how to check fuel pressure?
 

car: 1987 260E 2.6L 137000miles

How do I check the fuel pressure on this vehicle?

Right now it cranks but wont' start. Parts recently replaced with new ones: Fuel Pump Relay, Ignition Coil Module, Distrib+Rotor, Spark plugs + Spark Wires.

Have you checked to see if you've got spark? This is quicker and easier than checking fuel pressure.

OK. I got some weird surprises this evening.

This evening I went and checked one of the plugs to see if there are sparks. I unscrewed the plug closest to the firwall and put the spark wire on its top, then I realize oops I need to ground the metal part of the plug to the engine metal. Seems easy enough, but I got a problem I was alone and I need to go inside the car to crank the car and there is no helper to look at the plug for sparks. So thinking about it, I got an electrical wire and striped of the plastics on both ends so I can clamp one end with a vise plier to the engine metal and the other I clamp with another vise plier to the metal portion of the spark plug and place it on the windshield so I can see it from inside the cabin. I went inside and started the car, and sure enough I can see spark, but its really really faint. By now the car battery has already depleted (lights are dim and the starter just barely moved) because I have been trying to start the car for the last few days. Luckily I still have my old GM car which I haven't gotten rid of just yet, waiting to have my Benz running smoothly and stabilized first. Anyway, I hooked the two together with the booster cable and tried to started the Benz, to my biggest surprise the car almost started, it crank and u can hear that noise of the car about ot start up. Just as I thought it has started I let go of the key to settle it into running position, and damn! the car stopped. Subsequent tries did not succeed in starting the car.

Now this have me thinking of perhaps, perhaps the battery is shot and needs to be replaced. Or perhaps the starter. What about hte EZL (ignition control module could it be shot?) What does spark looks like on the plug? Does it flashes on and off in teh sequence of the engine spark sequence, is this flashing visibled to the human eyes or is it too fast to be discernable?

Right now I only hope to get the car running again so I can take it to the shop, hoping to avoid to have to pay for a tow truck.

your way of checking the sparks thru the spark plugs can cost you your safety, I suggest you ask a tech in your area to help you before your putting yourself into deeper trouble ( I am basing my opinion on your post, and it seems you have no experience at all in working on the high voltage current of a vehicle.

Well, I hope the fact that when I hooked up the plugs, the car engine was off, the key was off the ignition, ie. no current was going to the spark plug. Only when I have everything hooked up that I went inside the car, put the key in the ignition and started it. I was looking at the exposed spark plug through the windshield. I hope this is safe.

By the way, how do you normally check for sparks?

You can get one of these from most any auto parts store, this happens the be from Napa. I usually just shove a Phillips screwdriver into the plug wire.

Your way was maybe a bit clumsy but worked fine and caused no real danger. If you had left the plug too close to the hole it came out of, you could have had a bunch of mini explosions each time it fired.

I'd check all of your battery cables and try swapping the battery from the other car. If MB's is too far gone, it will put too much of a load on the jumper cables and the voltage drop will give you a weak spark.

Michael

Call MB road assitance
 

Hi throne7,

as far as I know, MB owners enjoy life-time, free of charge road side assitance. I'd push the car onto the road and call them (Being in the garage would represent no road hazard). Even if they cannot help you to jump start the car, they would be able to narrow down the problem area.

1-800-FORMERC

Good luck

FOLLOWUP:

1987 260E 2.6L

Yesterday morning I had my car towed (on a dolly) to my benz mechanic here in Toronto. Remember it won't start? Anyway, when it was at the shop, the mechanic check fuel pump relays, OVP etc all seems normal, so he plugged it back in. Car still wont' start, but the battery was almost all drained (remember its been sitting a while). He rolled over one of those big battery on the trolly? Hooked it up and started the car and it started. Wow!!! How come it didn't start before when I tried to jump it with another car? Anyway so the mechanic says the fuel pump relay or OVP wasn't seated properly. that's why it ddidn't start. So he sent me on my way, didn't charge me anything for it. My only cost yesterday was the $200 it cost to tow the car. I drove the car straight to work and parked it in the workplace parking as I can still put in an afternoon's worth of work. Towards teh evenings 6:10pm or so I happily punched out to head home and walked out to my car. Put in the key like usual, crank teh car , it crank and crank and craank but it won't start up. Damn!! Now I am screwed, cause I work 40 kilometers away from home and at least 60 kilometer from my mechanic. And the damn thing just wont' start. Remember how he jumped with the battery, I quickly flaged down my colleague and have him pull his car over so I can jump start the car. Same thing it will crank but wont' start. So I left the car over night in the work parkinglot and have my colleague drop me off at the Go-Train so I can go home. Suppose to be going out on a date with the girlfriend too. I have never been so screwed before. Anyway I took the train to work this morning and still the car is sitting there immobilized. I have no idea what to do now. Do I pay another $200 tow it to the shop, and have him hook up the battery start it and drive off somewhere, get stuck, and spend another $200 in a loop?? Stumped!!!

By the way, the girlfriend is nagging me to get rid of the car. Sell it, declare it lost, or something. She wants me to lease a soul-less japanese car like she is driving now, but its problem free.

Bump - whatever happened to the car? Was the root cause ever found?