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TBI won't idle and running really rich

I need to get this data log stuff. For one though, I am pretty sure mine is not CTS cause I purchased a brand new one and it did nothing (but I haven't looked at all the wiring to the CTS yet).

Well, looking more at it this weekend, I think that "3rd plug" I talked about isn't really my problem, because the more I looked at it, it really only goes to the ALDL, Check Engine light, VSS, stuff like that. Nothing really dealing with just start up and running/idle. So I think I need to look at our original grafting of my original harness and the TBI harness stuff again and make sure it is all in line.

Would a bad ground cause something like this too? I'm wondering if one of the grounds just sucks so it's causing the computer to freak out a little :dunno:
 
Man I don't know how I lived without tuner pro rt. Found yet another problem by logging data and reviewing. Map sensor wasn't changing go to check the sensor and sure enough the port snapped off of the map sensor so it wasn't reading at all. No wonder it didn't run right last run. It was reading ambient air pressure and going into the premapped fuel curves causing it to run supper rich.
 
I am really at a loss with all this stuff. Worked on it more today and now can't even get it to start. Will just crank and crank. Need to pull codes and get tunerpro
 
You should host a CO Crew m&g at the Kay household to see if we can put together enough brain power to figure it out. I can bring the ALDL cable and TunerPro.
 
jekquistk5 said:
Well just did a test run with my one transistor aldl cable and was able to get data in winaldl and tuner pro rt. Found one of my problems right away with tuner pro rt. Bad CTS reading -35C, put a spare I found in and it reads 3C. Now this is just key on, didn't want to disturb the neighbors.

I am going to do an actual running data log this weekend and see what else I can find. Seeing what my motor is doing is pretty cool! What else should I be looking for?
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My '90 Blazer I practically stole because it'd only run for a minute or two before puking fuel and black smoke, then stall. Not able to restart until dead cold again. Low-balled the guy, came back with a few parts...swapped the CTS and drove it home. Check engine light went out, even passed emissions soon after. :waytogo:
 
Kay86K5 said:
I am really at a loss with all this stuff. Worked on it more today and now can't even get it to start. Will just crank and crank. Need to pull codes and get tunerpro
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I was at the same point before tuner pro. Had to pull ECM fuse clean each plug and then it would fire. I wouldn't do anything till you get tuner pro and see the feedback. I had replaced the cts and it didn't change had to replace the cts and map sensor. Wouldn't have found the crack in the map sensor without tunerpro.
 
Well, we have everything hooked up correctly now that should matter. The only items that are not hooked up are the gauge cluster (oil pressure, gas gauge, engine temp...yes CTS is hooked up and working) and wiring for TC lockup, but all of those don't run through the ECM at all or shouldn't matter for start-up and running in park. VSS is hooked up, ALDL is now hooked up correctly, and from what I have found the grounds should be good. Once it starts up it seems like it is running better, but still need to keep my foot in it to get it to start and still running rich and pooring smoke out the tailpipes.

After looking at everything, we are wondering if the ECM has some damage to it because we just connected that ALDL connector without thinking and started it up (it had a 100% 12V wire in that connector going to a portion of the ECM that wasn't supposed to accept it). So I think the next step we are going to look at it getting another ECM and plugging it in to see if there is any difference. If anyone has a 7747 stock ECM for a 700r4 tranny rig, let me know :whistle:

Like I said, when we fixed the ALDL wiring and some grounds, it started running a lot better (after initial start up). Was starting to idle a bit better and wasn't as rough hitting the throttle from off idle, everything seemed smoother. But, still doesn't like start up and really rich. I did attach a scanner to the ALDL port too, but all it was saying was that the computer wouldn't connect to the scanner and couldn't provide any codes :dunno:. Hence, why we are thinking of getting another ECM and seeing what happens.
 
ktmoutfront said:
I have an ecm you could borrow.
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Thanks. I may be coming that way. I sent a message to Geoff (poorboyk5) to see if he had any too. He said he was going to check. I will let you know for sure. Thanks for the offer
 
ssyork has spare TBI parts he's looking to unload now that he's installing an LS motor. I know he had a spare ECM.
 
mrk5 said:
ssyork has spare TBI parts he's looking to unload now that he's installing an LS motor. I know he had a spare ECM.
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good call, forgot about ssyork going to a 5.3. I think I will message him too. Thanks Scott!
 
Have an update, this is copy/pasted from my build thread:


"Well, made some great progress over the weekend. Don't know if anyone cares about this, but I was excited :D. ssyork was kind enough to send me his TBI computer out of his rig (cause he is swapping a 5.3 in currently). He had a custom chip burned for his cause he had a vortec fuel pump and a 454 TBI unit, but I decided to just plug it in and see what happens. I could tell immediatly that it was cranking and trying to start way better, but didn't want to start, so I swapped out the chip's from my stock ECM. It still had a little bit of a hard time starting up and idling right off the bat. We had an old TBI unit sitting around, so we decided to swap the IAC too, and that seemed to help out quite a bit.

We then hooked up my dad's code reader to it, and it said no codes! :pimp: It seemed like after a little bit the computer started to learn and it started to run better and better. So I decided to pull it out of the shop and start to drive it around. The thing was smoking out the exhaust like crazy, especially just out of the right bank, to the point we were thinking maybe the valve's weren't seating all the way. But I just decided to take it out and stretch it's legs a little. After getting it up to 50 or 60 mph it stopped smoking!! And seems to be running a lot better. So I am going to just put the dash back together and run it for a while. "
 
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