[studybuddy]

Hey guys, I just got done installing new NGK Double Platinum plugs to replace the factory ones, and installed a Crawford cast plenum. I hooked the coil packs up, put dielectric grease on the plugs, made sure all the vacuum and coolant lines from the plenum were hooked up. I put the nylon washers on and it's all bolted down. We've done it all and taken all of it apart twice now and we can't find the problem. When I crank the car, I have to rev it to about 2k rpms to keep it from dying. If I let it try to idle, it sputters out. If I keep it at 1k rpms it has a really rough idle and barely stays cranked, but when I let my foot off the gas completely it dies. I'm out of ideas. I'm not sure if it could be a vacuum leak anywhere, but we tightened everything down right and it appears to be sealed.

Help! :ahhh: :ahhh:

 

[studybuddy]

Forgot to mention that after the first shot, I disconnected the battery for about 10 minutes and it didn't help anything. :dunno:

 

[350ztrackspec]

Could be your rubber seal around your oil filler got caught between the plenum and you have a leak, which will cause crap idle.

Or if you have taken of the Throttle body plug, you will need to to a TB reset to recalibrate it.

 

[smoothz]

Sounds like you have a vacuum leak, so your worst culprit could be the gasket like 'spec stated. I had to be really careful when installing my plenum.

 

[studybuddy]

The rubber seal around the oil filler did get caught the first time. I took it off and we tried again and had the same problem. It feels like either a vacuum leak or it's misfiring, but I can't troubleshoot it.

I did disconnect the throttle body and reconnected it. When I cranked it the first time I had actually forgotten to reconnect it and it died immediately. We figured it out after we cranked it and it died once though. What is that reset you were talking about? :dunno:

If it comes down to it, I have a spare gasket too. I can try that, but I don't think the gasket is the problem.

 

[Guest]

Gaps are the plugs gapped correctly?

 

[studybuddy]

The NGK box said not to gap them because they were brittle. They were all gapped to 4.0 though if I remember correctly.

 

[350ztrackspec]

The throttle body is most likely your problem. You cars throttle position is now confused as to where it should be. I dont have the link to TB reset procedure but if you do a search for "technosquare" you should find it easy.

I had a similar problem but a less severe degree. My RPM's were wierd, it was like i was accelerating when i wasn't.

All good after the TB (throttle body) reset though.

I hope this helps

 

[studybuddy]

Thanks for the help. :clap:

I'm open to other options from other members who might have other ideas. I'll be working on it again tomorrow, so the more I know going into it the better. I plan on calling Crawford Z tomorrow and see if they have any suggestions.

 

[studybuddy]

:bump: for Monday morning. :biggrin:

 

[studybuddy]

Can anyone link me to the afore mentioned throttle body reset precedure?

 

[westpak]

http://www.technosquareinc.com/350reset.htm

 

[sloe truk]

Buddy, did you put the 4 bolts in the lower plenum? The stock upper plenum has 6 bolts while the Crawford has 2. If you don't install the 4 short bolts into the lower plenum you'll have one **** of a vacuum leak. Don't ask how I figured this out.

 

[studybuddy]

http://www.technosquareinc.com/350reset.htm

Thanks! :clap:

 

[studybuddy]

Buddy, did you put the 4 bolts in the lower plenum? The stock upper plenum has 6 bolts while the Crawford has 2. If you don't install the 4 short bolts into the lower plenum you'll have one **** of a vacuum leak. Don't ask how I figured this out.

Thanks B. I definitely didn't do that. I'll install those and hopefully it will fix it. I'm still open to other suggestions from members though.

You have a PM. :wavey:

 

[Silver350z05]

i would definetly say its the plenum

 

[Eugene Relyea]

Hey guys, I just got done installing new NGK Double Platinum plugs to replace the factory ones, and installed a Crawford cast plenum. I hooked the coil packs up, put dielectric grease on the plugs, made sure all the vacuum and coolant lines from the plenum were hooked up. I put the nylon washers on and it's all bolted down. We've done it all and taken all of it apart twice now and we can't find the problem. When I crank the car, I have to rev it to about 2k rpms to keep it from dying. If I let it try to idle, it sputters out. If I keep it at 1k rpms it has a really rough idle and barely stays cranked, but when I let my foot off the gas completely it dies. I'm out of ideas. I'm not sure if it could be a vacuum leak anywhere, but we tightened everything down right and it appears to be sealed.

Help! :ahhh: :ahhh:

I’m having the exact same problem and I’m scratching my head,