Data logging
 

I bought a Moates ALDL cable and downloaded the TTS Datamaster software and I finally managed to record my first log. My car is running rich so I'm trying to be proactive in learning why. I haven't purchased the tuning stuff yet since it won't do any good if I'm not smart enough to figure out what the datalogging is telling me.

If anyone is interested I will post up with additional updates to my progress. And, if anyone wants to know anything about the cable and software I'll try to answer the best that I can.

Please understand that I'm not trying to post advice as I'm just learning myself. I thought maybe someone would be interested in this learning experience.

Besides, I wanted to be the first to post in this section.:D

How do you know it's running rich? Especially before you bought the scan software? What is your setup?

When I start the car it fills my shop with unburnt gas fumes that will choke you. If your standing behind the car the exhaust will burn your eyes and if you hit the throttle it will blow black exhaust.

I have +/- 200 miles on a fresh 383 LT1, ported stock heads, 58 mm TB, 30# ford SVO's, ported intake, custom cam. I have a tuner who burned a starter chip to get the new engine running and he was suppose to do the final tune but I took too long with the build and he has moved back to Texas. I spoke with him today and I ordered a Burn 2 and HDR1 so that I can read and write to the chip. I managed to get one log using Data Master and the ALDU1 cable from Moates.

Might want to look at getting an Autoprom. They make life much easier.

APU1 AutoProm Package: USB Version [APU1] - $329.00 : Moates.Net

You can tune in real time if you have Tunercat RTT.

TunerCat

Between the two, it makes tuning the chip cars much easier, and much quicker.

If you run in to any problems with your current tuner, let me know, I've tuned a bunch of those things. It's easiest to reach me by email.

Thanks for the advice. I have looked at the APU1 from Moates and decided to try my hand at datalogging first before I try programming. The original tuner also suggested Tuner Cats. The thing is my tuner is willing to help me where he can but his obligation ends with the tune and not operational issues. I already took my car to him after startup to get a final tune but he told me to fix some issues and bring it back. With the help from a CF member the logs I've managed to get show my BLMs split off the charts as soon as it goes into close loop. I believe this suggests a mechanical issue so I'm going to look into that first before I address the tune. One step at a time, (1) learn to understand data, (2) use the Burn 2 to replace the tunes that have been adjusted by the tuner, (3) if it comes to it learn to do my own tuning.

Update, a few weeks ago caboboy from CF started helping me and after recording a datalog using Tunerpro we discovered split BLMs as soon as the car went into open loop. In fact the left bank bottomed out at 100 and the right bank topped out at 160 within just a few seconds. At the same time the IAC went to 0 completely closed. Caboboy sent me a link to a article about split BLM's. It explained if your TB idle set screw is holding the blades open, then the IAC can do it's job properly. And on an LT1 it can cause the split BLM's Here is the article link.

LJ's LT1 4th-gen Tech Library (go to PCM tutorial, then split BLMs)

Anyway I had indeed messed with the set screw. Mine is an after market TB and I had a bad TPS and, but before I discovered that, I was messing with the idle set screw trying to get it to idle. Sure enough I started backing off the set screw and the IAC started coming up. Everything looked good and I thought I was on the right path. Didn't happen, as soon as the car went into closed loop for a moment it looked good but then the left bank started to drop and fell all the way to 100 bottomed out. Then the right bank followed all the way. I had changed it though and we noticed the left 02 sensor had started to bounce around. So I changed it and checked it again. This time the result was the same, the left side BLM dropped followed by the right BLM and the left 02 started to became erratic. I thought maybe the right 02 could be bad and it may actually be causing the left one to get off so I changed the right one. This time the split BLM came back. Not as bad but still back. According to the article the other things that can cause split BLMs are bad wires, plugs, injectors or intake manifold leaks. I pulled one of the plugs and it was black as coal so I'll be replacing them next.

pull the vac line off of the fuel pressure regulator. If it is wet with gasoline or even smells like it, that will cause the nearest or nearest two injectors to be overdriven with massive full head fuel pressure and will be rich as hell.

obviously all the other fundamental stuff like ignition health should be checked to, but the fuel pres regulator is a quick double check.

That and a leak down test was the first things I did. The regulator was dry as a bone.

I replaced the opti, wires, IAC, TPS, MAP, everything but the coil and the plugs weren't very old from my previous engine.

Update: Since my last update I have replaced my plugs and fuel pressure regulator. The scans that were done between the parts going in were first inspiring and then disappointing ending up basically back where I started. Only now I'm getting split BLMs in open loop. I still haven't done a compression test but I have purchased the tool.

I also purchased a Burn 2 and down loaded my tune which my origianl tuner had installed onto my memcal. You can see where he made adjustments for the basics (cyl. volume, injector size, fan temp. etc) but is not too far from stock otherwise.

I also got a Craftsman scan tool that covers OBD1 and 2. I mainly got it for the 07 but wanted one that would also read the 93. I had recently cleared al of the codes via paper clip but I have done several changes since then. Below are the codes as of yesterday. btw, for some reason the tool will not clear the codes on the 93 so I will have to do it with the paper clip anyway.

The list:
51 prom error
55 fuel lean
62 oil temp high
64 right 02 lean
65 right 02 rich
68 AC relay short

One other note, even though the same ECM and eproms were used in 92 and 93 the scanner would not work using 93 as the yr model but 92 did.

Good stuff. I bought the cable and TTS and a slow as snot extra cheap ass laptop for $100. It's so slow, I haven't even tried it yet (1 year ago), but I'm getting the same 'high fume' smell at start up, so you've given me a reason to start learning how to do this stuff as well.

The code 51 prom error needs to be addressed first. If it is in backwards or burned with bad code then it will run on the analog back-up circuit.

I've learned a bunch already and haven't scratched the surface. You'll love it though, it's pretty cool. I've been fighting the mechanical issues so much that I haven't really gotten to fool with the tune much.

The funny thing is that when I did the paperclip thing it didn't show that code. I got 41, 62, 64, 72 with the paper clip so it was a very different set of codes. Another odd thing was that the Craftsman code reader made me enter 92 as the model year instead of 93. They used that same ECM on both years but still I would think it to show the correct year. Is there anyway to check to see if it is running off the back-up circuit?

update: Tim (caboboy) sent me a tweaked tune and I burned it to the prom and was a possitive move just not enough and I still have split BLM's. After making a couple of logs over the last few days it looks like I have managed to get the BLMs even during open loop and both sides were bottomed out in closed loop. I had hoped this was a good sign. If I can just get the A/F leaned up then both sides should come up and then just dial it in. After the first tweak the left side went from a 100 BLM to 109-110 at idle. Unfortunately the right side is being stubborn and didn't come up.

I'm still having issues with the IAC also. Can't get the counts down to the ~40 range that I would like to see.

I think I have decided to put the stock throttle body back on even if it means starting over with the tune. Since there may be issues with aftermarket TB's this should eliminate that and I can concentrate on something else if this doesn't fix it. Once I get it stabilized then I can go back and work on more air coming in.

I still have some other suggested things to scratch from the list of possible issues also.

Socalman, this may be some interesting reading that may get you motivated. LT1 PCM Tuning - Tips & Tricks for DIY Tuning!

So, it's been a long time since my last update.

On my last pass with the datalogging most of my parameters were within OK operating limits except the BLMs still being high/low. So I drove the car into OKC and dropped it off at a shop recommended by some local Vette guys. They told me my car was fine. They said the ECM was doing what is was suppose to do and that the left and right sides were not far enough off to hurt. They did say that the 02's may not be reacting as quickly as I would like so I will be installing heated 02's. I'm hoping that will reduce some of the radical swings of the BLMs along with a little more tuning. The car does seem to run good and at idle is a little lumpy but I can get rid of that by upping the idle a little if I choose. I also took the car by a muffler shop and had the pipes move where it was burning the tunnel so that is finally fixed.

I may still have some code issues to deal with and tune tweaking but at least I'm safe from the fueling issues and hopefully will just get better. The heated 02 should stop some of the codes but we'll see.