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what to do when a reliable shop tells you "you don't need it"

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weith1111

20+ Year Contributor
1,182
52
Aug 7, 2002
Wheaton, Illinois
Let's say "hypothetically" you were running 550's with a supra pump and an AFC, and were running sooooo rich and the car felt underpowered (like slower than before you did all this work), you went to a reputable shop and said "I need an AFPR, it seems to be a part of the fuel system I'm missing, and my car is running horrible without it."

And the reply you got was "That's wrong, anyone telling you that is just trying to sell you some crap to make a buck, I'm running XXXXcc injectors on a stock FPR and have done tuning on numerous other cars without them, it's not necessary."

Your obvious reply would include things like, "other people say" and "isn't the fuel pump overrunning the stock FPR" and "the car is running really rich."

To which you are asked "how do you know it's running rich, oh by the pointless AF gauge that shows COMPLETELY rich at WOT? That this is crap too," you hear from this guy.

How do I pay them to tune my car, believing an AFPR is a necessity, but they/he/she thinks it is not? Especially if they are going to tune from wideband 02!?

I don't want to get my car back with it no better than it is now.

Please feel free to move if you think this is in the wrong forum, I'm basically asking if an AFPR is really needed, or if you can live without it, but would be stupid to do so. And, what is this guy talking about?! Every other person I heard from said it's a must, and makes a huge difference in power, mileage, tuning abilities, right down to making the idle more stable.


Thanks all.

Andy
 
According to your profile you are still on the stock FP. If so there is no need for an AFPR. You can get away with running a 190lph on the stock FPR, but if you move up to a 255lph, you definately need to have an AFPR.

Also, he is right, the blinky, blinky A/F gauge is basically worthless with the stock narrowband O2 sensor.

:thumb:
 
My profile says "supra pump" I don't know what it's actually called, but it's the Toyo pump said to flow somewhere around 250lph.

And although I can't find the link to show what I'm talking about, the AF gauge has been modified to show from just .85 to .95 or whatever, so it's really a WOT AF gauge. Someone must know what I'm talking about. I'll search for more info on this and post back.
 
Why dont you just buy it off the internet, and install it yourself, It took me about 45min all said and done.

Either way, its the shops loss, if they don't wanna sell you a part and charge you labor for installing it. Or tell them, "regardless if you think I need it or not, I want it, so install it for me".
 
Agree, and I will do one of those (install myself or just tell them do to it anyway). I think I grasp the technical reason for needing an AFPR, but what I'm trying to get at, is why would someone say this? Is it really possible to have 1000cc injectors and a monster pump, and not have an AFPR? Whenever someone has a definitive YES or NO answer I always think of the gray area. How can you be SO sure?
 
Funny you mention this, because this is exactly what happened to me and I listened to them and now I am sitting with a blown engine :mad: I am actually taking them to small claims BC there is no way that I can afford to do another rebuild. I am going to sue references from this site to prove that they were at fault.
 
if you have a supra pump,you need an afpr.it flows as much or more than the walbro 255,which is known to overrun the stock fpr.just buy one online,just like it was said earlier in the post.
 
spyderturbo007 said:
Are you saying that you are going to sue people from this site because they told you that you need an AFPR? I'm confused. :confused:

:nono: He's suing the place that told him he didn't need a fpr after he blew his engine. ROFL
 
Unless there is something wrong with the factory regulator, i dont see a need for an afpr now. 1g cars dont have the over running issues that the 2g cars do. It sounds like it's way out of tune to me. Tuning by the blinky a/f gauge is almost pointless. A good wideband tune is what i would have done. Also dont over look the obvious things like boost leaks and etc. btw did you lean out the afc when installing the 550's?
 
I didn't do any of the tuning. Had a shop set it up, roughly +5 on the low throttle, around -12 to -14 for the high throttle position. But this was done with some massive boost leaks and the ignition timing WAAAAY off. No idea why this wasn't mentioned to me.

So I fixed the 10psi leak and set the base timing to 5deg. Now I'm going back for another wideband tuning and expect some changes. I have mad lifter tick with the 264/272 cams/stock lifters though. Freaks me out about the phantom knock. I don't want another shatty tuning job from all the timing being pulled because of the lifters or something stupid like that. But there will be no way to see knock just tuning from wideband, so the engine could be recording knock, even though it's not there, and the shop would never even know it...

I really just need a datalogger, or someone to log my car!
 
Are you running a 2g mass ? Just curious why you are +5 on the low settings, thats rich. Are you running a chip or still a stock ecu?
 
I'de kick em' in the nuts and call it a day...

I dont think you can sue someone for giving information you think is false...

or wait what am i thinking you can sue someone for breathing your "own" air nowadays! :notgood:
 
fp-green-95tsi said:
Are you running a 2g mass ? Just curious why you are +5 on the low settings, thats rich. Are you running a chip or still a stock ecu?

No 2g mas. stock ECU. I don't really understand a plus on the low throttle either. Unless my understanding of how an AFC works is wrong. Doesn't the +5 mean 5% more fuel? Or is it telling the ECU there is 5% more air than there really is, so it is adding more fuel to compenstate? Either way + means richen it up and - means lean it out, right?
 
The best way to check to make sure if you need a AFPR at this point is to get a FP gauge. That will show you if you need one or not.

As far as the A/F gauge goes. "upgrade" or not, it is still incredibly inaccurate. The ONLY reason to have one of those gauges in the car is if you have it connected to a WB O2 controller. No if, ands or buts.

AFC's do not control fuel persay, they adjust the MAF readings. The +/- is the changes in the amount of air going into the engine that the ECU "sees". Lets say at idle the MAF is reading 500 Hz of air. You then add 20% with the AFC. The ECU now gets a signal from what it thinks is the MAF for 600 Hz of air. It then looks up on the fuel maps how much fuel to add and pretso you have more fuel at idle... get the gist? Less air means less fuel, more air means more fuel. You are correct to think that the positive side of the scale adds fuel and vise versa for the negative.
 
too lazy to read whole thread but just some comments.

-theres no way to sue someone when you are trying to get help with parts that should be used on a public road.

-you think your car is too rich but dont ahve a logger. you cant trust an air/fuel gauge that you are running rich. read up on tuning.

- you cant really determine whether or not you really need an afpr yet. buying one wouldnt hurt anything, but using the stock one is more likely going to complicate tuning and give you verying results between runs than it will make you always run rich. its always possible to lean out the afc so much that you arent running rich but not always safe if you cant control the fuel pressure.
 
you should not be at +5% if you have 550s in the car. Definitely not...

you should be more like -5-10%. My 2g with a s16g and 550s was at -16% on low and -26% to -29% on HI (depending on the weather).

i'm gonna take a major guess at some of your problems though, just from personal experience.

Your low fuel adjustments are way rich, and if you were to let that car idle for a while running rich, its going to foul out your spark plugs really fast, or at least cake them in carbon. Thats really gonna put a damper on your day when you try to go WOT.

you need to get yourself a logger and a wideband, and control your low fuel adjustments before your car gets messed up.

and back to the original question, i've been told that the supra fuel pump flows WAY more than a 255 and a AFPR is definitely necessary.

good luck man
 
Aermotive AFPR is a better FPR then our stock 1g, 2gs! Changing it out is never a bad idea regardless of "need". Besides, having the ability to read your FP is kinda nice!

You have to remeber airflow should be the only inconstent veritable. Thats why EFI has Ariflow Maps! If you can't supply correct fuel regardless of it being a pump, fuel filter, fpr, or dirty injectors your dead in the water.

Yes. Supra pumps out flow Walbro 255's. Yes 255's out flow the return compasity of our stock FPR's. Yes you need one!
 
" what to do when a reliable shop tells you "you don't need it" "

Easy, You find a new shop and tell everyone you know what they told you. That's all that needs to be done. Most shops get business by ''word of mouth''.
 
1993eclipseGS said:
" what to do when a reliable shop tells you "you don't need it" "

Easy, You find a new shop and tell everyone you know what they told you. That's all that needs to be done. Most shops get business by ''word of mouth''.

Good point. Everyone here is saying you need an AFPR with that pump. There might be rare instances where people haven't needed one but why not listen to the masses?

It isn't uncommon for a shop to give bad advice. There is a place near me that wanted to tune my car to 13.5:1 AFR and would always run my engine well into the redline when I dyno'd it. He knows his shit about a LOT of stuff, I question his tuning abilities though.

A proper dyno tune or any tune for that matter will have the timing logged too. Using that you can tell if you are knocking... along with the AFR :)
 
to be completely honest with you i let the shop i go to do all the engine and fuel work because i have no clue what i am doing, but i do know that if they tell me something about the exterior or interior of my car saying i dont need it i remind them that its my car and what i say goes if you want it and they wont do what you want go to a different shop or lay down the law
 
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