Car starts then dies if i touch the throttle - PeachParts Mercedes-Benz Forum

zakh · #1 07-25-2007, 07:07 AM

So heres the story...

Over the last year or so i have replaced the idle air valve, injectors, fuel pumps, fuel filter, fuel pump relay, cold start valve on my 190E 2.5 16 valver.

Anyway shes been running great, no problems.

Then i had cause to change the EHA valve. So i bought one, fitted it...fitted new o ring seals aswell.

The car struggled to start. But eventually it did but i really had to prod the accelerator to get it going, above 2.000 revs it was fine.

Anyway it turned out that they gave me the wrong EHA valve, my old one had a different part number.

So i fitted the correct one. Now it really really struggles to start. When it does its as if its running on three cylinders. It then just dies after about 10 seconds. If i try and touch the accelerator it instantly dies.

What gives?

Im a bit baffled.

I have checked the spark plugs, they are new along with the ignition leads.

Any help would be most appreciated.

thanks guys

mbdoc · #2 07-25-2007, 08:09 AM

The basic principle of CIS fuel systems is based on fuel pressure differential.
That differential pressure is regulated by the EHA. Measuring the fuel pressure, both upper & lower chamber would be a starting point on that type of problem.

Checking current flow to the EHA is also critical.

zakh · #3 07-25-2007, 03:31 PM

So my question is this.
Since i have put a new eha valve on, does it need to be adjusted in any way at all?
I have read many posts saying that it needs to be adjusted? Or rather the air/fuel ratio needs to be adjusted?

PBH · #4 07-25-2007, 04:19 PM

Your car must be too lean if it won't take throttle. Could you have created an intake leak when you installed the EHA valve? Or knocked off a vacuum line?

Since nothing else has changed I doubt it is the fuel pressure and I doubt it is the mixture screw. Try looking for a vacuum leak with quickstart.

zakh · #5 07-25-2007, 04:28 PM

I have double and triple checked everything. No vaccuum lines are disconnected or anything.

I disconnected the IACV and that helped but not by much.

A point to note is that i noticed quite a bit of fuel leaking from the top of the EHA valve itself.

saumil · #6 07-26-2007, 02:37 AM

Are you saying that the EHA is leaking ? Then thats the problem. Hopefully it is the o-rings and not the valve itself.

david s poole · #7 07-26-2007, 10:35 AM

also make sure that you didn't inadvertently break a wire on the plug that goes to the eha.