Ja, Boet...

1. Dump your "mechanic", he's an idiot. Carburettors are nicer for some people because they're easier to tune; however, fuel injection wastes less fuel and requires less tuning anyways.
2. Free flow exhausts and petrol engines usually means worse fuel consumption. Get a replacement stock exhaust, or live with the worse fuel consumption.
3. Perhaps the auto 'box needs some attention. There's plenty to be found on this forum on maintenance of the auto 'boxes.

Welkom!

 

Welcome! Nice to see another Saffer .

Is your problem not easy to fix, seeing as you know exactly what you did "wrong"? Revert it back to the same exhaust system as last time?

That consumption sounds rather bad. However, I doubt you want to convert it to a carb-fed system.

 

On replacing the exhaust, did they not sprung a leak around the fuel pump? Those hoses tend to get brittle with age, especially the one from the tank to the filter.

Agree with Frans, fire the idiot.

 

Thank you for all the replies.

I will start to look for a replacement manifold. As I understand I shouldn't have replaced it unless I was planning to have the head ported and gas flowed. I will look into the gear box as it does feel like she is pulling heavy.

LaubscherCalitz I have the fuel line on the "to do" list we did fix it as it ruptured with the last service but I will check it to make sure.

Thanx

 

Well, well, well, isn't this nice? An ENTIRE thread with only Safricans!:thumbsup:

 

If your car has a Lambda controller it needs an O2 sensor mounted somewhere along the exhaust. If this was not done right when the exhaust was replaced it will affect fuel consumption because the controller will not get a valid signal from the O2 sensor.

If necessary you can adjust the mixture as if it were a CIS with no Lambda. I have the instructions if you need them.

 

No W123's in SA were manufactured with lambda sensors. What you can check is the Warm Up Regulator (WUR). According to your year model it may be that the fuel is leaking to the vacuum line that ensures acceleration enrichment.

 

One more thing to check is the Decel Shut-off valve. It is a cylindrical shaped valve below the Inlet Manifold. The pipe from the top of the Air filter connects to it. a small vacuum pipe comes from it and connects to an electrical valve on the left front fender. If you remove this pipe during idle, and you suck on it, the engine should stop. If it does not, the valve is probably shot. It operates on the micro switch next to the throttle that senses when your foot is off the pedal.

The principle of this system is that when you take your foot off the pedal at speed, high vacuum in the lower intake manifold opens the air valve, allowing air from the air cleaner directly into the lower intake manifold, bypassing the upper intake manifold's fuel sensor plate and throttle. The resulting absence of vacuum in the upper intake manifold makes the fuel sensor plate return to its idle position, cutting off most of the fuel. The un-throttled rush of air into the cylinders also decreases pumping losses. The electrical switch is to ensure the valve only opens during deceleration/overrun, not at idle. If you connect the air valve directly to high manifold vacuum at idle, the engine should die. If it doesn't, the air valve may not be working or some adjustment may be off, or there may be a vacuum leak. You can live without this system, but your fuel consumption will be higher by 20% or more.

 

I was wondering what this convoluted circuit was for. I've spent many hours working by feel because of the location below the intake manifold. My air valve was not working due to a split diaphragm. Due to availability of a replacement part, I cut the housing open, sealed the diaphragm and clamped it back together.

The problem that I have with my 230CE with a manual transmission is that the valve is open at idle and when I apply throttle the engine stumbles as the switch changes state and the air valve closes changing air flow from this circuit to the sensor plate. This probably wouldn't noticeable with an automatic but with the manual it happens when I am engaging the clutch. This momentary loss of power made smooth engagement of the clutch frustrating.

My solution was to not use this circuit by disconnecting the switch at the throttle linkage. This bypassed the idle air screw adjustment. I added an adjustment screw that contacts the sensor plate to set the idle speed.

I'd like to get this working like it was designed but I need to learn more about this. In your post you stated "The electrical switch is to ensure the valve only opens during deceleration/overrun, not at idle". Seeing that the switch is actuated by throttle position, I don't understand how it knows the difference between closed throttle during deceleration and closed throttle when idling at a stop.

Can you tell me more about this?

Thanks

 

Now that's something I didn't know:thumbsup:

 

Good information. Thanks.

 

I now have an idea of why the decel shutoff valve circuit is not working on my 1985 230CE. The fuel pump relay (001 545 78 05) does not have a pin at connector place #5. This is where the micro switch connects.

What is strange is that the fuel pump relay from the other 230CE has the same part number but has a pin for connector #5.

However, the relay now installed may not have been there when I was trouble shooting the circuit because the other 230CE had a bad relay before I bought it and I swapped relays to get it running. I remember repairing the bad one (cleaned the contacts) but don't know if I swapped them back.

The help that I can use is to find the correct part number for the relay. And if I could get a link for the circuit description like frans-c provided for the 102 engine that would be great.

Thanks

 

I bet it's running lean now due to the lack of back pressure from your new freeflow exhaust. Enrich via the 3mm adjustment on airflow sensor, 1/8 to 1/4 turn clockwise. You could even first pull a plug to see if it is blistered or eroded, telltale of a lean fuel to air ratio.

 

Mighty impressive consumption for a 230E there:thumbsup:

 

Thank you plane,

I am not quite happy yet, there is still a few tricks that can be done, but I need to fix a few things before I experiment further, and I have to save a little before I can continue...

And I am looking at a 220/240D w115 or older project to do next.