how would a car run with too large of injectors?

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Grifter

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I added 30#'rs to my car, and the requisite new tune on the chip, or so i think. Ever since i put the chip in the car, it hasnt idled smoothly, and seems to miss under acceleration. no codes or anything show up. it also seems to idle rich. the exhaust even smells rich at idle (no cats, so i can actually smell it). my question is, if they didnt setup my new tune for 30#'s, would the car react this way since it thinks 24#'s are in there?
i need to get some 24#s and swap and see if that clears it up.
 
Leaky injector? Only thing elese is a bad program on the chip. Cant think of anything else right off.
 
shouldnt be, brand new 30#'s.. i hope i didnt get a bad one..

i think i tracked down a set of 24's to test with, will have to see what comes of it all.
 
Grifter said:
my question is, if they didnt setup my new tune for 30#'s, would the car react this way since it thinks 24#'s are in there?
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For a while? I would think that after a while the system would lean out by cutting back the injector-on cycle time. If it couldn't lean out enough, it would throw a CEL.

The issue I see with larger injectors(even tuned) when not needed is system duty-cycle. While you don't want over 85% continuous injector duty-cycle you don't necessarily want a ridiculously low duty-cycle either. Consider the spray pattern and fuel atomization. You want a drawn out spray for good atomization, not just a quick 'dump' of fuel.
 
its the stock maf. you couldnt get me to put a C&L in my car..

driller,
i get what your saying. the jump from 24's to 30's isnt that extreme. the car should compensate for the fuel quickly, considering the chip SHOULD be doing most of the work on that. the car has about 10mins of runtime on it since the battery was replaced.

i dont think that 30's would demand such a low puslewidth to keep the proper amount of fuel such that it wouldnt spray. 30's arent huge overkill

man i wish it would just throw a CEL so i had something to track down.. LOL
 
Grifter said:
driller,
i get what your saying. the jump from 24's to 30's isnt that extreme. the car should compensate for the fuel quickly, considering the chip SHOULD be doing most of the work on that. the car has about 10mins of runtime on it since the battery was replaced.

i dont think that 30's would demand such a low puslewidth to keep the proper amount of fuel such that it wouldnt spray. 30's arent huge overkill
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I agree going from 24's to 30's shouldn't of been that big a jump. But it is 125% of what it was. I'm not sure of the range the EEC can control but 25% may be near it's limit??

I'm not confident 10 minutes is enough. The EEC uses a multiplier to adjust the air/fuel ratio. Starting with a cleared system(multiplier = 1), it very well may take a few driving cycles to adjust to a 0.8 multiplier for the fuel injector duty cycle. The EEC simply averages out X number of complete driving cycles when altering these tables. True, the chip should've been pre-tuned to get close but without it being on a dyno with a gas analyzer, it's a shot in the dark at best. I had my chip 'custom tuned' and was still able to tweak a significant HP increase on a dyno-tune.

Just the facts of manufacturer variables and limitations of the EFI system.
 
Grifter said:
its the stock maf. you couldnt get me to put a C&L in my car..

driller,
i get what your saying. the jump from 24's to 30's isnt that extreme. the car should compensate for the fuel quickly, considering the chip SHOULD be doing most of the work on that. the car has about 10mins of runtime on it since the battery was replaced.

i dont think that 30's would demand such a low puslewidth to keep the proper amount of fuel such that it wouldnt spray. 30's arent huge overkill

man i wish it would just throw a CEL so i had something to track down.. LOL
Click to expand...

is ten minutes long enough to adapt?
 
Frat-man-du said:
Leaky injector? Only thing elese is a bad program on the chip. Cant think of anything else right off.
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im with frat man. whats on the chip
it would run normal. you will probl. be better off w/ a tune/ to correct the a/f
 
the chip is my old dyno tune, updated to take car of a few things, and add 30's.. all the other things are taken care of, just doesnt seem like the 30's are..
 
Grifter said:
the chip is my old dyno tune, updated to take car of a few things, and add 30's.. all the other things are taken care of, just doesnt seem like the 30's are..
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Have you disconnected the battery
 
Grifter said:
yeah, its been in and out a couple times too.. just put a new one in there..
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Well there is somthing else wrong w/ the car. if you had the chip tuned for the 30's it should be working fine.... try running the car w/ out the chip. it should run fine w/ out if even w/ the 30's.
 
thats getting to the question i'm trying to get answered.. assuming the chip was NOT tuned for 30's, does what i am describing sound like how a car would run with too big of injectors..
but yeah, i overlooked the simplest thing, pull the chip :slap:
 
Grifter said:
but yeah, i overlooked the simplest thing, pull the chip :slap:
Click to expand...

I found it easier to get a switch chip. Now I can just switch back to stock. :D
 
Grifter said:
thats getting to the question i'm trying to get answered.. assuming the chip was NOT tuned for 30's, does what i am describing sound like how a car would run with too big of injectors..
but yeah, i overlooked the simplest thing, pull the chip :slap:
Click to expand...

overlook look everything you disconnect again and make sure nothing is broke or not hookup.
 
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