turn signal bulb out? and rough idle on 300e
 

Well I switched over to euro lights (Depo's) on my 300e a few days ago, and I am very impressed with the quality and output of the lights. I have a few questions. I was unable to hook up the city lights because I could not get both wires in the holes in the pin top and soldered. Is there a trick to this? Do I just need another person to hold the wires?

Also, now when I flip on my right turn signal (same side I tried unsuccessfully to connect city light wire) the bulb out (!) signal usually flashes on the instrument cluster, but once in a while it won't flash. Could this possibly be a result of my soldering job? I'm not sure what to think because I was under the impression I was soldering to the pin for parking light control (pin #3), so why would the bulb out warning come on when the turn signal is engaged, if I did not even touch that pin? as a side note, I replaced both the bulbs in the side markers when I did all the other work, but my left turn signal has no problem.

And finally, my idle has become considerably rough on first startup and when idling in drive (not so bad when in park). The economy gauge on my instrument cluster hovers about a quarter of the way to max when the idle is rough in drive, and drops back down to min. when I put it in park. The oil pressure also fluctuates a bit during the rough idling and is lower overall then it used to be. Now, I recently changed the distributor cap and rotor in the car and left the old gasket and rear plate in place even though it was a bit chipped (still one solid piece). I did this because I did not have a replacement rear plate on hand. I do not have a torque wrench, so I estimated when I tightened up the new rotor. Could any of these things cause the idle trouble I am having? It only appeared after I did the work, but not right afterward, a few days later. Thanks in advance for any responses.

You need to troubleshoot the fuel and ignition system for the rough idle problem.

You may need new plug wires -- they are often fine unless distrubed, when they crack and start to missfire.

You could also have some vac leaks -- check all the vac lines and verify that you don't have a vac leak in the new headlights if you have hte vacuum leveling system.

Peter

rough idle
 

As far as your rough idle is concerned, you symptoms are exactly like mine, even the economy gauge is behaving the same way. All my electrics are changed, wires, plugs, cap, rotor etc. The diagnosis that the tech gave me is: my car has K-injection, or contiunous injection, one or two of my fuel injectors is either spraying to much or or not enough fuel, hence the rough idle. So instead of just replacing the fualty ones I am getting new injectors installed in a few days and the fuel distributer cleaned.

As far as your turn signal, I had the same problem, I changed my corner lights with some I got on ebay, the corner lights came with new bulb holders also, so I changed everything. The signals worked fine for a while until recently the left one began to malfunction. I thought it was the hazard swith but it wasn't, so I changed the bulb holder to the old one and voila!!!! No you did some soldering so you case is slightly different, but that info my help.

I forgot to mention that the turn signal bulb itself is actually working. It flashes fine all the time, even when the bulb out light does. I also just realized today that the bulb out light only flashes when my headlights are on and dissappears when they are off. Does this narrow it down for anybody?

As far as the rough idle goes I guess it's probably not the rotor being too tight then?

psfred: any advice on troubleshooting? I've previously only dealt with carburetors, how do I find a fuel injection problem?

theurig: your getting all the injectors replaced? About how much is that going to cost? (Sounds pricey) Is there another advantage to doing them all at once other than knowing that they are all replaced, i.e. no more problems?

Fuel injectors are about $20 each.

You need a digital VOM with a frequency/duty cycle function. Sears has several that run about $40 or so.

With the DVOM, you can measure the duty cycle signal from the oxygen sensor system and set the base fuel mixture. If you have a direct connection ammeter, you can also measure the current through the electrohydraulic acuator (EHA) that controls the feedback fuel mixture control,

However, the first thing I would do is check for vac leaks, especially at the idle control valve (silver "can" under the air cleaner, two large hoses) since a large vacuum leak will allow air into the intake that isn't measured by the fuel distributor air meter flap -- this causes lean running, rough idle, and poor vacuum. Idle speed is regulated by the idle control valve, so it won't change much, but hte vac leak will cause mixture fluctuations.

See the article on electronic engine controls in the DIY section on this site for details.


Peter

Nobody has any suggestions about the bulb? I looked again at all the wiring and everything looks totally fine, at least it looks exactly the same as the left side, where there is no problem with a bulb out light. Strange. I suppose I can live with the light flashing all the time. Just have to get used to it.

Make sure both bulbs are the same manufacture (front to rear in this case) and that the connections at the bulb base aren't dirty. Anything that produces a different current draw between the two bulbs will cause the lamp out to light.

I went through three sets of tail lights on my sister's Volvo before we got a pair that wouldn't turn the blasted lamp out warning on!

Peter

bringing back this old thread because I finally have a chance to hopefully cure the rough idle problem this weekend. Anyone know of a way to check my existing plug wires? I have a decent multimeter. Any other things to look out for when troubleshooting this problem? Can I adjust the idle control valve, if needed? Thanks in advance everyone.

idle control valve
 

you can try cleaning it. do a search and you'll find directions. I did it recently but unfortunately it didn't cure my slightly rough idle. I'm pretty sure mine is caused by fuel injectors because all the electrics on car are new and didn't fix idle (plugs, wires, cap, rotor).

you can use an ohm meter to check the wires,but this only finds bad wire. the insulation,rubber part of wire cannot be checked this way.
the best way to check wires is with a spray bottle of water,and a dark garage. spay the wires in the dark and you will see sparks jumping if the are bad.
works great
rich

I pulled my light out indicator bulb when I did my headlight mods.. I had it apart to put in the light height adjuster in the dash.

It was pretty easy to solder for me... Those holes in the connectors are HUGE. If you've got spares, you could just pull the old one off and then put both wires in a new one and solder.

I applied a little RMA flux to the existing solder, and heated. When it turned shinny, just put the extra wire in the hole. Everything flows out and remove the heat.

Yea- it was touchy juggling the stuff.

Michael

hey everyone. I just di the spray bottle test on my wires. I've got sparks jumping on wire one and two (front to back). They are jumping onto the plastic valve cover, oddly enough. These sparks are really tiny, would such a small spark cause a significant idle problem? Also, these wires are bosch, so they are not oe. Is it odd for a 124 to go through at least two sets of wires? (I bought it used). Auto Zone has replacement bosch set for about $100, should I use them or spring for oe wires? Is there that much difference? Thanks everyone.

Well, lets put it this way, you will have spent what you would have on an OEM wire set and it will burn through again in about the same time.

I'd not use anything but OEM -- aftermarked wires cost a lot less, but don't last very long.

Check the cap and rotor, too.

Peter

before buying wires i would take some of the previous advise and look for a vacuum leak first. this sounds like the most likely thing to do first.
with a bad idle you would look for some thing that has vacuum at idle. you may even be able to hear it. because of the wires you cannot use carb spray to check but that spray water bottle may also work for that type of vacuum leak. with the motor at idle give a good spray under the air cleaner and any other vacuum sources you may find. their shoud be a noticable change in idle if you find the leak. also spray water at the entire lenght of the coil wire. marbe even get a stick and wiggle the wires as you spray them, engine running.
good luck
rich