[Sean Mics]

New to the Mariah Owner's Club! Found the Club trying to find answers to my surging problem on the web. I have a 1997 Z210 Shabah 5.7L Merc that surges only under a load between 1500-3000RPM. I also found it to be intermitten. Could it be my ECM? I just had the carb done, plugs, fuel/water sperator, and cap & rotor in the last 4 months. By the way, where is the anti-siphon valve in the fuel line?

[ColoradoDiablo]

Anti siphon valve is right at the tank fitting usually.
Have you tested fuel pump pressure?
An intermittent symptom as you describe makes me think a electrical issue also. Check and clean all your grounds.
Just a thought or two.

BTW: Welcome to MOC!

[Sean Mics]

Originally Posted by ColoradoDiablo

Anti siphon valve is right at the tank fitting usually.
Have you tested fuel pump pressure?
An intermittent symptom as you describe makes me think a electrical issue also. Check and clean all your grounds.
Just a thought or two.

BTW: Welcome to MOC!

Thanks for the reply. I looked for that valve but I don't have access to the fitting unless I pull up my floor!? I havn't checked pressure yet. I guess I can put in a "in-line" guage to look at while running it on the water. I was thinking electrical also and have checked some grounds but will double check. Not familiar with the EMC and it's symptoms when it go'es bad? Well, thanks again for your input. The MOC web site makes me even more proud to be a Mariah owner!