ls turbo problems
Thread Starter
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Joined: Jul 2023
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ls turbo problems hopefully someone can help me out here as im in desperate need of it s10 lq4 stock bottom end new bearings rings btr 4 turbo cam 799 heads tbss intake running terminator x tr6s gapped at .25 7875 t4 turbo my problem is that the truck just runs horrible will not build boost until around 4k rpm then breaks up ive checked for leaks on the coldside nothing i do have a small exhaust leak on the header that i will be fixing shortly i do have a datalog of it any help is greatly appericated running summit racing bov and wastegate with around 11 pound spring i cannt upload the datalog as its not a supported file
timing at wot 14
cruise 20
idle 20
afr wot 11.7
cruise 12.4
idle 12.4
map reads around 140kpa with key on engine off
timing at wot 14
cruise 20
idle 20
afr wot 11.7
cruise 12.4
idle 12.4
map reads around 140kpa with key on engine off
Last edited by lsxs101; Jul 22, 2023 at 12:42 PM.
I'll try to look at it in a bit, but give me some more info. What injectors, size and brand? What fuel, and base fuel pressure? What is the exhaust setup, and where is the O2 in relation to the end of the pipe?
I think a lot of issues are based off of those things in general.
I think a lot of issues are based off of those things in general.
Thread Starter
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cant understand why the map sensor is reading so high ive tried everything new map sensor checked all wiring has good 5v signal at idle its around 150kpa when i revving it around 2500 it dips to 100 or so then if i rev it around 4k its around 240??im behind lost with it
TECH Fanatic
Joined: Jul 2022
Posts: 1,032
Likes: 389
From: Alaska
What is the exact model of MAP sensor installed ?
Your offset needs adjust to bring static, key on MAP to 100KPa
.
.
.
( Assuming you are near Sea Level )
Your offset needs adjust to bring static, key on MAP to 100KPa
.
.
.
( Assuming you are near Sea Level )
Last edited by Full Power; Jul 22, 2023 at 04:31 PM. Reason: altitude ?
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Verdad Gallardo TECH Fanatic
Joined: Jul 2022
Posts: 1,032
Likes: 389
From: Alaska
Seller lists data for your 3BAR MAP:
Linear 312.5
Offset -11.25
.
What are your settings at this point ?
Can you confirm +5 volts and GROUND to sensor ?
Can you obtain (static) 100 KPa at key on, engine off
What is actual measured battery terminal voltage, engine OFF, headlights ON ?
What is static fuel pressure ?
Linear 312.5
Offset -11.25
.
What are your settings at this point ?
Can you confirm +5 volts and GROUND to sensor ?
Can you obtain (static) 100 KPa at key on, engine off
What is actual measured battery terminal voltage, engine OFF, headlights ON ?
What is static fuel pressure ?
hopefully someone can help me out here as im in desperate need of it s10 lq4 stock bottom end new bearings rings btr 4 turbo cam 799 heads tbss intake running terminator x tr6s gapped at .25 7875 t4 turbo my problem is that the truck just runs horrible will not build boost until around 4k rpm then breaks up ive checked for leaks on the coldside nothing i do have a small exhaust leak on the header that i will be fixing shortly i do have a datalog of it any help is greatly appericated running summit racing bov and wastegate with around 11 pound spring i cannt upload the datalog as its not a supported file
timing at wot 14
cruise 20
idle 20
afr wot 11.7
cruise 12.4
idle 12.4
map reads around 140kpa with key on engine off
timing at wot 14
cruise 20
idle 20
afr wot 11.7
cruise 12.4
idle 12.4
map reads around 140kpa with key on engine off
Thread Starter
Registered User
Joined: Jul 2023
Posts: 6
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bad map sensor,next issue is temperature it just keeps climbing not sure if its because of the rear steam lines blocked off they came blocked off 799 heads of course im running the fron steam line right to rad new water pump belt thermo 160* any thoughts or opinions let me know i never let it get above 200 my fan is a single 16" 3row radiator 19pound cap i tried kicking my fan on sooner still no go kicks on around 170 wondering if its the fan rated at 1300cfm dont sound like much
TECH Fanatic
Joined: Jan 2009
Posts: 1,063
Likes: 475
From: Bostwick, GA.
"tried kicking my fan on sooner still no go kicks on around 170 wondering if its the fan rated at 1300cfm dont sound like much".
A couple things.
U R right about the fan. It is about 1/2 of what it should be in CFM.
Check the voltage at the fan. Also make sure it's not wired backward.
Is it fully enclosed in a shroud?
Might try a "jack it up, burp it" fill.
Is the Terminator a "kit"? If so, the ECT sensor may be fubar when you got it.
We find that sensor is whacked out of the box. Just changed 1 that was 20* hot.
Easy check: Cold engine, key on engine off, what does the IAT read vs the ECT?
A couple things.
U R right about the fan. It is about 1/2 of what it should be in CFM.
Check the voltage at the fan. Also make sure it's not wired backward.
Is it fully enclosed in a shroud?
Might try a "jack it up, burp it" fill.
Is the Terminator a "kit"? If so, the ECT sensor may be fubar when you got it.
We find that sensor is whacked out of the box. Just changed 1 that was 20* hot.
Easy check: Cold engine, key on engine off, what does the IAT read vs the ECT?
TECH Enthusiast
Joined: Feb 2020
Posts: 734
Likes: 209
^^^^ definitely, that fan is not up to the job. Fan cfm ratings are generally overstated and 1300 is low to begin with. Comparing amp draw is a bit better for fan comparison, something over 25 amps and full shroud would be a good starting point. A Taurus/ Lincoln 3.8L fan draws about 18 on low , 35 on high , low is good for 90% of all driving for me with large griffin rad. They are hard to find now and the dorman replacement isn't as good. . There's another cooling thread going right now , have a look at that regarding heater hose and thermostat details
The rear steam vents blocked off shouldn't be a issue at all, because that is a stock thing, however they can aid in trapped air.
I fought a lot with air in my system in my S10. A vacuum pump/fill system works great. Also, I always make sure my thermostat has a small hole in it, at the 12 o'clock area for air to move through.
I fought a lot with air in my system in my S10. A vacuum pump/fill system works great. Also, I always make sure my thermostat has a small hole in it, at the 12 o'clock area for air to move through.
I run LS1 Camaro/Corvette fans and have 0 issues. Runs at 180-190. I doubt they are 1300 cfm.
What does it do at freeway speeds? If it stays cool there, but not cruising around, you have a fan issue.
What does it do at freeway speeds? If it stays cool there, but not cruising around, you have a fan issue.
