ISCV questions.

[IndigoMKII]

Yesterday I pulled my ISCV off my upper intake of my 88 7mgte.

I noticed the check valve has a tear in the rubber check valve which I think is causing my slight hesitation on acceleration. My question is does the ISCV shut completely when you're away from idle speeds or does it stay slightly cracked?

The reason I'm asking is I have no vacuum leaks(Boost leak test and smoke tested) but yet the vacuum on my engine isn't strong enough to let my bosch bypass valve work. I'm still getting slight surge at low PSI so if my ISCV is staying slightly cracked open after idle speeds this would cause my vacuum leak without really being a leak.

Thanks in advance.

 

[IndigoMKII]

No one?

 

[hvyman]

You could test the isc to verify its working correctly. Also the rubber piece is to prevent boost from going in there. Na doesn't have it.

I'd still get a new one tho.

Any codes?

 

[IndigoMKII]

Nope, no codes. I've checked the ISCV per the resistance test and it's 21 and 22 ohms across all of them. I've checked all the wires from the ecu to the iscv and they're good. Manually stepped the motor from one side to the other, neither way is 'fully' closed. The rubber grommet is in there along with the check valve, which is torn.

When I took the ISCV off to clean it, the tip of the nozzle looked to be bent, is it supposed to fully seat and not let any air through? When I manually stepped the motor all the way, I can still easily blow air through it.

 

[IndigoMKII]

Well I fixed my issue incase someone else could use the answer to my problem.

When I first installed the 7mgte in the car and got it running. I let it warm up to operating temps then set timing with a timing light. Since then I had purchased a new TPS and several other things. After reading on the forums that setting the TPS does NOT affect your ignition timing I decided to ignore it.

So after diving into my problem and checking EVERYTHING, even as far as tracing old wires I've fixed and so on. So I decided since I was retracing my steps I'd check engine timing and ignition timing. I confirmed the engine timing was still right on where it should be, I checked my ignition timing. When I first put the timing light on I thought my timing light decided to take a crap seeing as I couldn't see the crank timing mark when the light hit. After looking closer I was 13 degrees off! Thank god I haven't ever driven this engine hard, hard to tell what my timing being that far off could of done. So I set the timing to 10 degrees with t1 and te1 jumped and took her for a run. Part throttle run up to traffic speed was MASSIVELY increased. By massively increased I mean seat-o-the-pants-meter was deep in the seat.

So now I've noticed that around 7-8 psi I hit fuel cut. This was when I was trying to merge into heavy quick moving traffic that I found the dreaded fuel cut.
Mods are:
ct26 57trim on WG pressure(7-8psi)
borla catback
AEM UEGO
Apexi intake adapter
Custom hardpipe 2.5"