New 308 GTSi Engine problem

Ok, I've had a bad day yesterday, It was my birthday and I went to a job interview and it ended up being one of those "fake jobs"(pyramid scheme) and as I rolled out of there I was just getting on the highway and while at the light my engine rev's up to 3-4 Rpm like it was in warm up. Well I had to continue on. This had happen once before a week ago and I brushed it off as a fluke. Well I was going down the highway at a decent speed. The RPM's started dropping slowly at a steady pace. It dropped to the high 2000's if I remember right, and I decided shut the engine down and restart it. I wasnt able to restart it and I became stranded Since my cell phone also died a couple weeks back and is in for repair. Luckily a kid gentleman stopped to my rescue in a Mercedes SUV. Who happened to be a brother of the owner of the local F-car dealer. Well I ended up getting a friend and towing it home. I found 1 problem one of the spades for the Water Resovair switch had it's cables come off.

That is all I glanced at Any Ideas would be very helpful and needed? Thanks to whom ever can help.

 

if I remember right (you should start getting worried right about now) the temp sensor in the expansion tank powers an electrovalve which in turn controls the auxiliary air valve.

When the coolant is cold, the aux air valve opens a passage bypassing the closed throttle plate, which means more airflow through the intake, thus causing more fuel to be dumped in and the idle speed goes up.

when the coolant reaches temp, the aux air valve closes and the only airflow past the throttle is what is allowed by the big idle adjust screw holding the throttle plate open a little.

so, if a wire comes off the coolant temp sensor, the aux air valve will be permanently held open (by vacuum), and your idle will stay high.

wrt why you couldn't start the engine, or why the rpms would be dropping on the highway, whoever corrects me on the above can explain

 

I thought the temp sensor controled the cold start valve. The aux air valve gets 12volts directly, and is held open by a temp controlled spring, not vacuum....as the 12 volts is continously fed to it, it slowly closes.


http://www.auto-solve.com/mech_inj.htm#MFI11
http://www.auto-solve.com/mech_inj.htm#MFI12

 

well i didnt actually time it, but previously the rpms did dropp back to normal, same when I was on the highway, I tried getting it out of gear and it did drop so I put it back in gear and continued going.

 

I had the smaae problem, get a new cold start valve for 2-300 hundred buck or by pass it.
Kelly

 

well it actually seems to be the Fuel pump or accumlator. But I am not sure as to what the accumlator does, Does anyone know ?

 

The accumulator,
It has three functions: To damp the fuel pulsation, to maintain fuel pressure when the engine is switched off preventing vapor locks and to reduce the pump's noise.

 

Cooly0,
Read this: http://www.auto-solve.com/mech_inj.htm#MFI05

Better yet, read the entire link:
http://www.auto-solve.com/mech_inj.htm

 

Accumulator failure symptoms are:

1) Very hard to start car when it's hot(vaporlock), car starts fine when cold.

2) Fuel dripping out of the small tube on the back of the accumulator, often only when fuel pump is running & shortly after shutting the engine off.
US spec cars have a small hose on the tube, unplug the hose to check. If gas comes out of the hose, accumulator is bad. Fuel leak usually shows up long before hard starting appears.

 

Well I have found it to be the fuel pump, I removed the plate the accumilator and pump sit on and hooked up the pump and it didnt suck one drop. I ordered another one and a fuel filter.