JS City Goblin - 2010 LS

[JSATX]

Pressure at pump right at 14 volts.

Well I fixed it....I think.

I cut off the factory fuel line. I never have liked it anyway as it is bent to a certain shape and doesn’t conform well. It was very easy to cut off. I replaced it with standard rubber fuel line and I like that so much better.

I bent the “flapper valve” out some so it would open under a lighter pressure....
And it worked. Maybe a little too well. Stays dead on at 42 psi now.

The main question still remains....why? What could have happened in the last few months to make the pressure control valve not function properly. I took the pump completely apart. I removed every little screen filter and every housing there is. All of it was very clean and nothing visually wrong.

I hope I didn’t create a bandaid solution. But hey, if the pressure is there and remains there throughout the rev range there’s really nothing else to worry about I suppose.

 

[Waterdriver]

Nice!
Time for a test drive?

 

[JSATX]

Nice!
Time for a test drive?

I wish. Rained all day. Soon though!!

Also the misfires almost comepletely disappeared. Still a few but I’d guess 70% fewer misfires right off the bat.

 

[TheNuker]

Great to hear you fixed it, just a note is that hose rated for fuel injected system? It only shows 3.4bar pressure rating. Don’t want you to have a blow out!

Nuker

 

[SliderR1]

also remember your injector tables are set up for a certain pressure at the rail, if its lower than programmed for, you won't be getting enough fuel.

 

[JSATX]

Great to hear you fixed it, just a note is that hose rated for fuel injected system? It only shows 3.4bar pressure rating. Don’t want you to have a blow out!

Nuker

Good eye. It’s just extra I had in the garage. It’s held 100psi for the last few weeks, I’ll get injection hose soon thanks.

 

[JSATX]

also remember your injector tables are set up for a certain pressure at the rail, if its lower than programmed for, you won't be getting enough fuel.

You’re correct. Which is why I’m so concerned with getting it correct before I have ZZP finish my tune. Once they got it drivable I told them they wouldn’t hear from me for a week or two as I focused on getting it running perfectly. I don’t want to “tune in” mechanical issues!

 

[JSATX]

While tossing and turning last night thinking I had just unknowingly ruined my pump (yes I can be a little obsessive) I had an epiphany.

The 99-2003 corvette has a similar “returnless” fuel system like the cobalt but instead of the return pressure valve being in the tank, it’s in the filter!

So I hopped up and looked into it. Sure enough the fittings are exactly the same on the corvette filter, and the corvette filters built in regulator keeps the fuel at exactly 58psi.

I’ll now be able to remove that internal flapper valve, which I don’t like anyway, and let the corvette filter do the regulating!

You might be thinking, why not just replace the pump assembly and be done with it? Well a couple reasons...first is my pump is not bad. It’s a $1 metal flapper valve that’s screwed up.
Next is I dont want to replace the stock pump with another stock pump. If I’m spending the money I’m going to get a high flow in tank AEM pump or something...but that wouldn’t solve my return issue!

So now I can use the corvette filter, remove the internal return pressure valve, and get the upgrade AEM pump, all for less than the price of the factory fuel pump assembly.

 

[KJP]

If you are going to make changes anyway why not just go with a return fuel system and 1:1 RR and have zzp adjust the tune for this? In the long run it makes tuning easier in my experience (not ecotec specific).

 

[JSATX]

If you are going to make changes anyway why not just go with a return fuel system and 1:1 RR and have zzp adjust the tune for this? In the long run it makes tuning easier in my experience (not ecotec specific).

It’s $250 for a return style fuel rail and $300 for boost reference regulator. If this was a 500hp build that would be smart. For 300 the gains are so minimal I don’t see it being worth it.

 

[JSATX]

Vette filter works great!!


This is the valve I removed.

 

[JSATX]

Can anyone with access to the factory manual help me out with the ignition wiring? Since Im making a full dash, I plan to attach the RFID key chip to the antitheft device and remove the ignition and install an ignition switch and push button start. Just need details on the wires going into the ignition/lock cylinder itself.

 

[Briann1177]

How do you plan on "attaching" the key chip to the antitheft device? Just wondering.

 

[JSATX]

How do you plan on "attaching" the key chip to the antitheft device? Just wondering.

It's a proximity sensor, I'm gonna epoxy the chip to the anti theft device attached to the ignition lol.

 

[JSATX]

Here are the plugs. Top goes to the anti theft device, bottom to ignition

Theft= green. Black/white. Brown. Red white.
Ignition = white/black. White. Brown. Yellow. Red/white.

EDIT:

Found Antitheft and ignition. Coulda guessed what the wires were for. It would be interesting to see what the green wire signal looks like on an oscilloscope.

 

[Briann1177]

My service manual says the key doesn't transmit unless it's in the ignition. I guess there is something in the lock cylinder that turns it on.

 

[JSATX]

My service manual says the key doesn't transmit unless it's in the ignition. I guess there is something in the lock cylinder that turns it on.

Well the anti theft device is powered by accessory power. So I think it’s more to do with that than actually being in the ignition. But thanks I’ll keep that in mind

 

[Brian74]

From what I’ve read, passkey II is relatively simple. The passkey III is the tough one. As far as I know, VATS can simply be disabled with HPT but I was unable to find a solid answer on it yet.

 

[KJP]

From what I’ve read, passkey II is relatively simple. The passkey III is the tough one. As far as I know, VATS can simply be disabled with HPT but I was unable to find a solid answer on it yet.

You should be able to under system general vats and set to none

 

[Briann1177]

From my understanding of HPTs, the vehicle needs to support that option too. Not saying ours don't support that option. I think Justin can easily test this by getting an unprogrammed key, turning off VATS with his new HPT, and seeing if it will start.