Rough idle since mods
 

Just recently put on the following mods: AFR165 heads, Typhoon Intake u/l, B303 CAM, 24LB injectors, C&L119A MAF in our 88GT that's been converted to MAF.

Everything is installed, timing set to 10 degrees, idle is really rough, fuel pressure is set around 40. Idle was fine before the above mods, any ideas on what else to check to get car to idle right?

Um, did you actually check the cam timing, or did you just get a new timing set and assume that it's right? Also keep in mind that it is a B303, so it's not going to have a smooth idle no matter what you do.

Other than that I'd check TPS voltage and make sure all plugs are firing. No check engine light?

Yes - we indexed the cam to zero. I feel real confident this was done right as we had a friend come in and do this for us.

It's called a cam.

What ?????

Degreeing the cam?
 

I think Capri 306 is talking about "degreeing the cam" to see if all the specs are correct. Wondering if Tireburner is sniffing "brake cleaner" again, LOL.

Rev

I think Tireburner was referring to the fact that the B303 cam isn't gonna "idle" no matter what you do. I'd check all the above mentioned stuff, scan the computer for history codes, and lastly check and see if you maybe don't have an intake and/or vacuum leak somewhere.

There we go.

THe B-303 is a pretty lumpy cam is NEVER gonna idle smooth. It's gonna lope. Get used to it..........besides, it sounds so cool:D



-Josh, aka the tireburner

Is the idle just loping a bit, or does it actually surge up and down? I am just wondering exactly what you mean by saying the idle is not smooth. I run the B-cam also and still fight off and on idle problems with it.

Just off the top of my head, make sure your TPS voltage is correct and make sure your IAB valve is clean.

reply
 

im sorry guys the cam my son installed was actually the E-cam. the bad idle is not the cam(lets say my x-cam had a better idle than this does) i dont think the idling problem is due to the cam. the car wont even idle most of the time it just dies. black smnoke is pouring out of the back. my son checked for vaccuum leaks, checked fuel pressure, checked the wires to make sure they were on right, checked the timing. we dont know what else to check.

fuel...
 

Black smoke is fuel...

The usual suspects for poor idle:

vacuum leak
timing
tps voltage
bad iac

btw, I have a b-cam and it lopes but idles at 750 and doesn't budge.

I have 24 lbs too and 40 psi is too much I think, you should be around 38 psi tops.

good luck...

Okay just thought I would add my two cents to this thread. I had the E cam and once I got it to idle it was awesome. Make sure you check the TPS voltage, .98 or .99 volts at throttle stop and no more than 4.5 volts and wide open throttle, DO THIS WITH THE CAR OFF AND KEY ON. Also go to a parts store and get a can of intake spray cleaner. It will help to clean out the IAC (Idle air control) valve. Lastly get the IAC adapter plate that will go between the IAC and its mount it has 2 adjustment screws on it so you can set your idle without messing with the throttle stop and the TPS. Once I did the above the car idled fine with an occasional hiccup. But, lastly what everyone else said is welcome to having a cam. The E cam will idle rough

Go up on the timing and down on the fuel press. My B and E idled smooth, With SPEED DENSITY.

I'd bet this is MAF related. Is the MAF calibrated for the injector size being used? Does the air filter get fan wash from the coling fan? If so, build a shield to keep the fan from blowing on the filter. Cleaned the MAF wires lately?

Another thought: MAF could be fixed high due to internal failure. Check MAF output voltage (at harness connector AND EEC-IV computer) and report back plz. :D