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tuners chime in

4K views 18 replies 7 participants last post by  87vette81big 
#1 ·
Ok here is the deal. I went to the garage today to get the idle set on the 86. Was going to use datamaster but I couldnt get it to connect. Set it to the correct com port ( com5 on mine ) and tested the connection. It recognized the ALDL adapter but popped an error message that said data not recognized. Went to winaldl and connected just fine. Did I miss something? Got the idle set, tps voltage at .54 dead on, iac count couldnt get below 85. As the range is 0-160 i figured right in the middle would be ok. Was trying for iac counts at about 30-40 but no matter how hard I tried couldnt get below 85. I even swapped the IAC motor. Anyway I still want to get the reading from datamaster but as I said I cant get it to connect. Could this have to do with the prom being piggybacked on a moates or am I looking in the wrong place. Any help would be great, and I know there are very good tuners here. Ecm is a 165 and vette is an 86. Any more info you guys need let me know. Noe time for a beer or 4 :cheers:
 
#2 ·
Don't have any answers but I am interested in the answers you get. :thumbsup:
 
#3 ·
It may be the MOATES piggybacked onto the stock ECM.
Are you using the Craig Moates APU1 or the Ostrich 2 Emulator ?
I have the Ostrich 2 Emulator.
Powerful tuning tool but I noticed strange engine running behavior using it at random. Burps & Hiccups, sometimes the engine would shut down while driving & restart 2 seconds later.
Stock EProm is pickybacked onto the Moates adapter.
Desired program downloaded & modified to your liking.
I also noticed terrible RF noise on the factory Bose Stereo using the Ostrich 2. Ear piecing squeals.
Had my fun playing & removed the Ostrich 2.
Decided I am still an old school Holley- Carter AFB carburetor guy.

Maybe remove the Moates temporarily & see if you can reconnect to the Datamaster.
 
#4 ·
It may be the MOATES piggybacked onto the stock ECM.
Are you using the Craig Moates APU1 or the Ostrich 2 Emulator ?
I have the Ostrich 2 Emulator.
Powerful tuning tool but I noticed strange engine running behavior using it at random. Burps & Hiccups, sometimes the engine would shut down while driving & restart 2 seconds later.
Stock EProm is pickybacked onto the Moates adapter.
Desired program downloaded & modified to your liking.
I also noticed terrible RF noise on the factory Bose Stereo using the Ostrich 2. Ear piecing squeals.
Had my fun playing & removed the Ostrich 2.
Decided I am still an old school Holley- Carter AFB carburetor guy.

Maybe remove the Moates temporarily & see if you can reconnect to the Datamaster.
Thanks 87vette I might try that. Havent bought the ostrich yet, but the more I hear I might not until I have to. I would remove the moates adapter but then I would only have the stock tune and the car wont run at all. Mods are First intake, 36# injectors, Melrose headers and exhaust, AFR 220 heads, K&N , Comp cams 12-268-4 cam, 1.6 roller rockers, trw flat top pistons, 11-1 comp. ,etc. , etc. Stock memcal will not even let the car idle as it is way rich. Tuning is about the only thing left so I got a tune from alvin and that is very close as far as I can tell so far. Dyno tune at wichita dyno sometime soon so that will get it all straight and I will post some results. Hopeing foe 400hp/440ft.lbs.

XQIZT - Hope I get some positive answers. Will probably help many here.BTW you ever get your issues fixed with your c4 or just moving on to the GF's c3 ?
 
#5 ·
I don't know how your tuner works, but could you remove the moates,set the iac to 30 - 40 and then put the moates back on...

Does the car have to be running to set that setting....

:huh:

I wish you the best of luck and look forward to hearing your fix even tho I have a C5 because I have some friends with C4s. I still love that car.:thumbsup: My first dream car.
 
#6 ·
I don't know how your tuner works, but could you remove the moates,set the iac to 30 - 40 and then put the moates back on...

Does the car have to be running to set that setting....

:huh:

I wish you the best of luck and look forward to hearing your fix even tho I have a C5 because I have some friends with C4s. I still love that car.:thumbsup: My first dream car.
Not sure that would work as the ecm would have nothing to adjust to. Ecm adjusts iac to maintain programmed idle. With engine not running there is no idle = no rpm reading = no iac. The tps can be set without running but not the iac/ base idle. Most set the base idle with iac disconnected but with the first intake it is easier to set by iac counts as you have to remove the throttle body to disconnect the iac. Good thought though. Thanks for the idea. Many minds are better than one- at least the one I have:laughing:
 
#10 ·
IAC counts are way off. I can get mine to within 20 counts with ONLY engine running. Are you SURE the AC is off?
 
#11 ·
Yes I am 100% positive the ac is off. 850 rpm is the idle in the tune. I know the iac counts are high but I couldnt get them to go any lower. I am going to double check the base timing when I get a chance. I dont think that should affect the iac counts though. As I said I even swaped in a new oem IAC and still couldnt get it below 80-85. I would have rather doen it through datamaster but it wouldnt connect. That is my main problem I was looking for a fix to. Now are you getting it to show a count of 20 or getting it to about 50 which would be within 20 of what is called for?:huh: Any other ideas here?
 
#12 ·
Here is how I do it. Run it for some errands and come home. At which time, I check the counts when it is in Park and everything off. If it is high, I screw it in, rev it and see what it falls to. If it is low, I screw it out and rev it. As to my counts, it is what the scanner says it is. Timing of course is spot on.
 
#13 ·
Suspect you may be ALDL Mode (Bit 5 set. Bit 5 = DIAGNOSTIC SWITCH IN ALDL POSITION).

When this occurs, target idle rpm is set to 1,000.

To test this premise, adjust your throttle opening to idle well above 1,000 rpm to see if the IAC counts will come down and control to the 1,000 rpm target.

FDB $0035 ;54, Minor Lp mode word #2
;
; Bit 0 = 1= OVERDRIVE ON
; 0= OVERDRIVE OFF
; 1 = ERR 14 or 15 THIS STARTUP
; 2 = REF PULSES OCCURRED (6.25 MSEC CHECK)
; 3 = 1= ALDL MODE, 8192 LOCKED IN, & MODE 4
;
; 4 = DIAGNOSTIC SWITCH IN DIAGNOSTIC POSITION
; 5 = DIAGNOSTIC SWITCH IN ALDL POSITION
; 6 = HIGH BAT. VOLT. , DISABLE SOLENOID DISCRETS
; 7 = SHIFT LIGHT (1= ON, 0= OFF)
;---------------------------------
 
#14 ·
Suspect you may be ALDL Mode (Bit 5 set. Bit 5 = DIAGNOSTIC SWITCH IN ALDL POSITION).

When this occurs, target idle rpm is set to 1,000.

To test this premise, adjust your throttle opening to idle well above 1,000 rpm to see if the IAC counts will come down and control to the 1,000 rpm target.

FDB $0035 ;54, Minor Lp mode word #2
;
; Bit 0 = 1= OVERDRIVE ON
; 0= OVERDRIVE OFF
; 1 = ERR 14 or 15 THIS STARTUP
; 2 = REF PULSES OCCURRED (6.25 MSEC CHECK)
; 3 = 1= ALDL MODE, 8192 LOCKED IN, & MODE 4
;
; 4 = DIAGNOSTIC SWITCH IN DIAGNOSTIC POSITION
; 5 = DIAGNOSTIC SWITCH IN ALDL POSITION
; 6 = HIGH BAT. VOLT. , DISABLE SOLENOID DISCRETS
; 7 = SHIFT LIGHT (1= ON, 0= OFF)
;---------------------------------
No Been there done that. Idle will come down to the programmed 850rpm, just cant get the aic counts down where I would like them. If I crank the idle up then aic will go to 160 and idle will not drop past where I set it. I did remember I used a new stock ( non heated ) O2 sensor and running melrose headers. Need to get that swapped to a heated O2 and check again. I was more worried about trying to figure out why I can connect with datamaster. Unfortunately tunepro doesent show open or closed loop. Without the heated O2 I think I am staying stuck in open loop and it is not letting the iac function fully. Thanks for the suggestion though.:thumbsup:
 
#15 ·
The other possibility is that you're not in PID control while you're making adjustments, likely due to the tps.

If you have positive rpm error and are in PID control, the IAC counts should come down to control the idle.

After you add throttle opening, reset the tps again so that the ecm still thinks the throttle is closed.

Example conditions from $32 mask:

**********************************
* PID ENABLE CONDITIONS
**********************************
LC64B: FCB 3 ; Enab T/F if TPS% >
; CALIB = Arg * 2.56, (1.17%)
LC64C: FCB 0 ; No store of new TPS if Diif
; fm old is <
LC64D: FCB 8 ; No Decay till TPS >=
; CALIB = Arg * 2.56, (3.125%)
LC64E: FCB 6 ; Enab C/L PID if MPH <=
; CALIB = Arg * 16/5, (1.8 MPH)
LC64F: FCB 4 ; 50 RPM, Min under spd error to enab PID
; Durring Xsission dly, CALIB = Arg/12.5
 
#16 ·
I did remember I used a new stock ( non heated ) O2 sensor and running melrose headers. Need to get that swapped to a heated O2 and check again. I was more worried about trying to figure out why I can connect with datamaster. Unfortunately tunepro doesent show open or closed loop. Without the heated O2 I think I am staying stuck in open loop and it is not letting the iac function fully. Thanks for the suggestion though.:thumbsup:[/QUOTE]

Hey Wildcat I had to heat my O2 sensor on my longtubes to get the car to come out of openloop. I bought a heated one and then built my own using a trailer light extension kit. I could send you some pics if you so desire. I used datamaster and had the issue you described as well. No matter what I do I have to reboot my laptop after plugging it into the car to get it to work. I didn't see where you mentioned putting a resistor between the A&B on your ALDL connector.
 
#17 ·
Hey Wildcat I had to heat my O2 sensor on my longtubes to get the car to come out of openloop. I bought a heated one and then built my own using a trailer light extension kit. I could send you some pics if you so desire. I used datamaster and had the issue you described as well. No matter what I do I have to reboot my laptop after plugging it into the car to get it to work. I didn't see where you mentioned putting a resistor between the A&B on your ALDL connector.
Thanks for the offer, but I think I have a part # for one that I can use the original connector and run a power and ground for. I will try rebooting the laptop after hooking up the ALDL adapter and see if that helps. I have an adapter that allows either no resistor or a 10ohm resistor that way I can use it on more than the chevys. It will work on any obdI system with that connector at the ALDL. Thanks for your ideas I will definately try them as soon as I get out from under this snow ( 18" last weekend ). Did you ever get your tranny fixed? Shop built or did you decide to do it yourself?:cheers:
 
#18 ·
I bought a reman from a place called shiftrite. I don't think it's going to hold up very well though-I'm going to take it somewhere to have it pressure tested in the car as i can get it to slip if i get on it hard in second gear. Before I chew it up I'll take it somewhere that knows what they are doing and have them look it over.

To be fair the car was a 350 when i bought the tranny and now it's a 383 so it's entirely possible that it's just not up to it. If I had overbought to start with I probably wouldn't be having any issues now.

On my laptop I have it set to use port 5 and can get it to connect with a reboot. I definitely had the connection issue you had when i first started though and now it works fine so there is hope.
 
#19 ·
If your C4 auto is slipping in 2nd gear, the 2-4 band is not holding as it. should. Need to start with a new GM ,Reverse input drum. Heavy duty 2-4 band like Alto Red Eagle or Alto black carbon fiber. Set servo pin to .080 inch clearance. Use extra long servo pin. Adjust clearance by maching tip in a 3 jaw chuck metal lathe. Very important to drill- set 2-4 valvebody steel seperator plate oil holes diameter intake & exhaust 2-4 correct. Makes for lighting fast upshifts.

BR
 
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