bosch 42lb green tops cold start issues

[rileymeekpierce]

Hello,
as some of you may be familiar with, I had an issue with my corvette and some knock retard a few weeks ago that i tracked down to injectors, cyls 1 and 3. I am wanting to make a bit more power and go over to e85, so i bought a set of bosch green tops, and plugged injector data into my tune. Now, during a cold start (still on 91), the car will run for a second or 2 and then die. I can't give it any throttle to keep it idling, it just chokes and dies. This problem stays until the car warms up and then idles well. I don't have a cold start log of the car, but I have a log of it running when warm, and the tune file. Prior to the injector install the idle was good, never had problems starting.

So far, I've been scaling down the injector offset vs volts vs vac table in order to lean idle out to 14.7 afr, but that hasn't helped this cold start issue.

I'm sure I'm missing something and would appreciate a more experienced tuner to point me in the right direction.


c5vetteidlelog.hplc5vette383VEtuning42lbdraft5.hpt

[blindsquirrel]

Where did you find the injector data? Where did you get the injectors from?

I think that if you need to tweak the injector data to make it run right, then the data being used isn't correct for those injectors.

[rileymeekpierce]

Where did you find the injector data? Where did you get the injectors from?

The injector data is from a sticky on the ls1 forum for these part number injectors(0 280 155 968 ). The injectors themselves are from a friend who bought them and then never used them. I don't know where he got them.

[blindsquirrel]

440ccHPT_Plug_and_Play_Data_FIC_42_GreenGiant_0280155968_GMONLY.xlsx

Min Injector Pulse = .243 or something, it's not in the datasheet

edit: And if it's still not right with that data, then the injectors are fakes/knockoffs and should go in the trash.

[rileymeekpierce]

Thank you blindsquirrel. I will use this data and let you know - maybe this is a lesson to just buy from retailers directly. is FIconnection any good?

[blindsquirrel]

Yeah FIC (either one of them) are fine but why do you need to spend that kind of money for such a small injector?

https://www.ebay.com/itm/274424906026

Those, from that seller, in that specific listing, are the only ones on Ebay I can vouch for. 50.4lb-hr and all the data straight from GM.

[Alvin]

Those old green top SVO's are pretty bad by today's standards.

Lots of counterfeits floating around too.

[rileymeekpierce]

440ccHPT_Plug_and_Play_Data_FIC_42_GreenGiant_0280155968_GMONLY.xlsx

Min Injector Pulse = .243 or something, it's not in the datasheet

edit: And if it's still not right with that data, then the injectors are fakes/knockoffs and should go in the trash.

Same issue. Starts, runs, dies a second later. Will throw these away and check out the link you sent earlier.

[blindsquirrel]

Does it stay running if you disable the injectors, and spray it with something flammable like brake cleaner?

[RDF1]

Yeah FIC (either one of them) are fine but why do you need to spend that kind of money for such a small injector?

https://www.ebay.com/itm/274424906026

Those, from that seller, in that specific listing, are the only ones on Ebay I can vouch for. 50.4lb-hr and all the data straight from GM.

Ive bought 20 sets of these now and they are very good. No issues at all.

[rileymeekpierce]

Does it stay running if you disable the injectors, and spray it with something flammable like brake cleaner?

I will check, but the damn thing started and idled fine before these injectors. I can also keep it alive with the gas pedal for a bit before it falls back to idle and dies

[edcmat-l1]

First off, is there a fuel pressure gauge on the car? That's diagnostics 101. After verifying the fuel pressure, does it have any codes? If FP is good and no codes present, multiply your IFR by .7 and see if it runs.

[rileymeekpierce]

First off, is there a fuel pressure gauge on the car? That's diagnostics 101. After verifying the fuel pressure, does it have any codes? If FP is good and no codes present, multiply your IFR by .7 and see if it runs.

Plenty of fuel pressure, primed and when running. No codes. I will try the ifr change.

[gtstorey]

Fuel pressure is a number, not a plenty.

[rileymeekpierce]

Fuel pressure is a number, not a plenty.

60 psi at idle. I've already checked this.

[SiriusC1024]

Post your tune with updated injector data, please.

[rileymeekpierce]

This is the tune file with blindsquirrel's data.

c5vette383VEtuning42lbdraft7.hpt

[SiriusC1024]

See how this goes. If it runs get a log, please.

[rileymeekpierce]

In fact it did. What'd you change?

c5vetteidlelog2.hpl

[blindsquirrel]

Compare > View Comparison Log