99 vette ls6 cold start idle and tuning HELP

[Proven Power]

vette was built by another tech i only know what i have been told about is ls6 engine bored and stroked g5x3 cam bbs 80mm intake and throttle body kooks long tubes and 3in exhuast system had rear o2s and no fronts just installed new o2s in front and removed rears i am posting tune as is and cold start to warm log about 16 min. of log keeps stalling can rev and sometimes will stay running has 42# blue giant injectors from bosch already changed flow for injectors just need help to get cold start and timing never tuned this big of cams

[FixedRoof]

If you are sitting there in park and it keeps dying, you need more timing in the idle spark in Park table. Looking at the scanner log, It's getting like little to no spark in park when it drops and tries to do. 14 degrees and dies. I have a G5X3 cam too (234/242 .598"/.612") It likes about 26 degrees at idle. Your low octane and high octane tables need more advance in the lower RPM areas as well. Idle Underspeed and table needs work too. You are not adding timing if it drops underspeed.

Your injector table looks a lil high too.

[Proven Power]

i dont know cam lift/duration or lobe sep could you post your tune so i can get an idea i mostly do tire size changes on 4x4 trucks never tuned large cams just tire size and timing/long and short fuel trims trans pressure and shift times

[Russ K]

There is a large difference between Bnk1 & Bnk2 fuel trims. Make sure that the front O2 sensors are not switched (left sensor plugged into right side).

Russ Kemp

[Proven Power]

Russ just installed left o2s pluged into left side and right o2s pluged into right side on frame rails

[Proven Power]

FIXED ROOF
should i just change all lower values to 26 Deg in low/high octane and park idle

It likes about 26 degrees at idle. Your low octane and high octane tables need more advance in the lower RPM areas as well

[FixedRoof]

You can try that, but you will have to play with it. Every car is different. Don't have a copy of my tune handy right now. You can do a search on the tune repository, as there are a couple cars on there with similar cams. Mine likes the 26 degrees but each is different.. also my car is an M6 which can affect it as well.

Also on the trims issue as Russ pointed out... You could have an exhaust or vacuum leak on one bank causing the trims to fluctuate. Buddy of mine had a vacuum leak from the intake not seating right. It causes problems with the LTFT's like that. Definitely make sure they are plugged in the correct sides. It's easy to screw up sometimes like with LG headers as the sensors are pointed in opposite directions.

Try disabling the MAF too and get the car to run decent in SD mode it. It may help out if you are fighting a screwed up MAF curve.

Steve

[EC_Tune]

If these are the Ford Blue Giants that have a dual cone spray pattern for the dual intake ports on the Fords, you will get a TON of port wall wetting with them and have transient issues "out the wazoo".

If not disregard the above.

[Proven Power]

injectors are blue giant how can i fix transient issues and could this cause fuel trim issues

[EC_Tune]

The easy answer: Change injectors.

To do transient fueling you need a load bearing dyno and a lot of patience and time. You have to have your steady state VE & MAF dialed in "perfect" (lol) before you can get into the transient fueling.

You have to make precise throttle transients from a steady state to find out what tranisent fueling is necessary to give you the correct AFR. Yes you have to have a wideband in the collector (or closer) as well. The wideband needs to be very fast reacting as well to see if you go rich or lean on the transients.

[Proven Power]

so i need to get timing and ve right frist corect before transients

[Proven Power]

i adjusted timing in idle park and raised timing in high and low octain log is cold start this am

going to adjust idle up 50 rpm

[FixedRoof]

Ok.. Looked at your new log. I believe you have a physical problem on bank 1 (driver side). The LTFT' and especially the STFT's are off the chain. The negative trims on bank 2 are because the PCM is trying to compensate for the issue on bank one. Your O2's seem to be working properly as they seem to be switching (cycling) normally. If you compare O2 mV readings from bank 1 and 2... bank 1 averages much leaner (lower mV).. It's trying to richen up the mixture +25 to compensate for the lean issue on bank one and at the same time lean it out - on bank 2. It's fighting itself.

You either have a vacuum leak on bank 1 or an exhaust leak. OR there is an issue with an injector. Like it's stuck open or something. Check your Injector o-rings where they go into the intake manifold for a vacuum leak there. You can also try old school tricks like using carb cleaner spray to help find a leak.

I see the MAF is 0 hz, so looks like it's unplugged. Thats a GOOD thing right now and it's not causing a problem.

Timing looks better, but thats not the problem. Also, I have NO idea about these injectors. They aren't commonly used on LS1's. The 42lb. Ford SVO green tops (Bosch) are the most common 42 used on LS1's... I've tuned a couple cars with them and they are relatively easy to tune. I don't know about that dual spray pattern thing.. I'd say it's not a good thing and yes you will be fighting transient fueling (if they are spraying off) with them once you get this issue figured out. That IFR table is about 8% higher than what I've used for a SVO 42. But i dont know about these.

Happy Thanksgiving.
Steve

[Proven Power]

found a tune for 2000 vette with g5x3 cam going to try some of those settings and do cold start log on sat. am thanks for help i will check for vac. and exhaust leaks then and post log and tune afterwards

[Proven Power]

this tune no cold stalling copied from HP Tuners Tune Repository seems to hav stoped cold start stall scan was lost hear is scan after warm up stays running in gear cold after warm up drove and cleared fuel from pipes looks like lt and st comming in now what do you think

[Proven Power]

this tune and log is most recent some look over i am going to drive vehicle and see how it does is not stalling at idle any more just not sure i am going the right way

[Proven Power]

no vac or exhaust leaks found tried just adjusting by sticky no luck iam thinking blue giant injectors are causing problems adjusted as good as can ltft and stft look better now on cold start but cant get vehicle to stop goin rich does anybody have part # for bosch green topps so i can get customer to get them

[FixedRoof]

bank 1 still has a problem. Here is a link for the green tops.

http://www.coolblueperformance.com/i...ROD&ProdID=220

[Proven Power]

thanks fixed roof found out injectorss are used one could be hanging open ????
ordered 42# green tops today need to start somewhere and that is a problem for sure runs rich all the time just can not remove enough fuel to make a change customer is good with that used old school trick carb cleaner around intake and injectors throttle body and so on no change in idle no vac. leaks checked exhaust system for leaks and none found

[Proven Power]

hear is new cold start log stalls out if you rev up and let idle down log is cold start to hot very long stalled about five times cold and hot