Got the MPFI in, all hooked up and running, but its pig rich, but not throwing a code 45 or any codes for that matter. Won't idle, or stay running. IAC is fully open and the ECM seems to be struggling to keep the engine running. I'm at wits end, my only guess is that the fuel tables are still set up for the 19lb injectors and not the 29'ers and she's washing in fuel big time. I know cross country diagnosis is tough, but any thoughts?



Kelly 'GhoSSt' Rosato

 

What scan logger are you using .
You right if teh injector setting is off that could be fight you . I also just had a problem similiar due to fualt O2. Car would start fine when cold (open loop) but then once closed loop do symtoms like you. IAC go way open,vacum go to 8" ,ecm struggling to keep the engine running.
Was the motor fire before this swap? All was mechinacal sound?


------------------
85 vette,383,miniram,ZF6,4.10's..best ET 11.66@1187.00 60' 1.62
w/100HP nirous 11.05@127
http://geocities.com/bowtie8

 

you installed 29 lb injectors in place of the 19lbers?

did you change the bpw in the chip atleast?

if you just installed the 29 lb injectors inplace of the 19lbers with no other changes then yeah, you are pig rich, 29 lb injectors over 19 is a hell of alot more fuel!

Either install the 19s or calibrate the chip for the 29s. It wont run with a chip set up for 19s but with 29 lb injectors.. but you can see that first hand

 

I agree with Pablo, if you have not adjusted Injector Flow Rate in the ECM Constants from 19# to 29#. I am finding that I have to modify my Injector Flow Rate to compensate for the higher fuel pressure I am using as I am rich "across the board".

 

I don't have the equipment to burn chips yet and nothing to log data with so I'm kinda flying blind here.


Motor ran 100% prior to the swap. No faults, strong running. Also, it does it from the get go, in both open (and presumably) closed loop.


No, when I got the MPFI system, Edelbrock offered to GIVE me the 29's in exchange for my 19's because of the future engine I was building. Howell Develepoment was SUPPOSED to send a chip ready for the 29'ers.



Now what? I can wait til Tuesday, call Howell, and have them FedEx a chip to me I guess.

Kelly 'GhoSSt' Rosato

[This message has been edited by GhoSSt (edited January 01, 2001).]

 

Kelley,
Remember, my offer still stands. If you bring that chip down to the springs, we can take a look at the base PW, etc.

 

Dan, you have mail.

Kelly 'GhoSSt' Rosato

 

29's vs 19's is 52% RICHER!!! Talk about cylinder oil-washoff!!! OUCH. Move BPW from 135 (that's where it should be???) to 88 and tune from there... DOUGH! Probably have to change/check your plugs after that, too.

 

Nothing from you there... sure you got the right address? dworkman@hpi.net

 

Yeah, musta lost it. All I was saying was send me a phone number at my email address pertech@justice.com and I'll call you on my dime.

Kelly 'GhoSSt' Rosato

 

*slap* *slap* *slap* *slap*

I know I know.

Well, this little scenario is going to force me to sit down and learn this, I can afford to pay for chips, but crap, not at this rate.
I DL'd tuner cat last night to play with and I almost have a fraction of a clue as to what it all means, but I'd be scared to try anything at this point. :\

Kely 'GhoSSt' Rosato

 

Adjust the BPW (Base Pulse Width)accordingly to get you in the ballpark. Who knows, all might be ok with just the BPW change, but doubtful.

[This message has been edited by FastBroker (edited January 02, 2001).]

 

Well, thats certainly an option. But the fact is that I learn nothing from that route and one of the rules (so to speak) of this forum was not to be begging for someone to burn a chip for you. If someone (like Dan) wants to offer, I'll take them up on it, buy the beer and give it a shot, but I don't like to impose if I can avoid it.

Kelly 'GhoSSt' Rosato

 

Ummmmmm .....
Please don't ever volunteer my time ... ever.

Kelly, I truly appreciate your response. What you said is 100% on the money.

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's after installing Hooker LT Headers and reducing weight.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

Happy New Year!!!

[This message has been edited by FastBroker (edited January 03, 2001).]

 

When Dan and I get together, I would like you to ask you review our work and any suggestions you have are certainly appreicated, as are any one elses that would like to 'look and see'. As a neophyte to this aspect I'm very aware of my shortcomings and open to having someone look over my shoulder, but I have to start somewhere.

Kelly 'GhoSSt' Rosato

 

Chapter Two: The IAC strikes out.

Ok, so the first issue we found was that the intake had a major vacuum leak contributing to the idle problem. We reset the intake today hoping to clear this up once and for all but another odd bit keep coming back. The system keeps destroying IAC's. The original one died, then I replaced it with the one from the Holley 670cfm TB, then it died, then I went and bought one and it worked for about 3 seconds then went static and died. When I had an IAC working (kinda) it woudld idle between 1100 and 1300rpm and surge up to about 2000.

I checked and the 4 wires from the IAC and they properly go to C3, C4, C5 and C6. So it isn't miswired. I'm not getting any codes or a check engine light. So I'm not sure now.
Anyone ever heard of an ECM eating IAC's?

Any thoughts?

Kelly Rosato

[This message has been edited by GhoSSt (edited January 06, 2001).]