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Idleing with 65# inj

Andrew_99GTP

Andrew_99GTP

New member
I have had an on going rough/ hunting idle problem with my car. It will idle perfectly at times but other times it will hunt a little bit or just be kind of rough. Sometimes it hunts worse than other too. Also I was doing some VE tuning and the car will almost not idle at all with the maf unplugged, shouldn't I have been able to make some progress on the VE tune and got it to idle better? Those of you running 65# injectors how does your car idle? I plan on swapping the stock ones back in soon, but I am waiting on an ICM since mine is shorted out and keeps blowing the fuse :mad:. Also the idle was way worse when I didn't have a maf screen in, I put one in and it got alot better but still just seems to idle like crap.

Forgot to mention that if I unplugged the IAC it car idles nice and smooth, not sure if this matters or not.
 
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Cleaned your IAC lately? They like to be the point of a lot carbon buildup. It may also need to be replaced.

Just a thought.

ICM? Is that like a BCM?
 
mine usually will run alittle rough at idle with a misfire here and there but if i turn on the ac while in park it will smooth out. I think i'm gradually getting it worked out by maf/Ve tuning. If i find the cure that stops it for sure i'll let you know.
 
Does yours ever surge? I just put my stock inj back in and ran the car on a stock tune and it still seemed to run "rough". I am not sure how it is supposed to sound anymore though. What are you mods Kent? Was your car worse before you started VE/Maff tuning. Also is there a chance you could pm me your IFR table, if you are using pt, or if not that could I pm you mine so you can compare them and make sure I am close to yours. I just did the math method 35/65= whatever it is.
 
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65#'s suck for idling.

Disc 79# High-impedance are a much better injector for our cars, or a Disc 66#. Talk to PRJ, he can get them for you.
 


Ok, so who else thinks the 65#'s could be causeing the surging? I put the stockers in last night and not much seemed to change, but I never let the trims learn. I think I will take the car out today and let the trims learn and see what happens.

BTW what is a Disc?
 
Sometimes a VE tune will make idling gradually worse. I usually try to get it dialed in, then keep the idle tables the same as I'm doing the VE tune.
 
TurboKent said:
mine usually will run alittle rough at idle with a misfire here and there but if i turn on the ac while in park it will smooth out. I think i'm gradually getting it worked out by maf/Ve tuning. If i find the cure that stops it for sure i'll let you know.
Click to expand...

How did yours run right after the turbo install?
 
I can't really remember without looking at the VE table, but I usually monitor the fuel trims at idle, then go over to the left of the VE table, see what stock is, and usually 4 columns will cover it. Add/subtract until things level out. But I've got a little easier way to tune the 42.5's than you do with your 65's.

Sorry, I'm not a whole lot of help. I can't hardly describe what I do to tune the car without sounding like a fool.
 


Ok that helps some :P, With the mods in my sig, with the stock inj installed do you think the car should idle like stock or would the cam and turbo mess with the VE enough to screw it up? I am sorry for all the dumb questions, I just need someone to tell me weather or not I am retarded.
 
right after the turbo install mine ran really rough, although i think kevin was high on crack or something when he programed my pcm. There were so many things messed up it's not funny. Ended up costing me a tranny rebuild on my zzp tranny.
And you mention that it keeps surging, any chance you have a vacuum leak? I know if just one of the small vac lines on mine comes loose it will do that. Also if you maf has gone bad and your VE tune sucks it will do that.
 
IFR.JPG


hope that helps
 
I dont' think I have a vac leak, my idle trims are so negative it isn't even funny. With stock inj and a totally stock tune they are close to -20%. My maf is good because I swapped it out with a good one and no change. I see you use HPT and HPT's IFR is lbs/hr and pt is in mSec/gram. I will have to see if I can convert it.
 
But I guess I have ruled out the 65# inj because it still surges at an idle with the stock ones. Could the cam and turbo be hurting my VE enough at an idle that my car over fueling its self could cause the surging idle?
 


Cams can make it pretty difficult to tune, but the stage 2 cam isn't really THAT aggressive that it won't idle right. Are you still using the stock throttle body and MAF?

I actually went through pains to get the idle right on my LS1 setup, but -20 on the fuel trims do sound crazy crazy rich.
 
my ltft use to be like that until i started tuning the maf. Now i have them down where they should be between 0 and -3. If you want i could also post up my maf tune and let you try that to see if it would help or make it worse.
 
I run the 65# injectors, and never really had any fit with them.

My idle sounds different...I think because of my Stage3 cam in there. Plus, I have a pretty loud valve train and forges pistons that like to knock a little. As for surging...from time to time a little, RPM's going up and down a little. Its not really revving the motor, or causing it to want to stall. Of course I didn't raise my RPM's that much for this cam...I think I only raised it 100 across the board from stock, I know others go higher to smooth things out, but then it sounds like the motor is racing its self some times. IMO.

~F~
 
Reptile said:
Cams can make it pretty difficult to tune, but the stage 2 cam isn't really THAT aggressive that it won't idle right. Are you still using the stock throttle body and MAF?

I actually went through pains to get the idle right on my LS1 setup, but -20 on the fuel trims do sound crazy crazy rich.
Click to expand...

Thanks for all the replys. Yes I am running the stock maf and tb still. I have the pcv plugged on the tb though, that is the only mod. I read somewhere that a cam sensor could cause a bad idle. I know I have the little dowel in the cam gear and I know it is in the right spot so I don't know what else that leaves. I guess as of now I have the stock inj in and I am doing VE tunes and I will keep up with them until the trims look right and then move on to maf tuning and see what happens. I have a question about tuning trims but I will start another thread about that so those of you that have responded in this thread please look at that one too ;). Thanks.
 
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