I recently purchased a 1986 190e (5-speed) and have been enjoying the vehicle much. However, I decided to do some routine maintenance to the car and replaced all the brake rotors and pads, along with the serpentine belt and spark plugs. All of this went extremely well and I was surprised at how easy and simple it is to work on this car. Unfortunately, I decided yesterday to repace the distributor cap and rotor as well as the fuel filter (all as preventative maintenance). The car was running fine until I unhooked the battery and replaced these items. When I started the car, it hardly turned over at all, and I could hear a pumping sound near the fuel filter... Today I tried it all again- and the car would not even crank at all (yesterday, a bit of smoke pooped out of the air filter). I thought I put the spark plug wires on wrong- but they look fine... I took off the rotor and noticed that the inside of the distributor looked like it had been scraped by the rotor's movement (BtW- when I tried to jump start the car- the distributor cap popped off its setting). I compared the new rotor and the old one- and the numbers are identical (excpet it one small spot where the old one says 1.8 and the new one says 1.7. Does that make a difference? In case, I put the old rotor and distributor cap on but it still wouldn't start. Also, I took a look at the fuel filter, and it has a slow drip. I know I should have replaced the two washers now (where the bolt goes in)... but it also leaks from the other side of the filter (both sides are leaking- ugh!)... What can be done about that leak and what do you suggest the problem in general to be with the car not starting? Thanks for any help which can be given! (I am also about to buy a new battery as the old one looks tiny and half the size of the battery tray.
Sincerely,
Tim

Some questions:

Why would the cap pop off?

Is the battery good?

How much experience do you have working on these things?

How do the new cap and rotor compare visually to the old?

The rotor end should not touch the cap electrodes.

How do you know the wires are in the right order?

Mike

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

I'm going to take a guess here: Did you pull the plastic plugs out of the fuel filter prior to installing it?

Definately a problem with the dist cap and rotor. And the battery makes life difficult...

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89 300te 222,222
92 300e 190,000

Thanks for your thoughts... I ordered a new rotor directly from the dealership today with my vin#- to be sure its right- but the distributor cap numbers match and look identical. However, ff the fuel filter had two plugs in it to protect it before installation (on both sides of the filter) then I definetly only took one plug out before installing it- I will check on that. As for the wire order, I know that I very carefully matched the wires when putting them onto the new cap. We'll see what happens with the new rotor and fuel fitler inspection this week (and maybe a new battery).
Thanks again!
Tim

You should also check your distributor to make sure it did not get bent when the rotor hit the cap.

John Roncallo

I, who really should have known better, did this very thing on my SL. What happened is I carelessly replaced my cap and didn't screw it down all the way,. I broke a tiny support inside the rotor, that holds it up so that the metal part is parallel with the distributor cap metal parts, and also holds the rotor in place to the distributor. None of this was visible from above the rotor. With this part broken, I was not getting a spark. I think that this part is designed to shear before the distributor gets twisted or possibly breaks an internal shear pin.

Furthermore, I smashed in the tab in the middle of the distributor cap, which I dug out (at $100 or so, I really wanted to try to repair it).

Anyway, after $25 on a rotor and CAREFUL reinstallation, it started in 1/2 second.

I felt that I had dodged a bullet.

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86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm