What do these two Solenoid valves do? 4EFTE Swap

M

MrComment

Fresh Recruit
http://www.sendspace.com/file/p5rvo2

Im doing an engine swap from a '95 Starlet 4EFTE into a '92 Paseo.

I need to know what these two Solenoid valve are called, what they do and how to hook them up? They get mounted on the firewall, and the Paseo looks like it had the black one already from the factory. However connecting just the black one up seemed to keep the engine from starting (i.e. fuel injector pulse width is too short). Im sure its because I dont know how to connect these two valves. With both valves disconnected the engine will start and run fine once its warm, but it starts very hard when cold.

Any help would be appreciated.

Thanks
 
weeJohn

weeJohn

Lifer
They are for increasing the ammount of air let into the inlet tract when the car is at idle, to up the idle when the a/c is switched on.
If you dont have a/c you dont need them, just blank of the pipes from the throttle body
 
M

MrComment

Fresh Recruit
Starts Hard

Ah, that actually makes sense then. I'll start combing through the A/C wiring diagrams then.

I have A/C so do these get connected to the AC1 (black solenoid) and AC2 (Green solenoid) terminals of the ECU then? It cant be that simple can it?

Also after doing a little more retesting, connecting or disconnecting the solenoids seems to make no difference on the Pulse width of the injectors like I thought before. I guess I just got lucky and the car finally had enough cranking and started when I disconnected the black one.

Which leads me to my second question.

I have an "extra" water temp switch/sender just behind the Upper Radiator hose. On the EP82 Wire harness its a single wire lead and is Blue-Yellow it also connects to the Engine bay Fuse box, (but the wires were cut out of the fuse box). I didn't reconnect this sensor, since I didnt know where to connect it to. (The Paseo doesn't use this sensor.)

I've been looking for a wiring diagram with this mystery coolant switch with no luck, but by chance would this sensor somehow tell the computer that the engine is cold? And therefore it needs to "Choke" or increase the fuel to the engine to get it to start? There isnt a huge output change from the sensor either. When the engine is cold it resistance is very low 3ohms or less, once the engine is hot it reads 20-25ohms. Which is sort of puzzling to me since I didn't connect it I thought it would have been trying to inject too much fuel instead of too little. Hummm, maybe it is, its been about 70F here when I've been playing around with it. Of course once the engine is 180F it starts right up, and the plugs are dry when I pull them out to check when it wont start.

I dont know maybe the coolant swith is also for the A/C?

Sorry everyone Im thinking out loud here.

What else would make the car start hard when cold. Otherwise it sounds good, and starts right up when hot. Compression is good +160psi on all cylinders. Spark is very obvious and seems strong. I would think 45psi fuel pressure is enough also? Sounds like its idling at the right speed to, but I dont have the Tach connected yet to know for sure, I also have a check engine light on, but again I havent connected the diag connector yet either. I want to get this thing running soon so I can loom this wiring all back up. Sheesh what a mess...

This is a black label 4EFTE ECU btw.

Thanks again
 
Last edited:
M

MrComment

Fresh Recruit
I think I should post a new thread for my Cold Start issue, since it isnt related to these two valves.

With that said,

Does anyone have any A/C wiring diagrams for an EP82? Or might be willing to give me the low down on the logic for when each of these two A/C solenoids kicks in. I'd be happy with experimental data from a working car, as well.

Just hoping that my only method isnt going to be, "by guess, by gollie."?

Thanks
 
weeJohn

weeJohn

Lifer
From memory there are 4 sensors around the top rad hose area. The 1 at the back is the fan switch sensor, the one with the green plug is the water temp sensor for the ecu (that is what "chokes" the engine), the next one along is the water temp guage sender and the forward one is something to do with the a/c.
Dont know what it does sorry as any experience I have with the a/c is to do with removing it.
 
M

MrComment

Fresh Recruit
I'll just make up a few spare wire runs before looming everything back up.

I want to get it back on the road soon, and well I'm getting antsy, it sounds like its going to be fun to drive.
 
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