New owner 1983 380SL I need help with a few fuel related problems

[Scott380SL]

I just purchased a 1983 380SL in pretty good shape. The engine runs good but idles around 1,000 rpm, the po said he had the smoke test done and the air flow meter boot needs to be replaced. I want to know what besides the boot what is needed to do the job and if the vacuum lines are special items or just standard hoses? The fan is staying on constant and it is hard to start after it's warmed up.
The next thing is a little strange to me, the fuel pump is wired to the parking lights. I was told to start the car then switch on the lights to turn the pump on. He said when the boot was fixed then I could remove the wire. I am thinking the fuel pump relay must be bad. Any other ideas?

Thanks
Scott

He told me the fuel tank, fuel pump, timing chain and guides and the idle control brain behind the glove box were all replaced.

[meltedpanda]

that should be a KJet system , lots of things to check to make sure they are in spec before replacing parts. EVERYTHING is related , from fuel pressure to air delivery. IF you don't have a good "know how" article, that is where you need to start. Id be glad to send you some info . PM me your email

[Scott380SL]

Sorry for the jumbled questions, it was a long day yesterday. I just found out the car is actually a 1984, would that still be the KJet? I am sending you my email for the info, thanks!

My plan is to concentrate on the fuel pump first so it's not connected to the parking lights anymore then the problem with the fan staying on. After that I can focus on the high idle if it still persist.
I am guessing he didn't want to pay his mechanic to replace the pump relay and instead ran a jumper. Are there any other reasons for running the pump that way?

Scott

[timm9]

Scott,

I went thru very similar issues with my 82 R107. The following link may provide you some useful information.

http://www.peachparts.com/shopforum/sl-forum/221171-380sl-hard-start-poor-mileage.html

[meltedpanda]

possible on the relay and the jumper being a quick fix. I will send you some info , read it and you will understsand the workings better of the Kjet , and then you will be able to focus on a plan

[Scott380SL]

Thanks for the information meltedpanda. I installed the new fuel pump relay and that took care of that issue.
I installed a new accumulator for the warm start issue and it didn't help. I bought a new fuel meter boot and went to install it today only to realize I needed the new flange. The old one was in good shape except it had cracking around the throttle body throat piece. I cut an inner tube put a sleeve over it and put on a regular hose clamp(the original was loose and would not tighten)
The car took a few minutes to get running and stay running then it idled at 5-600rpm yay!...? for a minute then it went back up to 1,000rpm The car seams stronger and like it's shifting stiffer but it could just be the way I was driving
I ordered a new check valve for the fuel pump because why not? I may get lucky.
I had a good look at all the vacuum lines and connections. I think they are fine except the y valve off the ICV, it has a crack I filled with rtv(I will replace it) I jumped the thermostat wires with no change. I popped the throttle linkage off(no change)

[neds380sl]

Hey Scott- I've sold my 380 sl, but had similar problems with it. Once fixed it was great. If you're having idle problems check the idle control switch. There should be a black two prong plug wire coming from underneath the front of the engine. The connecotrs are normally under the windshield washer bottle and hard to see. If you unplug the wires and short out the plug of the part that goes towards the firewall and the RPM's drop, then your switch is either defective or out of adjustment, usually defective. It costs $5 or so dollars but the cost to replace is big, but you can easily do it yourself if you have any talent at all. I don't and I did. Good luck with the car- I was sorry that I sold mine so I just bought a '99 SL500. Not expensive either. Ned

[Dmitry at Pelican Parts]

Originally Posted by Scott380SL

I just purchased a 1983 380SL in pretty good shape. The engine runs good but idles around 1,000 rpm, the po said he had the smoke test done and the air flow meter boot needs to be replaced. I want to know what besides the boot what is needed to do the job and if the vacuum lines are special items or just standard hoses? The fan is staying on constant and it is hard to start after it's warmed up.
The next thing is a little strange to me, the fuel pump is wired to the parking lights. I was told to start the car then switch on the lights to turn the pump on. He said when the boot was fixed then I could remove the wire. I am thinking the fuel pump relay must be bad. Any other ideas?

Thanks
Scott

He told me the fuel tank, fuel pump, timing chain and guides and the idle control brain behind the glove box were all replaced.

Congrats on the new purchase Scott, I've always been a fan of the styling of the R129s. I've attached a link to our site's DIY tech articles for future reference; in addition to what others have suggested. We're happy to answer any questions that you may have.

Mercedes-Benz SL-Class R107 (1972-1989) Technical Articles – Pelican Parts

[rowdie]

Originally Posted by Dmitry at Pelican Parts

Congrats on the new purchase Scott, I've always been a fan of the styling of the R129s. I've attached a link to our site's DIY tech articles for future reference; in addition to what others have suggested. We're happy to answer any questions that you may have.

Mercedes-Benz SL-Class R107 (1972-1989) Technical Articles – Pelican Parts

While your link is correct why do you comment on the R129 in your post?