9th (cold Start) injector help please
Thread Starter
Instructor
Joined: Aug 2014
Posts: 113
Likes: 11
From: Lake Stevens WA
9th (cold Start) injector help please
So Im curious how much effect the 9th injector has on start up. I have replaced pretty much everything in the fuel system on my project vette, injectors, fuel pump, flushed the lines, full tune up, basically everything but the 9th injector. its just horrible to start up cold, takes forever to get it to fire, but then once its ran for a couple mins, I can shut it off, just touch the key and it starts right up. It idles and revs great once running, though it will die switching between reverse and drive putting it around for parking and such. Just curious if thats what happens when the 9th is dead or if I need to check something else.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
9th
I have done what you did.
i replaced injectors, regulator diaphragm, fuel pump, all o rings in the fuel rail.
really hard to start, then starts right up all day.
next morning, same thing.
i pulled the regulator, got a new diaphragm again, same thing.
then
i pulled all the plugs.
#1 plug smelled like gas.
talked to the ppl about a replacement injector.
but the gas cap had no pressure.
i changed the gas tank pressure regulator.
then cap was pressurized.
then the front of the car smelled like gas.
the purge valve on the canister went bad. Changed canister.
purge solenoid did not close, causing it to run bad.
changed that. I thought the 9th was leaking, and bought the cold start injector removal kit on ebay for $20.
then i put in a computer chip (eprom) module from an 89.
in 1989, they eliminated the cold start injector, and programmed the eprom for cold running, eliminating the 9th.
so now i am back to the injector.
it slowly drains the fuel pressure into the cylinder overnight. But starts better because of the evap valves are working and gas tank has pressure.
so dead in the water until injector shows up
i replaced injectors, regulator diaphragm, fuel pump, all o rings in the fuel rail.
really hard to start, then starts right up all day.
next morning, same thing.
i pulled the regulator, got a new diaphragm again, same thing.
then
i pulled all the plugs.
#1 plug smelled like gas.
talked to the ppl about a replacement injector.
but the gas cap had no pressure.
i changed the gas tank pressure regulator.
then cap was pressurized.
then the front of the car smelled like gas.
the purge valve on the canister went bad. Changed canister.
purge solenoid did not close, causing it to run bad.
changed that. I thought the 9th was leaking, and bought the cold start injector removal kit on ebay for $20.
then i put in a computer chip (eprom) module from an 89.
in 1989, they eliminated the cold start injector, and programmed the eprom for cold running, eliminating the 9th.
so now i am back to the injector.
it slowly drains the fuel pressure into the cylinder overnight. But starts better because of the evap valves are working and gas tank has pressure.
so dead in the water until injector shows up
Last edited by coupeguy2001; Jul 24, 2020 at 10:10 PM.
Racer
Joined: Aug 2019
Posts: 260
Likes: 94
From: Wilmington, Ohio
So Im curious how much effect the 9th injector has on start up. I have replaced pretty much everything in the fuel system on my project vette, injectors, fuel pump, flushed the lines, full tune up, basically everything but the 9th injector. its just horrible to start up cold, takes forever to get it to fire, but then once its ran for a couple mins, I can shut it off, just touch the key and it starts right up. It idles and revs great once running, though it will die switching between reverse and drive putting it around for parking and such. Just curious if thats what happens when the 9th is dead or if I need to check something else.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 113
Likes: 11
From: Lake Stevens WA
No havent figured anything out yet, was hoping someone had something similar and got it going, my guess is its the 9th injector and I just have to hunt down a replacement, but they are hard to find and my vette is down the project priority list currently. I just had to move it the other day and it was a huge pain to get running. With an 85 I cant just change to a later year chip, so maybe I should look for a aftermarket burned one, could get my temp dropped down to 180- that way to.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
There is a switch on the front of the intake base that fires the 9th injector when coolant temps are low.
You could have a mechanic hook up a solvent feed to clean all injectors.
What is your fuel pressure before and after cold startup?
You could have a mechanic hook up a solvent feed to clean all injectors.
What is your fuel pressure before and after cold startup?
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
Did you put Bosch 3's in? They are known to have idle issues on Camaros (Iron headed L98's), seems the aluminum headed guys on here report they run "fine", but the data loggers and tuners on another TPI forum don't think so. My L98 is in an IROC, I am running Bosch 3's, I had to change the voltage offsets to get my idle smooth.
A few other things to consider is if you IAC passage is clean and your minimum idle is set where it can control the idle in it's range.
Thread Starter
Instructor
Joined: Aug 2014
Posts: 113
Likes: 11
From: Lake Stevens WA
So I took a couple mins and checked a few things. I am getting power to the cs injector at the wire going into the connector on cranking and the fuse behind the dic is good. Yes I switched to the bosch 3 injectors, I guess thats whats causing my idle issues. How did you change the voltage offsets? While I was checking the 12v at the cs injector the car started up rather quickly, way better than normal. I am wondering if there is something going on with that connector now. It always starts good after its runs the first time so I will have to play with it some and check it at another time. Will need to dive into it a bit farther and pull the valve cover bolts to get that hard line out of the way, So I can get to the pigtail and pull it off. I could get lucky and its just a bad connection at the injector I guess. Thanks for all the help so far, I really appreciate it, this has been a problem thats been bugging me for a year now.
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Melting Slicks
Joined: Jun 2011
Posts: 2,383
Likes: 385
From: Leland , North Carolina
If you have an automatic it's easy to buy the 9nth injector delete kit for $30 and have a chip burned with 89 program for $100 deleting it along with other stuff such as fans coming on sooner etc.
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
You need them updated in the .bin, custom tune. I do not have the equipment to burn chips, but I have the voltage offsets I will share if someone needs them. I would post them now, but I do not have a .bin on my work computer.
Last edited by KyleF; Jul 28, 2020 at 08:12 AM.
Safety Car
Joined: Mar 2003
Posts: 3,583
Likes: 504
From: Indianapolis IN
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (stock) 2019
That is not 9th injector related. The 9th injector only gets power during cranking. Once it fires off, the 9th injector is no longer in play. While it may contribute to extended crank times it will have nothing to do with the condition of it stalling due to moving between gears.
Did you put Bosch 3's in? They are known to have idle issues on Camaros (Iron headed L98's), seems the aluminum headed guys on here report they run "fine", but the data loggers and tuners on another TPI forum don't think so. My L98 is in an IROC, I am running Bosch 3's, I had to change the voltage offsets to get my idle smooth.
A few other things to consider is if you IAC passage is clean and your minimum idle is set where it can control the idle in it's range.
Did you put Bosch 3's in? They are known to have idle issues on Camaros (Iron headed L98's), seems the aluminum headed guys on here report they run "fine", but the data loggers and tuners on another TPI forum don't think so. My L98 is in an IROC, I am running Bosch 3's, I had to change the voltage offsets to get my idle smooth.
A few other things to consider is if you IAC passage is clean and your minimum idle is set where it can control the idle in it's range.
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
Did you data log? Do any tuning? How did the BLMs look?
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
I don't think it has to be a burn and go copy. You can edit the .bin for the correct year to have the right pulse width to CTS and there may be a few other correction tables, but I am sure you can get the extra squirt of fuel from cranking by manipulating the tables.
Last edited by KyleF; Jul 31, 2020 at 08:59 AM.
Drifting
Joined: Aug 2019
Posts: 1,339
Likes: 225
I'd still just fix the CSI system. Can't be too tough, as he's proven that it functions. I've owned my 85 for 35 years. It ALWAYS fires instantly, even if it has sat for years, which it sometimes does. I don't understand jacking around with things to 'improve" them when restoring original functionality is adequate.
Seriously: Do you really think this OP is capable / qualified to calculate the changes necessary in his .bin and then figure out how to implement them? I sure don't think he is. I personally know what .bins and CTS and PROM burning and Moats and logging, and all this stuff is. I've done it on Syclones and Typhoons. I highly doubt the OP has a clue as to where to begin to change his .bin to eliminate the CSI. Just gaining access to the ECM in an 85 is not a trivial task. It's fussy as hell.
If he fixes the connections in his CSI system, his car will again start reliably just like it was designed to. You guys are making mountains out of molehills.
Seriously: Do you really think this OP is capable / qualified to calculate the changes necessary in his .bin and then figure out how to implement them? I sure don't think he is. I personally know what .bins and CTS and PROM burning and Moats and logging, and all this stuff is. I've done it on Syclones and Typhoons. I highly doubt the OP has a clue as to where to begin to change his .bin to eliminate the CSI. Just gaining access to the ECM in an 85 is not a trivial task. It's fussy as hell.
If he fixes the connections in his CSI system, his car will again start reliably just like it was designed to. You guys are making mountains out of molehills.
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
I'd still just fix the CSI system. Can't be too tough, as he's proven that it functions. I've owned my 85 for 35 years. It ALWAYS fires instantly, even if it has sat for years, which it sometimes does. I don't understand jacking around with things to 'improve" them when restoring original functionality is adequate.
Seriously: Do you really think this OP is capable / qualified to calculate the changes necessary in his .bin and then figure out how to implement them? I sure don't think he is. I personally know what .bins and CTS and PROM burning and Moats and logging, and all this stuff is. I've done it on Syclones and Typhoons. I highly doubt the OP has a clue as to where to begin to change his .bin to eliminate the CSI. Just gaining access to the ECM in an 85 is not a trivial task. It's fussy as hell.
If he fixes the connections in his CSI system, his car will again start reliably just like it was designed to. You guys are making mountains out of molehills.
Seriously: Do you really think this OP is capable / qualified to calculate the changes necessary in his .bin and then figure out how to implement them? I sure don't think he is. I personally know what .bins and CTS and PROM burning and Moats and logging, and all this stuff is. I've done it on Syclones and Typhoons. I highly doubt the OP has a clue as to where to begin to change his .bin to eliminate the CSI. Just gaining access to the ECM in an 85 is not a trivial task. It's fussy as hell.
If he fixes the connections in his CSI system, his car will again start reliably just like it was designed to. You guys are making mountains out of molehills.
There are people who can burn you a chip, not that difficult.
Last edited by KyleF; Jul 28, 2020 at 12:13 PM.
Safety Car
Joined: Mar 2003
Posts: 3,583
Likes: 504
From: Indianapolis IN
Finalist 2020 C4 of the Year - Unmodified
C4 of Year Finalist (stock) 2019
In addition, I don't need to go do my own research. No problem = no need.No I did not data log. Tuning? I think I already covered that when I said I did nothing. BLM's? Why would there be a need to drag out my TECH 1 if there are no problems.
Moving on now....
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
Maybe I should just say it directly. Those who tune and log know adjustments are needed. Those who are satisfied as above usually say they run "OK".
My car "ran" with no codes for over 2 years.
What a difference now that I have an ECM I can tune. Even my wife noticed how much better it was and the lack of exhaust smell (no cat from PO).... but it ran fine before
Last edited by KyleF; Jul 28, 2020 at 01:04 PM.
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
I didn't "miss it", I just chose not to address the stalling. He's got to get it started before he can address the stalling. One step at a time.
I'm well aware that the Cold Start system has nothing to do with stalling. I know how the L98 9th injector system works, the wire colors I cited were from memory, I didn't look them up.
I DID take notice that you brought up Bosch III as a possibility for the stalling, and I'll be dipped in chit that he has Bosch III's. That was impressive. Great intuition.
Cut me a little slack. so far, I'm the only guy in this thread that made a suggestion that resulted in progress. His car started more easily during the testing. Your catch on the Bosch III's may lead him to fixing the stalling.
Tuning and changing .bins is a slippery slope, fraught with risk that the desired results will be difficult to achieve, and that unintended results will prevail instead.. The OEM calibrations are developed over thousands of hours of testing and validation by people with years of experience. Most guys messing with their .bins don't know what they are doing, and are literally experimenting, including the guys that sell their bins to others. Recommending that someone install someone else's "experiment" into their car as a solution to a non-problem doesn't make sense.
Arguing with others about the merits of changing calibrations is really cluttering up this guy's thread. Not cool. I'll delete these later.
I'm well aware that the Cold Start system has nothing to do with stalling. I know how the L98 9th injector system works, the wire colors I cited were from memory, I didn't look them up.
I DID take notice that you brought up Bosch III as a possibility for the stalling, and I'll be dipped in chit that he has Bosch III's. That was impressive. Great intuition.
Cut me a little slack. so far, I'm the only guy in this thread that made a suggestion that resulted in progress. His car started more easily during the testing. Your catch on the Bosch III's may lead him to fixing the stalling.
Tuning and changing .bins is a slippery slope, fraught with risk that the desired results will be difficult to achieve, and that unintended results will prevail instead.. The OEM calibrations are developed over thousands of hours of testing and validation by people with years of experience. Most guys messing with their .bins don't know what they are doing, and are literally experimenting, including the guys that sell their bins to others. Recommending that someone install someone else's "experiment" into their car as a solution to a non-problem doesn't make sense.
Arguing with others about the merits of changing calibrations is really cluttering up this guy's thread. Not cool. I'll delete these later.
I belive the two could be related.
However, I am never opposed to verifying something is working correctly first. If the CST has failed for some reason, it should be repaired. It cost nothing to check it.