94 Zr1 power key makes car act funny

[tccrab]

Here's everything you will ever need to know about your secondary port injection system.
http://www.corvetteactioncenter.com/...diagnosis.html

'Crabs

[Kevin]

Originally Posted by 94Zr1TX

When I say rough basically I just mean that it feels like not all the cylinders are firing. If you take a car and pull a few plug wires and go drive it...that's what it feels like. Does not bog down it just feels like I lose a few or more cylinders.

Sounds like what mine did when my injectors died. The problem with the dual mass is it absorb any small hiccups until they're really big which makes it hard to notice issues like this

[94Zr1TX]

Originally Posted by tccrab

Here's everything you will ever need to know about your secondary port injection system.
http://www.corvetteactioncenter.com/...diagnosis.html

'Crabs

Yeah I've been reading up there too. I appreciate the info.

I've got a vacuum pump on order to be here Friday to check for leaks and then see if my actuators are still good. Also have my gaskets on the way to button everything up at the end.

The previous owner said he had the injectors replaced as a preventative deal but I didn't see a receipt so it's possible they put crap injectors in I don't know. We will see when the plenum comes off in a few days. I'd much rather buy a $100 actuator than a $700 set of injectors. Plus that digs into my header money

[We Gone]

http://www.zr1specialist.com/HAT%20W...0Operation.pdf

[94Zr1TX]

Originally Posted by We Gone

http://www.zr1specialist.com/HAT%20W...0Operation.pdf

You're the man Steve. Thanks a bunch. I've been snooping around Marc's site quite a bit lately.

[94Zr1TX]

Ok so the vacuum lines hold vacuum just fine so that's not the issue. Next is to check the actuators. I hope to get around to checking that soon. Then I'll be back with an update. Thanks again guys.

[94Zr1TX]

Just wanted to update the thread. I kind of let the car sit for a while and then bought a few parts for it. I had decided to just let Corey Henderson figure things out for me, lol.

Turns out ONE bad injector was causing all kinds of crap with the car. It was supposed to have new injectors but the previous owner seems to not have been truthful about that.

Anyways the car got SW headers with hi flow cats, full 3 inch SW duals with the louder mufflers. Corey ported the plenum also, put 16 new injectors in, and dyno tuned the car. Car made 412/385 and sounds awesome. Corey also put a Hurst shifter in it. I will take some pics soon and hopefully make a post with some videos.

[Hib Halverson]

Originally Posted by A26B

May be that one of your secondary actuators has failed.

I'm with Jerry on this...secondaries on one side may not be working or the port throttles may not be opening fully.

If this is an engine which is not driven on the secondaries very often, it could be, as Jerry says, a bad SPT actuator or it could be one or more port throttles are sticking or the SPT linkage on one side is "gummed" up.

If the secondary pump was not enabling, the engine would have lack of power but not the vibration and, perhaps an MIL on due to a lean code.

If the engine idles and runs nice at light throttle, I tend to think ign. is not a problem.

[94Zr1TX]

I appreciate the response. We got it all fixed now though. Bad injector was the culprit. We had Corey Henderson work on the car and add some goodies. Check the post above yours Hib.

[Hog]

What is the driving procedure to get the Port Throttle injectors firing during a long highway cruise? I suggest that all LT5 drivers follow that simple bit of info.