Hello all,

I have been working with a setup I have over on the EFILIVE forum and cant get much resolution to this problem. Seems like not many people have much experience with Gen I small blocks tuning nor the Marine EFI intake. Hopefully you guys will have the support I need!!

So here is what I have:
97 350 Vortec engine in a 2001 S-10 punched out to 383. Compression ratio is right about 9.8:1 and running 93 octane fuel. Stock heads 64cc ported and polished heads, long tube headers, Comp Cams XFI 280 cam (08-467-, marine MPFI intake, 27lb injectors (2001 LS1 EV6 style), and CAI. I'm using COS5 with a 2002 Chevy Express Van tune in a 0411 pcm.

I have tried varying table B0102 and B4343 to make it start a lot easier but with no success. The injectors are spec'd out correctly and I have proper fuel pressure of 58psi when cranking. Just seems like I have way too much timing or too much fuel! I have the same issue no matter if I use the 12212156 OS or the COS5.

I can send you my tune via email!

Do you have a wideband sensor, and if so did you use it to complete the AutoVE procedure listed at EFI Live?

Did you change the engine parameters to reflect the extra cubes? There should be a table right on top that shows cylinder size of 43.75 which is for a 350. You want that to show 47.875 for a 383.

Have you taken any logs to show what the engine is doing? What temperature does the computer think the truck is at?

Sorry, don't have my EFI Live here at work, can't name any tables.

Yes, running FJO wideband, ran CALC.VE instead of AutoVE, cylinder and throttle body size have been changed, I can see all sensor values are correct but the pcm is commanding an AFR value of 5 when cranking.

it may be a while before i can get the file from(home) with my 383 with marine intake/zz4 cam setup i used to have but when i get a moment I will try to send it tonight if possible so you can compare your file top mine. I had to change a ton of parameters for mine and start up perfectly and run like a factory setup. it was probably 80+ corrections or more to gert it the way i wanted it for (ME) with efilive. PM me your email address and I'll give you something to compare with and see if it helps you some.
Robby

I never got mine to start correctly, always had to give it just a little throttle to start. If not it would fire and barely run for a few seconds then die. I sold the truck.

W_D_R wrote:

I never got mine to start correctly, always had to give it just a little throttle to start. If not it would fire and barely run for a few seconds then die. I sold the truck.

Mine does the same been to lazy to mess with it.

Most likely it's too much fuel.
I recall tuning this for the cam in the 350 way back in the day.

What software did you use to tune this setup back in the day, James B.?

I've had the OBD-II version of TunerCATs nearly since it came out. That equipment was a prerequisite to the Marine Intake swap ever being considered for us.
I still use TunerCATs today. I've got VDF's for 5 different PCM types and having unlimited VIN licenses is unmatched by ANY other product.

Would you still have the files for the tunes your worked on back int he day? Maybe i can preview them with Tunercat's software to make adjustments to my tune.

Has anyone been successful with this type of setup?? Looks like the most difficult part of it is due to the swap of injectors. Can anyone provide any tips?

injectors can be a PITA to tune since many of the values are unknown on many injectors....but there are alot of other factors that come into play...have you done RAFIG and RAFPN logs to correct B4307? even though you've done the CALC.VE, you may want to run the AutoVE to verify that you've got correct values in the VE table too.

do you have your tune and possibly a log or something posted somewhere? I'll shoot you a PM with my e-mail if you'd rather e-mail them.

Yes, have ran both RAFIG and RAFPN. Idle is pretty smooth while warming since I tweaked table A0008.

I will try running the AutoVE again to double-check my values. Would switching to speed density solve errors with this large cam setup?

I have had no issues with running a MAF on my setup with a ZZ4 cam. its not the same as your cam, but I don't see that being the issue. does it run better is SD vs MAF? and have you done any correction to the MAF table (like autoMAF)?

Have not tried adjusting the MAF values nor have i fully switched to SD. I guess that is my gray area here.....does the MAF have effects on cranking?

'eh, everything kinda plays together, VE will play a larger role, but if you're running the MAF it does contribute somewhat, you'll want to do an autoMAF to make sure it's seup correctly, just like the VE.

typically when you run a MAF, its actually a calculated blend between MAF and VE for fueling calculation. the engine will extrapolate between the two but rely more on the VE for transitional fueling, and more on the MAF for consistant states and higher RPM, but if they're both enabled, they will both play a role most all of the time. thats why its important to fail the MAF while tuning the VE, and disable the VE while tuning the MAF. you want to make sure they are corrected independant of each other...for cranking the VE will play a larger role, but if the MAF is enabled, then it'll still play a role.

personally I've always done autoVE since the calcVE stuff wasn't introduced until after I had already been tuning for a while. so I'm more familiar with the autoVE/autoMAF stuff. but that doesn't mean calc.ve is worse or anything. but since calc.ve is a calculation more than a real time correction like autoVE, its a good idea to run the autoVE to verify your values, because if you're values are off in the VE table, then when you extrapolate for the cranking VE, that will be off too....

also, if your IFR table is off, that error can be tuned into the VE when you do the autoVE/calc.VE/etc....so having a correct IFR is really important. are you injectors flow tested?

Yes, injectors are flow tested to 373cc, matches, and IFR is dialed in.

okay, I just took a quick look at your tune and I do see a few things that are a bit off and may help, but I'm just headed out the door to work and won't have internet access until tomorrow, so I'll have to get back to you...but real quick a few things to note: you still have all the injector dynamics of the poppets in the tune, the poppets are VASTLY different behaviorally than real injectors, try copying injector data from an LS1 tune for things like small pulse adders and offsets, etc...you have ALOT of fueling multipliers active, especially while cranking and initial startup, and A0008 seems excessively high at low temps, and your VE seems a little strange, I question some of the values in it, I'd definitely check it doing some autoVE, and if you need to change it, don't forget to re-extrapolate the crankingVE from the spreadsheet as well....

I'll change up a few little things in the tune and send it back to you to give it a try tomorrow.

I copied over all the injector tables from the ls1 engine except for IFR. I cranked up A0008 so high because that is what keeps it in order with AFR while warming up. Which multipliers are you referring to?

Damn juc Iv done everything you have mentioned and mine still idles/ starts like crap