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1990 300CE-24, 2000 ML55, 2005 CLK320 Cabriolet
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142 Posts
Discussion Starter · #1 ·
I have a slight miss especially at idle. Distributor and cap are only 2 months old. It is weird that the new spark plugs have no miss upto 1000 miles and then develops an intermittent miss at idle. No vacuum leaks.
I had replaced the spark plugs with F8DC4 and realized these have a resistor. The original sprak plugs were F9DC0 are non-resistor. I have ordered these new plugs.
I was thinking of a new ignition wire set made with Beru, $199 + shipping.
I have the 2 year old Bosch ignition wire set, paid like $129
Are the Beru superior?
any help would be great.
 

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W124
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5,881 Posts
You may not recall but the Bosch wires came with a lifetime guarantee. There was a card in the box. I personally wouldn't buy Beru because if there is a difference it isn't worth $80. Even if you bought them over the counter at the dealership you could get Bosch wires. What puzzled me was that over the counter at the dealershsip they don't give you the lifetime warranty card that you get if you buy them at Autozone or Pepboys or some place like that! You pay $160 or so for them from the dealership but don't get the same support you would get if you paid $129.
 

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1990 300CE-24, 2000 ML55, 2005 CLK320 Cabriolet
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142 Posts
Discussion Starter · #3 ·
I am told that Beru Connectors and Wires are better quality than Bosch.
They look like the same connectors that came with the car.
The new connectors are quite different than factory ones.
I am assuming that they have exactly the same resistance but
am not sure.
 

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1993 300E, 2003 996 Turbo X50
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624 Posts
Beru makes good quality parts but I certainly would not pay more than Bosch for them. The connectors design changed over time and the ones I replaced were different than the new ones. I only bought the beru connectors because the place I ordered the parts from had bosch wires that no longer come with the connectors. The old connectors were also Beru and they were installed at the dealer.
 

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1991 300CE, 1992 300CE, 1995 E320, 1998 E320
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19 Posts
freak, F8DC4 spark plugs should be fine for that engine. As far as I know Bosch resistor spark plugs have an "R" in the plug number. From reading the Bosch website all their spark plugs have some resistance to prevent radio interference/static.

I prefer Beru ignition wires over Bosch. Either way ignition wires should last for many years. Are the spark plugs gapped properly?
 

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1990 300CE-24, 2000 ML55, 2005 CLK320 Cabriolet
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142 Posts
Discussion Starter · #6 ·
The F8DC$ plugs are gapped correctly - 0.032, at the same time, replaced the distributor and rotor. The miss returned after 1000 miles.
F9DC0 are non-resistor, while F8DC4 has a resistor in them. Cannot buy F9DC0 any more, so
I bought BCP5ES which are exact match by NGK to F9DC0. However, I cleaned the throttle body with a mass flow sensor cleaner followed with WD40, like going back and forth with the engine running at 2000rpm. Now, the miss is gone. With the mass flow sensor cleaner, the engine wanted to almost die but with WD40, the engine was running fine.
I will wait and see. Now, I think have to replace the center bearing support on the universal shaft.
 

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300 CE 24V Sportline
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With the mass flow sensor cleaner, the engine wanted to almost die but with WD40, the engine was running fine.
I will wait and see.
Sensor cleaner and WD40? Please could you give me more details.

I have a similar miss at idle and a minor hesitation on take-off but otherwise pretty good.

All this follows new plugs, cap, rotor, leads, fuel filter etc. etc. etc.

Any comments gratefully received.

RayH
 

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1990 300CE-24, 2000 ML55, 2005 CLK320 Cabriolet
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142 Posts
Discussion Starter · #8 ·
Yeah, remove the air filter assembly.
Start the car. You can work the accelerator under the hood to
keep say at 2000rpm.
Get mass air flow sensor cleaner and spray around the butterfly
valve gently. The engine will want to die, but maintain the rpm.
now spray wd-40 around the same place, maintain rpm.
Again switch to the mass flow cleaner and then wd-40 etc.
I did this for almost like 30 minutes.
The engine appears to be lot smoother and there is no hesitation.
I plan to do this once a month.
Hope it gets rid of your hesitation.
Barry
 

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About a dozen 1988, 1989, 1990, and 1991 sedans, wagons, 4Matics and 1 coupe
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5,512 Posts
How much you want for your old wires?
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,908 Posts
Yeah, remove the air filter assembly.
Start the car. You can work the accelerator under the hood to
keep say at 2000rpm.
Get mass air flow sensor cleaner and spray around the butterfly
valve gently. The engine will want to die, but maintain the rpm.
now spray wd-40 around the same place, maintain rpm.
Again switch to the mass flow cleaner and then wd-40 etc.
I did this for almost like 30 minutes.
The engine appears to be lot smoother and there is no hesitation.
I plan to do this once a month.
Hope it gets rid of your hesitation.
Barry
I'm not sure why you chose WD-40 other than it's dirt cheap and the elixir of the weekend warrior. It only has one redeeming quality; water displacement. Depending on what your theory is for a follow-up on the mass air flow sensor cleaner, there would be no less than 15 other sprays better suited. But if you're a do-or-die WD-40 loyalist, there is nothing else I can say.:thumbsup:

Kevin
 

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1990 300CE-24, 2000 ML55, 2005 CLK320 Cabriolet
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Discussion Starter · #11 ·
I just had WD40 handy, so that is what I used. I just found it more effective
using it with the mass air flow sensor cleaner.
If you prefer to use something else in place of WD40, go ahead.
This seems to work for me.
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,908 Posts
I just had WD40 handy, so that is what I used. I just found it more effective
using it with the mass air flow sensor cleaner.
If you prefer to use something else in place of WD40, go ahead.
This seems to work for me.
That's cool...just don't like to see WD-40 recommended along with any kind of 'fix' when there are better sprays out there.

Kevin
 

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1990 300CE-24, 2000 ML55, 2005 CLK320 Cabriolet
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142 Posts
Discussion Starter · #13 ·
Yeah, OK. I don't think I was comparing different sprays. I just cited what worked for me.
Have been using this spray for this purpose on many cars and have had success on my BMW 335i, Porsche 911, Audi S6, Mercedes ML55 and VW Passat. But, if you have found a better replacement for WD40 to do the same thing along with mass air flow sensor to clean the mass flow sensor. I have seen noticeable improvement in how smooth the car is at idle.
I do this once a month on all of the above cars.
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,908 Posts
Yeah, OK. I don't think I was comparing different sprays. I just cited what worked for me.
Have been using this spray for this purpose on many cars and have had success on my BMW 335i, Porsche 911, Audi S6, Mercedes ML55 and VW Passat. But, if you have found a better replacement for WD40 to do the same thing along with mass air flow sensor to clean the mass flow sensor. I have seen noticeable improvement in how smooth the car is at idle.
I do this once a month on all of the above cars.
For starters, I would try LPS 1 and/or the CRC product of the same type as WD-40....both have similar properties, but do their work much better than WD-40.

Kevin
 

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'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
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10,908 Posts
I prefer PB Blaster over WD40 any day when it comes to penetrating oil.
Except that PB Blaster is a rust penetrate solution, not to be confused with a lubricant, as is often the case with WD-40. WD-40 is purely a water dispersant; not a good lubricant, or rust penetrate solution, in spite of its 'urban legend'.

bballfreak is chasing mass air flow sensor cleaner with WD-40....I'm not advocating this practice-just making a comment about the shortcomings of WD-40 and its highly undeserved reputation.

Kevin
 
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