Random stalling

[Blindedlegacy]

AH HA wiring to the isc connector looks jacked up and my isc sometimes doesnt click like its suppose to. So today imma fix that TONIGHT!!!

[Blindedlegacy]

Btw what the f is a fuel pressure up vsv and its purpose and location. I found bits and pieces but cant find a solid article

[cre]

There was a VERY detailed write-up on it on here a couple years back. I'll try to see what I can find later on. I don't have time right now.

It's used to modulate vacuum reference at varying loads. It's a good thing, all around. Do you have a specific questions about it or just curious? Yes, you do need it.

[Blindedlegacy]

Originally Posted by cre

There was a VERY detailed write-up on it on here a couple years back. I'll try to see what I can find later on. I don't have time right now.

It's used to modulate vacuum reference at varying loads. It's a good thing, all around. Do you have a specific questions about it or just curious? Yes, you do need it.

Well if you remember when I first got this car and joined this web site
I posted pics of 2 connectors I didn't no. one was the knock sensor and the other was never figured out. Based on the color of the wires and placement of the vsv on diagrams, that connector goes to that vsv. I don't know exactly how it works yet but the ecu hadn't had a reading from it since I owned it

[cre]

Originally Posted by Blindedlegacy

Well if you remember when I first got this car and joined this web site
I posted pics of 2 connectors I didn't no. one was the knock sensor and the other was never figured out. Based on the color of the wires and placement of the vsv on diagrams, that connector goes to that vsv. I don't know exactly how it works yet but the ecu hadn't had a reading from it since I owned it

I'm sorry, I don't remember... For a low traffic site there's enough to push it all out of my mind after a couple days.

The ECU doesn't "read" anything from the VSV. It doesn't even check load to ensure it's in place. There will be no code in its absence or if it's defective. If it isn't present it needs to be replaced. It isn't a common failure point but it is something which should be tested periodically as well... Fueling is the one thing that can destroy an engine in seconds.

Search the MKIII section for vacuum diagrams to see how it's supposed to be plumbed into the system. There are three nipples, one goes to the FPR, one to the manifold for vacuum and the third just has a small filter on it. You may find the vacuum diagrams in the FAQ section (if you find the vacuum line thread and it's not in the FAQ section let me know and I'll move it there).

[Blindedlegacy]

When I check that writing tomorrow ill try to see if every thing is plugged up where it should but as for the connector it done. It broke off about a month back so I'm lost there

[Blindedlegacy]

checked resistance of the isc again and it is still in spec.

check the wiring from fuse box to isc connector and the connect to the ecu connectors and all showed .5 ohms

cleaned the isc again with seafoam running though its airport this time. last time i removed it and cleaned it

some days i hear the isc clicking after shut off and other days i dont ( might try a different one if i can find one that is not 366 bucks

i found it weird that i held the vacuum line to the isc closed and the port on the throttle body closed and it continued to run

i also started the car with the isc connector unplugged and it just kept revving up

so im going to move to fuel and see if i can find something strange

i didnt get a chance to fully check the fuel pressure up vsv because that engine bay got a little too hot for me so im going to study up.

so i hope the info i provided can give you some clues because i am running out of options

[Blindedlegacy]

i really want to bypass this fuel pump resistor and see what happens because resistance for the fuel pump just sounds dumb. but i would like ur 2 cents to see if it is a good idea

[cre]

Nothing wrong with that at all I recommend it depending on the issue. I don't think it's the problem here though, but go ahead and try. I recommend you bypass at the bigger round connector as that will bypass both resistor and relay. Use an appropriately large gauge wire and a couple spade connectors to make a reliable and easy to remove bypass wire. Refer to the TEWD to see which two contacts you want to jumper.

[Blindedlegacy]

for the relay should i use a switch if i am going to bypass it because i dont want it on all the time