New engine runs, but hear popping

[pwcracer]

I finally (With your help) got the distributor and timing all set in my new engine. It runs but the idle is crap, I blame part of this on the Cam I went with, based off of crane 222333 I think is the model #. (It was a custom grind and they changed some things because of the sc)

I am hearing popping from the intake at idle and the idle is crap, until I get it to about 1300-1500, then everything smoothes out and it is fine. I checked all vacuum lines, etc and haven’t found anything out of place. This is pretty much a new engine for me, the only thing I re-used from my old engine is the SC, fuel injectors, rails, and CAI. The rest is all new (or at least new to me)

Before I killed my old engine I had a chip burned for my car, Do you think I need a new one with the new combo?
This is what my new combo consists of now..


306 block

performer heads

t-moss ported lower intake

new cam

Reman distributor from autozone..

 

[BigHairyMonkey]

i would get a custom burnt chip for any type of FI motor. That would probably solve all your part throttle driveability woes.

 

[ninety15.0]

Well i think that the tune is mostly to blame. What are you using for a Mass Air Meter? Have you cleaned the ISC recently. How did you set the idle? What are the cam specs? Did you set up the heads/valvetrain yourself?

Sorry for all the questions but i think they are all pertinent. let us know.

 

[pwcracer]

more info

The MAF is a 90mm from a lightning. I did set up the valvetrain myself, using 1.6 roller rockers. the cam is like a crane 2030 --270in/270ex, .533 intake .544 exhaust, they increased seperation to 114.


I so far haven't set idle, I thought it was set by the ecc... I didn't clean the ISC yet.

 

[ninety15.0]

Wow...thats quite a large cam. Lots of duration.

Anyways, I would try to set the base mechanical idle. some prefer to do this with the spout connector out, as it completely eliminates any way for the computer to adjust timing to alter timing. Make sure all accessories are off and turn throttle blade stop screw all the way out...then one full turn in. Start from there and increase idle speed as needed.

I would also make sure the timing is set properly. Maybe find TDC on # 1 and restab the dizzy....then set base idle back to stock 10°. The tune should take care of all timing changes within the computer....so the mechanical timing should remain at 10°. Clean the MAF and ISC. Then check Jrichkers surging idle checklist. Go through the WHOLE thing...step by step. You should find your problem.

 

[pwcracer]

ok

I checked the timing and it is at 10, I spent couple of hours making sure dizzy is set right. I will go over the idle checklist too.

Wanted to ask, if I had a bent valve for whatever reason, the engine shouldn't smooth out at higher RPM's correct?

I remember my piston to valve clearance was very close, but within the limits, I checked it several times with clay.

 

[5spd GT]

It does not point to a bent valve.

Do you think you could swap in your old distributor (if it still works) to see if the problem goes away?

A 114LSA should provide nice idle characteristics and a broader powerband.

What is the duration at .050" (Advertised durations can vary to much), just curious?

 

[pwcracer]

old distributor

Autozone took my old distributor for a core, I broke the hex shaft off on it anyways.. I would like to try another distributor and see if its better or the same. I doubt i could return one to autozone after trying it.. who knows.

I am not really sure the duration, i had delta cam grind it for me and they patterned it after that crane cam above..

 

[pwcracer]

car

I drove it around last night and it started idling about 900 rpm and the tach needle didnt fluctuate. It still idles rough but 10x better than before. I no longer hear popping under the intake. I do think I have some valve train noise however.

I didn't get on it too much, until I have a new chip burned, but it feels very fast.

Now I get to enjoy my 'vert for the last few days of summer

Thanks for all your help with my engine rebuild project!

 

[5spd GT]

So what was the 'fix'? Or did it just relearn...?

 

[pwcracer]

I think it was the relearn, I went over all the vacuum lines but that didnt change anything really. I still am going to get a chip re-burned (I think its only $75 now)