I would not expect so.

 

The "sewing machine" sound is what you want to hear in a normal roller valvetrain. If there are any distinguishing noises heard above the sewing machine sound then there's something wrong. The sound originates from the reciprocation of the trunnions and the bearings within the rocker bodys. The more aggressive the cam profile, the louder they are.

 

I think the 1.52 comp cams I currently have, do make a sewing sound. I mean the 502 is a mild cam, shouldn't be that loud

 

LOL that sucks. Is a tune necessary for 1.6 roller rockers?

 

Yup. I remember a lot of people complaining about the sewing machine noise of LS engines when they first came out, not correlating the noise with the OE roller fulcrum.

 

No

with that said if your valve springs are original, change them when doing 1:6 RR. Then you would benefit from a "performance" tune of PCM that would raise your shift RPM that your new valve springs would allow and the added lift from cam would yield a decent and noticeable HP gain.

 

I just got them put on the other day, didn't think it will be expensive to install them, sheesh.

But since the install, it feel very strong. The exhaust tone is more lopey, probably due to the added lift. Kinda louder to.

I can definitely feel the torque, very strong.

Also I been having a issue when I slow down my rpm drops to a point where the car sound like it's about to stall, I looked at the iac counts and they are at 56-60 range

I did notice my tps voltage seem to jump around at idle, it's not a solid number when the throttle is 0%

Like it be at 73 then next drive it will be at 75

Defective tps?



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your TPS may be just sticking or going bac. If you remove it and spray out the orifice on TB with TB cleaner (read not carb cleaner) and on TPS if its all gunked up that may relieve it or just replace it. should be around .67vdc throttle closed +/-

so you have valve springs and RR put on..or just RR?

 

I just replace that tps like a year ago 😭 I might as well just replace it again, what's the best way slot it? Last time I use a screw driver lol. Didn't quite get
it.

So even with a aftermarket throttle body, volts should be around 67 volts?

Also there is wire on the harness that goes to the o2 sensors that got burnt like months ago, and every now and then it will move around and cause the O2 to trip out, making my car run rough.

I zip tied it, but it still moves around a bit and I know the wire is expose to the heat as well since it got burnt. I will get that fix.

And yea I already have valve springs, valve seal etc. Did all that when I did my cam swap 4 years ago

 

slotting the TPS so you can clock it to "within range" is a better hack than cracking open the TB blades to get a aftermarket TB to get good IAC at idle

IIRC the +/- range for .67vdc is .20ish so it does not need to be dead nuts .67vdc at idle. 4.5vdc though at WOT. These are the parameters the PCM can deal with. The increase in VDC should be smooth and consistent as you open the TB blades to full while metering vdc

IMHO having the stock 48 bored to 52 is the best way to go for a larger TB and the stock intake manifold is already ported at 52mm. That way stock IAC and any tuning are happy and IAC counts are as they should be

 

LOL I should have stuck with the 52mm throttle body, but I couldn't pass on a good deal with a 58mm Holley.

Even tho it does come with complicated issues in order to run it.

I mean for the past days I been monitoring the motor with my scanner, and I think the tps is fine. Voltage been steady 71 when idling. I did tighting it a little, and maybe that was the issue with the voltage switching.

But I did notice my iac count pigged at 160, only until I start moving, the counts go down.

Also when I go into reverse, the counts drops to 56-60, which where it should be.

​​​​​​Maybe the iac is bad? Is it'll possible, to break the iac if you do the reset procedure wrong?

For example, I didn't know you had to hold the gas for 5 sec. I though you hold the gas, and when you start it, you let go of the gas and shut it off for 10 sec

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unless you make over 450 HP, you don't need the 58 and given they never really are "right" relative to IAC counts even after drilling, plugging etc...just put the stock TB back on

You can't "break a IAC but doing thee reset procedure wrong

 

Don't have it anymore. Stock one I had the throttle blades was bent, don't know how that happen, previous owner mistake I guess.

That why i said, I got this from a friend for a good deal, brand new.

I didn't have a choice at the time anyways.

I'm just gonna replace that iac, cause I don't think the counts should be pigged at 160 in idle.

 

To help prevent the split fuel trim / BLM issue I would suggest about 40-60 counts at hot idle with everything turned off and the transmission out of gear. Easiest way to do that is open the air rate set screw past where it needs to be open, 2-3 turns in should do it. Reset the TPS then start the car. Let the car warm up and then watch the scanner. The TPS should read 0%. Slowly decrease the set screw until the IAC counts start to rise to the range I suggested.

 

There a way to reset tps? I thought it was the iac that needs to be reset when opening the blades.

 

BTW guys, I'm planning on buying a new wiring harness. Is it hard to install harness while motor in the car?

 

Make sure to check the contact patch of the roller against valve tip. Changing geometry can throw things off

 

The shop who put it in check all that, I don't think it's that

The problem might be that wire I caught sitting on the passenger header a while back, the loom that surrounded the wire was melted onto the exhaust

I zip tied it away, but every now and then I have this problem where both o2 sense voltage will drop all the way to around 60-18 and will stay in the 2 digits while in close loop

Alsy my short term are locked at 128, but sometimes will move around, but right back to 128

I think that wire is damaged, but i check around where that wire was sitting on header and didn't see any burn marks on the wires, but yet when I move the wire around, the o2 start jumping around for sec then goes back to low

It's still goes into close loop tho, and no check engine light surprisely