code p02a1 (injector 2 leaking) runs smooth, HELP

chasten

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May 25, 2021
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Central Washington statw
ok i just checked compression all cylinders were 325 giver or take a couple pounds. i tested the voltage not sure if the meter is just too slow to register the peaks or if that’s accurate. the little bar graph on the bottom bounces off 40 v.
 

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Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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the graph on the meter will be more accurate than the digital numbers, the refresh rate is not fast enough. record the graph on your phone so you can see if its hitting peak voltage.

did you re-ohm your last test? where did you get the figures on the correct ohms needed? if from S&S and you are testing the solenoid side of the injector, clarify with them what you have found and if you are testing them as they would.

325psi compression is lllloooowwww for your truck. you should be seeing 400+. was the engine cold? are you cranking till the pressure stops building in the gauge?

if you get the code for cylinder 2, based on what im seeing, you should be getting it for cylinder 5 as well. is cylinder 2 the only code?
 

2004LB7

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Dec 15, 2010
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I don't know of any reliable way to check injector voltage without an oscilloscope. It's not just a voltage source. It pulses a higher current first to open the injector, then drops to a lower holding current. It does this about once every second during idle not counting the post or pilot injections.

LMMs are supposed to be 24 volts on the injectors but that is probably nominal and doesn't count the peaks or holding. You could just use the meter to compare each injector to each other and see if there is any outliers. Otherwise the actual number on the meter is not too reliable but consistency is
 

chasten

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May 25, 2021
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Central Washington statw
code is only for #2. on compression test, engine was warm to the touch but not hot. i just cranked for 10 sec then checked the gauge. i took a video of the graph bar (wouldn’t let me post) but it stops right at 40

on the ohm test. i’m a little lost. should i be testing between the pins on the injector or between the pins on the plug or ground and plug? should i disconnect the batteries first?
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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code is only for #2. on compression test, engine was warm to the touch but not hot. i just cranked for 10 sec then checked the gauge. i took a video of the graph bar (wouldn’t let me post) but it stops right at 40

Either your compression tester is leaking, gauge is bad or your engine is hurting. you might want to really confirm this before much else.

on the ohm test. i’m a little lost. should i be testing between the pins on the injector or between the pins on the plug or ground and plug? should i disconnect the batteries first?

As stated before, call S&S and verify with them what ohm's test they want. you stated in the first post that it was 10 ohms but .3 was what it should be. i can only assume you got that info from S&S in which case you need to clarify exactly what they want tested.

see quote above in red
 

2004LB7

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Get the engine up to operating temp before checking compression. Disable the injectors so they don't fire while cranking. Crank it over till it maxes out on the gauge. That is your reading. May also be a good idea to have a good charger on the batteries to keep them topped up so you get full cranking RPMs

Test the ohms from the two pins on the injectors and retest it at the ecm connector. The harness should add no more then about one ohm to the injectors ohm reading. It should be pin to pin and compare it to what S&S said it should be. Then test injector and harness for pin to ground, this should not read anything less then mega ohms
 

chasten

Member
May 25, 2021
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Central Washington statw
i used the HF compression tester, but i just pulled one GP at a time tested the cylinder then reinstalled and moved to the next one. should i re-do it hot with all the GP out ? i had a charger on the batteries
 

chasten

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May 25, 2021
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Central Washington statw
which pins should i be testing against each other in the ecu plug. there are fuel injector supply voltage 1-4
and fuel injector control 1-8
looks like injectors are paired 1/4 6/7 2/5 3/8 which pair of injectors get which voltage supply?
 

chasten

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May 25, 2021
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Central Washington statw
tested ohms of all injectors at ecm plug. tested #2 several times and got different readings till i improved my testing method (sewing needle with alligator clips) the last 3 times i pulled needles out then reset and tested 0.5

onto the compression test redo.

would a dirty injector cause this issue? i was very careful to clean all the lines really well and sprayed out with brakleen before installing. but i also built this in the driveway. also the fuel in the first tank about a year old. i was going to dump it but several shops said it would be fine to run. 6006E618-599E-4558-AF7E-EB6B7C1C6A01.jpeg
 

2004LB7

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I think your readings are ok. But run them by S&S to see what they say

Injectors have to be extremely clean when going together. Rust, dirt, etc makes for a very short lived injector. Also I would put some fresh diesel in it before testing again. It would be stupid to go through all this only to discover it was bad fuel
 

chasten

Member
May 25, 2021
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Central Washington statw
ya i’ve had a couple moments like that on this build. i filled it with new diesel yesterday. i was thinking about shorting the fuel system and letting it idle through a gallon of high strength 1:1 cleaner and diesel.

sent results to s&s. they haven’t been very responsive.
 

chasten

Member
May 25, 2021
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0
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Central Washington statw
re did the compression test. most tested at 395psi one tested at 390 and one at 400. i have a feeling that HF adapter doesn’t seat very well though.
tuner says tunes should have no affect on balance rates.
 

JoshH

Daggum farm truck
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Feb 14, 2007
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That code is set when an injector has a balance rate below -7 mm³. I'm not saying you are wasting your time verifying the wiring, but that would be setting a circuit code. This is something mechanical with the truck. I would try moving that injector to another hole and see if the problem moves with it. It could just be a matter of the factory calibration codes throwing things off. Aftermarket injectors typically don't come with new codes, so I like to make the codes all the same to prevent them from causing balance anomalies like this.