Car slows down when i hit boost??
 

I have a 93 Greddy turboed. It's a stock kit with front mount intercooler, and bipes ACU. Lately when i go into boost the car slows down? I installed a fuel pressure gauge and it's pegged at 40 and when i hit like 5psi of boost sometimes the fuel pressure shoots up to like 60psi then back down? Is this a fuel pump or FMU problem??

What FMU are you using? I don't think 90psi is very high. With the fuel pressure gauge you should pinch the return line and see upwards of 100psi. What injectors are you using? Post this kind of information in your signature please, along with your location in your profile.

Do you have a wideband? I'll bet anything it's your spark plugs and wires, when was last time you changed them?

wideband? afr's?

Is your fuel pressure regulator a rising rate adjustable one? If so, I think you're adding WAY too much fuel.

You're probably knocking/detonating and your timing is being cut. Does it feel any quicker partial throttle? If so, then you're probably knocking..

I have stock injectors and fuel pump. The bipes ACU is not pulling any timing. and i don't have a wideband.

Oh i'm using the stock vortech fmu from the greddy kit

get a wideband..

why dont you have one already..

Seriously, why dont you have one already?!?! Could be that youre running extremely rich making the engine to slug

Also could be a possibility.

Would you like to make your life easier?? Get a WB ASAP, dump your band-aids and an MS, knowing what goes on in your engine will save you lots of cash.

EDIT: I dont think you know, but most of the components of the greddy kit, except form the turbo/dp/mani, are shit and will eventually have to be replaced

Well i've had this kit on my car for about 8 years now. It was a install and forget thing. So never thought about a wideband. You guys have a recommendation on which to get?

most people go with the aem uego for a cheap permanent install but there are many great products out there ill let others chime in on there opinions

i own 3 wb's 2 for tuning and i have a aem that stays in the car so i can keep an eye on things.

My other 2 are the innovate lc-1 and lm-1, great for tuning but not as user friendly for beginners as the aem or plx might be

Most of the members have the LC-1. I personally have the PLX 300M (discontinued). IRCC look up Tyson87's threads, he got one for $187 from ebay.

Also I strongly recommend you upgrade your engine management, if youve had the same FPR for eight years you could be in the verge of replacing it. Im actually surprised your still have the original components after all those years, I often read how bad the Greddy components are.

EDIT: AEM is also really popular

Keep in mind the Greddy kit was meant to be used out of the box without a wideband. A lot of us on this here site ran it as such for quite some time. I'm not saying that it wouldn't be a good idea to get one, but the Vortech unit should run the car pig rich as to avoid any blown engine lawsuits towards Greddy. That being said, the OP should know not to touch anything until a wideband is obtained. a DIY intercooler kit from ebay would be a great and fairly cheap (although some time will be involved fitting it) upgrade. And I THINK as long as the pressure isn't touched, it'll only make the car safer, and again, no wide band would be needed. This is all assuming that the installation of the Bipes wasn't followed by a pressure jump or any other such crazy non-sensible addition of boost. My suggestion would be to buy my BEGI AFPR for $60 (see: classifieds) and at the same time get a wide band and some slightly larger injectors (1.8s) run 9-10psi safely and be happy. Everyone will say "MS MS MS MS MS", and it's true, even I switched, but it's still money, and you'll need a wide band with MS for sure, so ignoring that cost it's a $60 fpr or a $500 MS (assuming you don't build it yourself).

In my opinion, Even tho some kits are designed to be bolt on and installed without any tuning a wideband is one of the most important things to have when modding a engine for power.

They are relatively inexpensive and if you know what the proper readings that your engine should be than you can easily diagnose issues you may be having ( especially fuel related ones )

I bought this toy...
Innovate DB Blue Gauge, LC-1 Sensor, and Controller BEGi

Its an entire kit and it comes with everything you need to install it and run it. If you dont have an empty o2 sensor bung on your downpipe right in front of the cat, you will need to get one. The link to the kit i posted above will include everything you need including an o2 sensor bung for you to weld on there if you dont have a free one.

o2 sensor bung.. you can see it to the left side of the flex pipe..
Attachment 202506

Thats what the gauge looks like
Attachment 202507

Yes indeedy, get a wideband ASAP. I just don't like the people that say "get wideband or world will end". If your car has been running fine (although it's not anymore) for 6+ months without a wideband, chances are it won't blow up in the month or two it takes you to get a wideband. Which is the most time you should wait before buying and installing a wideband btw. wideband.

aem wideband:
http://www.autoanything.com/gauges/6...?kc=ffcategory

How do you know his injectors are not acting up and hes going at 18a/f?

The fact that it was running fine but not running fine now kinda shows something is wrong.

ok ok ok, bad time to bring up the wide-band-not-needed-once-proper-tune-(out of box)-is-established argument, but it had some basis.

When I got my wideband, it did indeed show I was going into the 17's during boost. It wasn't the injector's fault, it wasn't the FPR's fault, it wasn't the vortech's fault, and it wasn't the fuel pump's fault. It was the 1" piece of hose connecting the fuel pump to the pick up, which had a small hole in it, robbing pressure. My point is a wideband helps with tuning a car that's running decently, a narrow band would have told me the same thing my wideband told me, that something was wrong and I was running very lean.

I dont trust Anything a narrowband says.

I'm just curious, by 17s you're talking almost all the time when you're into boost?

No damage?

A narrow band in my case would have said lean. Testing fuel pressure would show low pressure, replacing fp didn't help, 2nd time taking fuel pump out and I noticed the ripped line, wide band wouldn't of helped. Full rich on a narrow or wideband won't tell you much. Again, they're great tuning devices but they're not the best to diagnosis a "broken" car. That said I'll never live without one.:fawk:

Holy fuckin shit whats with the newb feild day. ok hyper her goes your fuel pump is dieng. Plz get a real one and you will be fine.

My first clue is the car is only slower when you put more demand on it for power ie boost.

My second clue was that your fuel pressure went from 40-60 and back down to 40 while trying to accelerate get a walboro 190 hp and you will be fine to go back to the way things where.

MY 3rd and final clue was that your shit has been fine for 8 yrs nothing runs for 8 yrs and then magically goes out of tune.

Now you can listen to my sage advice or run all over the earth doing what these newbs suggest. If you think im wrong you could pm your symptoms etc to any other regular ie Braineak, olderguy, turbotim and they will say the same thing. GL to ya man.

Yea your lean.......

Check all your vaccume lines, If you have a leak, the afpr will not get the proper boost.

And what is up with the bipes, NOT PULLING TIMING! This could be a issue as well. What is your base timing set at?

You need to set the proper settings on the bipes and set the base timming to 14*.

Check all vaccume lines. And double check boost pressure. You will be lean anthing after 5psi. Or atleast I was!

BUT YOU SOUND LEAN FOR SURE.

17's in boost is basically so lean that the car would just fall on its face, not make any power. It probably bogs so hard that it cant even really detonate

Ok guys i ordered a Walbro 190 and it will be in tuesday. So today i was doing some tests. When i jumper the gnd and ten and turn the key to on there is no fuel pressure on the gauge? Does that mean the fuel pump is gone? but when i start up the car it's at 40 and it stays there even when i'm driving so i try to stay out of boost. And when i shut my car off after driving the fuel pressure gauge says at 40 even after 5 mins so injectors are fine.

is it a mechanical fuel gauge? If its mechanical it should stay the same psi after you shut the car off for days. It should not go down to 0 unless you have a fuel leak somewhere or ur fuel pump is shot and not holding pressure after you shut it off.

Do you have to crank on it for a long time for it to start?

Do a little search, but I am pretty sure that you want to jump Fuel and Ground, not Ten and Ground. The latter is for setting timing.

Like others said, at idle squeeze the fuel return line with pliers, and watch to see if the fuel pressure rises up to around 100. Your engine will start to bog down from the extra fuel when you do this.

happy tuning.

oops yea i jumpered the F/P and GND and the fuel pressure gauge says 40psi

Did you check the vaccum lines for leaks to the fpr??????????????????

yep checked it all but i'll double check again. Is there a way to test vaccum leak or do i just have to listen and feel for it?

u got a vac or boost/vac guage?

yep vaccum is always at 20 at idle like normal

does the car idle high or surge

It idles normal. No jumping.

Have you ever replaced the fuel filter? ive seen alot of cars where the owner has never done so. Im just guessing here. I try and change mine at least annually.

Hmm the fuel filter is still stock. I'll get that changed. It's got 176,xxx miles on it.

Take it to a local auto shop with a smoke machine. It fills your intake with pressure and smoke it will show you if anything is leaking. Its relatively simple to do as well so it wont cost much.

WTF man why cant you be more like him and give good advice
On the note of vac leaks, you can use a flamable spray liquid ie wd40 etc, to diagnose leaks as well. But with your idle being at 20 inches etc i think you are fine in that respect.

#1 ^ Please explain what you have in mind

#2 ^ Only tells you that you dont have a vac leak in your intake manifold however it wont tell you if you have a vac leak between the tb and the air sensor.

becouse the depressurization of his fuel lines means butkiss. Tmorgans idea of pressurizing the intake tract will actualy work. We allready established his FP was Dead anyway, so realy waiting until he swaps in the new unit is the best course of action for now. And someone has to step up and rag on the more experienced newbs. We cant limit the bashing or ration it ;)

Oh yeah and afm systems are as or more sensitive to vac leaks than most others the problem would either be a hose completely off or a failed hose venting at idle, becouse when there is a leak, the afm does not get enough flow to keep the trap door open. And this will shut off your fuel pump or lean you out depending on the severity of the leak.

wait so 20 is standard for vacuum? i sit around 24 at idle :dunno:

And I'm around 18. It depends on your tune as well as altitude. I'm at 7200ft.

hah makes sense I'm at 0......

Well the new fuel pump comes in tomorrow but i have to work the whole day so will swap it out wednesday and let you guys know if it fixed it. Will be picking up a new fuel filter today too while i'm at it.

any updates?