cant rev past 2k rpm when driving

[bensn8]

Shaeff, if I been following this thread correctly then another thing that you might check is if you have your AFPR plumbed correctly. There is an input and an output port if I am not mistaken. If you plumbed in reverse then that might explain why you run rich at idle and lose pressure at higher revs. The AFPR would in effect be working backwards.

 

[shaeff]

from my understanding, the aeromotive unit has two inlets, and one outlet. the inlets are on the side, the outlet is on the bottom. that being said, i've tried switching the inlets already, and still get the same effect, despite the fact that my stock FPR does the same thing, and it's impossible to mix that up. thanks though

-shaeff

 

[bensn8]

Have you tried to test the AFPR as I outlined four posts back? I really feel for you, I've been working on my car for two years now since I got back from deployment and I have still yet to drive the thing. Sad part is I will be deploying again and I don't know if I'll be able to get it back up before then.

Good luck.

 

[GrimJack]

Heh... I know where the guage sender is supposed to be plumbed - I was asking shaeff where his was plumbed. If it was mistakenly put in after the AFPR, he's going to get all sorts of silly readings under acceleration...

 

[shaeff]

aw damn. thanks for the though IJ.

bensn8, i'll give that a try. probably tomorrow or so.

grim, the pressure gauge is mounted right on the front of the AFPR. (in the spot specifically for a gauge)

http://store.summitracing.com/defau...earchinresults=false&N=0&target=egnsearch.asp
on the top of this pic, that's where the gauge goes. where that little brass colored plug is.

 

[suprabad]

hang in there...at least your getting some competent advise.

 

[GrimJack]

Well, that rules out my idea. I was a pretty long shot, anyhow.

Let us know when you get a temp line installed, and if that solves it.

 

[sigmanin]

holy shit man this is going to turn into the longest tech post in history

and i thank god agian that i live in michigan where jonez lives and would just trailer the bitch over to him and say fix!!!!!
so so far u have check what now
pump/fpr/injecter/filter
did u check ur rail??? cant remember i dont think a rail and clog but hey
damn that is like the whole fuel system nothing left but lines

what i would do if it was me is
run a soft fuel line from your pump right to the rail and one from fpr right back to the tank so u can check lines
plus when reving u can pinch the return line to see if it is your fpr thats not holding pressure

 

[shaeff]

heh, i do my own work. i have never taken it to a shop for anything aside from inspections, allignments, and putting tires on rims.

that being said, if i know someone is supra savvy, i'll allow that person to help me work on my car, but ONLY if i'm there. (not to supervise, but to learn more )

i checked the rail when i replaced the injectors. there is no obstruction in it. i've replaced everything except the tank to filter softline, and the hardline to banjo bolt softline. everything else is new.

today it was POURING RAIN all day. terrible. the pond in my backyard, it rained so hard. all i got to do was pinch the return hose, and the symptoms still recur.

between my new job and this rain, i havent gotten a chance to do anything else that i've been planning on doing. sigh.

-shaeff

 

[suprabad]

what i would do if it was me is
run a soft fuel line from your pump right to the rail and one from fpr right back to the tank so u can check lines
plus when reving u can pinch the return line to see if it is your fpr thats not holding pressure

I've heard this before but where...


11 DAYS AGO

What about just running temporary (for diagnostic puposes only) fuel in and return lines just to see if it alleviates the problem.

In other words get like 20' of fuel line and just run it out board (preferably along the same route as the suspect permanent line) and see if the car runs properly. This way you'll know if the hard fuel lines on the car are the problem with a minimum of work...make sense?

 

[shaeff]

heh, i have the line to do that, i just need it not to be a torrential downpour of rain to see if it works!

-shaeff

 

[shaeff]

well, it's been raining like crazy here, nonstop, so i havent gotten a chance to do ANYTHING.

but here's some good news: my new fuel lines and ANOTHER new filter came in the mail today. this weekend maybe.

-shaeff

 

[tubbie]

I gurantee you it's your fuel pump. When the deamnd for more fuel increases, the pump cannot keep up and pressure goes down. Replace it, even if it's with a stock one, try it. Reading through all the post leads me to believe it is your pump. Maybe you got two bad pumps from Walboro.....

 

[GrimJack]

I think he's already tried two Walbros AND his old stocker...

 

[xarewhyayen]

okay i did skip 2-3 pages of this... but i have to ask... i see that your injectors are low impedance.. am i correct in saying 89+ got the high impedence injectors? wouldnt the high impedance system conflict with the low impedence injectors? i could be wrong but i thought i did read somewhere 89+ was high impedance .. is ur supra 89+??... hope it helps... good luck

 

[stevevangst]

okay i did skip 2-3 pages of this... but i have to ask... i see that your injectors are low impedance.. am i correct in saying 89+ got the high impedence injectors? wouldnt the high impedance system conflict with the low impedence injectors? i could be wrong but i thought i did read somewhere 89+ was high impedance .. is ur supra 89+??... hope it helps... good luck

na that shouldn't be it, since you can use high impedance injectors in low system cars i'm sure you can use lows in highs impedance cars also, but I do know you have to put all the wires to the injector control togeter or someshit like that,I did it but it's been a long time and don't remember. but it should not be injectors, he changed them to the real RC's.....I could say what other guys say, fuel pump or fpr.....who knows, i'm in kinda the same boat with problems myself....

 

[GrimJack]

I'm still betting on some kind of blockage in the stock fuel lines.

 

[BuiltMK3]

This might be quite a long shot but when i had my supercharged integra i accidently crushed a small washer that goes between the fuel rail and the bolt on the end of the rail. I could hardly get any fuel into the car. It would idle ok but when i hit the gas it would rev real slow. Took me about a month to figure it out but once i replaced it it ran great. I don't even know if this washer exists on the supra but i just thought i would let you know. Hope this helps.

 

[suprastanger507mgte]

HAs anyone checked the Air Flow Meter if you still have that?

I know for a fact that the AFM or a busted intercooler line will not let you rev past that rpm.

I read through most posts here, but see reference to TPS but nothing about AFM, maybe I am missing it.

Check it.If its not plugged in properly or broken, it will do that too.

My 2cents.

 

[shaeff]

I think he's already tried two Walbros AND his old stocker...

you are correct, sir. i can drop the tank and replace my pump in like 15 minutes now. haha.

okay i did skip 2-3 pages of this... but i have to ask... i see that your injectors are low impedance.. am i correct in saying 89+ got the high impedence injectors? wouldnt the high impedance system conflict with the low impedence injectors? i could be wrong but i thought i did read somewhere 89+ was high impedance .. is ur supra 89+??... hope it helps... good luck

no sir. not the problem my chassis is an 86.5, so the resistences match. even so, that wouldnt cause fuel pressure to drop. my motor is an '89, my chassis is an 86.5.

here's some info on 550's.

the SOGI tech tip I wrote:

http://www.supras.com/04/resources/index.php?id=21&q=550

A common upgrade to the MKIII fuel system is the Lexus AFM and 550cc fuel injectors. Many ask about using various types of 550s, but there are really only a few options. Here are some notes and guidelines on what 550s you can use:

The MKIII turbo (and early NAs) use low impedance (3-4 Ohms) or "peak and hold" style injectors. High impedance (13-16 Ohms) or "saturated" injectors are the other kind. Peak and hold injectors are a bit faster acting than saturated and are therefore more desireable.

It is possible to use high impedance injectors in a low impedance system. However it is NOT possible to use low impedance injectors in a high impedance system (simple circuits->too much current flow = fried injector drivers)

So, that said, we are looking for low impedance 550cc injectors that we can use. There are a few different manufacturers of injectors, Nippon Denso (ND) and Lucas are the prefered manufacturers. Try to stay away from other companies (Ace, PAC, etc.) as their injectors are not as high quality as ND or Lucas.

There are NO plug and play low impedance 550s for the MKIII. While some people may bill their injectors as plug and play, they are either high impedance (there are a few high impedance 550s that will plug into the MKIII's harness) or the plug has been modified in some way. In order to use 550s on your car, you will have to replace the wiring harness side injector plug. Its not a big deal, just a little soldering.

ND made some low impedance 550s which are direct fit for the MKIII's fuel rail. Their part number is: 195500-1370. BE CAREFUL! for some reason ND used this same part number for their high impedance 450cc injector too. How do you distingush between the two? Look at the notch on the top of the injector connector-if it is in the center its low impedance, if its offset to the side, its high impedance.

This injector was used in only one OEM application that I know of: the first half of the '87 model year of the Mazda RX-7 Turbo II. This makes this injector a little hard to find. After the first half of the '87 model year, Mazda moved to high impedance 550s for the Turbo II and high impedance 450cc for the NA RX-7.

It should also be noted that any injector upgrades sold by aftermarket companies (HK$, Blitz, Greddy, etc) use these injectors or a variant thereof.

Here's the ND 550s:



Another alternative for low impedance 550s for the MKIII is the RC Engineering Lucas disc type injector, part number PL8M-550. This utilizes the same style injector connector as the ND and is roughly the same size. The disc type injector is far superior to the pintle style (ND is pintle style) in that it is much faster acting and it is more accurate.

Here's the RC 550s:



So, in closing, there are really only two alternatives if you want to get low impedance 550s for your MKIII. Good luck and happy boosting!

I'm still betting on some kind of blockage in the stock fuel lines.

me too! :: crosses fingers ::

This might be quite a long shot but when i had my supercharged integra i accidently crushed a small washer that goes between the fuel rail and the bolt on the end of the rail. I could hardly get any fuel into the car. It would idle ok but when i hit the gas it would rev real slow. Took me about a month to figure it out but once i replaced it it ran great. I don't even know if this washer exists on the supra but i just thought i would let you know. Hope this helps.

nah, i took the rail apart twice, (once to replace my 440's, and another time to replace my already new 550's with RC 550's. theres definately no blockage going to the rail.

HAs anyone checked the Air Flow Meter if you still have that?
I know for a fact that the AFM or a busted intercooler line will not let you rev past that rpm.
I read through most posts here, but see reference to TPS but nothing about AFM, maybe I am missing it.
Check it.If its not plugged in properly or broken, it will do that too.
My 2cents.

there's no way that the AFM could cause a drop in fuel pressure. the fuel pressure drop is what is causing the motor to fall on it's face when RPM increases. that being said, i already tried my old (known good, AND bench tested) stock AFM, and i've tried the LEX afm, and i've tried the LEX AFM with my stock AFM's electronics. all gave the exact same symptom.

and i have no codes.

-shaeff