4agte in aw11 afm problems need help!

[donnyavery]

i converted my 4agze to a remote mount turbo but it does not seem to be able to get enough air though the turbo at idle and wont rev over 3700rpms with turbo in line i got some pics

[te51levin]

Interesting setup. Any chance you have any vacuum leaks that need sealed up?

[mr2tim]

Well Don that looks like a whole lot of work you've put in there, looks pretty complicated with all that changed stuff.
If it was easy I guess everybody would do it right huh?

I did notice that your running a TVIS system still? If so is the system active soas the intake runs on the short runners during idle? like it's supposed to.

IDLE
1. If your not getting enough air at idle then the turbo is in the way? It appears obvious to this S/C guy that your not pushing enough air thru the system with the slow turbine spin? If so bypass the turbo during idle, I know my S/C unit is not spinning during an idle.

LOW REVS
2. Not being able to spin fast enuff huh? Maybe not enuff exhaust flow thru too big of a exhaust pipe going into the unit? Logic seems to dictate if you decrease the tubing size diameter entering the turbo the velocity of the gasses will be increased accordingly resulting in faster turbo spin. Your photos are inadequate to make this judgement as they do not include any feed piping pictures.

BTW you identified the engine as a 4a-gze right? The thread is entitled 4agte, just what is in the pictures? gze block and gte induction? If so are the TB and AFM matched with the injectors in any way?







QUOTE=donnyavery;444383]i converted my 4agze to a remote mount turbo but it does not seem to be able to get enough air though the turbo at idle and wont rev over 3700rpms with turbo in line i got some pics[/quote]

[donnyavery]

im not using the tvis i have 2 1/4 pipe to the turbo an the same for charge pipe you think making it something like 2 inch well got to go back to work ill be on to see what yous have to say in like 5 1/2 hours thanks for the responses

[donnyavery]

BTW you identified the engine as a 4a-gze right? The thread is entitled 4agte, just what is in the pictures? gze block and gte induction? If so are the TB and AFM matched with the injectors in any way?

i used the early 4agze motor (i did that swap a year ago and it been fine till the turbo) afm,tps,and fuel system. Only thing from n/a motor is intake and the throttle body

here are the build pics
donny's mk1 mr2 Photo Album - MySpace Photos

[Papo J]

Check the BOV, it could be opening at idle and causing your problem.

[muffinman]

I like the work you've done on the car.



sorry to go off topic but aren't those speakers in the seat uncomfortable?

[donnyavery]

the speakers are coming out im changing the seats as soon as i get it going again its my every day driver and weekend track car

[donnyavery]

i changed the exhaust to 1 3/4 pipe and not change tomorrow im going to try to put the s/c throttle body tomorrow and thinking of trying to make a bypass from the charge pipe to afm pipe with some sort of one way valve if any body has any more suggestions please keep them coming i got to get the car back on the road a.s.a.p.

[te51levin]

This isn't a matter of the wrong size pipe, or the "wrong" throttle body. Unlike Roots superchargers, stationary turbochargers do not pose a restriction to an idling engine, and they should never be bypassed, nor should you build a purposefully restrictive exhaust system upstream of a turbo for any reason. 1.75" pipe is far too small. It is smaller than Toyota used on any part of the naturally aspirated exhaust system! You may need to neck down to that size at the turbocharger, but running any length of small tubing like that will choke your engine at any power level, create some serious heat, and potentially fatigue the parts to the point of failure prematurely.

Air is air when we are talking about low load, low speed conditions like this. At this point you need to determine whether the problem is one of plumbing (physical blockage, air or vacuum leak, etc) or one of management (TPS not communicating properly with ECU, defect in the wiring, etc).

Are you using the NA throttle position sensor with the SC computer? If the ECU isn't getting the information it needs from the TPS, it will not recognize what the throttle is really doing, and will not manage the engine correctly. It could issue the wrong spark timing, causing the engine not to rev, or it could even shut the injectors off outright if it thinks the throttle is closed and expects the engine to be idling.

One more thing to consider: is your knock sensor present, functional, and connected properly? Knock sensor failure or absence on a 4AGZE puts the engine into "safe mode" where it effectively won't rev at all, even under no load. This plagued a friend's GZE swap until we popped in the smallport knock sensor I had laying around, and now it runs perfectly. That one little detail made all the difference between a functional car and a useless moaning pig.

[donnyavery]

i change the piping and afm around and it working at idle but have not hod a chance to get the car out any thoughts or for see able problems?

[te51levin]

Not many people blow through a flapper style AFM, so we'll see how that goes. Let us know what you find on the knock sensor. I think that is going to be your problem.

[donnyavery]

the knock sensor is new i broke the plug end off the old one so i bot a new one from toyota and i checked its plugged in thanks for the suggestion

has any one converted the afm to gm of ford style blow through air meter? like this

[te51levin]

They don't send the same signal. If you're willing to go that much trouble, you need to be on MegaSquirt instead.

[donnyavery]

if i could pay for fuel management i would but the hole car is do it do it you self so i am but as i thought it did not go into boost before it cut out im thinking about putting a set screw in the afm to keep from being forced open all the way yes no?

[donnyavery]

the sensor stop was a no did not work

[te51levin]

Hold on here. You are just guessing now, trying monkey-rig fixes. That's not the way to address this. You need to do some old fashioned diagnosis. By that I mean you need to be testing parts and connections to make sure they are working and communication the way Toyota intended.

[donnyavery]

the afm works when it bolted on the throttle body side when its on the intake side of the turbo it don't get enough air through it car as no no check engine light o2 sensor is new knock sensor in new tps is giving good reading i don't know what to check or change so this is why I'm trying stupid **** I'm out of ideas the car has to be on the road now thank for your input anything helps out do u have any other oppositions

[mhamrick]

It is odd where the motor is falling on its face. Have you checked you turbo? I mean is it holding pressure? If you gave a little more info it would help.

If it was a vac leak then it would then it should die after it warms up. You have the correct VAC line going to the BOV right? I saw on another forum where a guy hooked up the BOV with the wastegate.

Oh and turbo will function properly with a proper length header. That is probably going to lag laaagggggg llllllaaaaaaaaaaaaagggggggggggggggggg!!!!!!!!!!!

[Papo J]

For an AFM turbo set up to work properly you need to have the AFM before the turbo or it will be slammed open as soon as any boost is made. The BOV should also be closer to the TB and not before the AFM. Have you checked the BOV and made sure it's not opening at idle?