Car bogs at wot

[AL92]

My car runs excellent with light to medium throttle but go wot and it just bogs out and goes nowhere.

So far I have put in redlline injector cleaner,run only 92 premium,have n1 downpipe and catback,have changed out plugs to nkg,have changed wires to accel,have new fuel filter ,therm ,air filter ,pcv and have done MCCC on engine and engine flush and new syth oil.Have done vac line removal as per taboo site .I recently bought maft and gm maf and will put that on in next few days.I have new coil pack on order although the old one didn't test bad and have new supra tt pump on order as need it to support future mods.

I have hooked vac guage to engine and it shows steady normal vac.
I have no funny noises in engine runs and sounds smooth except when mash the gas.The factory guage is moving around
I have ordered boost vac guage but it hasn't shown up here yet.
I am running out of things to do and ideas on what to do next.
I have no check engine codes.I also checked timing and most sensors like tps etc.

I have checked top of engine for boost leaks and found now with visual check and looked under car and lower hose on intercooler appears on.

The car is running great other than this .It is for sure boosting.

I am hoping since this is the advanced forum you guys might have some better insight into this problem than posting on the problem forum.

Oh forgot,also put in new o2 sensor the other day.

 

[mccurdy]

im getting almost the same thing as you. I put a new o2 dump housing in though, and took it for a drive. still used the same o2 sensor though. and i suddenly hit a problem. i cant boost past 5 psi now under higher throttle. I can get up to 90 mph fine, i just cant mash on the car or it starts to hesitate and get slower. i cant notice any leaks anywhere either

hope someone can help us.

 

[Tevenor]

What did you gap your plugs at? Did you pressure test for leaks? There are leaks that only show up under pressure.

You give us a lot of parts that you are 'going to install' but you don't let us know the Stage 0 things that should be checked.

 

[AL92]

Well further updates..put in new gm maf and transtator.Car started right up and idles fine..everything on maft set zero across the board.
I also picked up my boost gauge from store it showed up finally.

I installed it also.

I get around 15 at idle..I am at 1900 feet above sea level and think they said you lose a hg or so for each thousand so that would be equivalent to 17hg at sea level.The car revs up ok at light throttle exactly like before and boost goes to about 10 psi when you step on it and then but won't hold it at all just bogs out.Exactly what it did before.

I have no restrictor in the boost solenoid and no manual control or electronic just stock.

So not sure what you mean exactly tevenor.Is 17 pretty low vac.??
What is normal at sea level or what is you guys vac and what altitude do you live at..?Try to compare.I for sure have no boost leak on the upper intercooler set up.Might have one under there its so freaking wet and muddy out haven't taken out the bottom and taken out intercooler but hose was on when I looked a few days ago.

My new ignition coils didn't show up yet .One guy not sure he knows what he is doing tested them but dont' think it was done right .I figure get them as preventative maintenance car has 130,000 miles on it ,not sure original engine ,no nothing about the car..it was auction vehicle.

I have the toyota twin turbo pump coming in monday but not sure if
should install it with afpr.

As said the car runs smooth at idle..smooth at part throttle..will rev to redline no problem if you step on gas gradually but try to leave the lights hard or punch the gas and bog bog bog..go nowhere..

And mccurdy our problems sound identical..let me know if you figure it out too please..this sucks..

 

[LandoAWD]

I for sure have no boost leak on the upper intercooler set up.Might have one under there its so freaking wet and muddy out haven't taken out the bottom and taken out intercooler but hose was on when I looked a few days ago.

For sure? Did you build and operate a boost leak tester as per www.vfaq.com?


You didn't tell us the plug gap either.

 

[AL92]

Sorry I meant not sure if should put in tt pump as don't have afpr yet.

And to be clear again since buying car 2 weeks ago and when bought it would barely run at any throttle idle was all over etc to running good now with exception of the wot problem..I put in redline water wetter,run only premium 92 octane,new pcv ,have new air filter,new therm,
new ngk iridums gapped .32 stock recommended gap for turbo cars they are specific for the car.Have new accel wires.checked wires with light testers that go between plug and wires checked fine.Mopar ccc in top of engine and then put some on pistons.Engine was flushed and syth put in.Checked vac lines..seem to have fuel solenoid vac lines hooked up to vac canister lines by accident but just corrected that and still same problem as before.

Whats left that can cause this.It sound like very common problem.

 

[Tevenor]

Take those irdium pieces of crap out, get same base stock NGK BRP6ES's and gap them to no more than .028. Then go out and run it and see how it feels.

 

[LandoAWD]

Originally posted by AL92
Sorry I meant not sure if should put in tt pump as don't have afpr yet.

And to be clear again since buying car 2 weeks ago and when bought it would barely run at any throttle idle was all over etc to running good now with exception of the wot problem..I put in redline water wetter,run only premium 92 octane,new pcv ,have new air filter,new therm,
new ngk iridums gapped .32 stock recommended gap for turbo cars they are specific for the car.Have new accel wires.checked wires with light testers that go between plug and wires checked fine.Mopar ccc in top of engine and then put some on pistons.Engine was flushed and syth put in.Checked vac lines..seem to have fuel solenoid vac lines hooked up to vac canister lines by accident but just corrected that and still same problem as before.

Whats left that can cause this.It sound like very common problem.

Ditch the iridiums, put some BPR6(or 7)ES plugs in gapped at the standard .28-.30, and report back. Its a 7 dollar investment, but it may be worth a shot. Do the boost leak test regardless of what you THINK you know about the car. 15psi through a rubber hose with a hole in it will open up the hole quite a bit.


Edit: Damn Sean, beat me to it. That's because Tev > Lando.

 

[mccurdy]

I did a boost leak for my car, found nothing. I checked everywhere too. I noticed my car starts to bog ONCE my WG opens up and it starts dumping my o2 to the atmosphere. They like co-incide with each other. Im runnin the NGK's too, and just left them at whatever gap they were at when they were in the box. They're the eclipse Turbo NGK's too.

I noticed driving today that if im in first and i redline it at WOT, it'll bog and slow down once the O2 dump activates, yet i can still drive it to redline under WOT. then i hit 2nd gear , and give it WOT and once it starts venting around 5-7 psi (disconnected my Profec-b) , the car jerks violently and just boggs. Almost like sputtering from bad spark plugs, yet i checked the plugs and they were fine!

What the hell is going on?! Plus if im in 2nd gear, and im slowly giving it gas and accellerating, once i hit about 4,500 rpm, at maybe like 10-15% throttle on my SAFC2, the car jerks real bad and sputters and boggs down. Please help us guys!

 

[Tevenor]

Originally posted by mccurdy
I did a boost leak for my car, found nothing. I checked everywhere too. I noticed my car starts to bog ONCE my WG opens up and it starts dumping my o2 to the atmosphere. They like co-incide with each other. Im runnin the NGK's too, and just left them at whatever gap they were at when they were in the box. They're the eclipse Turbo NGK's too.

The plugs are not gapped properly out of the box. Make sure the gap is at .028.

 

[AL92]

That sounds exactly like my problem except maybe a get a bit higher on the boost gauge than you but still same effect.

I guess I could take out the brand new iridiums and try cheap plugs.Even though lots and lots of turbo cars are running them now but its an easy thing to change.

I haven't leak tested the car.I haven't take out the intercooler and checked it yet.I will shortly.Actually would it be ok to just run new hose to blow off and bypass intercooler right now for testing.Don't have too much access to garages here right now and its not warm out..well it was 32 f today but thats rare.its usually more like -20.

Well hopefully get this figured out shortly.I love my car but not like this!!!

 

[AL92]

The recommened gap in the manual is .32 I am pretty sure.The iridiums come .32.Are you telling me the mistu ignition is such a pos that it can't fire .o4 bigger on stock boost cars..

 

[Tevenor]

Originally posted by AL92
The recommened gap in the manual is .32 I am pretty sure.The iridiums come .32.Are you telling me the mistu ignition is such a pos that it can't fire .o4 bigger on stock boost cars..

The manual says .030. And frankly that's for a stock car. Is your car stock? If you aren't going to accept the opinion/answer we give you, don't ask the question.

I run my spark plugs at .026. Guess what? That's a lot below 'recommended gap'. But guess what? I am also making twice the horsepower of stock. Go figure.

 

[mccurdy]

Hey AL, I solved my problem. It was a massive I/C leak on one of my hoses. The hose was cracked all the way around, but it was inside a fold on the piping so i couldnt see it until we checked everything in detail.

needless to say, i get so much power from the o2 dump my wheels spin if im cruisin in 3rd and throw it into 2nd =)

plus EVERYONE looks when u smash on it with an o2 dump tube. bro, i recommend everyone to get one. No boost creep, a huge power increase, and sounds mean so all the ladies are like..."Do me...do me right here right now..." , and being the dsm'er I am, who am i to stand in the way of a ladies dream....

always, always keep extra 2-3'' hose in your car at all times incase the shit that happend to me happends to you.

hope u solve it soon bro.

 

[AL92]

Glad to hear that mccurdy.!! Happy for you man.Do you have a vac guage in your car.Mine seems to be pulling 15 and hear it should be
17 to 18 or so anyway.Its steady but low.

I really really wish had my garage so could go over this thing right.I have to keep borrowing buddies garage here and there to test things out.

I am getting so many opinions on this and ideas to stop this wot bog.Sounds like it can be many things.Bad fuel pump,bad ignition coils,bad tps,big vac leaks,etc.I guess just a matter of trying them all if necessary.

Anyone one else..will vac guage show leaks .I also can't get over 10psi it seems even though have boost solenoid restrictor removed.
And think even when accidentally had boost solenoid hose not connected boost still dind't go past 10.

 

[Tevenor]

A boost leak won't show under vaccum in all cases because it isn't a vaccum leak. It's a boost leak. So comparing vaccum levels at idle is NOT A GOOD TEST.

In order to test a system for a leak that appears under pressure, (prepare yourself I know this might be a shock) you need to pressurize the system to duplicate the parameters of the leak.

So before you ask the same question for the 4th time, you have 2 things to do:

1) Regap your plugs to .028 from .032. I don't care anymore if you keep the same plugs or not.
2) Pressure test the intake system as described in the VFAQ's at www.vfaq.com

 

[AL92]

Well agree its time to quite messing around and do the leak test ..off to home depot shortly to ge the parts
And agree can't hurt to try the cheap ngks with the small gap.Not like its hard to chance plugs in these cars.

So sorry don't mean to be stubborn .I want to fix my car!!

So guess take some bets to see what exactly the problem is.
Some people say fuel pump,some ignition coils,some tps,some boost leaks,some the iridiums.Some ecu..have to pull that out too and check the caps.Just wish it was warmer outstide..

 

[AL92]

Ok more stuff..On way out and about to go to home depot to get stuff form the leak tester first car was cold and it seemed to run excellent ..very litlt bogging at least thru the midrange..hit 10psi quick all was pretty good.Figured maybe fuel injection cleaner did something maybe.
Then as drove car more and it got hotter I guess first the bog started
at wot and then it got worse and was noticeable off wot and then the engine started to run terrible and was missing and sounding like it wanted to stall vacuum dropped even lower and was wondering if would make it home.

So was in parts place as figure will make intercooler bypass to check for leaks for now and talking to old guy about my symptoms he asked if car had been run low or out of gas recently.I said yeah ..when got it at auction there was zero on there fact has to bring my gerry can the idiots at auction don't have gas pump and didnt offer any gas..jerks..
So betting the pump was damaged by the low low gas in tank.Makes sense..Supposedly they work ok cold like it has been and then get worse as heat up which also fits the symptoms becuause it has been boggy when warm not just wot.And like was said boost goes to 10 or so,no overboosting or fuel cut happening here.And no leaks in upper intercooler hoses or vac lines and the bypass will eliminate for test purposes any chance of leaking intercooler or lower intercooler hose.

Keep you guys posted..

 

[Tevenor]

I am going to beat my head against a wall. Let me know when you figure it out so I can stop.

 

[mccurdy]

fuel pumps dont do that though. They dont stop working all the sudden once the car warms up. Your still flowing the same amount of fuel, the fuel pump isnt the thing that warms up, the engine is. The fuel pump is in the back of the car @ the gas tank.

I still think you gota fatty leak somewhere. You said u leak tested (pressurized) the entire system after the turbo?

 

[AL92]

Umm ,pumps are electric motors not mechanical and damaged electric pumps can act pretty weird from talking to several people.I know its in the back of the car and not near the engine.

So if not that then what..huge vac leak..maybe.My quick idea was to use a rad hose to run straight from turbo to upper intercoller hose inlet bypassing intercooler and intercooler lower hose.And maybe even run the hose to the tb and not use blow off valve just for a test drive.Not sure how bad it is to not use blowoff for longer period.

I still intended to make a leak tester just not that impressed with mickey moused one might have to make a nicer one as sounds like be using it a lot on these cars.But the real solution obviously is to dump the crappy factory hoses and go with silicone or hard lines and t bolt clamps.That should be the end of the boost leak after the turbo problems and leaks in front of turbo aren't as bad.And I will be replacing all vac lines still on car with silicone have disconnected most of them as per taboos site instructions.

Also likely will get a datalogger this next week also ,just need to find reasonably priced compatible palm type thing.

If I have a huge leak then it just got much much worse as said car was running decent when cold then got boggy at full throttle ,then got boggy all thru the range then started to run really crappy.Maybe that sounds more like a bad ecu.

And fixing this stuff isn't that easy.The car throws no codes at all.And the engine aside from running lousy at end of today still sounds ok mechanically no bad noises,knocks etc.

I will get it figured out likely in next week or so.And Tevenor sorry if this
is driving you crazy but hey its not quite so simple as change out my plugs for cheap ones.Its not blowing out the spark off idle and thru the range the problem is all thru the range now.It ain't the brand new plugs.
I will put money on that.

But it still might be the coilpacks or ecu also.And its not that easy to just check this stuff out outside in the cold and snow.And money is a bit tight near Christmas so dont' want to take it to garage to analyse it unless last resort.

But I really like this car and it will be fixed.No matter what it takes.

 

[AL92]

Oh and buying apexi turbo timer in next few days.Actually found place near me that has one in stock.I hear they have capability to monitor o2s.
So that might be useful ..I would assume car 02s would show very lean if the fuel pump is not working right.

Dataloggers were out of stock last time I checked their site and with mail and customs and stuff it would likely be two to three weeks to get it up here this time of year.Still know a talon guy with one.But he don't seem to be around this weekend.

 

[LandoAWD]

Originally posted by AL92
Oh and buying apexi turbo timer in next few days.Actually found place near me that has one in stock.I hear they have capability to monitor o2s.
So that might be useful ..I would assume car 02s would show very lean if the fuel pump is not working right.

Dataloggers were out of stock last time I checked their site and with mail and customs and stuff it would likely be two to three weeks to get it up here this time of year.Still know a talon guy with one.But he don't seem to be around this weekend.

Tuning by O2 voltage is not a good practice. The factory sensor does not react fast enough to give you a TRUE idea of whats going on.

 

[AL92]

Today installed new coilpacks had on order for week or so.The car runs excellent now goes cleanly up to 13 psi .I have only modded the stock bcs so far.No problems.

So it seems several things can make these cars run bad.

I am still proceeding with supra pump install it showed up today and afpr
and bigger injectors.All things I need for planned evo 16.

And those iridiums are working just fine at 13psi..see how they do with the new turbo and if need a colder heat range denso makes iridiums in various heat ranges.