I have an 86 Iroc-z tpi, pretty much stock. I took my heads off last month and had them redone, pressure tested and new valves and seals. Anyway, when I was removing the tpi runners, I remember removing a plastic cap, blocking one of the runners where it bolts to the Plenium. I put it all back together and forgot to put this back in and now I don't remember exactly which runner it was in exactly. I have trouble starting it when it's cooler outside now and am wondering if this is why. Can anybody tell me what the purpose on this is, and if it works in conjuction with the cold start valve "which I still use" which runner is it supposed to be in? I've been looking everywhere on this site and have not seen any reference to this.

 

Need pics bro, no idea what you are referring to.

 

The plastic part was probably blocking the ninth injector hole which was on pre 89 cars I believe. It didn't block a "runner" opening as that would hinder airflow to that particular intake. Just my opinion, I am usually wrong.

 

That's what I didn't understand. It was blocking one of the runners, and I looked through my Chilton's and Haynes and never saw anything about this in there. That's why I figured I'd try on here to see if anybody heard of this.

 

That's really vague, but I think I might have an idea...

I don't know of anything "blocking one of the runners," or even which runners you mean, but since you're asking if it's related to the cold start injector, I'll begin by guessing it's on the driver side near the cold start injector, right? And after putting things back together, you're having cold start issues...

So I'm guessing you re-connected the electrical connector to the cold start injector, but you didn't re-connect the injector's "fuel line," so there's no fuel feeding the intake, even though the injector is connected, hence your cold start issues.

The cold start injector has its own "fuel line," a tube that runs from the injector to the back end of the ruel rail. That's how it's fed its fuel. And there's a "cap" that snaps the tube onto the injector. So is this cap you're talking about connected to a tube, and the tube runs to the fuel rail? If so, then snap it onto the end of the cold start injector, and your problems will be solved.

I'm guessing that's it, because I just don't see anything else that looks like a "plastic cap." And your coinciding cold start issues are too coincidental for it to be anything else.