Hey guys need your help on some stuff here. Last week I changed my timing chain (1987 300E 159000)everything went pretty smooth(Friday) Saturday morning the car stalled right in front of the mechanics shop and refused to start. It finally started back about 20 mins later. Mechanic checked it seemed a bit puzzled. The car ran for about 15 mins again and stalled again. At this point he said it could be two things 1 The Coil 2 Tsz control module.
This car before the timing chain change had a hard start, but after the timining chain was changed the Friday the hard start was gone. So what I'm asking is what do you guys think it is? The coil price isn't that bad, But that TSZ Module is 1100.00 bucks.

Since the hard start disappeared right after the new chain was installed, but has since come back. I'd make sure that all the electrical connectors are clean. Take some electrical contact cleaner to all visible electrical connections. There also is a paste you can apply to help prevent any future corrosion on connectors.
My guess is that while replacing the chain, they removed some connectors, dislodged some corrosion, which has since accumulated again possibly due to weather, or moisture around the engine.

Start with the simple things. Replace the distributor cap and rotor and plugs if you haven't.

Be sure that the fuel pump relay is new.

I have seen this symptom caused by 3 major components.
crank sensor
coil
fuel pump relay.

Good luck

I have not replaced a 300E EZL yet.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

OH ya, just buy a wheel barrow full of parts and throw at it! No need to figure out what's going on! All you mechanics over there! You're fired! We hired us about 5 parts replacers to take yer place! First get a fuel pressure gauge, put it on the car, then drive it until it happens. You can monitor if a drop in fuel pressure is what is causing the stall. THEN maybe start suspecting fuel pump relays and pumps and filters, etc.. Asssuming that is fine, then do a quick check and see if it has spark or not, and follow a reasonable diagnostic path. This throwing parts (and money) at a problem is just foolish, what ya need is to DIAGNOSE and repair the problem, not just replace parts til it's fixed!!......Gilly

While I generally agree that Diagnosis By Replacement at the customer's expense is a poor business model (at least as viewed by the customer), it can be a very cost-effective technique if known good parts, like relays etc, are on hand at no cost to the mechanic to swap in and out. Additionally, methodical diagnosis can yield contradictory and confusing results when the basics are overlooked. I get nervous when people start talking expensive modules before they ask when the last ignition tune-up was.

I concur that the problem is likely a high resistance connection that was disturbed.

"UH HUH". Sure, you can VERIFY your diagnosis by having a known good part (gives ya a warm feeling all over), this statement about "methodical diagnosis yielding contradictory and confusing results when the basics are overlooked", that sound like hogwash to me. Doing the test, that's all about basics. When your doing a test, say an electrical test, your checking power supplies, grounds, input and output signals, the works. Eventually on a test like this, on a car as complex as anything MB has produced for the US in the last 30-35 years or so, they're going to say "replace the control module" when enough has passed the electrical test, and USUALLY they are right. Lets say on this guys car, the fuel pressure is the problem. Gonna throw a relay at it? Hope not. It wouldn't be the first time I've seen a car towed into the shop someone couldn't figure out with a fuel pressure problem. Oooo, nice new fuel pump relay some "other" shop threw in (just keep throwing parts at it til it runs). Too bad the damn thing was out of gas!!! Hey! Ask 'em if they want THE FUEL GAUGE FIXED, TOO!!!.......Gilly

Gilly,

I'd have to agree. I can't tell you how many times I have customers come in to buy new parts, an AC blower motor for example, only to come back a week later wanting to return the part as defective. Of course, a large retail chain will warranty it without question, then 2 days later the customer comes in again complaining about horrible parts. As a courtesy one might step outside on request, and it turns out to be a faulty fuse... not even a relay... a fuse... People are too quick to throw money at any situation, and too slow to use common sense. Ohh well, good for parts sales, bad for the poor manufacturer who gets sent back alot of so called "defects".


Jason

I'm not a tech, but I feel like I have to throw in my $0.02. A Mercedes is just a car, and cars are just like any other machine. I consider cars deterministic machines with input and output. Everything in a car is causally related and at any given time, any car might be in a particular state. Essentially, the tech's job is to solve for the unknown in the machine if the output isn't correct. My interpretation of Benzmac's recommendation was that if these three things are working, then a large amount of the puzzle is solved. This leaves us with the perhaps only half of the possible problems.

If you haven't realized it yet, I'm trying to justify Benzmac's response in my eyes. In saying that this symptom is caused by three major components, he's trying to provide a "most plausible" scenario. It's a little like hands on Mathematics. Your Algebra teacher is going to look at the answer you give first, if it's wrong, then quite possibly the parentheses are in the wrong spot or you misplaced a minus sign. "Fixing" either one of these might be just what the doctor ordered.

Another angle I would like to explore is that the things Benzmac said might have caused the problem, crank sensor, coil, fuel pump relay, are givens. Okay, perhaps not the fuel pump relay, but the coil. In this case the coil is no more nor less important than like Gilly said, having gas in the tank. It's axiomatic just like you have to plug your TV into the wall for it to work, or if we want to pick on a component, we should make sure the plug is properly wired first.

It's obvious that just like there are different kinds of people in this world, there are different kinds of techs who approach problem solving differently. I'm a chef, a tech of a different sort. I see people with food problems both on and off the job. When people ask me why their stuff doesn't work I don't even ask them what they did, I just tell them what needs to be done right first. Make sure you have skillet (battery) is hot (charged). Some people can't do that, they have to go through the whole process before making a diagnosis, which I can't.

Kuan (definitely not a tech)

Kuan - you're a chef?

Could have fooled us, from your explanation - thought you were a tech ...

__________________
... Kerry

126 tailed by a 203, 129 leading the pack.

Benzmac posts on this website as a service to all of us and is not compensated for his time or knowledge. He wants to help all of us maintain our automobiles. Cut the guy a break and say thank you for all of the advice that he gives for FREE. He is right more times than he is wrong. Benzmac thanks for your help and knowledge over the past year.

Paul

1999 300dt

Searay,

I don't think anyone here was trying to mix it up with Benzmac. I read everything Benzmac says religiously because it makes sense to me most of the time. I can understand though, how some of his responses may be misconstrued as "just throw parts at it" fix. What I tried to illustrate was that there are different ways of solving problems, and that Benzmac's misconstrued "throw parts at it" method was really a most (statistically) probable method, similiar to methods used in other fields.

Kuan

...hold on, hold on you lot ! what I saw in Benzmac's reply was a few nickel and dime bits. What were they, distributor cap, rotor, plugs and wow, a fuel pump relay ! These are not really out of reach items for most MB drivers are they ? If the bloke had complained of a coughing engine and the reply came, " well matey, we are going to have to replace the engine, then the transmission and oh ! if that does not sort it out, we are going to pull the drive shaft and diff out for a shop overhaul ! " Of course you would walk away from that, I would.

I reckon Benzmac has given all of us sterling support, certainly since I starting using this site anyway and if I were him reading these lambastings on his professional integrity, I would frankly, be a little pissed and inclined to pull the plug on the lot of you.

Wake up, smell the flowers and buy yourself a spare set of plugs, almost as cheap as the few beers we all owe Benzmac for his support.....HIC ! Cheers people !

__________________
1993 190E 2.0L (Euro.) sold
1991. 500 SEL (Euro.)
1991. 300 CE (Euro.) sold
1993. 500 E (U.S. spec.)

Gilly -

If you want to rant like you have been doing, go find a chat room. If you want to offer diagnosis or advice or suggestions or intelligent commentary based on your obviously vast experience, then feel free to do that here.

Benzmac and the rest of the techs have been a great help to those of us with an interest in our cars and who are unwilling to simply hand our bank accounts over to dealers and shops.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Woah!!

Everyone in here is being pretty quick to bash. What Gilly said wasn't a bash on good ol' "Mac"! HE was reminding the rest of us who don't do this for a living to not get carried away with parts swapping before we take steps to diagnose and narrow the problem field. We all know that Benzmac knows what hes doing, and don't be so quick to drive another automotive professional away from the board. Gilly is a Junior member, but the posts I've seen, frankly I have liked and mostly agreed with. Also remember that conflicting opinions are important because no one thinks of EVERYTHING, and there may be more than one possible solution. By the way, BE NICE

Jason M.

When I read Benzmac's reply, I read between the lines. I think he was diplomatically saying that "If you have a leaky faucet you should check the washers before digging up the street.... and that some mechanics will charge you for digging up the street when they stopped the drip simply by changing the washers!

Smiles!

__________________
Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra