As most of yall know, I'm not exactly fond of TBI PROM tuning, so I went with TBICHIPS.com chip to get me running. Brian's chip works pretty good with my only issue being the open loop mode. It currently fluctuates up and down until it gets warm, then it runs flawlessly. Anyways, I was thinking that maybe a 3 wire might help alleviate some of that since the fluctuating seems to only occur when in open loop.

Thoughts? . . . . .

 

Couldnt hurt, but if it suddenly runs 'flawlessly' in closed loop then it sounds like your O2 is working. The tune on the other hand sounds like its not

 

where is the 02 in the header? my non heated 02 is right behind collector in exhaust pipe. Bosch. goes CL like clockwork at about 160-165 and stays. but my headers are coated? that may make difference. a heated one may be helpfull if headers are not ceramic coated.

 

Been running uncoated headers for 10 years with Bosch el cheapo with no probs.

What do the datalogs look like in open loop?

 

You're asking the wrong guy. I couldn't even get ALDL to datalog . . that's how bad I am with this computer/PROM stuff. . . totally inept.

The O2 is in the header part itself just before the collectors. And yes they're ceramic coated.

There are no issues when it hits 160-165. It stays in CL and runs like a champ. In OL however, it idles radically up and down.

 

That's a problem with the tune not the O2 sensor. If it hits closed loop and runs good that means the O2 is perfect and is doing its job well.

 

My guess would be that its really lean at times. Like around 16-17:1, or worse. When the engine runs lean the power output changes very rapidly as the AFRs vary, making it run erratic.

 

dim has said everything I would have said... that's all I have to say

 

OL idle for me is better than CL !! ?? i might suggest enrichening OL idle(as i did). seems as soom as i hit CL idle does pulse. but not always. seems once the stall prevent occurs(iac get awakened) the pulse surge rares it ugly head. and it chases it tail. BUT my issues with idle i am convinced are PW related as running 17.5 FP with 80 inj's at 750 rpms. will up commanded idle speed to 850 and see if that helps.

 

I really wasn't concerned whether or not the O2 works seeing how it's less than a year old, but more in line, would a 3 wire O2 get me to CL faster so it doesn't pulsate like that? It's annoying to say the least.

 

not sure if forcing into CL is the right strategy. it is based for most part on coolant temp. i would think around 160-165 is about right for CL. on a cold day(wisconsin april) when it flips to CL the drivablity suffers as engine is not heat soaked. no heat in intake. especially the manifold is cool to touch. atomization is poor. . i may even burn a chip to prevent CL until coolant is say 180 deg for cool weather use.

i think you need to consider getting that winALDL up/running...

 

Have tried and failed atleast a dozen times.

 

i am a computer nitwit. very frustrating i agree. after a multitude of mods would not run period. i was forced to learn if i wanted a car that ran as well as the investment in parts and labor i committed. if your ECU is supported by winALDL i see no reason why someone here cant walk you through getting a connection. i went through the "issue" twice. once on day one and then again when would not connect due to USB/new komputer. now i will approach it a third time since i bought TunerPro RT 4.0 and have not yet found time to start it up .

 

At very cold temps that can cause problems since closed loop only allows AFRs around 14.7:1

 

Yeah you aren't necessarily going to want to enter closed loop as early as you can. It's all in the tuning.

With a small amount of tuning I'm running my 305 w/ ZZ4 cam at a rock solid 750RPM idle with BBC injectors on a Holley 670 with a base pulse width of 75 in the PROM. I'm having no idle issues really with that low BPW.