ok ..

ive been trying for the last couple weeks to get my 91 camaro tuned ..

vortec heads, edelbrock intake, hooker 2055 headers / y-pipe, comp 501 cam

....................


it was running allright for the first 1500 miles, before i even thought about tuning, but turns out i had the wrong plugs (too short for the vortec heads) .. and it would run like crap on cold days ..

now i got the right plugs, and it runs almost flawlessly when it is cold .. but as soon as it warms up a little .. it looses all its power ..

ive noticed lately a check engine light comes on every now and then for a couple minutes .. and during the check engine light, it become sluggish

cleared all the codes .. and ran it for a few miles this morning on a vortec sa table .. ran fine in the cold, but started being sluggish once it hit closed loop ..

checked it again, and now it has a "43" stored into the computer .. but the light doesnt allways come on while driving

also .. in the datalogs .. ive noticed once it warms up .. the "knock retard" starts going from 8* - 20* .. but there are no "knock counts"

im running a vortec timing table which is VERY conservative on the spark values .. the max is around 28 i think .. no more than 32 max ..

another thing that is weird .. the "spark adv. rel. to Ref pulse" most of the time sits at 23000* .. what causes this .. it flickers between that and the actual value ..

Rbob suggested the oxygen sensor was bad since my blm's sit at 108 , but i changed it with another one and there was no difference ..

i did one run this morning with the same chip and it ran awsome for a couple minutes .. one point had smoke pouring from the back tires at part throttle off of a culdesac .. hahah .. but then it started acting up again ..

any ideas? b/c im fresh out .. ive been searching for days and cant find any answers that would cause this except a bad knock sensor ..

its the original knock sensor .. i replaced it during the rebuild but advanced auto gave me a 350 sensor instead of a 305 which caused me alot of troubleshooting during the first 20 miles .. lol .. so i put the "stock" one back in ..

would that explain my mysterious knock retard / and spark adv. during ref. pulse readings ..

if i didnt have the knock retard, then the car would run pretty strong ..

(sorry for the long post, but im fresh out of ideas and its getting frustrating)

thanks,

Adrian

 

There is a problem with the knock sensor or knock sensor to ECM wiring.

The ECM reduces the timing when a malf 43 is present.

The .ads file is incorrect.

I suggested an O2 sensor, wiring, enhaust grounding, or an ECM issue. And this was because you stated that once the ECM went into closed loop the BLMs dropped to 108 and the engine ran poorly.

RBob.

 

if its realy bothering you at the moment, try making a chip that keeps it in open loop the whole time so it will run ok for the time being

then continue to brush up on tuning background and analyze your situation, learn the tables abit better. Then get back at it in your free time.

I cant realy help you anymore since i'm not aware of the 8D ecm... i only know alittle bit about MAF setups

 

Is it when it warms up or when it goes into CL?
Makes a difference as to what you need to adjust.
Still a problem with the knock sensor. Check that your memcal,adapter and everything is tight and not vibrating loose.
Are you sure you have a V8 memcal?

Is the AS it warms up or after its warm?

There is a SA Vs. Temp Vs. load table you may want to look at to see what it is being commanded to do AS the engine warms up.

SA bouncing can also be caused by the RPM error table attempting to stabilize the Idle speed. You could reduce them at the lower error ranges to obtain less change. There are two tables. One is Spark Advance at 81F0, the other is Spark Retard at 81EB. Don't get radical, just cut the lower 3 cells by half and watch for the reaction to the change. If it made no difference, put them back.

Another possiblity is that you have a very bad, leaky injector.
Put a gauge on the rail and see if it holds pressure. Could be fighting a loosing battle with BLMs if that is the case.

 

when i said "warms up" .. i mean closed loop ..

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so the 23000* means the ads file is incorrect .. im using the one off of tunerpro's website .. ill try to find another one

................

i went and got a new knock sensor .. suprised the guys at orielly's when i pulled out the ohm meter and told them thats not the right one to three different sensors .. haha .. eventually i got the one with 3.9K ohms .. all the others (including the one i bought 3 months ago were 100K)

............................

i might have a leaky injector, ill check in about 10mins .. noticed last time while i was messing with the adjustable regulator that the pressure dropped really slowly .. about 1psi / minute .. maybe it has gotten worse ..

dang .. i hope i dont have to throw $250 at summit today .. lol .. but if that fixes it i wouldnt mind ..

...........

Thanks again for all the responses ..

im going to go mess around with it and see what happens ..

Adrian

 

ok ..

put the new knock sensor in .. still get a code 43 .. im thinking now that the connector might be faulty .. its a little sloppy ..

what else contributes to a code 43 ..

now whenever i start it .. it wants to idle like normal .. up to 1200 then slowly down as it warms up .. but as soon as i start driving .. it pulls out 20* timing when i only have 18* in that certain area and it starts puffin smoke and flooding its self ..

i had this problem when i first put the motor back in ..

is there a way to just re-wire the knock sensor .. i got a remanufactured ecm that only has 1500 miles on it ..

which pin would it be on the computer .. im gonna try and track down a pigtail real quick ..

...................

checked the fuel pressure .. its fine along with the injectors .. no leaks ..

im assuming all my problems have to do with a knock sensor problem .. ive been thinking ..

if the computer takes out timing .. it doesnt burn all the fuel .. therefore the blms sit at 108 most of the time b/c it "thinks" its running rich ..

is this right, or does it pull fuel to (dont think it would b/c its trying to stop the knock)

adrian

 

You are correct.
If that much timing is being pulled, you would be running rich.

 

ok .. so my best guess so far is the connector on the knock sensor being loose ..

found out the knock sensor hooks up to gf9 (which ever pin that is on the ecm) ..

so im thinking of rewiring it .. and if that doesnt work .. then i guess my ecm is fried ..

ill keep yall informed on my progress..

adrian

 

ok .. did a little searching around on here ..

found out its the gf9 pin .. and found a diagram to show me which one it is on the connectors ..

pulled the green connector of the ecm .. and checked the lower 9th pin with a multimeter ..

im getting no reading at all when i put it to a good ground ..

so after this .. im guessing that:

1) the connector is messed up on the knock sensor
2) the wire has broken from the knock sensor to the ecm (ill have to find out what caused it)
or
3) a ground wire from the motor to the firewall is messed up (but i HIGHLY doubt this since there are plenty of ground straps including the main battery negative)

i went to orielly's a second ago and they were closed 4 minutes before i got there .. .. and none of the other two parts stores have ANY harness pigtails ..

so i guess ill have to wait till tommorow .. and ill rewire the knock sensor .. then the TUNING SHALL BEGIN ... haha .. or so i hope ..


Adrian

 

If your engine setup has a fan switch in the passenger side head, check that the connector for it and the knock sensor aren't swapped. I recall on the earlier cars this was a common error.

The ECM reads the resistance of the knock sensor to ensure that it is there and the wiring is OK. If the connector is loose on the sensor pin that will cause DTC 43's.

There is also a forced knock test for DTC43. Some calibrations have this disabled. If it is currently enabled I'd recommend disabling it.

Push comes to shove you could wire a 3.9K resistor to the ECM knock sensor input pin.

RBob.

 

I GOT IT FIXED !!!!!



now i can do this REALLY easy





and this ..




lol ..


neways .. found out that part of the wire was corroded .. looked like someone had cut the wire before and just taped it together in the loom ..

so i cut the wire and connected on a new knock sensor pigtail ...

now i got NO engine codes ... and it purs like a kitten ..

im running the stock tune, so its down on power a little and probably a few knocks b/c the timing is way to much for the vortec heads

so im about to go and start datalogging .. and the tuning BEGINS ..

other than that .. it runs extremely smoothly now .. just like a new car instead of my rugged 55' ford i used to have that i took off a field (sat for 15 years)

thanks for the help,

adrian

 

ok,

downloaded the datamaster trial ..

at first it just looked like a different version of tunerpro .. and $120 vs. $30 .. come on now ..

BUT ..


did a recording with it up and down the street .. then plugged the file into ve master ..

and kaboom .. IT RUNS BETTER .. and the ve master program is WAAAYYY faster than calculating each individual ve box ..

did about 3 more times ..

and now im sitting at about 115-126 blms most of the time .. except idle, but that might be b/c of the cam ..

..............................

now i see why the program is $120 .. it saves WEEKS of time / effort trying to tune the ve tables ..

got about 16 "trial recordings" left .. so im going to get it as close as i can for now ..

i only have a knock count of 3 .. and its up above 3000 rpm somewhere ..so ill take it easy untill i can scrounge up $120 from someone .. lol .. probably paint a fence or something , heck thats how i bought the tuning stuff .. hahha ..

im running the stock timing table on vortec heads, so i might be a bit off in some areas .. but it doesnt knock .. so ill work on the sa table later..

other than all that .. its running perfectly compared to last week .. and it goes a couple seconds faster 0-60 now .. lol .. its about 50 feet shorter ..

Adrian

 

Keep tuning man, you'll get. Just don't change too many things at once, and try and keep track of the changes you make from bin to bin.

 

The programs will only get the "Rough" VE dialed in close.
You'll need to sharpen your skills to get the rest done.
After it gets close, the programs automatic calculations will overshoot and never really nail it.
I have found that by leaving the setup alone and averaging 3 or 4 VEMaster corrections to the SAME bin for aprox 15 minute drives each, Take the corrected tables into Excell and get the average for all the correction tables and you'll be very close.
Making individual drive and changes won't get you there.
Glad to hear its going better.

ScannerPro is the next revision to logging with TunerPro.
It has some features similar to Datamaster and can be customized by the user. you'll appreciate the flexibility of programs that can be customized once you get in deeper and making more changes.
for the quick start, DM and VEMaster can cut some time roughing it in.

 

scannerpro.... are there definitions available for the $42 mask yet? Or is that something I have to try and make? Sorry adrian lol

 

Since he's running good now I'll toss a bone.
I threw this together quickly by importing the std ADS file and then adding some displays from the $8D one I made up.
Use a combination of the internal editor and the text file (to locate items by "Hash ID") and setup the histograms and monitors better.
Text needs to be adjusted for display purposes and you can asign items to display gauges as you see fit.
Just a startpoint, I'd like to see more people using SP.

 

JP, I appreciate it! I would like to try this proggy out on some other rides, I'lll have to tinker with it.

Thanx again


Adrian, how you making out man??