Okay - here's teh deal:

I had 85lb/hr injectors in my 670 holley TBI on my 355 cid camaro. I put a 350 knock sensor in, had a chip made by someone from these boards, put a fuel pressure gauge in and did everythign I could think of to make the car run right. All last year she ran REAL rich (black plugs) despite my best efforts until I found out i had 85lb/hr injectors. I called holley - they sent me "new" 65lb/hr injectors (supposedly) and now i have a problem.

In rich mode, the car idled fine without any problems (a little fast though) but once she exited rich mode and warmed up, it surged really bad and wouldn't maintain any idle. I turned the idle and fuel pressure up (16 psi) and it still wouldn't hold any rpm OR take any throttle. My father (who knows his stuff) says it was exhibiting lean behavior. We put the 85lb/hr's back in and she runs fine too.

What do you guys think? I'm really looking for Jon Prevost's input (or someone with similar experience) because I'm so tired of banging my head against a wall and he's one of the best i can think of on the boards (no butt kissing intended).

My guess is that the injectors holley sent me aren't correct b/c of the hassle i recieved on the phone from them (kinda like they just threw some crap at me to shut me up) or just goofed up. But I dunno. Please help me out here, someone. I dont wanna struggle this summer.

Ty

PS - I do still have to replace my knock filter, but i doubt that's a big issue here.

 

When you put the smaller injectors in did you reset your computer? You might also want to give TBIchips a call or e-mail.

Steve

 

did i reset my computer? um...the short answer is no, I didn't know you were supposed to. Anyone want to back that up?

Ty

 

scratch that - my computer was cleared because i had my battery disconnected for days beforehand.

Ty

 

chances are you fuel tables are all screwed up. with the 85pph injectors if it runs, then your fuel tables , or injector constant (i will have to go home and look to see how the TBI does the injector constant, are going to be way out of whack when you put 65pph injectors on.

have you done any datalogging? hooking it up would tell you real quick if you are lean or not. if you are lean, either get the stuff to do your own chips, or call your chip maker, and have him send you a new chip that has the correct injector information in it.

 

well, the 'kid' that made my chip said it was for a 350 and stuff...i probably just got yanked. bummer.

Ty

 

it may have been for a 350, but a chip is designed to figure fuel flow based on a certain sized injector, when you lower that by 20pph, of course you are going to go lean.

 

Doing any serious engine mods (while keeping the stock EFI) without a laptop scanner is like doing brain surgery with your eyes closed.

 

okay okay okay



if you dont have anything good to say...

 

but it is the truth.

 

Done with finals, Formula SAE slowed down, moving into new place for the summer but I AM still here. Give me a little more time, I haven't had internet for a while (long while) and my computer is no more as in DEAD, ceases to be.
I was working on commenting the ECU file I released when it crashed hard.

 

sorry about the puter

i had a wierd burning issue, i was using a friends laptop to try to do some burning at a gathering this weekend, got on to diy-efi and downloaded your ECU file, he had gmedit already loaded, and we used my programer, long story short nothing burned would run in my car, we even took the bin we grabbed from my chip, opened in gmedit, saved as a diffrent name, and when we burned them, the data was completely diffrent. is the 8746 ecu file on the diy-efi site bad or something?

 

It might have been edited by somebody and reloaded because I'm unaware of anybody else having troubles. Make certain it isn't the programming voltage on the burning software.
I was so close to finishing my new version of that ecu file which had those comments about the diagnostics and options flags etc. It was great....but now it'll have to wait until I can get a new computer.
I'm super busy for a few more days and probably up until mid week next week. Today, tomorrow, and the next I'm working at National Trails Raceway. Then I'm busy with a new job at work I never get any rest. Infact I've got exactly 7 hours before I need to get up and drive off to the track.
Maybe the weather will be better tomorrow, crossing fingers.

 

yeah everything was set right, it just didn't work, luckily i had the .bin file form the chip i drove in with. last time i try to be cool and tune on someone elses equipment. the burning was all set right, it cranked the original .bin file out just fine, and ran just fine, but everytime we saved a modifiacation with that .ecu file, it changed the first several bits.

 

Did the SES light flash rapidly? That would be a checksum error. The cksum is in the beginning of the BIN.

RBob.

 

no i only got a checksum error when i put the chip in backwards

it started jsut fine, but idled at about 2k, and ran reallly really rich. i think that it might have been limp home mode.