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I finally have my truck back on the road. Drove to town today, and on the way home decided to log the trip. I started out with a BLM of 153 cruising down the hiway, but it soon went to 126 at the same speed and rpm. I guess that 12 psi will work ok. It still needs a little bit of tuning, but for a stock BIN I shouldn't complain. Here is the log. Comments please.
Sorry I missed your post Jim... :confused:
I thought you put 5.7L injectors in that 5.0L? Sure is adding fuel?
The way it is, whatever injectors it is learning but BLM is awful high in 15x, idle and lower is 114. All stock I would expect closer. If it's adjustable add a pound to 13 PSI. Another thing to look at when idle is low BLM and drive and cruise is high BLM is fuel filter. Could this be getting plugged with all the fuel system work you have done?
Looked again and batt voltage may be what's keeping fuel pump a little low. At cruise you have about 13.4? Should be closer to 14.1... then at the little idle at end of log it was 12.4, when you turned it off it went to 11.8... so do you have a weak battery or questionable alternator? Lower voltage = less fuel from electric fuel pump.
Also the little idle at end of log showed IAC count of 35ish... I'd turn the throttle blade screw in 1/4 turn and get that lower. Lower IAC always helps idle quality.
It's doing it's job! But BLM shows a high low difference in some cells of up to 14! That's a big spread. It's in the ballpark and should be running OK?
Yes those are 5.7L injectors, I don't currently have the adjustable regulator in the throttle body, it was one of the variables I eliminated while I was trying to figure out what was wrong. The battery could be a problem, it's an old battery as my battery died in the middle of all this and I pulled the battery out of my son's ford pu which isn't being driven. I will check the output of the alternator as soon as I get a chance. The truck is running quite well, and the log showed improvement in the BLMs at cruise towards the end of the run. I am driving it to work this week just to see how things go. The idle quality seems okay, still does that funny shudder thing, but no worse than when I started. I will put the adjustable regulator on and try 13 psi when I can take it into my son's work, or I can borrow the snap-on tool overnight. I really think that I want to spend the money and put an external regulator on it when I can, it is a real pain to check the fuel pressure the way I do it now. Thanks for responding.
Something is wrong then? Those BLM should be all pulling fuel = under 128 with 5.7L injectors!
I always like 13 PSI over 12, but there's no reason to be adding pressure right now. You should have way to much fuel.
I agree with that, I have always thought that it should be way richer than it is showing. I just don't know what to look at next. The fuel pump is new, the fuel filter is new, the injectors were cleaned by witchhunter, and I know they flow lots of fuel (when it had the return line problem, it looked like a fire-hose at the injectors). Any thing I should be looking at in particular? It has alway run really lean on data logs. This particular bin has been superceeded, maybe there was something in it? Do you think that there is a mechanical problem I need to look for?
Maybe? But normally superceded bins were emmissions or driveability... what is it again? Let me, or you can too, compare it to another 5.0L Manual? I'd compare the entire bin but especially the fueling tables.Quote:
Originally Posted by jim_in_dorris
Just the voltage issue is all I can see. How about that dam complcated dual tank switch? Is it still in there? Wonder if it could be slowing down fuel flow?Quote:
Originally Posted by jim_in_dorris
It's a 5.0L 700R4 with 3.73 gearing. Mods are true dual exhaust with 2.5" pipe, dual cats, and flowmaster 40's. Also ultimate mods on TBI with 1" spacer and salad bowl. Lots of air moving thru. I don't think the fuel rate is an issue. If I pinch the return hose, it darn near floods the truck. I think it may be a combination of voltage (low battery volts) and the amount of extra air from my mods.
Your exhaust is letting it breath out easier. Your TBI mods are letting it breath in easier. SHould still be same amount of air at cruise speed... may help lower TPS% and raise MAP, all good for MPG. But it does not explain why you have more then enough injector and still have high BLM? High BLM is adding fuel.
You sure those were 5.7L injectors? I'd never be able to geuss that with that log... I would have expected BLM to be lower then 128 all over.
They are gm5235206's I am pretty sure those are 350 injectors. I looked them up and they are 55#/hr 5.7L injectors. My temperature shows 180-183 on the log, but I have a 195 thermostat. That would seem like it would run rich if the temp was a problem. Question, if it is a 5.7L engine with 5.7L injectors, with a 5.0L calibration, would that cause that? Or if a PO had changed the cam, would that cause it? I can't see the block casting # to tell for sure exactly what block is in it. I do have an ASDU prom I could try to see what happens.
I had noticed the CTS reading 180 and was going to suggest a 195. You would not be the first to run at 180 with a 195 T stat... seems like some cheap brands just use one and stamp it both temps?
5235206 are 5.7L injectors. But GM says they are 61 Lb/hr in $0D bins so I go by that.
I'm not really sure what would happen with 5.0L chip in 5.7L as far as data? Your not really sure about this motor are you? Idle shows 35 MAP at 550 RPM, so I really doubt this cam is more then stock.
Yeah stick the ADSU in and data log!
Leave a minute or so idle at end of log this time. Did you turn TB screw in 1/4 turn to lower IAC counts yet? Does not have to be near as big as last log unless your driving that route anyway.
I will try that. Supposedly 2 owners ago the engine was "freshened up" whatever that means, so i really don't know.
Could have TPI heads on it. I know first hand that a TBI 305 with TPI heads will run lean on a stock TBI 305 calibration even with 350 injectors. Even a 350 calibration ran lean. I had a stock 350 cam, TPI heads and headers at the time.Quote:
Originally Posted by jim_in_dorris
There maybe a simpler explanation than that. Is this truck equipped with an air pump? If it is are you sure it is diverting the air back into the air cleaner with a warm engine?
No air pump. I will have to look at the heads to see if they are tpi heads. Do the TPI heads flow that much more than TBI? Actually thinking about it, they are centerbolt heads, were any of the tpi heads centerbolt?
Yes casting number ending in 081 are TPI 305 centerbolts used from 87-92.Quote:
Originally Posted by jim_in_dorris
Its not that the flow that much more, they are non swirl and that really changes the timing and fueling requirements.
I will put it this way... I saw more of a difference tune wise going from TBI to TPI heads then there was going from TPI to Vortec. The swirl ports have a very odd tune that is both lean and retarded when used with any other head.
I would be willing to bet it has the hotter 350 cam in it if it has TPI heads. The 305 TPI longblock makes 230-260hp depending on whats bolted to it where the stock TBI is lucky to make 190-200.
Well, we guessed wrong. I pulled a valve cover today and have 193 heads. I really hope that the block is 350 also. No wonder it's lean, a 350 with a 305 calibration. i will swap to my 350 prom and see what happens
SO all this time it has been a 5.7L TBI motor with a 5.0L chip and injectors? Cause you swapped injectors right?
no, it had 350 injectors in it when I go it. But the chip is a 305 chip for sure.
SO someone dropped in a motor and not the ECM...
Anyway good for you, I'd rather have the 350 then a 305... of course not many people would have ever been able to figure that out?
It took taking a valve cover off and finding out what the head castings were, not something I would ordinarily do, but the lean problem was driving me nuts. I am going to try to get a peek at the block casting number behind the motor tomorrow to make sure. I may pull the alternator and check there if I can't see behind the block. If I do that, I have almost all the parts to convert it to a serpentine belt system. All I will really need is a new belt.
Might be easier to do than that. Just look at the driverside of the block, near the block drain and the last 3 digits of the casting number should be there. 427 or 638 or maybe even 880 for a 350.Quote:
Originally Posted by jim_in_dorris
Looked behind the head, it's a 5.7L for sure. Installing ASDU then logging.
Wow!!! what a difference. The big problem is staying off the skinny pedal.:jfj: My gas milage went down, but I think that the winter blend is showing up a the pumps, and that has a big effect. After running lean all those years, I am confident that the hiway lean cruise patch will restore my fuel economy when I finally get this thing tuned correctly. I have a short log, but it consisted of lots of WOT because it was fun. I did see a few spots with some knock, I will have to look closer when I have a little time. probably Thursday. I will spend a little time on the log, so I can get a idea what is happening. I am going to wait to post it until I at least review it. I hope it isn't too bad. I still have an irregular stumble at idle, but it isn't as noticable. Since I have another set of 193 heads, I may clean them up and do a valve job on them and slap them on because I am starting to think the stumble is a bad valve. If I do that, I may think about a cam at the same time. That is still a ways out, next spring at the earliest, but something I can consider. In the mean time, I want to get the tune close.
Well, there's a problem we can deal with! :thumbsup:Quote:
Originally Posted by jim_in_dorris