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89 300SE rough starts

My 89 300SE 6Cyl. has started a rough starting process here recently....it will start and then act like it is going to die whether it is cold or hot, if you depress the gas peddle when starting it seems to start better, I would not think you would need to do this though, am I correct? Once it starts and gets running it is fine on the highway and even in town driving, it idles ok and has good pickup too. Could dirty injector(s) be a problem? or are other issues at hand? I put a can of injector cleaner through it a while back, could this have broke something loose and clogged an injector partially. Thanks for the help... Tim

Reply to
timhmax
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If this came on suddenly I'd suggest you check two things.

Electronics - specifically a relay called the "over voltage protection relay" (has a fuse on its top). If original very suspect.

Fuel pressure regulator. This device ensures the fuel pressure is a constant XX psi (probably about 43 psi). These can be easily checked. Look for a small can attached to the engine's fuel rail (pipe to the fuel injectors); it will have a small hose attached to it that goes to the intake manifold. Remove the hose. If gasoline drips out the regulator is defective and ought to be replaced.

Reply to
T.G. Lambach

Hi,

my problem looks pretty much the same: how can I remove the OVP: can I just pull it out of its socket? To verify the fuel pressure regulator: should the engine be running or not?

thanks very much!

Rémy K. Euro 420 SE (1989)

320000 km

T.G. Lambach wrote:

Reply to
"Rémy K."

Relay plugs into a socket.

Shut off engine, detach hose from pressure regulator.

( I shut off the engine for safety - moving parts vs. me and fire if gasoline leaks from regulator.)

Reply to
T.G. Lambach

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