My 1991 190E 2.3 does not start

Hi there, My 1991 190E 2.3L hard to start in cold or hot. Every time to start the car,I need to step on the gas pedal or need to crank the engine for a long time!Once the car start , it just run fine!I have to start the engine like that no mater the egine hot or cold.But if I stop the engine and start it again in couple second, it start ok! Anyone know the problem is or have the same problem please let me know! Thanks! Quang

Reply to
quangcar
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How old is your battery? Are the radio, air conditioning, headlights or any accessories on while you're trying to start?

Reply to
Michael J. Astrauskas

Hi Michael, the battery is 4 year old. Every thing is off while we try to start! Quang

Reply to
quangcar

Quang,

There are two electric relays (switches) that are suspects, that is, one OR the other, not both.

One is the fuel pump relay - it turns the electric fuel pump ON and OFF. These get tired and become intermittent both during starting and while driving. While starting, sometimes the engine doesn't start and while driving the motor simply quits with no warning - just as if one turned the key to OFF. If there's been no problem during driving the fuel pump relay is probably OK and should be excluded.

The second suspect relay is the "over voltage protection relay" which controls some engine functions, especially when the motor is cold. These OVP relays also get tired and "act up". Look back to a post about 10/19 with a heading 300E Misfiring and read through the messages to the (fixed) outcome.

Tom

Reply to
T.G. Lambach

Reply to
Wan-ning Tan

Ok, that seems like a good theory.

How about a different theory? :~)

What about a temperature sensor problem?

Reply to
Martin Joseph

The owner stated no-start in both cold and hot engine so I exclude the temp sensor. A major leak can depressurize the system much quicker than the engine cools down.

With a major leak, I would take out spark plugs and see if there is any gas smell. If yes, replace the injector for that cylinder. If none, regulator is likely the problem.

However, I have to admit I am not familiar with this particular eng> >

Reply to
Wan-ning Tan

I have tried to jump start the car to see what happen. When I jumped start the car, it works! The car started fine! It started right away! So I sent the battery out to check from 2 stores, they both checked and said the battery was fine!!!!! Quang

Reply to
quangcar

Electrical problem. OVP is the prime suspect, IMHO.

Reply to
T.G. Lambach

What does the Over power relay OVP job? When I jump start my car from the orther car; I Have check the battery from the other car was 14.8 V with engine running(without only 12.6V)! My car could start with that 14.8V! Does OVP increase the 12V battery to 14.8V when the car start? Quang

Reply to
quangcar

No, but it might prevent the full current from getting to the starter...

Marty

Reply to
Martin Joseph

This excellent description of the OVP relay's function was posted on

10/19 by WS:

To explain:

The OVP relay protects the sensitive electronic circuits, i.e. your ECU from high voltages.

It basically consists of a fuse, followed by a relay energised by a small circuit, which has a zener diode built-in. This relay feeds the the SRS, ECU and ABS (any others?). If the voltage goes too high, the zener conducts, and shunts the circuit to ground, cutting out the relay, and if very high, blows the fuse.

These relays get tired, as basically, it has to activate continously when the engine is running. 10 years ± is about the lifetime.

When it cuts out, your engine reverts to "dumb" mode, and won't compensate for temp, O2, timing, etc.

Regards, WS

Reply to
T.G. Lambach

On further thought, I think it's your battery that's bad, regardless of what the autoparts people are saying.

Try getting a loaner from another vehicle and connecting that in place of yours as a test. I bet it works fine.

Marty

Reply to
Martin Joseph

I have change the OVP relay,but did not work! also Have change the fuel pressure regulator, did not work ! Anyone please tell me know I should change : Battery , fuel pump relay or air flow sensor ? Thanks! Quang

Reply to
quangcar

Hi there, I have just tried to jump start the car again.this time , it does not work! So , I do not think would be the battery! Quang

Reply to
quangcar

Well you seem to have eliminated the prime suspects (fuel pressure and OVP) but now I'm wondering if there could be an issue with the ignition coil. I'd hate for you to spend +$100USD on a whim so you might want to check the ignition coil resistance before going any further. You can google on "testing ignition coil" to see how to do this, but you'll need to find the right specs. for your car.

Josh

Reply to
Josh

quangcar, It could be the fuel distribuitor - a welll known nightmare part integrated in the 103/104 engines like yours and mine.

Sds,

mobi

Reply to
mobi

Hi there , Let me make it clear that the coolant boiling problem happen every time I turn off the key and the engine is not running ! When engine running , it is fine no matter how long distance you drive ! Either it is boiling or seem getting some air in to the coolant! Every time the engine off !!!!! Thanks!

Reply to
quangcar

I had a similar problem in my Jeep because a replacement radiator was too small. It also happened to be that the water pump was wearing out, causing circulation to be reduced.

Reply to
Michael J. Astrauskas

I have found the problem. It was the cold start valve leaking. and the fuel accumulator was bad! Thanks for all your inputs! Quang

Reply to
quangcar

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