Vortec 454/4L80e HD swapped 1999 Tahoe OBS

[randeez]

Alright guys, here’s a video of some lugging it’s doing. May be related to FPR or injectors. It lugs down under consistent throttle position. You can hear the engine lug and drop in RPMs, even though throttle doesn’t change. It’s very noticeable while driving, and you can feel slow you down. Possible FPR and/or injectors. Leak down test is positive, and smell of fuel under the hood. What are your thoughts y’all?

is the converter locking?

 

[bigfootchiro]

is the converter locking?

It locks up just fine, but I’ve had this sneaky suspicion that it’s trying to lock and unlock and lock and unlock, which would cause what I’m feeling. The transmission has all new solenoids and MAP inside, though. After replacing the TPS, this issue went away for a while, now it seems to be coming back for a vengeance.

 

[bigfootchiro]

me? ive already got enough injector to do 1k+
but they kinda expensive, theyre tested/matched set and tune data they provide takes all the guess work out of getting them going. i went from flex fuel injectors to 1200cc and it started right back up and idled like stock since day one.

stock flex fuel injectors would be good for him, would flow enough for about 550hp, but they are about an inch shorter than the standard ls1 injectors would need to figure out what size hat adapters. and all the data for them can be found in stock tune files.

Can I run flex fuel injectors, and run E85 with tuning? Are the hat adapters where the harness plugs into the injectors?

 

[randeez]

It locks up just fine, but I’ve had this sneaky suspicion that it’s trying to lock and unlock and lock and unlock, which would cause what I’m feeling. The transmission has all new solenoids and MAP inside, though. After replacing the TPS, this issue went away for a while, now it seems to be coming back for a vengeance.

the lock up will be controlled by the tune on a 4l80, but if there are any misfires/knock itll unlock. and yea i meant you may want to not have it lock up so soon, maybe leave it unlocked until overdrive (4th)

the hats are just to extend the injectors from manifold to the fuel rail, the plugs would probably be different also, neither is expensive 50/ea for a set of 8. but if you figure the cost of injectors, hats, adapters itll prob work out to be close. may be easier just finding some 55lb or 60lb injectors that are the right size and plug

dont know if you could do a flex fuel tune on a 0411 pcm, may have to be one or the other

 

[bigfootchiro]

the lock up will be controlled by the tune on a 4l80, but if there are any misfires/knock itll unlock. and yea i meant you may want to not have it lock up so soon, maybe leave it unlocked until overdrive (4th)

the hats are just to extend the injectors from manifold to the fuel rail, the plugs would probably be different also, neither is expensive 50/ea for a set of 8. but if you figure the cost of injectors, hats, adapters itll prob work out to be close. may be easier just finding some 55lb or 60lb injectors that are the right size and plug

dont know if you could do a flex fuel tune on a 0411 pcm, may have to be one or the other

The trans doesn’t lockup until in 4th around 47 at the lowest, but that’s the “feeling,” like it’ll lock for a quick second and release; however, I don’t think it’s the TC causing it. The leak down test I did earlier was positive, and I could smell fuel under the hood. Can’t seem to get much live data on my scanner with this PCM like I did the 350, so it’s harder to diagnose.

 

[bigfootchiro]

 

[bigfootchiro]

Hydroboost conversion plate

 

[randeez]

mhmm mhmm mhmm

dont look to bad, i just cut the oddball stud off my hydroboost plate lol. if its ever an issue ill just drill thru the stock hole and nut and bolt it

 

[bigfootchiro]

mhmm mhmm mhmm

dont look to bad, i just cut the oddball stud off my hydroboost plate lol. if its ever an issue ill just drill thru the stock hole and nut and bolt it

Is the stud on yours supposed to keep it from flexing/twisting?

 

[randeez]

? dunno...that plate looks like my stock vacuum booster plate. the hydroboost plate for mine 3 of the 4 are studs on the plate....the 4th one is not symmetrical