New TBI owner in need of some help....

[simadownow6988]

Hey guys,

I have an issue that I hope someone can point me in the right direction to fix.
I bought a 1989 K5 Blazer a few months ago. The owner had done alot of upgrade work to the Blazer and it was a great price for what it is. The previous owner had a GMPP motor dropped in 2 years ago. Its a 1996-2000 model Vortec crate motor with a GMPP intake manifold for TBI.
After driving it a few days, I noticed it was running a little rich and hesitating on idle. Upon research, I found Brian with TBIChips.com. He recommended that I replace my fuel pump with a higher volume one, get a 3 wire o2 sensor since I have long tube headers, run a custom chip, and get rid of my Holley tb for a custom 46mm (which he gave me the info to TBIparts.com).
After installing all the products, including the 46mm tbi with 18 lb spring and flow matched injectors, I cannot seem to get my idle down below 1200. The guy with TBIparts (that built my tbi) has been helpful with my issue, and he even had me send back the tbi for inspection (which came out fine). I have replaced the new TPS and IAC, but no change. No vacuum leaks either.
Brian with TBIChips is basicly telling me that he cannot help without a computer hooked up to it.
Any ideas? Any help will be much appreciated...

[Fast355]

Hey guys,

I have an issue that I hope someone can point me in the right direction to fix.
I bought a 1989 K5 Blazer a few months ago. The owner had done alot of upgrade work to the Blazer and it was a great price for what it is. The previous owner had a GMPP motor dropped in 2 years ago. Its a 1996-2000 model Vortec crate motor with a GMPP intake manifold for TBI.
After driving it a few days, I noticed it was running a little rich and hesitating on idle. Upon research, I found Brian with TBIChips.com. He recommended that I replace my fuel pump with a higher volume one, get a 3 wire o2 sensor since I have long tube headers, run a custom chip, and get rid of my Holley tb for a custom 46mm (which he gave me the info to TBIparts.com).
After installing all the products, including the 46mm tbi with 18 lb spring and flow matched injectors, I cannot seem to get my idle down below 1200. The guy with TBIparts (that built my tbi) has been helpful with my issue, and he even had me send back the tbi for inspection (which came out fine). I have replaced the new TPS and IAC, but no change. No vacuum leaks either.
Brian with TBIChips is basicly telling me that he cannot help without a computer hooked up to it.
Any ideas? Any help will be much appreciated...

Not sure why he wanted you to switch out the TBI other than the fact that most people connect the map sensor to the wrong port (the rear one) on the Holley TBI units and cause a rich idle and an off-idle hesitation.

[simadownow6988]

I really hate hearing that. He never mentioned that it could be as simple and cheap as moving a vacuum line (which mine was located on the back). That was 450 bucks wasted....

[Fast355]

I really hate hearing that. He never mentioned that it could be as simple and cheap as moving a vacuum line (which mine was located on the back). That was 450 bucks wasted....

Don't get me wrong, the factory style unit is better and the original design holley injectors are known to cause issues, but there is a known driveability issue when the MAP vacuum is attached to the rear port. Where the port is locate is right in the IAC passageway. As the IAC opens it causes a loss of vacuum signal to the MAP which cause the engine to run rich. When you open the throttle the MAP does not change much and the engine develops a lean bog from lack of MAP AE. The problem is noticeable enough that from my experience I can see it in a Datalog alone.

[simadownow6988]

Ok, gotcha. It is a little relief to me knowing that I now have a better tbi.
Any idea of what could be causing my issue. I ordered an ALDL cable off ebay from a Red Devil River. I also downloaded winaldl last night on my laptop. I will be reinstalling the tbi tonight and hooking a computer to the vehicle. Is there something I can do to post maybe a screen shot on here to help you guys help me?

[DanofMostTrades]

Sorry simadownow6988, I can't really help you much as I'm a newbie, but I just ordered that motor your running and am excited to see someone else with the same setup I want to run. I still have my stock throttle body and need to upgrade. If you want to sell that Holley, PM me a price. If not how was your experience with TBIparts.com? What all did you buy that added up to $450? I have also had a frustrating experience with Brian at TBIChips.com, but lucky for me I found this forum before buying anything more than the fuel pump. The guys hear have told me that winaldl is nearly obsolete and I should download TunerProRT, which I've done but can't play around with it til I get my motor. Have you bought a chip from Brian yet?