Idle starting issues

[junker68]

Just got a 1980 450sl and as stated in an earlier thread, I'm trying to sort out an idle problem.

I haven't really started to troubleshoot the rough idle, other than fix a couple of vacuum leaks.

Here's an issue I have when starting the car.

When starting the car, if the car doesn't catch/run and stay running, I'm not able to start the car again for about ten minutes. Meaning the starter turns but it doesn't catch/run. The starter just cranks.

Also, if it helps with diagnosis, if the car runs for a while and I turn it off, it will start right up again. The issue only appears to be when the car doesn't catch/run.

I'm hoping solving this one issue may lead to my rough idle issue.

Thanks in advance,

Dwayne

[meltedpanda]

could be one of several issues:

lack of fuel pressure ( rest pressure)
sticking airflow sensor
restricted injectors
AAV getting power?
cold start valve not operating

[optimusprime]

Fuel pump relay .

[Frank Reiner]

j68:

The cold engine, no second start symptom may be caused by a combination of two things: The main mixture adjustment is set on the lean side, and, the control pressure regulator, aka, warmup regulator (WUR) is raising the control pressure too quickly. After a cooling period the WUR again reduces the control pressure, the mixture is a bit richer, and the engine will fire.

[junker68]

Thanks all,
I'm going to attempt to check and sort things out.
I'll keep everyone appraised,
Thanks!

[junker68]

Well, so far, I have replaced all of the rubber vacuum connectors. All of them were either loose or leaking. It made an improvement.
Also replaced the distributor cap which had a "burnt" plastic connector and the screw down clamp was not fully screwed down, so the distributor was dancing around. I'm surprised it ran with that issue.
I was looking over the engine and saw that two of the injectors' plastic housings were cracked, so I decided to pull an injector.
The injector was a mess, the housing was cracked and the rubber o-ring on the housing was brittle and at the same time hard, there was no flexibility to the o-ring.
So I thought, let me replace all of the injectors, can't hurt.
So I pulled all of the injectors, that was the easy part. I'm having a bear of a time with the plastic housings. The last two are stubborn and I ended up ripping the top of the plastic off of one of them.
Any ideas on removing the last two injector housings. The housings twist and turn it just does not want to come out. I've had the last two soaking in PB blaster for a day hoping it would loosen things up. I would have thought this would have been the easy part!
As always, thanks in advance for any thoughts/tricks in removing these little buggers!

[meltedpanda]

Soaking is your best bet. Tapping lightly around the base may help. You can also try to tighten just a td and then back out. Impact wrench may be needed

[junker68]

These don't screw out, they just pull straight up and out.

They wiggle and they give a bit, but they just won't come out.
I can only imagine that the rubber o-ring got so hard, the plastic is having a hard time getting past the the o-ring.

I've read of other posters having a hard time getting them out, but eventually they give.

I can't believe it is this tough!

[meltedpanda]

Oops. That's right you have the Kjet. Keep soaking try tapping base

[junker68]

Well, I was gone for a couple of days and the last two plastic housings pulled out like a wet hotdog going down a hallway.

Any recommendations for cleaning the ports of the residue left behind. It's 34 years of carbon and grime.
I'm a little nervous about the debris going down into the chamber, I vacuumed out as much as I could.
Currently, I'm in there with a q-tip trying to clean it out the best I can.

[junker68]

Just keeping everyone up to date, may help someone in the future...

Got the car running again. After a few nervous moments in which the car would crank and not catch, she finally did. Figure the fuel was making it's way back to the injectors.

Once started, it idled much better, has a slight "miss" once in a while. I wasn't able to take it on the road, that will be tomorrow.

It starts right up after it cold and hot start, so at least we made some progress!

Still some troubleshooting to do to get rid of that slight miss/rough idle.

[meltedpanda]

Originally Posted by junker68

like a wet hotdog going down a hallway.

LMAO

[junker68]

Panda,

I always like that saying, heard it a few years ago.
Of course it's not often used in the context of car repairs...

[junker68]

Just want to take a moment and let everyone know how I made out and what was done to remedy my issues.

That's actually one of the best things we can do on this board is to follow up and let everyone know how different suggestions worked out.

I kind of took everyone's advise and piecemealed my way to a nice running car.

I did the following repairs to my "new" 450sl.

Changed all of the vacuum rubber, changed fuel filter and fuel pump, changed all injectors and casings along with the rubber seals - a full tune up.

All of the above got my car running - idling better. There was still a hard start in the am along with a rough idle and a lack of power at low speeds.

I then jumped into the WUR - warm up regulator. I took it apart and cleaned it. I did not, knowingly, make any adjustments to it. It wasn't in the worst of shapes, but it cleaned up a bit and the screen was a little dirty.

When I reinstalled it, because of it's previous shape, I did not think it would make that much of a difference...
Holy mackerel, it was like night and day and it's close to the way it rolled of the assembly line. The power and the start up, what a feeling. As a result and at my previous settings, the idle was at 1500 rpm and I had to turn back the idle screw 1 1/2 revolutions as a result.

Anyway, I wanted to share this with everyone.

Thanks to everyone here for their input.

Dwayne

[meltedpanda]

I just love happy endings