another going from the front of the other cam cover to the area where the cold start valve is.

If im not mistaken these cars use vaccum for allsorts off stuff like central locking etc,,Many lines to check for leaks, The egr valve is seen on the right sidea bit back. If wanting tampering with,

Yot woundnt want to block that tube rerute if nessesary , or block the other side off the tube and let it breath naturally, Note I think that works , o je exept for emittions .so better rerute to filter with and oil pick up can inbetween. If the tubes are before the tb plate i think you might aswell leave them where they are.

Dont forget to reset the computer ...
MOB travelling in Europe

Thank you for the help.

I will drive the car to see how much it increases the gas mileage and get the car re-smogged and publish the data

David

I am uploading an updated .PDF file with the after groove emission data.

Mileage: was 15-17 in city. Is 15-17 city. No improvement.

I reset the computer by disconnecting the battery and connecting positive and negative cables.
The oil is changed every 5,000 miles
Last tune up about 30,000 mile ago
What about O2 (Lambda) sensor(s)--how old? - as old as the car (Don’t know what that is)
Are you using stock Mercedes cap/rotor/ plug wires? No, purchased online
I did not touch the egr valve
Both hoses on the cam covers are not blocked off.


Issues:

The checkengine light suddenly came on.
At 1,700 rpm and above, when you are driving the car, and let off the accelerator, the car seems to bog down. When you step back on the accelerator, it takes off again.
Also, the check engine light came on.

I reset the computer again by disconnecting the battery and connecting the positive and negative cables and letting it sit for 24 hours disconnected.

The check engine light came by on after 20 miles of driving.

No other gas mileage improvement.

If the check ingen light comes on when you back off on the throutl and it boges down there is a small hole where you cut the groove. I had that happen to my buick