97' s14 wiring/Noise from ascd relay/under intake manifold.....

[SMM]

Ok so when I turn my car off, the ASCD relay (blue one behind ecu) starts clicking then this weird sound starts coming from under the intake manifold (sounds like a fish taking the line with the drag loose on your pole if you know what I mean) then the relay will click a few more times and then the sound will resume.

I cannot for the life of me figure out what is wrong. I checked all grounds. Checked all wires made sure none of them were exposed. Changed out the relay.

Sound continues.

Sound will go away when.
-Key is turned to ACC
-Car is on
- Car is in neutral with car off


I looked through the FSM, don't really understand what to check. Not good with wiring diagrams.


This is a big problem as I do not want my battery to drain while at work/school.

Any help/ideas is appreciated.

[projectRDM]

Unplug the relay. Check each terminal per the FSM.

There's nothing under the intake manifold that's ASCD related, the throttle cable wouldn't make any noises, the actuator might but you would see it pulling up on the cable and hear it more in the wiper motor area.

[SMM]

I will check it out tomorrow. I just suck at this whole reading of the wiring diagram in the FSM.

The sound is coming directly beneath the upper runners on the intake mani.

What all is there that would even relate to that relay? The pump and actuator are no where near there.....

[Z U L8R]

please isolate what component is making the noise under the intake. then we can determine if it's shorting or backfeeding low voltage somehow to that ascd relay circuit. sounds like the relay's getting residual power but not quite full power to click it all the way on, that's why its clicking at you.

thank you,

also is this 97 s14 stock or swapped?

Dave

[SMM]

^ I am at school now I will go check, I am on break before my next class.


Car is stock currently.

[SMM]

The thing making the weird sound is a black plastic thing and it has a connector on it. It is directly under the top of the intake manifold in the middle.


Not sure what it is...

[Z U L8R]

sounds like the idle air control valve air regulator valve. is it half black plastic and half aluminum with a thick vacuum hose going in one side and out the other?

the power supply for that unit is black with a yellow stripe and should be getting ignition 12volts. on your white "dash" plug that's by the ecu. the little flip up lever looking plug. it will be a black/white striped wire should be on the bigger pin half of that plug if memory serves. i don't have a wiring diagram in front of me at the moment.

before we get ahead of ourselves, first verify that this is the component we're talking about, then we'll continue with isolating your issue.

gl,

Dave

[SMM]

http://i50.tinypic.com/nd3dvk.jpg
http://i49.tinypic.com/14o9heb.jpg
http://i50.tinypic.com/2v00u9y.jpg

Here are some pictures.

The thing that you speak of that is half plastic half aluminum is in the second picture with the green sticker which has a green nissan sticker, this piece is not making any noise. It is actually the black piece in picture one, and in picture two (has a gray connector on it) which is before the piece you mentioned.

The third picture of the circular plastic peice that says nissan on it connects to the black piece making the noise via a black hose that comes from under the intake which has a yellow dot. (bigger hose on bottom of circular piece)


I do not see this piece on other spare motors I have. I am assuming it is because OBD2 s14's had more emissons pieces.

[SMM]

http://i45.tinypic.com/2dl57vr.jpg

[Z U L8R]

thank you, that's what i needed to know.

i'll get back to you

Dave

[Z U L8R]

that is called the evap canister purge volume control valve...it gets powered up by "ignition 1 relay, IG1" just as your ascd hold relay does as well. there are however a lot of other things on this circuit therefore lets start with where we have problems, and go from there.

let's narrow down the problem by, unplugging the ascd relay.

if you unplug the ascd relay does the purge control valve stop making noise?

now plug the ascd relay back in. and turn your key on or whatever you do so it should make the noise again.

this time unplug the purge control valve, does the ascd relay stop clicking?

post results please

Dave

[SMM]

With the car off. Relay clicks and then sound starts. This process will just keep going and going. Sometimes it will stop and other times it will never stop.

With car off, when the valve starts making sounds if you unplug the relay it will stop.



I will try and unplug the valve tomorrow and see if the relay still clicks.I am not with the car currently and I will post up my results.


Just out of curiosity. What does this evap valve do? Harmful if deleted?


Thanks for the help.

[Z U L8R]

the valve is part of your evap system, which is an emissions control device.

your car is an obd2 vehicle therefore it monitors a lot more things than an obd1 vehicle. the evap system is one of them.

in your gas tank, you have gas fumes. those fumes are filtered through the charcoal canister, then directed back into the engine via various valves and solenoids. these valves and solenoids as well as the changes in air fuel ratio from when they're being used is also monitored by the ecm.

therefore to conclude..... if you delete it, it's not harmful, but it's not helpful in passing emissions either.

however!

the ascd relay is the relay that powers up the ascd control module, aka cruise control....therefore if you delete the relay...the only thing you're losing is cruise control.

if you're ready to give up and delete things, delete the ascd relay......

since i'm not there to work on the car, i'm limited to what i can suggest in helping you solve this equation..because it's eventually going to come down to testing circuits, components, and the other electrical integrity of this vehicle...

your easy fix. take the relay out. however the real fix will be to test the relay. test the control valve how the fsm explains to, do a thorough visual inspection and look at the related electrical components for corrosion or burnt/bad connections, then test the wiring for shorts if no problem is found in that order...

i wish i was there to look the car over cause i'm interested in knowing what the real problem is, best of luck to you and if/when you discover the culprit, post back up with what it was and hopefully that'll help someone else, take pics too :)

Dave

[SMM]

Ok seeing as I am not good with reading wiring diagrams/testing circuits nor do I have the correct tools to do so I was just going to take out the realy. I do not care so much as I have never even used cruise control.

So I take out the clicking blue relay behind the ecu and try starting the car. Car will not start, its trying to crank but will not fire. Have both spark and fuel.

So I put relay back in and the car starts right up. So I let it idle for a minute to burn up the fuel, then I unplugged relay and the car shuts off....


Can I just unplug the evap valve under the intake? I do not care about emissions, and I live in florida so I have nothing to pass.

[Z U L8R]

you know you have 2 blue relays by the ecu...one is the ascd relay, the other is the ecu relay...

are you sure your clicking relay is not actually the ecu relay...... it kind of has to be....because the ascd relay would not kill the car if unplugged...

sure you can unplug the control valve....but i have a feeling it either won't affect anything......and surprisingly if it does....i doubt this will be the last of your issues concerning this matter.

try swapping the ecu relay with the ascd relay. the ascd relay has a green wire, a pink wire etc etc going to it.

hopefully that's all the problem is, that'd be great.

Dave

[projectRDM]

Dave answered it, but you can unplug the volume control solenoid easily in front of the engine, above the radiator hose inlet are two large gray plugs, the smaller of the two is for the solenoid. You can disconnect there and then see if it's the culprit. Better than loosing the ASCD. If not, swap relays.

[SMM]

I have double/triple checked. I have 2 relays located behind the ECU. I have also checked all around that area for more relays.

One is Brown
One is Blue


I will try unplugging the valve and the smaller gray plug and see what happens.

I do not care about cruise control. But I do see your point in not finding the real issue.

I will probably just delete the valve. What all should I block off/take out when removing this, I am sure I could figure it out.

[projectRDM]

I have double/triple checked. I have 2 relays located behind the ECU. I have also checked all around that area for more relays.

One is Brown
One is Blue


I will try unplugging the valve and the smaller gray plug and see what happens.

I do not care about cruise control. But I do see your point in not finding the real issue.

I will probably just delete the valve. What all should I block off/take out when removing this, I am sure I could figure it out.

If only one relay is blue, the other brown, than your car is an auto. The brown one will be the ASCD relay. Manual cars use a blue relay since there's only one circuit to close.

The valve can be deleted by just unplugging it and capping the two hoses. You will get a CEL doing this, but it will not affect drivability.

[Z U L8R]

super Russ :D

[SMM]

Ok.

Yes my car is auto.

It is the blue relay (ecu) that is clicking away.

I unplugged the small gray plug weird sound went away. Ecu relay still clicking.

Now with the gray plug unplugged car off ecu relay will click. If I remove the relay and wait a minute then plug it back in the relay will not click anymore.

I believe before if I removed it and plugged it back in (car off) it would begin clicking again.

Another thing, if I leave the relay clicking and disconnect the battery it will stop (of course) but as soon as I plug it back in relay will resume clicking.

[projectRDM]

Something is backfeeding through the relay. Since it's a very complex and multipath circuit you're going to need an FSM and a good multimeter to start eliminating culprits, I'd say the relay itself is fine and it's something else, a sensor, that is causing the issue.

Open the FSM up and trace the entire path of input and output of the ECU relay, following every leg of the circuit, then test each item it terminates at. There really isn't an easy way to diagnose your problem.

[Z U L8R]

it sounds like a bad ecu to me. ie the ecu self shut off aka ecu relay circuit in the ecu is bad...

it should be the only wire going to the relay that's either orange, or thin red with a black stripe, not black with a red stripe.

you could either A, try a known good ecu, or B wire up the ecu to key on ignition power, which is not the correct way of fixing this but will work nonetheless. i would rather not tell you how to do the latter because i don't really want you messing with the factory wiring....and you can find another ecu pretty cheap. so i would rather you fix this correctly and not have problems later on down the road. yes there's a way to fix this problem for less than a dollar but it's the half ass, lazy ass, wrong way to repair vehicle shade tree way of fixing things and i already feel bad for all the other s chassis' and people who buy these cars after you, who had owners that didn't care, hacked up the wiring and zip tied body kits on em n things of that nature lol.

i'm being sympathetic to the guy who buys the car from you which is why i'd rather you fix it correctly.

Russ you are right, and your advice is 100% legit. the relay gets power and obviously is getting power. so that end of the circuit checks ok. the ecu is now deduced as the other end of this "faulty circuit." which is why i'm recommending he tries another ecu.

the ecu sends the ground to the relay via the orange or red/black wire (depends on the s14) then the relay clicks over and sends power back to the black/white striped wires to power the ecu.

therefore the problem is once again deduced to this self shut off aka ecu relay circuit in the ecu.

i guess you could unscrew the covers from the ecu and see if you see any burnt traces, popped diodes/resistors, or burnt transistors in there, but even if everything looks hunky dory and you don't see anything burnt or out of place doesn't mean there's not a problem with it, which is why i'm recommending you try a known good computer.

i hope you understand, best of luck

Dave

[SMM]

I get what you both are saying. I hate buying half assed projects/ghetto rigged shit.

This would happen the week after I start my conversion harness so I can run an s13 tuned ecu. I hacked up a perfectly good s14 ecu for the plug.

My friend has one I can borrow though. I will test it out tomorrow. I am also thinking it is the ecu.

This is only my daily because I like keeping the miles off my vette. But I may just park the 240 until all the mods are put on and what not.

[Z U L8R]

or you could give me your vette ;)

[SMM]

^ HAHA in all honesty I hate the thing. I prefer my twin turbo cobra over it every day of the week too bad I sold it.