Sims

This is not an F-Body engine but you guys seem to be very knownledgable about ODB1 setting and tuning TBI engines. I just rebuild the 4.3L V6 in My 89 S-10.. heres the deal..
its got a bigger cam now (.500/.500 gross lift)(266in/270ex duration) with bigger valves and porting on the stock heads (1.94/1.6now 1.94/1.5stock). I also got a 670CFM holley TBI.. the issue I'm having is that the holley has 50lph injectors and my stock Rochestor 220 has (I believe) 40lph injectors. I cant get it to idle properly with the holley as it appears its just flooding the hell out of the engine, could this be a programming issue becuase it thinks that the stock injectors are still on there and the engine is breathing a lot better now? TIA for your thoughts.

jeepguy553

Yes. You need to get a logger and a chip burner. Once you get those things, you will probably be able to fix the flooding thing. That 670 cfm TB seems a bit much for a 4.3L.
Another thing you might try is to take the injector pod off the top of the OEM TB and bolt it onto the Holley TB. That will probably help a lot, but the only way you're really gonna know is to get a logger of some kind.

Sims

like a wideband o2 setup?

jeepguy553

The WB would probably help too. Grumpy is gonna see this and tell us that we both need to get a WB...and he's right.
By a logger, I meant WinALDL or something similar. The chip burner can be whatever you pick as your weapon of choice.

Bill usn-1

Try bolting your stock injector pod on the holley TB and see if that helps.
You may not even need bigger injectors.
It's almost a bolt on item.

Sims

they dont fit, I already thought of that one.

Grumpy

You will need to do some programming.

Go to www.tunercat.com, you'll see listed a 4E editor, I think that's the one you want.

A WB does make life alot easier. As would having played with an editor before you did all that work. Now you have a steep learing curve, being forced upon you. Take notes, read the archives.

jeepguy553

Yep...Grumpy is once again right. I am not following what you mean by "they don't fit." Are you referring to the ALDL cable or are you having problems with the actual datalogging?
The WB, I think, takes some modifiying to get in the car, but I am probably wrong on that one since I don't have one...YET.

Sims

I meant the stock injectors dont fit in the holley tbi, quoted the wrong post..

jeepguy553

The injectors themselves won't fit, but IIRC, the entire FPR and injector pod assembly will. I did it with a Holley 670 TB. The TB came from a ProJection system, but they fit. Give it a try and see what happens. I bet you are pleasantly surprised with the results.

Sims

if you mean to swap the top end of the TBI over to the holley we tried that too dont forget this is a 4.3 TBI unit not an F-Body TBI unit.. likely different. I've got a weeks vacation coming up and I'm going to attempt to tune it then. Last night I pulled codes.. getting EGR (cuz its removed) And o2 Rich Sensor.

jeepguy553

I still think the entire regulator and pod assembly from your OEM unit should bolt on top of the Holley unit. Got any pics of them side by side? I may take a look at the TB you have on Summit and see if I am right.

jeepguy553

If this is the TB you have, I bet your OEM injector pods will bolt on it.

Sims

well I shouldnt say that with 100% certainty.. but my dad tried it since hes been working on it while I've been working and since I dont live at home I cant really work on it in the parking lot of my place lol. But he said it didnt fit.. I'm pretty sure that its a TPS issue at this point, becuase I remeber him saying something about bending the throttle level on the TPS side accidently at some point.. so I bet its wayyy out of whack at this point..

JP86SS

iTrader: (1)

You may be overlooking another variable, The coolant temp will effect the pulse width if the temp is lower than the stock ECM is looking for and cause too much fuel.
Have you installed a lower temp thermostat?
Check the temp sensor as well.
Just a thought.

Sims

it is running a bit cool becuase of a coolant leak where the thermostat switch for the e-fan is.. stupid *** thing, cant get it to seal.