cant rev past 2k rpm when driving

[shaeff]

thanks for the input when it stops raining here, i'm planning on replacing the two stock rubber lines for the feed side. (tank to filter, and front of hardline to where the FPD used to be connected) while i have that all off, i'm going to hook up a fuel pump to the hardline going the length of the car, and see if there appears to be any obstructions. this is definately a fuel issue, despite what my friends tell me...

i get answers from them like, a higher compression ratio will do that, or, it's your 1mm OS valves doing it man, you should have stayed stock, blah blah blah.

and this one's great: your injectors (550's) are way too big for your fuel pump. you're outflowing the fuel pump.



-shaeff

 

[suprabad]

Hey Shaeff-I've been following this and WOW! Mind Bogglling! I really have to give you credit for not having gone insane or on a shooting spree.

I was curious did you ever get your injectors sounding right or get them looked at? I remember this was an issue when this nightmare first came to be. Maybe I missed it but I reread the thread and don't remember if you actually verified that whatever injectors your using now are working properly (I know your on your 3rd set since you got the pair of fake RC's).

I think barring the injector problem (defective) that you are on the right track with checking the fuel lines. I had a 1966 Shelby Mustang that I upgraded the fuel pump from mechanical to electric. The electric was so much more powerful then its predecessor that it sucked up a bunch of crap off the bottom of the tank and clogged up a feed and a return line under the car. Took me a month to figure it out cause I was looking at all the complicated stuff and overlooked the small stuff.

As I'm sure you know, whenever you mod you create alot of variables and when there is a problem you usually end up going through everything just like your doing now. In re-reading your thread this is about all that's left barring some kind of Jap kibuki curse

I feel your pain and send you good vibes. :biglaugh: :icon_bigg

 

[shaeff]

haha, thanks man. what keeps me going is the fact that this car should be sick when i get it running properly. i've already got a catback picked out (if it's not sold yet). you can see my mods here:
http://www.supramania.com/forums/member.php?userid=70

thats why i havent gone crazy, yet. when i found out that my injectors were fake RC's, i got pissed and just bought real, new RC's. i'm assuming that they were only part of my problem, as now with the new 550's, the car idles much, much more smoothly, and they all make the same clicking sound, rather than 4 different sounds like the old ones.

the other 550's were just some generic 550cc low impedance injectors. thats what i was told by RC when i gave them the P/N.

as for checking the fuel lines, i REALLY believe that something could have gotten in them and made a nest or something. i've replaced everything except the two stock softlines, and the large one that goes front to back.

everything else is brand new. i'm hoping there's an obstruction in one of them, somewhere. the way my fuel pressure acts, it sure seems like it. (it'll maintain fuel pressure at idle no problem, when i rev the motor, it drops to about 10psi, then SLOWLY returns back to 32psi vacuum line attached.) thats exactly what would happen if my filter was clogged up(even though it's new) or if i had an obstruction in the line.

yes, considering i replaced a brand new walbro 255 pump with another of the same (thought maybe my pump was dead out of the box) i used the old wally to suck up the (tiny) amount of crap that was in the bottom of the tank. the pickup filter was pretty clean, but now my tank is wicked clean inside. i dont think that any particles would make it past the walbro's pickup filter, and if it did, somehow, i'd imagine that the toyota filter would grab it.

thanks man. i need all the luck i can get

-shaeff

 

[suprabad]

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?

Just a thought

 

[shaeff]

that does make sesnse, except it'd kindof be weird to connect it. every place for the feed line has a threaded fitting. i guess i could try to find out the thread pitch and rig up some connections. thats a good idea. i'll see if i can do it up. thanks

-shaeff

 

[lagged]

reccomendation: braze on (or tube flare thingy) a 6an fitting to the fuel feed hardline on the tank and run SS braid all the way to the filter, then from there to the feed at the rail.

 

[shaeff]

thats not a bad idea, but i'd rather figure out for sure what the problem is before i go doing more upgrades... ya know? i'll definately keep that in mind.

now, here's another question. i'm about to go call champion and buy those new fuel lines and a new filter.

what do you guys think about running a can of seafoam through my tank?

http://www.seafoamsales.com/motorTuneUpConsumer.htm

Common Reasons Service Technicians Use SEA FOAM MOTOR TREATMENT

When your vehicle has a rough idle, hesitates, stalls, pings or has an after run problem – this is often due to carbon buildup.

Your service technician can offer a reasonably priced fuel systems cleaning with the use of SEA FOAM products to solve these carbon problems.

When your vehicle’s fuel injectors need cleaning – this is often due to residue left on injectors from poor burning fuels and contaminants.

Your service technician can offer an inline fuel injection cleaning with the use of an injector cleaning machine and SEA FOAM MOTOR TREATMENT. SEA FOAM MOTOR TREATMENT is also added to the fuel to disperse moisture, clean fuel lines and injectors while driving.

When moisture needs to be removed from fuels or an anti gel or de-icer is needed – these conditions are due to condensation in the fuel tank and extreme cold weather creating gas line freeze or diesel fuel gelling.

Your service technician can recommend the use of SEA FOAM MOTOR TREATMENT in the fuel tanks to dry moisture and cure these problems.

When there is moisture detected in the oil – this problem is due mostly to poor ventilation and condensation. Sometimes, however, there is a bad head gasket, cracked head or block that must be replaced.

Your service technician will diagnose the problem and recommend the repairs. As part of the diagnostics, a SEA FOAM MOTOR TREATMENT can be used in the oil crankcase to cure the moisture problems. A SEA FOAM MOTOR TREATMENT can also be used in the oil crankcase after repairs to make sure moisture is eliminated.

When valve lifter noise is apparent or piston rings seem to be sticking – this is often due to dirty and gummed up oil passages, varnished lifters and buildup of gum, varnish and carbon in the piston ring areas.

Your service technician can offer a SEA FOAM MOTOR TREATMENT that will clean sticky lifters and free sticky rings. By doing this treatment you will be able to determine if there is a varnish problem or a mechanical problem.

To help pass emissions tests – high emission numbers are usually caused by extreme carbon build up, dirty emission control items such as: pcv valve, egr valve, oxygen sensors or bad spark plugs and wires.

Your service technician can provide a pre-emission test service that includes SEA FOAM MOTOR TREATMENT as a cleaning agent to help pass emissions tests.

When fuel stabilization and engine fogging is needed – fuels of today become stale in less than thirty days. Therefore, stabilization and engine fogging are needed when vehicles, lawnmowers, snow blowers, outboard motors, chainsaws, motorcycles, gas in cans and engines are put into storage.

Your service technician can provide fuel stabilization and engine fogging services with SEA FOAM MOTOR TREATMENT.

so, what do ya think?

thanks,

-shaeff

 

[IJ.]

Shaeff: I read this each day in hope of the "AHAAAA" moment when you finally sort it!

Sorry no input on the SeaFoam.

 

[suprabad]

Shaeff...my experience is that all this "mechanic in a can" type stuff is snake oil.

Don't be mad at me for asking but is it possible your trying to avoid your major problem here? I know when I get frustrated with stuff I try to distract myself with trivial shit like seafoam or...whatever. Just tying to help keep you on track here, sorry if I overstepped my welcome.

Have you tried my idea of running some temporary fuel line to see if it alleviates the problem? It's a cheap and easy test and will save a ton of money and time and at least you'll know if it is or isn't fuel line.
Either way you'll be one step closer to solving your little mystery.

I too look forward to your upcomming "success post".
You'll get it handled. Good luck!

 

[GrimJack]

Seafoam takes care of carbon buildup. Didn't you just put this engine together? If so, there's no way that carbon could be a problem yet - it's unlikely to ever be a problem for us, I find that carbon only builds up on cars driven by grannies.

I'll throw in with the rest when I say that I read this thread daily in the hopes that I get to see the "HOLY SHIT I FIGURED IT OUT" post sometime soon.

 

[shaeff]

haha, yeah, you guys are right. no seafoam for me. i cleaned the poo out of this sucker when i had it apart. i just figured i'd give it a shot. oh well. haha. no seafoam for the supra.

suprabad: i just started a new job working from 7pm-5am (sometimes 8-9am = overtime up the wazoo= $18.75/hr in a liquor warehouse on the bull line. i'm mad tired, so i have slept all day, and not worked on the car in about 6 days.) and yes, i'm trying to avoid the major problem, heh. dammit. you caught me.

that all being said, i wanted to replace the last two stock fuel components in the fuel line for piece of mind anyway, and the new job has allowed me the cash to do so. two days ago i ordered the two softlines and another new filter. i'm going to clean out the stock hardline under the car with a very thin wire or something, which is what jeff at champion said to try. (he thinks its a clogged fuel line too)

i'll post pics of my setup, as jon @ MDC suggested, that maybe another pair of eyes looking at my setup might see something my tired of searching eyes overlooked. so i'll post pics soon.

**warning, my car has been sitting for 9 months, so it's damn dirty, as well as the engine bay. it WILL be clean when it runs properly **

-shaeff

 

[suprabad]

maybe another pair of eyes looking at my setup might see something my tired of searching eyes overlooked. shaeff

That's a really good idea! Sometime it's hard to see the trees from the forest. Especially if you've been staring at the forest for a long time...you know what I mean.

I applaud your tenacity, lesser men would have given up and bought a box with wheels, not you dude! You are a rare breed of cat (i.e. balls, humility and vision).

Think how good it's gonna be when that monster 7m roars to life and you get to go out there and hand a few doubters their asses! :evil2: All the bullshit will have been worth it.

Hang tough, I know you're almost there.

 

[MDCmotorsports]

Shaeff... if I was closer I would be there working on the damn thing. 100% guarantee its something I have been through with my car.

 

[suprabad]

jeopardy theme song plays in the background...

audience eagerly awaits progress...


anticipation builds...building...building...building... :aigo:

 

[stevevangst]

AHHH FU$K......HEHE shaeff my car is giving me problems AGAIN..... OVER AND OVER AGAIN. DA DA DA... I am parting it out this week if this problem is not slove.....god dang it.....I HATE SUPRAS WITH PROBLEMS.... then again mostly every supra goes through problems. hehe....right Shaeff....no more 600hp supra now, it's more like 300hp.

 

[shaeff]

haha, that sucks, steve. i'm still waiting on those gas lines from Jay Marks. right now i'm at like 50hp. i'd rather have 300 than 50. hopefully i'll get the lines by friday, and have them on this weekend at some point. if all goes well...

-shaeff

 

[IJ.]

Shaeff:

Damn this distance thing I just stripped ALL of the Gas lines from my car and chucked em out....

they were in perfect condition as we don't get the White Vomit here (snow)

You could have had them free.

 

[bensn8]

O.K., I am new here and have been reading this thread and hoping that Shaeff solves the problem. Hope you don't mind that I add my two cents.

Shaeff, when you are at idle your fuel pressure is fine, when you rev, your pressure drops, Correct?

I would take a good look at your AFPR again.

To my understanding of the fuel system, Fuel pump via fuel lines to fuel rail, Fuel rail into injectors out to your AFPR to return line back to tank.

The AFPR works to restrict the amount of fuel returning back to the fuel tank. As the vacuum increases (higher revs) more restriction is applied by the AFPR (1mmhg increase equals 1psi of Back pressure), the more restriction applied by the AFPR the more fuel remains in the fuel rail (at a Higher pressure) and you will see this increase at your fuel pressure gauge. If the AFPR is not working right, you will have a steady return of fuel back to the tank and at higher revs starve the motor for fuel and see a drop of fuel pressure.

To check this, find the fuel return line coming from your AFPR that goes back to the tank. Clamp this line (not to tight at first) vise-grips will do. Now start your car and increase your revs, at the same time increase the clamping force on the vise-grips, you should now see the pressure rise on your fuel gauge and notice that your car runs smoother. If this happens then it is your AFPR. Did you use teflon tape at the fittings? Some times this can leave strands of teflon in the AFPR that clog off air ports. If this is the case take it apart carefully and blow the shit out of it air.

Hope this helps, and good luck from the island of Guam.

 

[GrimJack]

Another silly question - where is your fuel pressure gauge sensor plumbed? Before or after your AFPR?

 

[bensn8]

Gauge is plumbed before AFPR. On the line exiting the fuel rail or in the port on the AFPR itself. What you are actually reading is pressure being held back by the fuel pump. In a simply system... Fuel pump pumps fuel to fuel rail, rail distributes to fuel injectors, unused fuel returns back to tank. Now as the revs increase more fuel is needed. The pump begins to pump at max capacity, the fuel injectors use more of this fuel and then the AFPR increases it's back pressure on the fuel exiting the fuel rail. This increase of back pressure (restriction on the return line) increases the pressure in the fuel rail. Imagine a water hose with several small holes in it... with the faucet turned on wide open (fuel pump at max) and the end of that hose wide opened (AFPR wide opened) you would see leaks at the small holes in the hose (injectors) and the hose itself would not be under any pressure (Fuel Rail). Now is you were to close the end of the hose (AFPR putting back pressure on fuel rail) you will see large streams of water at the holes (more fuel at the injectors) and notice that there is now greater pressure in the hose itself ( fuel pressure in the fuel rails.

Hope this helps