Overcoming 2LTE fuel cut limit (3 Viewers)

[GTSSportCoupe]

Thankyou for reply yes we hit 18psi today no engine light. 2lte auto mate. I used boost controller inline of map sensor now I want to up fuel should I revert The fuel resistor back to stock or try a different one to make it richer.
cheers Joseph

Boost controller in front of the map sensor will work too, but it does give an abrupt pressure control (like a fuel cut defender would).

Adjust the spill valve for more fuel, not the fuel resistor. The spill valve tends to add more fuel across the whole power range; the fuel resistor is a smaller amount and seems to have more effect only in the lower rev range. It is day and night difference between the two.

Pop the cap off the spill valve, and mark where it's set. Release the lock nut and turn in for more fuel and out for less. Turn in just a bit at a time (maybe 1/4 turn). Don't turn in more than about 3/4 turn. At 1 full turn, the engine can go into run-away the first time it revs up. You can test this while parked, and be ready to turn the screw out - its the only way to stop it. Sounds scary, but if you're careful, it won't happen. Mine went into runaway and it wasn't too big a deal. You can tell when you're getting close if the revs hang a bit when you rev it.

But if you're hitting 18psi, it's possible your fuel (spill valve) has already been turned up?

 

[Mountainwolf509]

Boost controller in front of the map sensor will work too, but it does give an abrupt pressure control (like a fuel cut defender would).

Adjust the spill valve for more fuel, not the fuel resistor. The spill valve tends to add more fuel across the whole power range; the fuel resistor is a smaller amount and seems to have more effect only in the lower rev range. It is day and night difference between the two.

Pop the cap off the spill valve, and mark where it's set. Release the lock nut and turn in for more fuel and out for less. Turn in just a bit at a time (maybe 1/4 turn). Don't turn in more than about 3/4 turn. At 1 full turn, the engine can go into run-away the first time it revs up. You can test this while parked, and be ready to turn the screw out - its the only way to stop it. Sounds scary, but if you're careful, it won't happen. Mine went into runaway and it wasn't too big a deal. You can tell when you're getting close if the revs hang a bit when you rev it.

But if you're hitting 18psi, it's possible your fuel (spill valve) has already been turned up?

 

[Dari Desilva]

Hey Guys, I'm sorry for the delay. Busy with the start of school etc. Anyhow, I just ordered fittings for the flow controllers from Mcmaster carr. A barbed fitting for vacuum hose on one side, and a little air filter for the other. I also ordered barbed Tee's for the vacuum hose. Will pickup some vacuum hose also. This way you get a kit that is ready to go. I'll try to pre-set the flow valve too, so at least you're in a good starting spot. I bought enough that I have 10 sets available. Will try to ship out later this week to those who have already indicated interest. Have 6 more up for grabs if anyone else wants. So far cost for all the parts is at about $15 per kit. Not sure how much shipping will be, but will go for the cheapest Canada Post option.

Hi Nick, do you have one of these kits still available? Would like to get one for LJ78 with a 2lte. Thank you.

 

[GTSSportCoupe]

Hi Nick, do you have one of these kits still available? Would like to get one for LJ78 with a 2lte. Thank you.

I'm sorry, I don't have anymore! I've been thinking of building an electronic version though.... Will let you know if that comes together. Hard to find time.

 

[Dari Desilva]

I'm sorry, I don't have anymore! I've been thinking of building an electronic version though.... Will let you know if that comes together. Hard to find time.

Please let me know if you make the electronic kit. I am looking for a way to increase some low end torque. The hardest is when I reduce the speed to around 25kmph. It it too fast to engage the 1st and the 2nd takes for ever to speed up.

 

[GTSSportCoupe]

Please let me know if you make the electronic kit. I am looking for a way to increase some low end torque. The hardest is when I reduce the speed to around 25kmph. It it too fast to engage the 1st and the 2nd takes for ever to speed up.

When tuned properly these trucks have tons of torque in 1st and 2nd. 3rd is a big slow until the torque converter locks, and then they should pull good again. Although it has been a while since I've driven a stock one.

What work have you done to yours? Do you have a boost gauge and pyrometer?

 

[Dari Desilva]

When tuned properly these trucks have tons of torque in 1st and 2nd. 3rd is a big slow until the torque converter locks, and then they should pull good again. Although it has been a while since I've driven a stock one.

What work have you done to yours? Do you have a boost gauge and pyrometer?

It has a new 3L complete head. I have a valve to slow the opening of the waste gate. Mine is a 5 speed manual. I do have a pyrometer, boost gauge, a 2nd temp gauge and 2nd oil pressure gauge. I have a new 82C thermostat. The coolant temp climbs to 90C quickly and stays mostly constant. It goes to very close to 100C with AC on, on very hot days. The pyro is stays low but climbs to 600-650 going up hill or at highway speeds (110-120kmph). The boost goes up to 10PSI. Besides the difficultly getting up to 60kmph, the cruiser starts and runs great. It looks good inside and out also. I have 265/65R17 tires (it’s the same height at the original) therefore, my speedo works perfectly also.

 

[GTSSportCoupe]

It has a new 3L complete head. I have a valve to slow the opening of the waste gate. Mine is a 5 speed manual. I do have a pyrometer, boost gauge, a 2nd temp gauge and 2nd oil pressure gauge. I have a new 82C thermostat. The coolant temp climbs to 90C quickly and stays mostly constant. It goes to very close to 100C with AC on, on very hot days. The pyro is stays low but climbs to 600-650 going up hill or at highway speeds (110-120kmph). The boost goes up to 10PSI. Besides the difficultly getting up to 60kmph, the cruiser starts and runs great. It looks good inside and out also. I have 265/65R17 tires (it’s the same height at the original) therefore, my speedo works perfectly also.

Nice! You could adjust for 12psi boost; this might drop your EGT's a bit. If they're still high, you could turn down the spill valve just a touch. I've never driven a manual version LJ78, but I do find it strange that yours feels low on torque the first couple of gears.... Might be worth asking someone else who has a manual trans one also if they have the same problem.

 

[Dari Desilva]

Nice! You could adjust for 12psi boost; this might drop your EGT's a bit. If they're still high, you could turn down the spill valve just a touch. I've never driven a manual version LJ78, but I do find it strange that yours feels low on torque the first couple of gears.... Might be worth asking someone else who has a manual trans one also if they have the same problem.

Question. I adjusted the waste gate valve a few times, but my boost will not go above 10psi. My boost guage is attached to the hose between the sensor and the filter. I recall reading that it needs to be attached between the intake and the filter. Could that be the issue? Or could it be that my ECU is cutting off fuel at 10PSI. it will not budge from max of 10PSI. Thank you

 

[GTSSportCoupe]

Question. I adjusted the waste gate valve a few times, but my boost will not go above 10psi. My boost guage is attached to the hose between the sensor and the filter. I recall reading that it needs to be attached between the intake and the filter. Could that be the issue? Or could it be that my ECU is cutting off fuel at 10PSI. it will not budge from max of 10PSI. Thank you

That is the wrong spot to put your boost gauge. You should 'T' it in between the intake manifold nipple (just below throttle body), and the little boost line filter. Having it 'T'ed in after the filter might be cause your power issues. It takes a lot of air to fill the volume of the hose to your boost gauge, and the filter limits the air flow. So it will effectively add a delay to fuel compensation.

As to why you cant get above 10psi, it might be the problem above, or possibly there is a problem with your manual boost controller (or installation). Feel free to put some pictures up of this stuff and I can let you know if anything seems amiss.

 

[Dari Desilva]

That is the wrong spot to put your boost gauge. You should 'T' it in between the intake manifold nipple (just below throttle body), and the little boost line filter. Having it 'T'ed in after the filter might be cause your power issues. It takes a lot of air to fill the volume of the hose to your boost gauge, and the filter limits the air flow. So it will effectively add a delay to fuel compensation.

As to why you cant get above 10psi, it might be the problem above, or possibly there is a problem with your manual boost controller (or installation). Feel free to put some pictures up of this stuff and I can let you know if anything seems amiss.

1. Boost gauge - I tried a few things. I connected a hose from the [Intake >> Tee for boost gauge >> Boost sensor], bypassing the filter. The boost will not go above 10 PSI. Then I connected the [Intake >> Tee for boost gauge >> filter >> boost sensor]. The boost will not go above 10 PSI.
2. then I adjusted the manual boost controller max possible, the boost will not go beyond 10 PSI. Then I removed the boost controller (back to OEM), max boost goes down to 6 PSI.
3. I have an NXS boost controller. I extended the spring inside hoping it will increase the boost but no luck. See the pix attached.
4. Do you have any suggestions on what boost controller I should buy? I assume there is a problem with the NXS controller.

Thank you.

 

[GTSSportCoupe]

Then I connected the [Intake >> Tee for boost gauge >> filter >> boost sensor].

Just keep it connected like this ^^.

The manual boost controller you have should be fine. But to test if it's failed in some way, just remove it and the boost hose completely. (have the waste gate connected to nothing.). You could cap off the line from the turbo compressor housing. This should give you maximum boost possible, as the waste gate won't open at all. Don't worry, it won't hurt anything. 2LTE can't provide enough fuel to damage the CT20 turbo.

Now, one thing to realize, is it takes a certain amount of fuel to generate enough exhaust flow to get more boost from the turbo. It requires energy at the turbine to compress air. So it is possible that for some reason your engine is not getting enough fuel. Things that could cause this are a failed boost sensor (no fuel compensation), incorrect correction resistors on the side of the injection pump (if pump has been replaced and resistors of new pump not carried over), or a plugged fuel filter. Or even, possibly someone has messed with your spill control valve setting.

 

[Dari Desilva]

Just keep it connected like this ^^.

The manual boost controller you have should be fine. But to test if it's failed in some way, just remove it and the boost hose completely. (have the waste gate connected to nothing.). You could cap off the line from the turbo compressor housing. This should give you maximum boost possible, as the waste gate won't open at all. Don't worry, it won't hurt anything. 2LTE can't provide enough fuel to damage the CT20 turbo.

Now, one thing to realize, is it takes a certain amount of fuel to generate enough exhaust flow to get more boost from the turbo. It requires energy at the turbine to compress air. So it is possible that for some reason your engine is not getting enough fuel. Things that could cause this are a failed boost sensor (no fuel compensation), incorrect correction resistors on the side of the injection pump (if pump has been replaced and resistors of new pump not carried over), or a plugged fuel filter. Or even, possibly someone has messed with your spill control valve setting.

Thanks for the advise. I capped the line to the turbo housing, and had the waste gate hose connected to nothing. Well...well. the boost did not go above 10 PSI. the boost controller seem to be working fine, therefore, I re-installed it. There is something else that is limiting the boost. The resistors on the side of the injector pump is original. The pump is original with the cap still on. The fuel filter is new, OEM. Boost sensor seem to be original. I am happy to replace it. I will look for the part#. thank you.

 

[GTSSportCoupe]

Thanks for the advise. I capped the line to the turbo housing, and had the waste gate hose connected to nothing. Well...well. the boost did not go above 10 PSI. the boost controller seem to be working fine, therefore, I re-installed it. There is something else that is limiting the boost. The resistors on the side of the injector pump is original. The pump is original with the cap still on. The fuel filter is new, OEM. Boost sensor seem to be original. I am happy to replace it. I will look for the part#. thank you.

Maybe inspect your turbo? Take the intake hose off, and inspect the compressor; make sure it's not damaged. Spin the turbo and make sure it spins freely. Feel for side/side and in/out play.

 

[Dari Desilva]

Maybe inspect your turbo? Take the intake hose off, and inspect the compressor; make sure it's not damaged. Spin the turbo and make sure it spins freely. Feel for side/side and in/out play.

I don't think its the turbo. I removed it, cleaned it, etc. it spins well, and no play. I was surprised how good it looked. I assumed it was the original, but it look too good for the age. Also, as soon as I hit ~2500 RPM, the turbo kicks in nicely.

 

[GTSSportCoupe]

I don't think its the turbo. I removed it, cleaned it, etc. it spins well, and no play. I was surprised how good it looked. I assumed it was the original, but it look too good for the age. Also, as soon as I hit ~2500 RPM, the turbo kicks in nicely.

It could be the wastegate has an issue and is opening to early? Maybe try wiring it closed?

I'd suggest turning up the fuel at the spill valve, but I don't think fuel is your problem based on the high EGT's you're able to hit.

Something is up, as most 2LTE owners I know are able to hit more than 10psi on stock fuel settings.

 

[uzimuffin]

Hey All. Well I felt I could not ship all these out unless I tried the new pieces to make sure they all worked. Threw them onto my truck this morning and they worked perfectly. So now I just have to assemble and ship. Hopefully in the next two days.

So you'll get the bleed valve, filter on one side, barbed fitting on the other, vacuum hose and a barbed vacuum T. All you do is cut the vacuum line between the boost hose filter and boost sensor, and fit in the barbed T.

Here are some pictures from this morning:

View attachment 2080051

View attachment 2080052

View attachment 2080053


For those with the 2LTE, this is where you will insert the air bleed valve 'T' fitting.

View attachment 2080079

Hello,
A little late to the party but any chance you still have one laying around?

Thank you

 

[Mohamed zanaty]

hello q. We changed the 22r motor to the 3rz motor and everything works fine except the tachometer doesn't work, what is the solution to this problem?

 

[GTSSportCoupe]

Hello,
A little late to the party but any chance you still have one laying around?

Thank you

Possibly; I'll have a look. Will be about a week though, as I'm busy as heck and heading off camping in a couple days.

 

[uzimuffin]

Possibly; I'll have a look. Will be about a week though, as I'm busy as heck and heading off camping in a couple days.

No worries, take your time.
Have a safe trip.

Thank you