Getting Started: LO3 Camaro

[TerryD]

So @Fancy and @imiceman44 collectively set me up with a ALDL cable and I've downloaded TunerproRT.

I found the $61 .bin and .adx (at least I think) and have them loaded. I've got to double check my ComPort in TP now that I've read through Mark's tutorial.

I'm still not even 50% that I know how to get it to log, but we'll see. I wanted to start this so ya'll can help me along or make fun of me or whatever as I'm figuring this out.

I'm hoping to drag the Camaro out Saturday morning and see if I can start pulling data from it.

 

[TerryD]

Downloaded ALDLdroid and got an adapter to hook my cable up. Checked it out and looks like I have the elusive 1988 ONLY LO3 ECM.

So now on to more reading and research. Gonna watch knock this evening cruising around and maybe bump it 4°.

 

[TerryD]

Managed to get TunerPro RT to talk to the ECM. My Knock counts had an ERROR in that field. I was using the 89-92 $61 mask though (because it was what I had loaded). I'll find and load the 88 mask tonight if I can find a good one.

My display was still blank and I was having to read from the list rather than any gauges. Not sure what I'm doing wrong yet.

 

[TerryD]

OK. Found the $4D mask for the 1988 ONLY LO3 ecm. Played my data log (very short) through that mask and got knock counts and I think better data.

What is an acceptable knock count? After about 20min run time and a few hard pulls merging on the interstate plus a few 50mph up pulls to nearly 90mph on the interstate, I was showing a total knock count around 46. I checked my timing this evening and it was -2*. Bumped it up to around +4* which made some difference in drivability as well as dropping my IAC counts from 30ish to around 20ish (according to the $61 mask on my app which I'm trying to correct as well if I can get access to my phone files)

I did learn a little tonight and I'm hoping to do some more logging this week and even try to run some logs while headed to the big cruise-in Friday.

Car has a fresh tune-up, new O2 sensor, fresh air filter, and new fuel filter. It looks like I need to find an air dam for under the front. My temperatures are still staying up at highway speeds because I can't build the high pressure pocket in front of the radiator. Guess it's off to the scrap yards to try to find one. I can't seem to find them aftermarket.

 

[dyeager535]

I thought LMC was repopping the air dams? I recall someone was, because at one point anyway, they weren't making the ones for tow hook equipped trucks.

Anyway, I'm not sure there is an acceptable number for knock. Probably going to be harder with that ECM...thats the "slow" data speed right? I can't recall the number, the "fast" ECM's transmitted at 8192, slow was three digits, which makes it a bit tougher to see whats going on as precisely. But I'd want to see where the knock is occurring, and I'd want to see whether or not timing is being pulled.

Part of the knock sensor circuit is SUPPOSED to be a check of it upon startup, but I've never seen what that actually looks like in a datalog. No clue if those knock counts would be logged. If you see knock count and some knock retard occurring when the vehicle is being driven, I'd say that isn't acceptable.

I like exporting the logs to excel to look at that sort of thing, but it's how I taught myself to use the data output from Tunerpro, and there are other ways. IMO its just very clear that way where knock is occurring and where I need to consider adding fuel, pulling timing, or both.

Again assuming this is a "high" compression engine (compared to the 350's of the era) it may very well be sensitive to heat. How hot is it getting, and when? If you can correlate the coolant temp to the knock, then that might be a factor. Otherwise while not optimal, might be other things to look at. Adding 4* of timing is pretty significant, if you got into actual tuning you could set it at 0* as it should be (there are probably some tables that are now off that reference base timing at 0*) but where the knock is occurring will give you some idea.

IIRC the knock count "resets" at 255(?), I'd rather be looking at knock count over run time to ensure it isn't ridiculous. But if it was THAT bad, you'd probably feel flat spots in performance. It doesn't take much knock induced spark retard to feel performance fall off.

 

[TerryD]

I thought LMC was repopping the air dams? I recall someone was, because at one point anyway, they weren't making the ones for tow hook equipped trucks.

Anyway, I'm not sure there is an acceptable number for knock. Probably going to be harder with that ECM...thats the "slow" data speed right? I can't recall the number, the "fast" ECM's transmitted at 8192, slow was three digits, which makes it a bit tougher to see whats going on as precisely. But I'd want to see where the knock is occurring, and I'd want to see whether or not timing is being pulled.

Part of the knock sensor circuit is SUPPOSED to be a check of it upon startup, but I've never seen what that actually looks like in a datalog. No clue if those knock counts would be logged. If you see knock count and some knock retard occurring when the vehicle is being driven, I'd say that isn't acceptable.

I like exporting the logs to excel to look at that sort of thing, but it's how I taught myself to use the data output from Tunerpro, and there are other ways. IMO its just very clear that way where knock is occurring and where I need to consider adding fuel, pulling timing, or both.

Again assuming this is a "high" compression engine (compared to the 350's of the era) it may very well be sensitive to heat. How hot is it getting, and when? If you can correlate the coolant temp to the knock, then that might be a factor. Otherwise while not optimal, might be other things to look at. Adding 4* of timing is pretty significant, if you got into actual tuning you could set it at 0* as it should be (there are probably some tables that are now off that reference base timing at 0*) but where the knock is occurring will give you some idea.

IIRC the knock count "resets" at 255(?), I'd rather be looking at knock count over run time to ensure it isn't ridiculous. But if it was THAT bad, you'd probably feel flat spots in performance. It doesn't take much knock induced spark retard to feel performance fall off.

Per Wikipedia, the LO3 was 9.3-9.5:1 compression.

I've seen where folks say add anywhere from 2° to 12° to base. What I know about engines and timing, the 12° seems pretty extreme but I wanted to pop some in and see.

Now that I can get my software working, I'm going to try some longer logs with some uphill runs to see where the knock is showing up. I use a lot of data logging at work so I'm hoping that'll help me correlate where it's common.

And yes, the TBI ECM is 160 baud as opposed to the TPI stuff. Pretty sad.

 

[dyeager535]

Per Wikipedia, the LO3 was 9.3-9.5:1 compression.

I've seen where folks say add anywhere from 2° to 12° to base. What I know about engines and timing, the 12° seems pretty extreme but I wanted to pop some in and see.

Now that I can get my software working, I'm going to try some longer logs with some uphill runs to see where the knock is showing up. I use a lot of data logging at work so I'm hoping that'll help me correlate where it's common.

And yes, the TBI ECM is 160 baud as opposed to the TPI stuff. Pretty sad.

I haven't seen anyone here get away with anything over 4* base timing without running into knock. But every rig and engine is different of course. As I read over on thirdgen somewhere long ago, you give the engine the timing it wants, not what you think it should be. So if you can get away with advanced timing, and it helps, why not. But this is also why the aftermarket chips (the junk ones like Hypertech) had people install colder thermostats...because all they were doing was bumping the timing way up, and the colder temps helped keep knock from being as big an issue. Changing base idle is what is called a "global" change, like bumping fuel pressure up. If done via tuning, it's possible some timing can be added in some areas, and taken out in others, which would allow some better performance without running into knock which is what can happen with a global change.

It will be enjoyable to see what you do and your results.

 

[TerryD]

I agree, and I just started at 4° as an arbitrary test point. I'm thinking I'll drop back to the factory 0° and do some logging to get a good baseline.

The initial timing being at -2° is a little worrisome. These engines are known for timing chain/set issues so I may gather some parts and change the timing set and check the distributor this fall as a preventative measure.

 

[TerryD]

Found a NOS air dam for $100 on 1A Auto. Got it on the way. Hopefully it'll be here in time to mount up before the cruise-in on Friday.

Maybe that'll help with some of the cooling issues at speed. I guess my mechanical fan hid those issues on the 84.

 

[dyeager535]

My buddy said that once he put a new timing set in his TBI motor, he had to back down from 4* advanced otherwise it knocked.

He is pretty good at that sort of thing, I doubt he messed that up.

 

[TerryD]

My buddy said that once he put a new timing set in his TBI motor, he had to back down from 4* advanced otherwise it knocked.

He is pretty good at that sort of thing, I doubt he messed that up.

I was taught to degree cams and set at least 2° advance to account for timing set break in and wear with performance engines. So I completely believe that it can affect the engine long-term.

 

[dyeager535]

What are you seeing regarding temps while driving? I'm always interested in this sort of stuff, especially before/after when changes are made.

 

[TerryD]

What are you seeing regarding temps while driving? I'm always interested in this sort of stuff, especially before/after when changes are made.

Over 210 regularly right now. I'll have to do some driving logs and post them up. Then a log after the air dam is installed and see what kind of improvements I see.

 

[TerryD]

Base timing is set back to 0° BTDC.

I'm getting about a -1/2° "tick" in the timing that I'm beginning to suspect is wear/play in the distributor bushings. It is a 90k mile 80's model car after all. Any recommendations for a good EFI distributor for this thing?

Then I broke the silencer/ring out of the air cleaner to help it breathe around the injector pods easier.

 

[82355]

I thought LMC was repopping the air dams? I recall someone was, because at one point anyway, they weren't making the ones for tow hook equipped trucks.

Camaro, not a truck.

Martin

 

[dyeager535]

Camaro, not a truck.

Martin

My mistake...I was thinking Camaro motor in a truck lol.

I haven't seen any good "stock" replacement distributors. The cheap chinese ones are all that I can think of. Delco would probably be chinese at this point too. Not terrible to swap the distributor, I bought a cheapy just to have a spare, but I ended up using it to do a quick test too. It works fine, but I'm sure it's not up to old Delco standards, but not much is.

 

[TerryD]

Pulled a few logs yesterday. Still getting knock counts even with 0° base timing.

I'm gonna drop the ECM and make sure someone hasn't shoved a JET chip or something in it.

 

[dyeager535]

Hopefully not one of those chips, I don't know what you'd do at this stage except go to programmable, EBL, use another ECM/PROM, or try and get lucky that someone has one for sale. Looks like most (all?) ECM's remanufactured for that application require you to swap the PROM.

 

[TerryD]

Here are the logs I did yesterday evening if anyone wants to review them in TunerPro RT.

The couple samples it got during the full throttle run shows O2 Volts right at .9 at the top end.

It looks ok so far for a OE calibration vs everything I've been able to read.

It's a $4D mask if anyone is interested in looking at them.

 

[dyeager535]

Does tunerpro work on the phone? I'm probably behind the times, back home I have an old laptop I have dedicated for tuning, here I dont have it.