120# injectors, one is weak causing issues.

[diponyou]

Well I just got done installing some racetronix 120# low impedance injectors.

After the first start it had a slight miss at idle but it leveled out once a load was put on it.

I checked the injectors and noticed the #2 injector is noticeable quieter than the rest, I put a stethoscope on it and you can hear it pulsing but it is much weaker than the other 5.

Yesterday I was driving and even though the miss was there at idle it was VERY strong, a/f reading was on point. Then randomly the a/f reading went to shit and it was leaning out very bad.

Reset the ecu, swapped mafs, o2 sensor, iat, verified scanmaster settings, good fuel pressure, spark plugs, new coil pack...

I just dont get how it was running awesome under boost and then all the sudden its leaning out whenever boost goes over 10psi. Yesterday it was seeing wot at 22psi and it was perfect.

Today I tried getting on it and it was backfiring and falling on its face at wot !!!!!!

I have a new ignition module waiting to go in, and a ls1 maf and translator that will be going in soon. But other than that I am out of ideas.

If I need to send the injector back I will, but would one weak injector cause all this even after it was fine yesterday?

 

[Phoneguy]

What brand of injector?

Bryan

 

[diponyou]

racetronix specials?
Not sure what brand they carry but it is their low-z 120#s

 

[Phoneguy]

There was a recall on the Injector Dynamics but I think they were the 160's.

Bryan

 

[diponyou]

I will contact them tomorrow and see what they say. Everything was perfect before the swap so I know its nothing on my end. And its only 1 injector.

 

[Phoneguy]

Im sure they will take care of it...

Bryan

 

[diponyou]

thanks

 

[Squid4life]

Might replace the inj harness with a new one from caspers. They sell a new stock replacement as well as one with thicker gauge wires. Maybe the harness is getting weak from being flexed, bent, twisted, plus all the heat cycles?

I know i ohmed it out once and it was good, but that was years ago...

 

[CGASTON]

Well I just got done installing some racetronix 120# low impedance injectors.

After the first start it had a slight miss at idle but it leveled out once a load was put on it.

I checked the injectors and noticed the #2 injector is noticeable quieter than the rest, I put a stethoscope on it and you can hear it pulsing but it is much weaker than the other 5.

Yesterday I was driving and even though the miss was there at idle it was VERY strong, a/f reading was on point. Then randomly the a/f reading went to shit and it was leaning out very bad.

Reset the ecu, swapped mafs, o2 sensor, iat, verified scanmaster settings, good fuel pressure, spark plugs, new coil pack...

I just dont get how it was running awesome under boost and then all the sudden its leaning out whenever boost goes over 10psi. Yesterday it was seeing wot at 22psi and it was perfect.

Today I tried getting on it and it was backfiring and falling on its face at wot !!!!!!

I have a new ignition module waiting to go in, and a ls1 maf and translator that will be going in soon. But other than that I am out of ideas.

If I need to send the injector back I will, but would one weak injector cause all this even after it was fine yesterday?

Here is what you can try.

Without or without someone helping you, you need to monitor your IAC counts. Discount the connector to #2 injector. What does the IAC do? Does it increase in counts, trying to increase? Or does it just stay the same. Now you suspect that # 4 is good. So do the same thing to it? If it is good? You should see the IAC move noticeably.

Now switch injector harness for # 2 and # 4. At idle, you should be fine doing this. Don't rev it up. Now discount the harness one injector at a time. Does the IAC Move. Again.

If you IAC barely moves, then highly likely that the injector is bad. Now to be safe can switch injector 2 and 4. Does anything change? Disconnect #2 now. The IAC should move noticeably. Now disconnect #4. It should act as #2 did before you switched plugs.

If the problem stays on number 2 then you you need to check out your injector harness or cylinder!!

Sent from my iPhone using Turbo Buick

 

[SHADOWII]

I don't see it stated, but do you have the mod'd ecm w/the low impedance drivers?

 

[Chuck Leeper]

Check ohm readings on all 6........
What are you firing these injs with, a stock ECM? If so, has it had the drivers upgraded for low imp injs??
As mentioned, if the harness is the original... change it.

 

[diponyou]

Yes the ecu has been modified to drive the low-z injectors.

I swapped the injector plugs around and same issue, #2 is barely working. Now for some reason it is idling super lean, like 17:1. There is a local guy that cleans and flow tests injectors. I am going to bring him the bad one and a good one and see if he can get it going before I send it back.

Any ideas on the lean idle?

 

[Chuck Leeper]

Take all 6 to him.
U have a data logger or a Scanmaster readings to post up?

 

[CGASTON]

Yes the ecu has been modified to drive the low-z injectors.

I swapped the injector plugs around and same issue, #2 is barely working. Now for some reason it is idling super lean, like 17:1. There is a local guy that cleans and flow tests injectors. I am going to bring him the bad one and a good one and see if he can get it going before I send it back.

Any ideas on the lean idle?

What about swapping #2 and #4 injectors. Need to see if the problem follows. Just swapping harness is a small part of the check. You need to verify if the problem in #2 goes to #4. If you dont, how will you know it is injector or cylinder.

Clint

 

[diponyou]

Take all 6 to him.
U have a data logger or a Scanmaster readings to post up?

I can post them up a little later today. I took him the inectors, he is just going to compare the flow rate between them and make sure the bad one is working properly after he does his thing to them.

I noticed my iac at idle was around 40-50 which I know is high.

What about swapping #2 and #4 injectors. Need to see if the problem follows. Just swapping harness is a small part of the check. You need to verify if the problem in #2 goes to #4. If you dont, how will you know it is injector or cylinder.

Clint

I will swap them if the guy is able to fix it later on this evening. And even if my cylinder was bad, the injector wouldn't be affected by that...it should still pulse at the same intensity as the other 5 correct??



Would one faulty injector cause the wideband to read lean?

 

[pacecarta]

any news on this

 

[CGASTON]

I can post them up a little later today. I took him the inectors, he is just going to compare the flow rate between them and make sure the bad one is working properly after he does his thing to them.

I noticed my iac at idle was around 40-50 which I know is high.


I will swap them if the guy is able to fix it later on this evening. And even if my cylinder was bad, the injector wouldn't be affected by that...it should still pulse at the same intensity as the other 5 correct??



Would one faulty injector cause the wideband to read lean?

I just went through the same problem. Worked with Cal on it. I was able to determine a bad injector. Act like a dead cylinder.

 

[pacecarta]

I just went through the same problem. Worked with Cal on it. I was able to determine a bad injector. Act like a dead cylinder.

more concerned with his results on the 120s from rtx as i have a friend who made the switch to e85 and only changes were
the fuel (e85) , new pump and lines , xfi firmware upgrade to 2.0 and a new e85 tune from cal , tr6 ignition and the injectors (new 120's from rtx)
the car wont idle or stay running without holding pedal at around 3k

swapped back in the stock delco ignition setup and runs the same
so whats left is...
the tune which im pretty sure thats not it
or the injectors which i cant really tell him to try disconnecting one at a time as it wont idle low enough to try that

at this point im going to bring him my 120s and swap those in next and hope its that simple

 

[diponyou]

Injectors are good.
I guess that one is just more quiet than the others. But it flows within 1%

Went up to nick Micales house yesterday. We upped the base fuel pressure and I upped the wot pressure on the chip.

Still cutting out at wot, once it hits like 18-20psi it acts like spark blowout. But it is definitely better than before. No More lean spikes.

 

[diponyou]

more concerned with his results on the 120s from rtx as i have a friend who made the switch to e85 and only changes were
the fuel (e85) , new pump and lines , xfi firmware upgrade to 2.0 and a new e85 tune from cal , tr6 ignition and the injectors (new 120's from rtx)
the car wont idle or stay running without holding pedal at around 3k

swapped back in the stock delco ignition setup and runs the same
so whats left is the tune which im pretty sure thats not it or the injectors

im going to bring him my 120s and swap those in next

Let me know how that goes. I'm not ruling out the injectors just yet.