idle issues wit 272 cams

[93AWDTALONwc]

Hello everyone... I have an issue i cant resolve. I put a rebuilt engine in my car with a built head, oversived valves springs+ret bc272s, 2g maf,cyclone intake man, vaccum delete etc...

For some reason the car wont hold a good idle below 1k, aand i hear some kind of electrical buzz somewhere on the fuel rail...
Any ideas any input helps.

 

[toofast82]

Obviously 272 cams is going to have a choppier/lopier idle than stock cams.

I see you have a custom chip: Is it properly compensated for the 2g maf and injectors you're running?

Is it running fine everywhere else in the rpm band? What's your vacuum at idle?

 

[93AWDTALONwc]

The chip is compensating for the 680's and the 2g mas but at the time jeff burned the chip i had every thing else with a stock head...
Vacuum is at 30

 

[untouchablecc]

Wow i never seen my idle dip below 20 at idle.

 

[93AWDTALONwc]

Sorry i was reading the gauge wrong it fluxuates from 10-14 @ 1100

 

[toofast82]

The chip is compensating for the 680's and the 2g mas but at the time jeff burned the chip i had every thing else with a stock head...
Vacuum is at 30

I was concerned that maybe the 2gmas wasn't properly compensated for, but since you said JeffO did the chip, I'm sure it was done right.
I would expect vacuum on 272s to be ~10-14"vac at idle depending on how lean the idle is.

If there are no boost/vacuum leaks and the timing is set correctly, I'm gonna say you're going to need a wideband and something to control fuel(safc,etc) to get the idle dialed in

Can you take a vid of it idling/running?
From what i've seen at idle with cams(264s,272s) on 4g63s, if its a long lope at idle and possibly a slow surge, its probably lean.

Also, how low are you trying to get it to idle?

 

[project98dsm]

When you had your chip burnt did you tell them ahead of time that you were going to be running 272s? I don't think they'd make the assumption of increased idle on their own without your recommendation, even though they know it would be a good thing to do seeing as you'd need an idle adjustment to pull better vac at idle with more aggressive cams. You should check up on that.

 

[93AWDTALONwc]

i was concerned that maybe the 2gmas wasn't properly compensated for, but since you said jeffo did the chip, i'm sure it was done right.
I would expect vacuum on 272s to be ~10-14"vac at idle depending on how lean the idle is.

If there are no boost/vacuum leaks and the timing is set correctly, i'm gonna say you're going to need a wideband and something to control fuel(safc,etc) to get the idle dialed in

can you take a vid of it idling/running?
From what i've seen at idle with cams(264s,272s) on 4g63s, if its a long lope at idle and possibly a slow surge, its probably lean.

Also, how low are you trying to get it to idle?

i have an afc and a wideband alredy... What about the electrical nouise comin from the fuel rail???

when you had your chip burnt did you tell them ahead of time that you were going to be running 272s? I don't think they'd make the assumption of increased idle on their own without your recommendation, even though they know it would be a good thing to do seeing as you'd need an idle adjustment to pull better vac at idle with more aggressive cams. You should check up on that.

i tried multiple times via email to contact jeff to re flash my chip but got tiered of waiting for him to respond so i just put it back together

 

[gsx4g64]

I would suggest sticking with jeff... I use to use his chip in my first setup.... hks 272's, 720cc, and a Safc i broke into the 600hp range... he makes a great product. once you great it dialed in, you will be fine...Are you trying to take out or add fuel at idle? I think jeff chips handle fuel for you at idle.

 

[93AWDTALONwc]

i would suggest sticking with jeff... I use to use his chip in my first setup.... Hks 272's, 720cc, and a safc i broke into the 600hp range... He makes a great product. Once you great it dialed in, you will be fine...are you trying to take out or add fuel at idle? I think jeff chips handle fuel for you at idle.

i love the chip man, but i cant get jeff to reply back to me so he can burn it again it suxxx

 

[project98dsm]

"PLEASE NOTE: I will not be able to ship any product the week of 4/26 thru 4/30. Sorry for any inconvenience!"

This is on his homepage for the website. Maybe he's taking a vacation and he doesn't have access to a computer . Who knows? Give it until after the 1st of May and see if he gets back to you. I'll be trying myself because I'm going to need my chip reset as well seeing I decided last minute to change my MAF setup.

 

[93AWDTALONwc]

"PLEASE NOTE: I will not be able to ship any product the week of 4/26 thru 4/30. Sorry for any inconvenience!"

This is on his homepage for the website. Maybe he's taking a vacation and he doesn't have access to a computer . Who knows? Give it until after the 1st of May and see if he gets back to you. I'll be trying myself because I'm going to need my chip reset as well seeing I decided last minute to change my MAF setup.

I HOPE SO ### IVE BEEN TRYIN FOR MONTHS NOW

 

[toofast82]

i have an afc and a wideband alredy... What about the electrical nouise comin from the fuel rail???

You should be able to tune it to idle well with the wideband and afc. Just dial in the cold start to as close to 14.7:1 as you can and the ecu should take control of it in closed loop.

As far as the noise, we may need a vid. Keep in mind there will be some noise from the injectors.

 

[T Money]

I idle my 272s between 900-1000. Anything 800 and under gets pretty rough.
Are you sure your base timing is set correctly?

 

[93AWDTALONwc]

I swaped out the ecu and it was able to idle without diein out...
Tomorow ill reset base idle ill let u guys know what happens

 

[rx7ttlm]

That sounds like a wide range for vacuum at idle, I have huge cams (FP3) and my idle HOT TO COLD only fluxuates 3 in/hg. Within a minuite its only about 1-1.5 in/hg delta. Maybe vacuume leak, cams timing incorrect(off a tooth or not degree'd?), I dunno, just sounds strange, maf could need dialed in, maybe you have a friend that has a snapon code scanner, I can get some good data off my brick... may be worth a try.

Cheers

 

[93AWDTALONwc]

ok so after constant medeling I found some craks on my manifold.. swaped it out and now the car will turn on but then shuts off imeadiatly, if I give it throtle to try and keep it on it dies automaticaly.. heres a list of things i swaped out trying to fix it
--silver box for injectors
coil pack
ignighter
main relay
ics and cas maf ect....
nothing seems to fix the problem Im fed up and cant think of any other ideas also ive noticed that the injectors somtimes make a noise

 

[Jay's_GSX]

Sorry to hear about your bad news, I'm going through the same problem too on the noise buzzing sound after I put in my 272's intake exhaust. It seems like it would go away and come back. I really don't know what it is either. I just hope it's nothing to serious... Plus when I drive my car at regular shifting 3k rpm the ilde would drop and die!!! It ildes at 800 rpm, is that to low???? Please help!

 

[johnmarines]

I think the noise you arehearing is the PCV on the valve cover right next to the intake.

 

[project98dsm]

Nothing new in the past couple of days? See if you can track down someone with a mechanic's stethoscope and probe around your injectors among other things in that general area. Believe me, those things work wonders. I once thought I had lifter tick on the intake side of my head on my 2g...borrowed a stethoscope and ended up being a spun thrust bearing. Sound bounces around in our engine bays like one of those 25 cent rubber balls out of a gumball machine. But as far as the noise coming from the fuel rail, are you sure it's an "electrical buzz" or is it more like a faint "clicking" or "ticking" sound? It's possible it could just be your injectors pulsing.

 

[1fast fwd]

Definitely check for vacuum leaks. Get a leak tester and go from there. Good luck

 

[Jay's_GSX]

ill check on the pcv valve when my car cools off. and yes i do need to do a vacuum test. and for the ticking noise, it really sounds like a electrical buzzing noise...

 

[johnmarines]

ill check on the pcv valve when my car cools off.

Just pinch the hose thats connected to it and if the noise stops then thats your problem.

 

[EclipticalGS]

do a Boost leak test, set your base timing to 5* BTDC, if you still cant get it to idle, then maybe your ecu or chips messed up. Is your cam timing correct?