Do have an exhaust leak?????

I have the 58 mm holley tb with a camshaft that has 248/254 duration. I do not have any problems with split BLMS. IAC counts are around 80ish. Long term fuel trims are around 128 give or take a few points (no more than 3 though). I have also done the IAC mod. (ran a 3/8 host from the rubber intake elbo to the intake hole underneath the TB).

Sure sounds like an exhaust leak......
Are you running open headers???????

 

Did you cross one of the electrical injector plugs?
Just thowing this out for thought?

 

No crossed injectors but yeah its Open Y-pipe with race muffler right after the Y-pipe so it all comes out around the CAT area, would this affet it? But why would it read leaner on the driver's side if its got more tubbing on that side than the passenger side which is the right side & is reading richer?

Thanx guys, can't get my mind off this, thanx though now that I know a bigger cam is having more luck I have more fishing to do, I am sertain I don't have an exhaust leak but I will sure check.

 

Ps. I'm also thinking of doing a compression check, maybe a valve is staying open? I dunno I'm about to cry here

PS. what do you mean by:

(ran a 3/8 host from the rubber intake elbo to the intake hole underneath the TB).

can you explain it in more detail, where is the hole underneat the TB? LMK thanx bro.

 

someone siad program it for open loop idle.. how can i go about doing that.. my car with the listed cam runs perfect in open loop, but so rich it dies in closed. Open is relying on the o2's correct? and closed is running off the map/preset computer settings? I am tying to learn about this stuff and its been hard to find info on.

.544/.560 232/242 110lsa.

 

Unplug your o2's and see how it runs. This is a temporary fix for split BLM's. When u unplug the o2's it will be in open loop. Let us know what happens!

 

My guess is you have a exhaust rocker too tight. Or Bent. During heavy load or mid load crusing the unburnt fuel and fresh air dont have enough time to reach the O2 sensor before it gets burnt. But at idle it does.


Lewis

 

I'm thinking somewhere along those lines aswell, I mean everythign is new, wires, plugs, opti etc... Although I doubt its a bent rocker maybe a valve? I know I didn't mkae any of the rockers tight, I'm really really good at adjusting rockers very nicely, maybe a compression check would tell me if I have a bad valve perhaps?

 

so what do you guys think, compression test determine whether I have a bad exhaust valve? LMK thanx.

 

I meant a bent valve.


Lewis

 

what are some of the other simptoms of a bent valve? Maybe a leaking valve? Either of those would cause a major loss in compression durring a compression test right?

 

Ok I'm told now that a compression test prolly wont reveal much, & that its prolly not a bent valve because a bent valve will cause very uneven starting, like vum,vum,vum,vum, vuuuuuum, vum vum. which starting, but a leaking valve won't & it'll mess up idle BLM's but not cruising. I was told to do a leak down test where you put pressure in the cylinder & listen for hissing on exhaust & intake. 80 psi is a good setting aparently. Also I will connect the rest of the exhaust & make sure there is no vacume leaks.

 

I'm going to follow up on some tests for my car this weekends I'll keep everyone posted so that you could keep me on top of things

 

I think it's the other way around.

 

it is the other way around.