carls1982z

Hello, trying to figure out why my car when it hits closed loop,, i get a major !! surge,, up and down and then quits.[just took out of storage]-----After racking my brains out here. Here is what i done . - NEW intake gaskets,, complete tune up,- 02 sensor,, plugs ..wires ,new distributor.--- STILL MAJOR surging when it hits closed loop. - I tried driving veh and its terrible, -when driving feels like your shuting ignition off/on at times.------ Car is fine in open loop.- Makes me wonder, ?? ive always been chasing a off gas surge in this thing, -related ??? -----ANY IDEA guys im lost,,, Thought about running my own 02 wire from pc to 02 sensor and trying ???????? --- HELP lost .--- p.s. - Ive down loaded new bins to try,, and still problem is there. - Im a 7747 ecm, with prominator

RBob

iTrader: (1)

What do the BLMs do when the ECM goes into closed loop?

If there is an instant change in how the engine runs then check the stoich constant. This is one item that is changed immediately upon going into closed loop. The commanded AFR is changed to the stoich value.

RBob.

carls1982z

i started new bin also TOO try to fix,-- BLM they are rich when it hits closed loop as i suspected with new ASDU BIN.-I drove it tonight here and is bad bad bad, so i loged the blm and going to download it tomorrow.--- CAR allways had a slight OFF GAS surge now its worse ,,, related ???-In my bin the stoich AFR IS SET TO 14.70----Bill at speedtronics has my bin now and is burning it into a 2732 ??? Then wants me to try it in another [which ? ] ecm and recheck-------also rbob there isnt a instant change in running,,, when it hits closed loop.-may take 40 sec or 45 sec before it acts up -------

carls1982z

BUMP

RBob

iTrader: (1)

OK, the BM are rich (what value?) when the ECM goes into close loop. What so they then do once the ECM is in closed loop for a while?

Note that you should set the BLM key-on init values to 128/128.

RBob.

carls1982z

I noticed they stayed at min blm of the bin [108] rich------Not sure what you mean exactly on the setting key on, blm 128/128. ?? Do you mean in the bin, too set the,,Validate at initial min and max too ,,,128 on both ???? of them

RBob

iTrader: (1)

A silicone poisoned O2 will report rich and drive the BLMs down. A lean mix will also cause surging.

RBob.

carls1982z

update,,Second new 02 installed,,, When car goes closed loop.---BLM show rich.---idle goes to stall then gets caught ?? and recovers, for 4 seconds then repeats this.-- rev engine to say 2200 rpm and rpm is up/down repeatedly about 300-400 rpm.- LET it idle, and still goes to stall then is caught, -- winaldl shows 128 blm with veh off, and key on it shows 125.-----Ive played with fuel pressures up/down,, and also B.P.W.,, DOESNT HELP.-Ive raised my stock 02 constants [rich,mean,lean]up 100.00 and still no affect ????? --- Lost as to what to look for.- HELP...--- ps,, 02 sensor stays mostly at around 955 volts,, reading from winaldl

carls1982z

more specs on my stumble and recover,,--NEW BIN installed,[ASDU] and basically stock and set the BPW TO my fuel pressure.--Car idling in park shows rich in winaldl, but lean on wide ban ?? 21.00 AFR.--When car is smooth running it shows rich on winaldl, and 02 volts are staying mostly around 850 volts,Car then stumbles and then it reads 0.40v using winaldl, them back smooth idle, and around 850v 02. ?---NOW looking at wide ban, when the stumble happens it jumps from lean 21.00 to 9.00 afr. -recovers and then back lean on wideban. - HELP.-----WINALDL, SHOWS IM RICH when smooth idle, butwide ban says on lean ???

carls1982z

still sounds like 02 problem doesnt it guys ????

carls1982z

SO, you guys have no more thoughts on my problem ?? - Basically it is up and down ARR , from max lean on wideban, then spikes to rich of 9.00 AFR,about every 10 seconds,,--.--WINALD SHOWS my 02 is at about 855volts then instant ,50 volts [ no in between ]-- LOST as to what to check next.- Ive already tried multiple bin with same results ??

pandin

Try raising your Injector constant 2# from what it is and see if the blm's raise. If not raise 2 more #'s until you see something between 108 and 128.

carls1982z

Thanks pandin,,I need all the help i can get.-- Ill give it a shot.--ive have put in bigger injectors,, 90lbs just so you know----Do you know the address of it in tuner pro that i use ??? as i seem to not locate it, or other name for it ???

carls1982z

now i know what you meant,, BPW.-BRAIN FART HERE.- My blm already shows rich --[108] but im lean on wideban. ???? - Gonna see how the new three wire 02 works out thats coming.-ill let ya know- by the way im 90lb injectors and 18 psi fuel, so i have my BPW set to 90 bpw

Grommet

I'm having similar issue to carls1982z - low blm indicating rich but wbo2 reports actually lean (15-16:1). Watching this thread closely!

747 tbi, 350 with Comp 260H cam, headers, Edelbrock Performer TBI in an '88 pickup.

Grommet

Btw - I already have a 3-wire O2. Also running stock pump and injectors (55 #/hr) at 16 psi. I'm looking into replacing the pump so I can get more pressure, 16 psi is all I can get at the moment - I figure this shouldn't be a factor at low rpm though.

BPW currently set to 135, I will try increasing this as well to see the effect.

carls1982z

hey grommet,, what your 02 sensor show when having problem. - Switching ?? voltage ?? curios here.

Grommet

O2 swings constantly over wide range when idling, ~.3 up to .9, reading this thru WinALDL so updates very slow.

It doesn't stall but the stall saver does kick in once in awhile. I just noticed this problem yesterday when I enabled closed loop by setting the "minimum coolant temp for closed loop" into a reasonable range. When I set this very high (140) it stays in open loop and runs much better, I was doing this to try to get my base fuel table close.

Did you try adjusting your BPW yet?

carls1982z

hey grommet, Your problem sounds like my car last year -same thing.-- I cured it by raising my 02 lean/mean/rich 02 tables higher than my stock settings [i think i raised mine 100.00 on all of them ,,and cured the problem----You will have to relog and set blm as normal after tho !!!.---raising these TABLES EQUALLY,,will help push AFR RICHER

95 4x4

iTrader: (1)

Possilbe you could have an intake leak ? In open loop it does not read your 02 sensor then when it goes into closed loop it reads the 02 and if it has a leak it will richen up the fuel just a thought .

carls1982z

is that reply for me or grommit,, ?? As i have replaced all my intake gaskets and search for leaks

95 4x4

iTrader: (1)

It was mean't for you , just a thought it sounds like an air leak just my 2 cents .

Grommet

Thanks carls1982z, I'll try this tomorrow and let you know!

carls1982z

I seached for air vacumm leaks and seems fine,,, Whats a good way of checking the header gaskets for possable air leaks,, if any-----Im still waiting on the new 02 sensor to come

95 4x4

iTrader: (1)

It will have to be a pretty good sized leak if you have one . Header leakes usually sound like a lifter ticking . Do you have a vaccum gage to see what kind of reading you get that will tell you . Your WB is it before your 02 sensor ?

carls1982z

Ill let you know on that vacumm reading.-- And my wide ban is after my 02 sensor.--02 is in left header,, --wide ban is just after right header collector.

carls1982z

yes my vacumm is a steady 19 inch, as i thought.--Ran veh again here and noticed while its shows lean [21.00]on wide ban and then stumbles to rich [9.00 AFR ] I can see that winaldl shows while its lean the [ INT] will slowley lower from 128 dowm to 108,, then car stumbles and recovers to 128 on [INT] THEN IS SMOOTH AGAIN [LEAN] for about 7 sec ? then repeats the stumble ..-- STILL WAITING ON NEW THREE WIRE 02,, IF THAT doesnt do it ??? ECM ???

95 4x4

iTrader: (1)

Rules that one out . Can you set your VE table at idle in open loop using the WB , basically what i'am saying is adjust your VE table using the WB and once you got it close . Then enable closed loop and let the PCM take control of the BLM's and see what it does .

carls1982z

so raise my temp table so as to stay in closed loop,,, and adjust the fueling off my VE 1 TABLE,, using wide ban ?? to get it close.-- Thought of this but havent done it.--- Was always told start the fueling tuning.. in closed loop to get it close then innable open loop.

95 4x4

iTrader: (1)

By enabling open loop you bypass the 02 that is the idea and use your WB to tune the VE . This way is alittle bit more work but it gets you results . Then when you enable closed loop you use the 02 again and the PCM adjusts the BLM's and you have a very good starting point .

carls1982z

so after i save a log in my zetronics w/ban. I then just read say a certain rpm/map and adjust. that ve table,,-- Does sound time consuming, But gotta try.

95 4x4

iTrader: (1)

Yep you got it , once you get things sorted out make sure your motor is at operating temp to finalize the VE table . I'am curious as to how far out it is , keep a before and after copy of your table . Also why the bigger injector's missed some thing some where ?

carls1982z

Reason i went bigger injectors is there are many diff opionions on the stock crossfire injector specs,, and the pressure they are rated at .--And with my mods to eng, i wanted to be sure i had big enough [not go static] and to know the true specs.-When i bought the new ones they were rated for 90lb at 15 psi, So i then bought and sent them out to another place to be flowed and checked, and they are a TRUE 90 lb injectors at 15 psi.----There are alot out there, that claim they are 90lb,, but are lucky to be 80lb's

carls1982z

I guess Im chasing more than one problem, As no matter how rich i set my fueling [gurgles rich] my wide ban shows lean.,, max at 21.00 AFR.-- Anyone know a good sight to just order a zeitronix wide ban sensor ???

lt1z350

iTrader: (2)

did it start doing all this after storage? fine before you parked it? if so I would look for corrosion on a sensor and also check all the sensors and make sure they are working as they should. I had chased my tail on a stalling problem where I was losing spark on my lt1 car and changed every thing in the ignition and it turned out to be a bunch of nice green corrision on the optispark plug. It happened while the car sat for 5 months. So not the same problem butif you are not getting a good connection somewhere can cause crazy stuff and your problem is off the wall. By the way on my 92 formula I went to a heated 3 wire on it and ran so much better so nothing else that will make a improvement and worth the trouble. Especially if it is located farther down the exhaust like in a collector as they cant get hot there and read funny. Really sounds like you have a short or something electrical going on and not a tuning or mechanical problem.

carls1982z

if i remember correctly,, late this past summer the wide ban would show that lean condition, then it would disapere just as fast as it came.-But i was able to log in winaldl and set blm and veh didnt have that major surge and stall.-- Wide band wouldnt have affect on the running, the way its wired in, as its for checking AFR, AND im using the narrow band for fueling correction.--I can richen this veh up in open loop till it smoking out exaust, and wide ban shows lean.-Ill have to check my other items that effect fueling, map and temp sensor-- ps,, still waiting on new three wire 02 to come.--And i ordered a new wideban

lt1z350

iTrader: (2)

yeah if it is puffing black and showing lean there is a problem with the wide band. only thing that can cause that other than a bad sensor is if you did a calibrate on it by accident with it in the pipe and reading exhaust rather than reading fresh air. might want to check that out before condeming it as bad.

carls1982z

not sure on that calibrate ?? the wide ban,, or how i would check

lt1z350

iTrader: (2)

i have a inovative on mine and it has a calibrate button right on the box. what ever one you use you will have to pull up the instructions on it and check it.

carls1982z

Im using the ZEITRONIX unit.--I checked the instructions and see nothing as to calibrat it.--maybe mine doesnt have it. Only thing i found was ,,it says to leave the wide ban powered as long as its in the veh.--- I always unhooked it,, oops

Dominic Sorresso

The ZT-2 doesn't need a calibrate function like the LM-2 does.

carls1982z

yes, after chasing my tail trying to figure this major running problem,, I decided to put my stock injectors back in.--Guess what ,, problem is fixed.- I had bought the 90lb injectors rated at 15 psi, and sent them out to one other place and they even said they were fine and were 90lb at 15 psi,-- guess you never know.- 240 dollars waisted

95 4x4

iTrader: (1)

We all have our own gremlins one time or another , so back to the tuning ?

carls1982z

wonder what the problem is with the new 90 lb ones was ????? I set the pulse width, to my pressure, and even tried leaning and richening fuel with them with no results ??? ANY thoughts.--- now i get to retune my stock ones. all over

LoudmouthSS

iTrader: (6)

had the same thing happen to my car. Take a look at your coolant temp sensor. I thought nothing of it because on previous datalogs everything was fine. I went to take a look at it and could see the brass was cracking...went to loosen it and it fell apart. Same exact symptoms though, as soon as it would hit close loop it would start running very erratically, stalling, surging, running pig rich...pretty much undriveable.


oops didnt read the last post...glad you got it fixed

carls1982z

ill check it,,[temp sensor] but seems to read correctly, and with stock injectors back in it seems good