[loxos]

About three months ago i purchased a '90 560SEC for $2000, i knew it would have problems but it ran and could get me around town. I had the engine tuned to hopefully fix its rather rough idle, and that mechanic made it run so rich i got 1 mile per gallon then when i got it home it wouldn't start. After kind of tuning it myself it got it to another mechanic that my friend recommended and he tuned it back to functionality but it was still rough. Within the last month the idle got worth and it started to stall at any speed (sitting at a light, pulling into my driveway, and scariest of all at 80mph on the freeway). I took it to the mechanic and he said it was my fuel distributor and he replaced that. The idle was smoother and it didn't stall for a week. This week i took it back after two weeks of intermittent stalling and he couldn't figure out what could cause it. I have read or been told by friends that it could be the fuel filter is clogged, the fuel pump is giving out, the injectors are clogged, there is a wire loose somewhere, or it's a vacuum leak.

So i guess i'm just here to ask which is the most likely cause and where should i start. It is not a pretty engine right now and needs a lot replaced and reattached, but i need to hit the biggest problem first and fix the stalling.

Also i could never figure out what the tiny box in the last picture does, it has two vacuum lines attached and one is not attached to anything.

 

[Firewater]

You're missing a connector to your coolant temperature sensor.

 

[Firewater]

Also, take the airbox off and take pictures of the area just above that. Ensure that all the vac connections are attached to the Idle Control Valve right above where i circled and the Warm Up regulator which has two fuel lines going to it.

 

[281lxm]

If you do not have records, change out your fuel filter. Clean the idle control valve. Don't worry about the last pic, it is mostly smog control stuff and that is the least of your issues.

 

[GreenT]

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Take a closeup pic of the ICV and EZL.


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[loxos]

Tomorrow morning i'll get on taking the pictures as its to dark now for me to get any decent pictures. Another problem i noticed is the oil pressure needle fluctuates a lot when i come to a stop, it drops to 1 on the gauge and when i'm moving it steadies out at 3. How worried should i be about this?

 

[281lxm]

Normal, as long as your level is good. It should spank up to 3 bars When you accelerate, if it doesn't then you have a problem.

 

[GreenT]

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There's something really goofy about this engine. It looks to be hacked badly.


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[loxos]

Ok, i thought there might be something wrong with that because the lower the pressure the rougher it runs, but that might just be the higher RPM making it less noticeable.

 

[281lxm]

Well you have an idle problem so it pulses, sending the oil pump to pulse also. Who hacked into the wiring? Do you have service records?

 

[GreenT]

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The more I look.... you're missing throttle linkages, some lines have been disconnected/re-routed, the ICV connections look all wrong...

Can't wait to see under the air box. This is gonna be fun.


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[281lxm]

Somebody always tries to build a better mouse trap. Original fuel lines looking brittle, SLS looks empty too.

 

[luckymike]

The little box you asked about is part of the air pump system. The air pump should run for the first minute or so after you start the car cold.

 

[GreenT]

The air pump should run for the first minute or so after you start the car cold.

Nice. You may have just diagnosed a strange noise my '90 just started doing on cold start.

Thanks for the lead.


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[luckymike]

Nice. You may have just diagnosed a strange noise my '90 just started doing on cold start.

Thanks for the lead.


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You're welcome. Hoping it's that simple!

 

[GreenT]

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Me too. I was thinking water pump...


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[loxos]

I do not have the service records, but if anyone knows a way i can get them i'll try.

 

[loxos]

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The more I look.... you're missing throttle linkages, some lines have been disconnected/re-routed, the ICV connections look all wrong...

Can't wait to see under the air box. This is gonna be fun.


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Under the airbox is the only part i know 100% functions as i had the fuel distributor replaced.

 

[281lxm]

Why in heavens name would a mechanic replace fuel distributor and not have proper linkage, springs and icv.

 

[loxos]

Well I'd say that's why I stopped going there but I actually stopped when they left a rag in my engine area that caught fire on my drive home. If you didn't notice the mild fire damage towards the back of the engine. They patched everything that was melted before I got to my extinguisher.