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-   -   My last cry for help on my 300E (http://www.peachparts.com/shopforum/tech-help/80725-my-last-cry-help-my-300e.html)

mike690003 11-29-2003 05:12 PM

My last cry for help on my 300E
 
Hello Board, my 300E has this frustrating hesitating problem:


During the first start of the day, the car idles seamless and throttle response is great. Well after about 10 minutes of driving, the car will develop a slight hesitation. After about 20 minutes of driving, the car will SEVERLY hesitate and idle becomes rough. When I press on the gas, the car will NOT respond for about 2 seconds, and then shoot off like a rocket. This is very dangerous when I an trying to merge into traffic.

I have a feeling that it might be fuel pressure related, because it is as if the fuel pressure builds up overnight, and then after driving the fuel pressure will fall and that is when the car starts to hesitate.

Any opinions on what could be the culprit??

Electrical?
Fuel pressure?

Ohh I have changed so many parts

mike690003 11-29-2003 05:15 PM

The list of parts:
 
-OVP Relay
-Voltage Regulator
-new fuel filter
-New Cap
-New Rotor
-New plugs
-New wires
-new vacuum lines
-injector seals
-new injectors
-new radiator
-new thermostat
-new vacuum sensor on top of engine(has 2 vacuum lines coming out of it)
-New coolant temp sensor
-new aux fan temp sensor
-new gas cap
-New fuel sending unit
-Cleaned idle control valve
-new 02 sensor
-fuel mixture was corrected to spec
-cleaned all electrical connections
-new air filter
-cleaned throttle plate
-new aux fan
-spent lots of $$$ on Techron
-Spent lots of $$$ on diagnostics

michael cole 11-29-2003 05:32 PM

fuel pump relay.known to develop poor solder connections

mike690003 11-29-2003 06:35 PM

Is there any way to open the relay and check the soldering joints without damaging the relay (any further)?

Jugo Driver#1 11-29-2003 07:06 PM

Could be a crank shaft position sensor or a bad fuel pump. The pump building pressure is impossible over night it only looses it. See how much fuel pressure you have and check volume of fuel too then if everything checks out i would change the csps.

mike690003 11-29-2003 07:41 PM

What is the price of a crank shaft position sensor???
Where is it located??
Can it be tested?

I know that fuel pumps are pricey, so I hope that mine are good.

haasman 11-29-2003 07:51 PM

This might be a long-shot, but someone had posted that they also had a weird hesitation problem, went through a long list of parts and repairs, time and money, but it turned out to be the ceramic insulator behind the rotor, under the distributor cap.

Now how anyone would ever know to check this, amazes me. My guess is that it was cracked and allowed the coil spark to ground out to the head.

Since your problem is worse as the engine gets warmer, it may follow that a tiny hair line crack expands as it gets warmer.

May be worth it to check it out. Only takes a few minutes.

Haasman

mike690003 11-29-2003 07:56 PM

I have heard of that problem before, but I never thought it might be the problem to my cars hesitation.


What is that ceramic insulator called?
Is that an expensive part?

haasman 11-29-2003 08:09 PM

It is called a Suppressor Cover, made by Bosch, lists for $63.00, but our friends at FastLane (this site) sell it for only $20.51.

It is found online in the Engine Electrical section, just below Starter drive in the list on the right.

Haasman

mike690003 11-29-2003 08:10 PM

Thanks a lot!! Tomorrow I will check mine and see if it is cracked.


Any more suggestions?

tecqboy 11-29-2003 11:46 PM

If the engine runs good when cold, but runs poorly when hot, check the EGR valve and the vacuum hose leading to it. The diaphram should not be cracked and it should be free to move the "plunger" in and out. The EGR valve is closed when the car is cold, but is modulated as needed when the engine is up to temperature. If it sticks open, the engine will run poorly at idle or low speed. Carbon build up is the culprit for sticking most of the time, but it can be cleaned off. Also look at the gasket.

joe p 11-30-2003 12:29 PM

Try this, and it will set a check engine light if your equipped. Pop up the passenger carpet and unplug the O2 sensor, if the hesitation goes away, check the base lambda adjustment (after plugging the O2 back in) if it is in line (35-55%) check for vauum leaks including the vacuum switch on the head for the EZL. Check the throttle plate for sticking and clean it up a bit while your at it. I had one of these doing something similar that had a rusted out freeze plug at the rear of the intake, due to roller noise, you never heard the leak, it had been covered up to a point by way of a overly rich CO adjustment.



Joe

mike690003 11-30-2003 09:48 PM

Today was a good day
 
Hello Board,

Well today, I checked the supressor cover. It had a few small cracks on it, but I had trouble removing it because the plate in which the rotor was attached to, would not budge. There was an allen screw in the center that I removed, but it still would not move. Does anyone have directions on how to remove the "rotor plate" so I can examine the supressor cover better???

Cap'n Carageous 12-01-2003 10:50 AM

Quote:

Originally posted by joe p
I had one of these doing something similar that had a rusted out freeze plug at the rear of the intake, due to roller noise, you never heard the leak, it had been covered up to a point by way of a overly rich CO adjustment.
Joe

Just curious, how did a rusted freeze plug cause a vacuum leak??

cc260E 12-01-2003 11:31 AM

Have you checked the fuel pump relay? some soldering may broken.


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