QuestionQUESTION: Hey Robert, I hope you can help me here. I had a hot start problem, after changing both fuel pumps,oil,wires plugs dist cap and rotor button, now it won't start.It's a 1991 300ce. I have fire(spark) and fuel but it just don't hit a lick. I have checked everything but caan't seem to find the problem. Please help.
ANSWER: Buddy,
Have you tried spraying a little starting fluid into the throttle body intake. If the vehicle begins to run and die, then you probably have a problem with the fuel/start relays. OR Many of the vehicles have a low Oil cut out sensor, a good idea to keep from having damage from low/no oil, but if the sensor is defective it would not allow the vehicle to start.
You may have a problem with the ignitions switch. I have seen instances when the key is rotated to the engage starter position a warn contact in the switch will not allow power to the electronic. I noticed this with my 420SEL. Just as I would release the key to try a restart there would be moment where the vehicle would try and start.
I finally had a new ignition lock installed the problem and that solved the problem.
There is a method of determining if your are getting power through the switch by checking two of the contact ports on the diagnostic that in under the hood.
You will need to get that info from a repairman, or take it in to have it checked.
Good Luck and let us know how it turns out.
Rob
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QUESTION: Thank you very much for your response, I had thought of an oil pressure switch as I notice the oil pressure guage doesn't rise even after starter engadged for more than 15 seconds, Do you know if that switch is normally open or closed and it's location?
ANSWER: Buddy,
I suspect that it is normally open and closed as the pressure rises. I am more concerned about the lack of indication on the oil gauge. If the gauge uses a pressure tube, you may have a more serious problem. How many mile on this vehicle and how often has the oil been changed?
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QUESTION: Hey Rob, I was wrong about the oil pressure guage, it does rise after 15 seconds of starter engadgement,and the car is trying to start. I'm hoping that oil pressure cut out is the culprit, do you know where it is on the car, maybe the one under the intake manifold and I have read that with that mechanical fuel injection, the car will run without a working computer,is that true? I guess that is two questions and thanks for the rocket return on the last question.
Buddy
AnswerI am unsure of the location.
And unsure about the ability to operate without the computer.
It should not take 15 seconds or longer to get the engine to start. Do you notice that the attempt to start is just as you release the starter engagement?
IF so it may be in the switch. It actually starts momentarily and goes dead then it could be the fuel pump relay or the over voltage protection relay.
