sorry matt you did email me rite back i just never check my email i was expecting a call. thanks for the help and ill be in touch with you soon.

by the way my. i installed a vortec 12:1 fmu and it would still lean out rite away in the first few pounds of boost.

i even blocked off the return line with vise grips it held the pressure at 80psi i hit the throttle and it poped withing the first 3 pounds of boost. i have a in cab fuel pressure guage and the pressure didnt drop at all. maybee my injectors are plugged?

no matter what the computer dosent seem to add fuel ever .

im waiting for the quote on magasquit and im thinking its probly the best route at this point .

the stock fuel pump will lose a lot of fuel volume as the pressure increases. with an fmu. an aftermarket high pressure fuel pump is required as there designed to flow more volume at high pressure.

today ii bought a new boost gauge and hooked it up. to my surpeise i was building 15psi of boost at 3000rpm so i took it back in the shop and reved it up a few times the engine build 8psi at 5000rpm just sitting in the shop.

the turbo is suppose to have a 7-8psi wastegate but it building way more. i used and air compressor and with 8 pounds at the air line it didnt even move at all. it took 20psi to get the wastegate to open when it was running in the shop.

the wastegate is adjustable but ive moved that rod in and out and it never opened any earlier than 20 psi.

am i missing somthing here?

to lower the boost you need to lengthen the wastegate rod which decreases the tension on the spring in the actuator. put a vacuum gauge on the wastegate actuator and see if it holds vacuum. if it doesnt hold vacuum then it wont hold pressure causing boost pressure to spike. if this is the case then you need a new wastegate actuator.

ive lenghtend the rod all the way to the point that the rod fits on without haveing to pull the rod. the problem is still nearly the exact same.

to me the problem is in the acuator it takes 20 psi to get it to move , like the spring is way to stiff. this acuator is a gold color that has a adjustable rod but no way to change the spring at all.

the actuator is not repairable. it needs to be replaced if leaking.

i feel stupid for not checking this earlier but it was brand new so i figured it was working. after i got the boost gauge i relized it was makeing way to much boost and then did this as an easy way to look for leaks.

i put 10psi in my air compresor ran it to the actuator with a vacume/boost gauge to a tee and heres the results.

i cut it open carfully and shure enouf i found a hole in the diapham that was leaking.


my new acutuator will be here by friday.

thats what i figured. glad you got it worked out.

even when the boost was to high i knew it was going to need to have the blow off routed back to the intake. it was becomeing way to rich and stalling out when the blow off valve let the metered air out of the charge pipe.

heres the way its all ran as of now.

https://www.homemadeturbo.com/attach...ine=1343780953

this video is just warmed up at idleand a few revs up off idle.

any idea why its not staying at the 14.7 like the factory manual says itll be at?

injectors?

its running better now but is still way lean when it makes boost the engine is still around 17-1 not popping anymore but isnt makeing power at all.

seem like its still starving for fuel

air leak? what did you do for fuel mods again?

fuel mods are vortech 12:1 fmu otherwise nothing.

im almost positive that theres no leak but ive been wrong plenty of times before. ive cheked and tripple checked for leaks thinking myself leaks would be most likely the problem.

fuel pump builds an maintains pressure at 80 psi.

the engine now boosts 8psi but it leans out and stays around 17:1 afr under boost but watching fuel pressure its staying at 80 psi.

while driveing and boosting it just feels like it isent makeing power. probly due to the lean condition but with the new actuator at least the wastegate is keeping boost down to 8psi and not popping.

at this point im positive the computer or injectors are not working properly.

the friend of mine that i mentioned earlier is still haveing great luck with this exact same setup and never ever goes leaner than 15:1 even under full boost with no fuel mods of any kind. and hes makeing more boost than i am.

wtf?

if megasquirt wasent so over whelming to me id try it but im 100% completly lost when it comes to wireing or even makeing any sence of schematics.

when using an fmu you need to replace the fuel pump. as pressure increases, volume decreases so you need a pump that can support high pressure. a walbro 255l high pressure fuel pump should solve your lean boost problem. as far as being lean under natural aspiration there must be a air leak or a failed sensor causing the lean condition.
find out from your friend exactly what parts he has on his setup because ive never seen a high boost vehicle using only an fmu last longer than a couple of trips down a track. he must have larger injectors and an fmu.

im so mad right now im about to give up.

ive bothered him over and over about what else he did to make his engine run. he swears and i believe him that there stock injectors and that theres no mods to fuel at all no fmu. nothing.

what sensor could cause this?

i just installed a in cab fuel pressure gauge so i could monitor the fuel pressure. it will go from 35 to 80 psi and never droppes at all while under boost. even when i boost up to 8psi. it will hold 80 psi so to me its not a fuel pump issue.

ive just installed new mas airflow and a new 02 sensor wich was rediculas amount to pay for those parts.

im gonna look again for air leeks today maybee ill use air pressure and see if it holds.

thanks for the help im lost at this point.

a walbro 255l/h fuel pump will exceed 80 psi without sacrificing flow volume. the stock pump can only produce the 80 psi and its working hard to do it.

theres too many sensors than can cause a lean condition. do u have a check engine light on?

the most common air leak in a home made turbo system is boost pipe leaking or the bov isnt adjusted right but it looks like you have a recirculating bypass valve setup. how did you route it?

pretty simple blow off just returnes to the intake before the turbo but after the mass.

https://www.homemadeturbo.com/attach...ine=1344011846

hear you can see how it all lays out. the mass airflow is before the airbox. i thought that by moveing the mass to the intake pipe it would change things but it ran exacly the same.

https://www.homemadeturbo.com/attach...ine=1344011846

as far as the fuel pump goes im listening to what your saying but if the gauge says its staying at 80 psi the hole time it under boost wouldent that also mean its makeing enouf volume also?

ill buy a new pump i just think that theres another problem and it will take a week to get a new pump here not to mention figureing out how to route it. theres an in tank pump right now.

as far as i know theres no injectors that innerchange with these otherwise id buy them too.

the only other thing i can think of is the air intake temp sensor. where did you put the sensor? if the sensor was left unplugged the computer will think its 285 degrees air temp and lean out the fuel and retard the timing.

if larger injectors are used an ecm tune is required.

i snagged a iat sensor last wek at pick n pull ill throw it in there. the stock iat sensor is still in the stock location screwed into the airbox.

ive noticed something durnig warm up the engine is running around 14.5 afr and bounces around a bit but stays close but as soon the water temp hits 160 or so the engine will run a little rougher and will then lean down on the afr. i wonder if its switching from a preset warmup stage or something.

almost like a cold start preset or something.

its an obd1 and the check engine light is off, when i run the jumper to see if theres any codes it flashes 1 pause 2 wich is how it says everthings ok.

the factory service manual says the engine should be running at 14.7 at idle wich it isnt, but the computer isnt throwing any codes im startin g to think it may not be working correctly. in the factory manual it says if i were diconect a sensor say the colant temp sending unit it would cause the engine to run in limphome wich is a preset setting that will run the engine really rich. mine dosent run rich at all when i unplug that sensor.

i almost think that the computer is just stuck in a position and not hbelping to control the engine.

ok that explains it. the computer runs off a map in open loop till the engine warms up. when the engine warms up then the computer goes into closed loop. closed loop means the computer is now adjusting the afr based on sensor data. the computer is doing its job but its only as good as the data it gets from the sensors. this was the issue with obd1. the software had very little parameters to check if sensors were failing or giving false data.

try unplugging the maf sensor and trying it again. if that doesnt work then try unplugging the o2 sensor and trying it again.

so i put a plate between the blow off valve and the charge tube to block it off from letting any air out ran it and it ran night and day differance for the better. after that i gave it more timeing like 5 btdc and all of a sudden i have some serious power. its hard to really go threw the gears in my neighborhood but up to 5000rpm it pulls like crazy in first and sencond gear.

theres no exhaust so ive got to get some on there then ill be able to test it a little better maybee on the back streets around here or something.

in the meantime im going to order a new walbro 255lph pump im shure the old intank is tired it had 160,000 miles on the rig i pulled the tank from.

it nearly dies when i unplug the mass but will run / the 02 sensor dosent do alot plugged or unplugged bolth throw the check engine code for each sensor when unplugged.

the thing to remember is i have to unplug the battery for a minute or so to get the codes to clear after i plug stuff back in.

im interested in doing the megasquirt so ill probly be researching the system. ive started a new thread looking for help on the ms so if i feel like i can get it working ill be takeing on that project next.

just the sound of that turbo is awsome i now see where the turbo can be addicting.

thanks for the help busa its good to have a helper im always way overthinking stuff and forget the basics.

good. glad you got it sorted out.......