E300 Hard Start Cold

[cotterpin]

I have a 97' E300D with 150K that is VERY HARD to start cold. Glow plugs cycle through appropriately. I brought it to the first shop and they thought the intake manifold was overly clogged with carbon. They had it dipped and cleaned - no change.
I bring it to the 2nd shop and they say:
1. "The flaps are broken in the intake manifold. You need a new manifold" Could this have happened during the prior cleaning? If everything else listed below is wrong does it still actually need a replacement manifold?

2. "The EGR is throwing codes" If the intake was clogged up isn't it likely that the EGR would be too? And on other cars (TDi), I have drilled out the manifold and re-cleaned and revived them. Is this possible on the 300E?

3. " Needs a K40 Relay" This makes some sense to me as it also runs like crap at highway speed when I accelerate.

4. "Plastic fuel lines and Orings are leaking at the Injection pump". Makes sense... "

5. "And the fuel is leaking back into the tank and the pump is having to re-prime each time. May need a shutoff valve and a junction block resealing" . I didn't think the shutoff valve served this purpose.

It "seems" as though a lot of stuff is being thrown at this but maybe 1 or 2 items may be the real culprit without doing it all. Any help would be really appreciated.

Thanks,
Rob

[kerry]

I'd test each glowplug to make sure it is good. I'd also try an alternative fuel source in a bottle to rule out the air leak problem. Can't help on the rest.

[TMAllison]

No to the manifold and EGR. Never heard of the EGR failing to work except when gummed up; the transducer that controls it, yes.

Do you have a CEL lit up? If so, which codes?

Your first order of business will be to fix ALL fuel leaks. That sounds like the sole cause of your hard starts.

The K40 provides power when requested to numerous devices. It can send a faulty signal to shut off valve to close while driving or not to open when attempting to start. You didnt mention either of those issues so suspect neither is a problem. If they are, you'll deal with them after the leaks are fixed.

A faulty EGR and leaky Delivery valves at the IP can both affect performance too.

[e300D97]

Speaking from experience

First and foremost, is the Check Electronics and Check Engine light on?

Second, start with replacing all fuel lines (clear ones). I had the same problem. You can test this by filling the tank, and parking facing downhill. See if it starts any easier.

Its possible that the shop that dipped the manifold left the flaps and transducers on when they dipped it and thus ruined the electrics of the transducer.

A plugged EGR valve would give you surging and a CEL. There is a small vacuum line that comes off the manifold and goes to a pressure sensor on drivers side, make sure that its there and connected.

Where are you located? maybe someone can direct you to a reputable shop.

[nhdoc]

All of the problems you're having can be attributed to something as simple as a leaky seal in the fuel system...air in the system and the fact that the fuel drains back to the tank are signs and the symptoms can be hard starting, surguing, etc...I'd start looking at the fuel system first, and then see what else is wrong later. It is the most common problem with these engines. Replace all of the clear fuel lines and the pre-filter o-ring and the shutoff valve o-ring first. The parts are cheap and you can do it yourself in a couple of hours.

Then verify that the delivery valves on the injector pump aren't leaking too by cleaning off the top of the IP and looking for leaks there.

[cotterpin]

The CEL came out Engine Electronics. This would appear after driving and then accelerating and the car would then loose power.
I believe the fuel is leaking back. When I got it started cold, it would take 3 major attempts letting it cool in between, with the pedal mashed to the floor.

So first, replace plastic lines and Orings and check operation of EGR valve.

Thanks,
Rob

[nhdoc]

Originally Posted by cotterpin

The CEL came out Engine Electronics. This would appear after driving and then accelerating and the car would then loose power.
I believe the fuel is leaking back. When I got it started cold, it would take 3 major attempts letting it cool in between, with the pedal mashed to the floor.

So first, replace plastic lines and Orings and check operation of EGR valve.

Thanks,
Rob

I believe you have multiple problems here. First fix the air in the fuel lines, which I believe will cure your starting problem. Then, reset the CEL and see if it comes back. If so, scan the code and report it here and we can help you from there.

BTW-One of the ways you can know the starting problem is from leaks is by either filling the tank all the way or parking nose down before shutting down. If fuel is leaking back it won't with a full tank or nose-down...usually that problem is made worse by a less than half-full tank of fuel or parking nose up. Have you noticed that it is worse when the tank is below 1/2 full or do you routinely park on an uphill slope?

[Chris W.]

I don't know this for a fact, but I would think that messed up resonance flaps would not affect starting at all. A diesel will start and idle if it gets fuel and heat, i.e. working glow plugs (as well as compression, which we'll take for granted here). The flaps are for off-idle conditions as far as I know.

If you are in there doing fuel lines, put a new lift pump in. It's relatively cheap and solved some weird problems I was having with stalling. By any chance does your fuel tank whoosh when you open the cap? New lift pump and plastic lines...

Rgds,
Chris W.
'95 E300D, 241K, starts instantly hot or cold

[TMAllison]

Repeat the 606 mantra with us: "Fix the fuel leaks first".

I would add to what Marty said and suggest you note the codes present currently before deleting them, then drive a bit and check again which, if any return. Post both sets of codes.

Don't bother putting the pedal to the floor while priming (cranking to get the air out), the IFI computer and IP don't care how much throttle you give it until it starts.

[cotterpin]

I am currently taking care of the fuel lines and replacing the K40Relay.
I will post the Codes as soon as I get them.

Thanks for all your advice.
Rob

[Sbean]

My son and I recently replaced the clear (previously clear?) fuel lines and stopped the air leaks in our 99 E300. Does anybody know if one can get just the O-rings that seal at the ends? It sure looked to me as if the only problem was the O-rings, not the fuel lines. They all had a flattened shape so that a cross-section looked like a "D". Steve

[TMAllison]

Originally Posted by Sbean

My son and I recently replaced the clear (previously clear?) fuel lines and stopped the air leaks in our 99 E300. Does anybody know if one can get just the O-rings that seal at the ends? It sure looked to me as if the only problem was the O-rings, not the fuel lines. They all had a flattened shape so that a cross-section looked like a "D". Steve

They are listed here...JADAVIS on the forum sells a viton kit on his website that i alwasy forget the name of.

OM606.962 o-ring size

[nhdoc]

Originally Posted by Sbean

My son and I recently replaced the clear (previously clear?) fuel lines and stopped the air leaks in our 99 E300. Does anybody know if one can get just the O-rings that seal at the ends? It sure looked to me as if the only problem was the O-rings, not the fuel lines. They all had a flattened shape so that a cross-section looked like a "D". Steve

I do the lines because as they age they darken and it is hard to see if there is air in them. They are relatively cheap and last a few years...so I do them when they get hard to see through. But, yes, you can just replace the o-rings if the lines are OK otherwise.

[deltajetfixer]

Originally Posted by nhdoc

I do the lines because as they age they darken and it is hard to see if there is air in them. They are relatively cheap and last a few years...so I do them when they get hard to see through. But, yes, you can just replace the o-rings if the lines are OK otherwise.

I agree that the lines darken, but as far as "lasting", I think they have more than just a "few years" left of useful life.

My '82 BMW runs the same type of lines at 70psi (Bosch CIS) and has the original lines.

I wish they were as inexpensive as the E300's though ($32.00 each times 4)!!!