3rdgengmachine

i just recently ported my plenum and runners a bit on my 87 tpi and when i put it back together i have a slow responding idel.Iv checked everything and all i can figure is that where the egr holes are its blowing air in insted of sucking it out and the ecm is trying to compensate and when it cant get it right it finnaly gives up and just does it by rpms insted causing the slow response time in cutting the idel down to 600.Thats my last resort cause everything elts checks out(havent changed ecm yet) so my qustion is i should be able to cut the back side of the holes a little lower than the front so when air passes it pulls it out insted of blowing it in.Do you guys think my theory is right or am i just all wrong lol.The problem just started when i done the porting so it has to have something to do with that. Im lost so i need all the help i can get thanks.......

brians88gta

sounds like u got a vacuum leak and its messin with the ecu because it has no way to read the incoming air thats not going through the MAF i would check there first make sure u put all vac lines back on?

Damon

At idle the EGR system shouldn't be functioning at all. There should not be anything going in or out of the holes in the plenum floor.

3rdgengmachine

There are no vac leaks like I said I have check everything and i mean everything 3 times lol the holes are my last option and changing the ecm.See im thinking that maybe I have the front of the holes a little lower than the back causing air to be forced down in the holes insted of sucking it out which is what the ramps are there for in the first place by the way they look.I might be wrong but thats what it looks like to me.And Im guessing that they might be messing with the ecm causing the delay of ideling down.I never had this kind of problem at all till I did this and everything elts checks out so I hope fixing it so the air will suck on the hols insted of blowing in them will fix the problem if not all i can do is change the ecm then put a stock plenum back on which i dont want to do at all.Keep the ideas comeing everything helps I might have over looked something simple I checked everything but you never know...........