merc 190E non starter

hope someone can shed some light on this one, mercedes 190E 2.0 1992 with mechanical injection. it wont start, we can get it running using easy start but it wont idle and the throttle needs to be pumped or held above 2000rpm to keep it running, theres a good spark, all the vacuum pipes are good and not disconnected, there are no leaks anywhere on the inlet manifold etc. we've replaced the fuel pump on advice from mercedes. (thanks guys, £150 down the drain) we've checked the relay and relevant fuse behind the battery (which i believe is part of the cold start injector?) I'm pretty sure the problem is fuel related as once ive managed to fire it up using easy start (aerosol) it runs great above 2000 rpm, but anything under and it dies. any help greatley appreciated. regards. steve UK.

Reply to
anon
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Could be lots of things from a leak in the air intake system causing the Airflow sensor to missread, to timing that is out of kilter.

Or it could just be bad gas or gook as we call it technically.

Tough to guess really.

Marty

Reply to
Martin Joseph

Is the problem sudden? Or did it come on gradually?

Did it begin after some engine work? If so what, exactly was done.

If this engine used an electronically measured intake airflow sensor I'd say to test the MAS with an ohm meter.

You checked for vacuum leaks and found none, go one further step by disconnecting the vacuum brake booster and plugging its vacuum hose. This eliminates the brake booster as a potentially large vacuum leak.

Very badly retarded ignition timing would cause the symptoms you describe. Anyone touch the ignition timing?

IMHO the cold start system can be excluded because the engine won't idle when it's running. The cold start system works only during cranking and the first few seconds of running so it can be excluded.

Another poster suggested bad fuel - can't disagree. Unfortunately it's hard to substitute good fuel without draining the whole tank etc. if only to find that's NOT the cause. Of course if you have reason to question the fuel's quality then I'd move this possibility higher in the priority list.

Plug brake booster's hose, check ignition timing and then, if nothing found, drain the fuel tank - in that order.

Reply to
T.G. Lambach

many thanks for your informative reply, it turned out it was the fuel pump, but for some reason took a while to either build up pressure or to bleed itself, never had problems before with petrol engine fuel systems needing time to bleed air from the system, but either way it seems to be fine now. regards. steve.

Reply to
anon

TO TG LAMBACH I have a similar prob with my 92 190e, 2.3 L sedan. When I turn the ignition on, all the electrical works and the fan turns on making a szhheeuu noise and then turns off, and the car doesn't stay on. What is the first step my mechanic needs to check- step by step- in order to get the car up and running again.

I really value your feedback,

April

Reply to
MBENZ4APRIL

OK, April, let's begin.

I don't understand your reference to a "similar problem." Whose problem

- give a reference so I can look at it.

Let's go through this one.

You turn the key to ON, not start, and the instruments light etc.

What fan comes on? The heater fan? Or a fan under the hood?

Then, you turn the key to START and the starter cranks the engine? RRRRRR

The engine starts but immediately quits? And won't start thereafter?

When did the problem start and who has looked at it?

I await your reply.

Tom

Reply to
T.G. Lambach

This problem began about a less than a week ago, after I purchased the car from a guy that said it probably needed a new timing chain in order to start and run the engine. My mechanic did some work on it to check the electrical, however, when I turn the key to the on position the lights and the fan and everything turns on, then when I turn the key all the way on, the motor does not make a rummhhhrummmhh noise at all and the engine fan turns a little but then stops.

Reply to
MBENZ4APRIL

You bought a used car without knowing if its engine ran???

So now, when you turn the key to START there's no RRRRR from the starter and the engine's fan moves a bit.

Your mechanic looked at the electrical and said ________________?

Reply to
T.G. Lambach

Sounds like a dead battery.

You shouldn't be trying to start the car by the way, until you have figured out what the seller meant about the timing chain/belt... If you are lucky enough that the motor isn't already completely shot (ie bent valves, cracked head etc.) then it would be good to verify the chain or belt is still intact and in the right orientation.

Your best outcome, would be a seller that didn't know what the heck he was talking about.

Marty

Reply to
Martin Joseph

April,

I suggest you take your car to a good Merc. Mechanic. It could be an engine problem (timing) or an electrical like dead battery, bad starter, damaged or bad wiring.

Good luck

Reply to
saeef

my experience is that it is 'often' a simple problem and, typically, we look for more esoteric causes. Check your battery and fuses etc. Case in point, I just finished fiddling with my '93 190e that was running rough ... it was missing on #2 cylinder. Having recently replaced my plugs (Champions) I ignored these and kept working, reworking, and reworking again ignition parts like distributor, rotor and wiring etc..... couldn't get it work .... finally checked thos g.. damn Champion plugs..... of course that particular one had an open circuit. Lesson, don't buy Champion ever.

cheers and good luck in finding your difficulty

Ii article , saeef wrote:

Reply to
Guenter Scholz

Huh, a spark plug is supposed to be an open circuit.

Marty

Reply to
Martin Joseph

sure, to the outside 'pin' ... but short circuit to the inside pinn. Having said all that, however, after a couple of days I'm back to rough running and cylinder #2 is still missing. I notice though that if I simply open the distributor and wipe the cap on the inside, that helps a lot to make it run smoother .... I don't get it. The distributor cap looks OK, a bit scratched up maybe but no noticeable cracks or anything .... I'm starting to guess that there is maye a few problem causing items interacting. But, still , simply wiping the cap's inside helping a lot to make the car run smoother should be telling me something..... but what

cheers

Reply to
Guenter Scholz

Just for grins, try removing the distributor cap and replacing it without wiping it out, and see if that temporarily makes a difference.

On small-diameter distributor caps, the air inside can get ionized and cause spark jumping and misfiring. I don't know how long the air stays ionized after the engine stops running, but if you put the cap back on without wiping it out and the car still runs smoother for a while, that might have something to do with it.

MSD, the ignition company, recommends drilling small holes in the distributor cap to help exchange the air if you have a small distributor cap. I've gotten two suggestions from them. One was to drill 1/8" holes around the cap, at rotor-height and evenly-spaced between the terminals. The other was to drill two 1/8" holes near the base of the cap, on opposite sides of each other, and preferably away from the cap hold-down points.

If you have a spare cap lying around, or if you're willing to experiment with your current one, it's worth a try.

Reply to
Scott Gardner

He said it was the alarm on the ignition switch, however he was very wrong because then when my mechanic looked at the car the second time he came over , he took it apart-the engine and the camshaft had defects: the camshaft was broken on the end and the cylinder head or gasket set???? needs new valves -should I have them soddered at a machine shop or buy used ones? I do not have much money to play with as I payed the guy 750 for the mercedes, then he says the cylinder head and valves need replacing. This was done on Tuesday and Wednesday of last week.

I hope you can tell me what the best way to go about it is, you seem like you know a lot about Mercedes and it is nice to know someone can help.

Reply to
MBENZ4APRIL

thanks you guys, the mechanic that I am working with has been working on Mercedes and Mitsubishis for about 20 years. I just need to find out where I can find two valves for my cylinder head on my 92 Merc for cheap and a camshaft for cheap, so far I have found a camshaft for 195, kinda pricy, but it is the cheapest and the cylinder head gasket set costs 90-100 dollars, so if you can help it would be great because right now I am without any transportation.

Reply to
MBENZ4APRIL

My engine has no cracks, but my cylinder head has valves that needs replacing and my camshaft is broken, thus my car will not run unless I replace them my batter is new, the spark plugs are new, and everything else works, except I don't have a car that runs.

Reply to
MBENZ4APRIL

This is the result of a broken timing chain or belt. This is going to be EXPENSIVE to repair. If you aren't ready to spend $1500 or so on fixing this, write the car off now.

Marty

Reply to
Martin Joseph

Maybe there is a gasket missing and moisture is building up in there? Or perhaps there is a vent that is plugged? I personally would replace the cap and rotor.

Marty

PS Are you going to apologize to the Champion people :~)

Reply to
Martin Joseph

Engine valves aren't soldered or even welded; they're replaced. You seem to believe that this is a small repair - like a leaky radiator - it's not - it's a big, costly mess. That's why the car was so cheap.

Here's what will be needed - more or less:

New timing chain(s) New cylinderhead gasket New valve cover gasket New coolant Oil change and filter

New camshaft Some new camshaft bearings Some new valves Some new valve guides Some new rocker arms New valve stem seals

Alternatively, a used cylinderhead from a wrecked car would be a substitute for the last six parts plus the labor to install those parts on your car's cylinderhead. The chains and gaskets etc. are required in either case as is the shop labor to remove and replace the cylinder head and timing chain.

At the end of all this pain you'll hopefully have a running engine - then the question becomes: What about the rest of the car? What else needs to be fixed so that it's roadworthy?????

If you have limited time and limited $$ the best alternative might be to sell this hulk, for that's what it is, and move on to something that's running and can be driven now.

Final thought. A local community college may have an auto shop class that might be interested in using this job as instruction for its students. That means weeks, not days, to repair it; the labor is free but not the parts.

Hope this puts the situation into focus.

Reply to
T.G. Lambach

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