mercedes 190E starting problem

[t***@gmail.com]

I have a 190E 2.0 (1990) which was running perfectly until 2 days ago,
when I tried to start it and the engine just cranked and cranked
without even a cough or splutter. I immediately suspected a fault in
the ignition system but checked this only to find the plugs are
sparking (cheked by holding HT leads a short distance from earthed
metal). I changed all four plugs anyhow - stilll no start. Then i
suspected a fuel pump or relay problem, so i bypassed the relay by
bridging the 30 and 87 sockets on relay with a piece of wire, and the
pump whirs away fine. what is the most likely solution considering the
plugs spark and the fuel pump and relay are fine? Any help would be
vastly appreciated before I spend a fortune getting out a mobile
mechanic

Thanks

tom

[Tiger]

Overload relay?

How old is the fuel pump relay?

[Tiger]

I am thinking another possibility of fuel enrichment problem... similar to
choke for the colder morning.

[t***@gmail.com]

Cheers for the suggestions - if the pump is pumping and the plugs are
sparking and the car still wont start isnt the overload relay ruled
out? Not sure when the fuel filter was last changed, Iv'e only had the
car a couple of months in which time its been running fine. Is the
fuel pump easy to change? Also I am concerned as to why it is not
starting atall - I have seen loads of problems posted on these pages
where the car starts and then dies, or has trouble cold starting etc,
but mine wont fire atall. Does this change the diagnosis?

Thanks

[Tiger]

I would start with simple diagnostic first... then continur crossing off
potential problems. Another possibility is factory alarm if you have one...
I would unplug it if you do have one.... easy way to test for this is to
simply leave the window down... lock the car... and then pull up the door
lock plunger... and open the car... if horn beeps and light flashes... you
got alarm.

[t***@gmail.com]

The car has an aftermarket alarm and immobiliser that was already
fitted to the car when i bought it. I did suspect an immobiliser fault
but ruled it out as firstly the immobiliser light goes out when you
unlock the car, and secondly i have tried starting the car with the
alarm on and the starter will not turn, proving that the imobiliser is
working where supposed to. Plus why would I get a spark?? I have read
many stories about the OVP relay on these cars - is this a likely cause
- and if so is there a way i can test this (eg bridging the pins like i
did on the fuel pump relay)? Finally, my OVP relay seems to be loose -
i.e. it is not plugged into anything like the fuel pump one is - it is
sort of attatched to the car by wires but not actually plugged in - is
this normal?

PS - already checked 10A fuse on top and its fine

Thanks

[Tiger]

OVP is supposed to be plugged in like the fuel pump relay... actually, they
are supposed to be next to each other if I remember correctly.

[T.G. Lambach]

You do not report wet or damp spark plugs. The fuel pump may run but is
fuel getting into the cylinders? Probably not.

When was the fuel filter last changed?

Been buying fuel at a different station? (May have water in the fuel.)

The next test is the fuel pressure.

[t***@gmail.com]

I think the plugs were dry but I wasnt really checking al that
intently. Doesnt fuel evaporate quickly anyhow? Another thought, what
is the relay behind the fusebox? It is the same size and shape as the
fuel pump relay - part number 201 821 00 47. Cheers guys

[t***@gmail.com]

Thought id update you on the situation. Today I had a mechanic round
and we carried out lots of checks on the car. Number one was to see
how far fuel was getting so we undid the inflow pipe to the fuel
distributor and found there was fuel getting there at high pressure.
Then we checked each injector outlet on the top of the fuel distributor
in turn, only to find that none of them had any fuel coming out!

So... we took out the fuel distributor and dismantelled it only to find
a large blockage of gunk inside it. After careful cleaning and putting
back together we returned the part. However, concerned as to where the
gunk was coming from we checked the fuel filter, which looked pretty
new, but we changed it anyway. My guess is that on old filter wasnt
working properly and that was the cause of the crap getting to the fuel
dist. in the first place. Having replaced it we ran off a bottle of
fuel from the inflow to the engine to check it was clean - which it
was.

So, with the fuel dist cleaned out, we checked the injectors again -
and found great fuel pressure on each one. Great news....except the
engine still would not start. Each of the plugs was wet when removed,
and on testing each plug a fat blue spark was found.

AAAArrrggghhh - help me please - - it has compression, fuel and spark
- so why wont it run!!!??

Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the
engine/cylinders/manifold, so im going to chek it again in a few days.
Is that a fair suggestion??

Finally, is it possible that too much fuel is coming through and
flooding the spark plugs before they have a chance to spark??

Any help greatly appreciated

tom

[Tiger]

I think yes after reassembly, too much fuel. You need to lean out the
mixture... do 1/4 turn at a time and see if you can start the car up.

There is also a possibility as you disassembled it...it won't work as
something is not adjusted right. This is a highly technical job as Bosch
said... I never took one apart yet.

[Richard Sexton]

Post by t***@gmail.com
Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the

Uh...

When I bought my first Mercedes about 10 years ago it was a real
ratbag poor excuse for a euro 70 280SE. It wouldn't start when I
went to test drive it so the guy pulled the plugs, fired a propane
torch on them to burn away the gas and oil and then it started.

Waiting 2-3 days seems kinda lame.

[T.G. Lambach]

Sounds like your man knows what he's doing so go with his suggestion.


I'm a bit skeptical that the fuel distributor mess caused an otherwise
well running motor to suddenly quit - gradually yes, but suddenly ??

If there's further difficulty:

Check the spark's timing vs. the crankshaft

Open the oil filler and watch that the cam turns while the engine is
cranked - If it doesn't, that's for sure THE PROBLEM!

[t***@gmail.com]

Cam turns when the engine is turned over, so thats not the problem.

I let the car dry out for 5 days and still nothing. So....

Its not the distributor, becuase I replaced it. Its not the coil,
leads, or plugs, bcause they work fine and the plugs are sparking with
fat blue sparks. Its not the fuel pump or relay because plenty of fuel
is getting to the cylinders as the plugs are wet when removed, and each
injector has been tested and is working fine. So what can it be!!!!???

Could it be a blown OVP relay that is the problem - i.e can this
prevent the car from starting completely? But then if it is that then
why does the fuel pump deliver fuel to the cylinders and the spark
plugs spark? Also are there any other fuses/relays on the car that
could have blown besides the ones in the fuse box under the bonnet?

none of this makes sense. In my opinion it is something very stupid
that i must be missing, as the car has gone from a great runner to a
complete non-starter with absolutely no symptoms in between - how
bizarre!

Any help much appreciated

[t***@gmail.com]

Thought id update you on the situation. Today I had a mechanic round
and we carried out lots of checks on the car. Number one was to see
how far fuel was getting so we undid the inflow pipe to the fuel
distributor and found there was fuel getting there at high pressure.
Then we checked each injector outlet on the top of the fuel distributor
in turn, only to find that none of them had any fuel coming out!

So... we took out the fuel distributor and dismantelled it only to find
a large blockage of gunk inside it. After careful cleaning and putting
back together we returned the part. However, concerned as to where the
gunk was coming from we checked the fuel filter, which looked pretty
new, but we changed it anyway. My guess is that on old filter wasnt
working properly and that was the cause of the crap getting to the fuel
dist. in the first place. Having replaced it we ran off a bottle of
fuel from the inflow to the engine to check it was clean - which it
was.

So, with the fuel dist cleaned out, we checked the injectors again -
and found great fuel pressure on each one. Great news....except the
engine still would not start. Each of the plugs was wet when removed,
and on testing each plug a fat blue spark was found.

AAAArrrggghhh - help me please - - it has compression, fuel and spark
- so why wont it run!!!??

Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the
engine/cylinders/manifold, so im going to chek it again in a few days.
Is that a fair suggestion??

Finally, is it possible that too much fuel is coming through and
flooding the spark plugs before they have a chance to spark??

Any help greatly appreciated

tom

[t***@gmail.com]

Thought id update you on the situation. Today I had a mechanic round
and we carried out lots of checks on the car. Number one was to see
how far fuel was getting so we undid the inflow pipe to the fuel
distributor and found there was fuel getting there at high pressure.
Then we checked each injector outlet on the top of the fuel distributor
in turn, only to find that none of them had any fuel coming out!

So... we took out the fuel distributor and dismantelled it only to find
a large blockage of gunk inside it. After careful cleaning and putting
back together we returned the part. However, concerned as to where the
gunk was coming from we checked the fuel filter, which looked pretty
new, but we changed it anyway. My guess is that on old filter wasnt
working properly and that was the cause of the crap getting to the fuel
dist. in the first place. Having replaced it we ran off a bottle of
fuel from the inflow to the engine to check it was clean - which it
was.

So, with the fuel dist cleaned out, we checked the injectors again -
and found great fuel pressure on each one. Great news....except the
engine still would not start. Each of the plugs was wet when removed,
and on testing each plug a fat blue spark was found.

AAAArrrggghhh - help me please - - it has compression, fuel and spark
- so why wont it run!!!??

Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the
engine/cylinders/manifold, so im going to chek it again in a few days.
Is that a fair suggestion??

Finally, is it possible that too much fuel is coming through and
flooding the spark plugs before they have a chance to spark??

Any help greatly appreciated

tom

[t***@gmail.com]

Thought id update you on the situation. Today I had a mechanic round
and we carried out lots of checks on the car. Number one was to see
how far fuel was getting so we undid the inflow pipe to the fuel
distributor and found there was fuel getting there at high pressure.
Then we checked each injector outlet on the top of the fuel distributor
in turn, only to find that none of them had any fuel coming out!

So... we took out the fuel distributor and dismantelled it only to find
a large blockage of gunk inside it. After careful cleaning and putting
back together we returned the part. However, concerned as to where the
gunk was coming from we checked the fuel filter, which looked pretty
new, but we changed it anyway. My guess is that on old filter wasnt
working properly and that was the cause of the crap getting to the fuel
dist. in the first place. Having replaced it we ran off a bottle of
fuel from the inflow to the engine to check it was clean - which it
was.

So, with the fuel dist cleaned out, we checked the injectors again -
and found great fuel pressure on each one. Great news....except the
engine still would not start. Each of the plugs was wet when removed,
and on testing each plug a fat blue spark was found.

AAAArrrggghhh - help me please - - it has compression, fuel and spark
- so why wont it run!!!??

Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the
engine/cylinders/manifold, so im going to chek it again in a few days.
Is that a fair suggestion??

Finally, is it possible that too much fuel is coming through and
flooding the spark plugs before they have a chance to spark??

Any help greatly appreciated

tom

[t***@gmail.com]

Thought id update you on the situation. Today I had a mechanic round
and we carried out lots of checks on the car. Number one was to see
how far fuel was getting so we undid the inflow pipe to the fuel
distributor and found there was fuel getting there at high pressure.
Then we checked each injector outlet on the top of the fuel distributor
in turn, only to find that none of them had any fuel coming out!

So... we took out the fuel distributor and dismantelled it only to find
a large blockage of gunk inside it. After careful cleaning and putting
back together we returned the part. However, concerned as to where the
gunk was coming from we checked the fuel filter, which looked pretty
new, but we changed it anyway. My guess is that on old filter wasnt
working properly and that was the cause of the crap getting to the fuel
dist. in the first place. Having replaced it we ran off a bottle of
fuel from the inflow to the engine to check it was clean - which it
was.

So, with the fuel dist cleaned out, we checked the injectors again -
and found great fuel pressure on each one. Great news....except the
engine still would not start. Each of the plugs was wet when removed,
and on testing each plug a fat blue spark was found.

AAAArrrggghhh - help me please - - it has compression, fuel and spark
- so why wont it run!!!??

Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the
engine/cylinders/manifold, so im going to chek it again in a few days.
Is that a fair suggestion??

Finally, is it possible that too much fuel is coming through and
flooding the spark plugs before they have a chance to spark??

Any help greatly appreciated

tom

[Roland Franzius]

Post by t***@gmail.com
Thought id update you on the situation. Today I had a mechanic round
and we carried out lots of checks on the car. Number one was to see
how far fuel was getting so we undid the inflow pipe to the fuel
distributor and found there was fuel getting there at high pressure.
Then we checked each injector outlet on the top of the fuel distributor
in turn, only to find that none of them had any fuel coming out!
So... we took out the fuel distributor and dismantelled it only to find
a large blockage of gunk inside it. After careful cleaning and putting
back together we returned the part. However, concerned as to where the
gunk was coming from we checked the fuel filter, which looked pretty
new, but we changed it anyway. My guess is that on old filter wasnt
working properly and that was the cause of the crap getting to the fuel
dist. in the first place. Having replaced it we ran off a bottle of
fuel from the inflow to the engine to check it was clean - which it
was.
So, with the fuel dist cleaned out, we checked the injectors again -
and found great fuel pressure on each one. Great news....except the
engine still would not start. Each of the plugs was wet when removed,
and on testing each plug a fat blue spark was found.
AAAArrrggghhh - help me please - - it has compression, fuel and spark
- so why wont it run!!!??
Anyhow, my mechanic rekons the car was flooded prettly badly and to
leave the plugs out for 2-3 days to dry out the
engine/cylinders/manifold, so im going to chek it again in a few days.
Is that a fair suggestion??
Finally, is it possible that too much fuel is coming through and
flooding the spark plugs before they have a chance to spark??
Any help greatly appreciated

Disconnect the fuel pump from the fuel pump relay. Let the motor get dry
- some cranks with open plug holes or just wait.

Put the plugs back in its place, remove the air filter and while
cranking let someone pour fuel directly in the fuel distibutor hole. If
no firing happens there will be a voltage, a timing or a valve problem.

If the engine is firing check the fuel pressure, the cold start
regulator system and the start enrichment valve and of course all the
vacuum lines at around at distributor and intake manifold.

[t***@gmail.com]

Sorry bout posting my last message 6 times, not sure why it did that!

What do you mean by the fuel distributor hole? Do you mean the one to
the right of the fuel distributor with the plunger that goes up and
down?

I didnt think you could do that on an injection engine, only
carburettor engines.

As for drying out, how long do you think i shoud leave it for - and how
much of a chance is there that this is what is wrong with my engine?

I really cant understand how it can go from running fine to not
starting atall overnight, with no previous symptoms. Is the OVP relay
ruled out as I am getting fuel and spark?

Cheers

[Thom]

Post by t***@gmail.com
Sorry bout posting my last message 6 times, not sure why it did that!
What do you mean by the fuel distributor hole? Do you mean the one to
the right of the fuel distributor with the plunger that goes up and
down?
I didnt think you could do that on an injection engine, only
carburettor engines.
As for drying out, how long do you think i shoud leave it for - and how
much of a chance is there that this is what is wrong with my engine?
I really cant understand how it can go from running fine to not
starting atall overnight, with no previous symptoms. Is the OVP relay
ruled out as I am getting fuel and spark?
Cheers

I had the same problem in my 300E. Ended up being the Dist. Cap and
rotor. Take it off and see if there is any condensation. Mine had it.
I would get spark, but not enough to start the car.

[retroaddiction87]

replying to tom.h.schofield, retroaddiction87 wrote:
maybe you should try the cam sensor and or the crank sensor even though you
have a spark it does need to be sparking at the right time. Sensor
faulty,Water ingress in the connector or simply dirty well worth a check