...

 

You need a functioning ignition system... if you have questions about it I would replace it.

Find out what is in your exhaust. There shouldn't be anything in a decat... maybe an extra resonator

Start from a logical place and start checking stuff out

 

Willing bet my pinky toe your problem is either low compression or your ignition system or both. Do a proper hot compression test because cold numbers are meaningless. If it passes, look at replacing your starter, plugs, coils and wires. The SSV doesnt seem like the issue as much as what you wrote here.

 

Try this : run the engine for 30 seconds at idle , turn it off , wait 1 min , then watch the ssv while someone turns the ignition on then off.
The ssv should open as ignition is switched off then close a few seconds later.
This tests the solenoid,the actuator and also the vacuum tank for leaks.

If solenoid and actuator work while engine is running but not during the above test ...it's a vacuum leak.

Also : again after 1 min, reach under the intake manifold and pull off the hose that goes to the vacuum tank ... you should hear a sucking noise as hose is removed. No noise ...no good !

 

The decat has a resonator on it, I'm just not sure if the catback has catalyst remnants from before (it's not my catback).


Is there a way to check the ignition without buying new parts? I don't want to spend money on parts that I don't need, I'd rather keep that money for a rebuild










I'm worried about the flatlines over 6k and the marbles in a can noise. Is that detonation?

Can low compression cause the flatline?



Switch the ignition off and on as in switching the key from the on position to off or shutting down the engine? I don't know how to check if the solenoid works with the engine on
Also I've never heard of a vacuum tank before :/

I've tried switching the plugs for the air pump and the SSV (connected the SSV plug to the upper solenoid and vice versa) and connected the air pump vac line to the SSV. I couldn't get the SSV line to the air pump so I put a screw in it to prevent a vacuum leak. Low and mid range power is restored but there's still a flatline over 6krpm and the sound is a lot worse

 

yes

And yet ...there is one under the UIM

Different issue
Get the highest octane gas you can before you try anything else.
Then check the APV is working . You can do that just by listening for the dc motor after turning ignition off.
Other than that ...check coils using a hei coil tester as per the test procedure in the diy forum ...

 

I use 98 RON octane gas and I premix as well using 2 stroke scooter oil
Should I listen for the sound after warming the car up and then turning it off?
Yea I really want to do the coil test but it's Sunday night, it'll have to wait until tomorrow IF I can even find a tester like that
Thanks for the help, it means a lot to me

 

Doesn't matter ..... it's the last sound you should hear after switching off the ignition . It's a DC motor and should go 1/2secongd one way then 1/2 secong the other . Listen to the tone of it ..... should sound like it has a small load on it . Record it and post if you don't understand .

 

If the throttled is goosed really hard in neutral by someone else while you watch it then you can see the SSV open/close. You can also see how easy it opens/closes by hand to manually actuate the lever arm and help determine if it’s stuck or might have a solenoid or vacuum tank problem instead.

the APV can be checked by pulling the actuator motor off and cycling it by hand to see if it’s crudded up or not, but you have to make sure it’s back to the closed position before putting the motor back on. There are various threads on here already detailing that out. It only throws a code if stuck open, but not closed.

 

The way I suggested in first post is better as it tests everything ..... solenoid,actuator and vac tank . But it seems that isn't his issue anymore so point is moot.

 

with the engine off,
and will it kep sucking for long?

 

If all is good vacuum will hold for hours ....overnight even!

 

I can hear a DC motor stopping half a second after I turn the ignition completely off. Is that the APV motor?

Also, the procedure is idle with the engine on for 30 seconds, turn it off and wait a couple minutes then pull the vacuum hose?

 

it goes in this order :
Ignition turned off
throttle does a little test cycle and SSV opens with a 'click'
SSV closes with a 'clack'
APV motor opens valve (dc motor noise)
APV motor closes valve (dc motor noise)

So three different things making noises the last one being the APV.

Yes to testing vacuum in tank but re-re what I wrote in my first post..... You have found the hose I'm talking about I presume ? It is around the back of the plastic manifold.

 

Theres a line with a green/white floater looking thing in its middle, is that it?

I disconnected it but I can't hear anything unusual, everything is off

 

That's it . Re-read instructions please

 

I let it idle for 30 seconds, turned it completely off, waited a couple minutes and took it off and I couldnt hear anything.

The SSV actuator changes position when the key is turned on and off but I dont know if it works when 5he engine is on. I can hear a marbles in a can sound over 6k rpm.
There's also a weird hissing noise when the engine is on, sounds like a vacuum leak

 

If it sounds like a vac leak then there probably is a vac leak ...find it and fix it .

 

Okay I'll track the leak down but I'm worried because my vacuum hose line doesnt make any sound like you said it should

I also changed my airbox back to the stock one and the sound appears to be gone as well as the flatline, its slower than normal but it's 40 degrees Celcius here and I had 2 friends in the car with me so I don't know if there's an issue or if it was just the heat and the weight

 

Nevermind the sound and the flatline are back with a vengeance. The sound is not as loud this time but the flatline is worse

 

Ok so you checked it like i said after waiting a min or so and no sound as you removed the hose ? That plus you hear a vac leak ...pretty obvious where you should look then.
Under full throttle as the vac tank drains the ssv will close and then the engine will run lean causing detonation especially in ambient temps as high as 40C !
This could be an engine killer so get onto it asap!

 

I idled with the engine on for 30 seconds, turned it off and waited for a minute then took the hose off. I couldnt hear anything
I'm a dumbass and I dont know what to do lol sorry. Did the vacuum tank **** itself? What should I do to fix it?
I keep trying to test if it works and I can hear the detonation, then I stop immediately. I'm scared to death cause sometimes it's kinda hard to start now

 

Well , I'm assuming you also did the check to see if the ssv worked a min after turning off the engine and found it didn't ? Then did the hose pull off test?
So if you have now confirmed the vac tank is draining via those two tests...you will need to remove the upper intake manifold so you can get to the vacuum tank to test it and figure out where the leak is.

 

The SSV looks like it works when I turn the key on and off a minute after I shut it off

 

Well if "looks like it works" then doesn't that mean that it works ? If that is the case ...then it isn't your problem.