Also, this is a great writeup.
My TBI adventure...so far
- Thread starter cruiser enthuiser
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cruiserbrett
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Depends on what ecm and vss you are using? Whats the number on the ecm tag? 1227747? 16197427?
Running 1227747 ecm. Ordered new vss sensor today. I also learned that I should be running a preheated o2 sensor w/ my headers.
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- #144
Nick, replied to your PM.
Digger, my understanding is that the ECM getting half speed shouldn't cause your idle issues. So long as the ECM is getting a signal from the VSS that you're increasing or decreasing speed, it should prevent you from having driveablity issues. I think your idle and stalling problems are caused by something else. Did you do the IAC reset procedure and adjust TPS voltage? This was Cruiser Brett's advice to me (he is wise in the ways of TBI) and it made a big difference.
Incidentally, I am having my own VSS issues but they are related directly to problems with the speedo drive gear in the transfer case. I believe the bonehead PO of my rig tried to rebuild my TC and screwed it up. I have been putting off dropping the TC and tearing into it because I really enjoy driving it and dont know s*** about rebuilding one
-Ed
Ed, swapped out IAC but did not do the reset. My TPS is not the adjustable type (though, I have been thinking of switching to one). I just xfered to Hawaii this last fall, if I was still in Sacto I would have liked to have driven out to Reno and helped you with your TC. I'm ditching the whole Digital Dakota setup and doing the same VSS setup you are running. thanks for the help and I will keep you posted. You writeup is awesome! Digger.
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- #146
Hawaii, eh? Must be awful
I swapped the IAC for a new one when I was having idle issues too. Didn't make any difference until I did the reset procedure and then voila! Problem solved.
Good Luck!
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- #147
Jack, sorry I missed your question all that time ago.
In the interest of full disclosure I should say that I actually re-installed the EGR a short while after it was up and running. Yes, I was occaisonally getting an error code that I believed was related to the lack of EGR - a lean exhaust error. I surmised that this was because the EGR was not programmed out and so the computer was always accounting for those exhaust gasses as part of the fuel mix because it had no way to know they were not in there. Also, I had to pass and emissions test. After a failed attempt I decided to put it back on as well as the smog cannister (I had left all these connectors in my harness just in case). While adding the EGR back on seemed to make the engine run very slightly better, it did not resolve my lean exhaust error code. In fact, I still get this code today and what's odd is I know it runs slightly rich. I attribute this to a tuning issue - using the 7747 ECM on a very similiar, but different motor than it was made for - and until I am willing to pony up the cash for a new chip or a programmer, I'm not worried about it. It runs very good and I am just enjoying driving it right now.
-Ed
How do you know it is running rich?
Hi,did you had more power running with the carb or now with the tbi?
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- #150
Based on my emissions test results. High CO readings, particularly at idle.
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- #152
Mine ran terrible with the old carb. Reliability was the issue, power not so much. If I was a better mechanic I may have been able to rebuild it and had it running sweet, but I'm not. I considered replacing it with a new quadra-jet - I had always heard good things about 'em. But I had just recently had several very irritating off-road experiences with my old carb so EFI sounded really appealing and TBI was reputed to be the most affordable and reliable option out there.
I'm very happy with the power it puts out now. My next major upgrade will be a transmission with an overdrive that will let me enjoy the V8 on the highway.
-Ed
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First i had a chevy 283 v8 on my 1974 fj40, then did a egine swap to a 88 350 5.7 tbi ,same as your tbi donor ,the thing is that didn't feel much difference in power between engines.
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