BoOsTin FD

The forum is giving me hard time searching. Gives me timed out window.

Anyway, Recently fd started to run really rich. I get backfire, stupid A/f gauge is always in the last bar of green, and you can smell fuel from exhaust. My buddy told me when i floored it all he can smell is a lot of fuel.

I also get very bad gas milage. On one of my other threads, i've been trying to figure out, why is it cutting out and breaking apart at 4k and up. And that is always over 8psi. 7psi runs perfect, Rich, but perfect.

What i have done so far is, changed plugs and wires (they have around 2k on them. Changed fuel filter, Checked all vacuum hoses, check valves, leaks, etc. I cleaned my apexi filters as well, replaced oil and oil filter.
Problem still remains.

Somehow i thought it might be turbo related but, i'm afraid if i change them it will do the same thing. They boosted fine and i had no break ups, and then all of a sudden it started. It's been like this for over 2 months now. Didn't have much time to play around with it until now.

My mods are, Dp, new hi-flo cat, new catback, PFS ecu (I tried leaning it out, but it runs even worse), Apexi Intakes, Sillicone Vacuum hoses, Profec B, magnacore 10mm wires etc.

Please if anybody had similar problem, let me know what it might be so i can change it or at least check it.

Thanks to all.

Amel

Jay7 Nyc

iTrader: (3)

checked map sencor on driverside against firewall?

BoOsTin FD

By checking you mean, making sure that the hose is new and pluged in on both sides, map and UIM then yes.

Amel

su_maverick

I am going through the same thing with mine. Its running low on boost and I passed emissions by one point on fuel density. They are looking at it now. The first possiblitites that came to mine
1.) Bad O2 sensor
2.) Dirty fuel injectors
3.) Low compresssion (bad sign if it is that)
I will keep you up to date as to what is going on.

BoOsTin FD

I changed my o2 sensor Recently too. I would send injectors to get cleaned but I have to remove rat's nest in order to get to them, and i don't wan to do that yet.

Amel

BoOsTin FD

UPDATE: I have replaced Water Thermosensor which didn't show ohms according to the manual. That little thing costs 30 bucks at auto zone. Anyway, Idles better, It doesn't run as rich, however stupid hesitation or whatever you call it is still there.

I also notice that when it happens, on my PFS keypad, on the o2 sensor reading it shows 0 when that occurs. As if there is no fuel, like a fuel cut. So by my calculations, that means there is a problem with fuel delivery right?

Amel

Hyperite

Is that zero VOLTS? or zero A/F ratio? Is it bucking? Check your fuel maps (got gas), ask your tuner (if it wasn't you), and check the fuel pump voltage (make sure it's at 12V at those RPMs, or jumper it and see if that helps).

BoOsTin FD

Yeah 0 volts i think. It's a PFS PMS ecu with that keypad and has o2 sensor monitoring by volts. So when that bucking happens it's around 5k and at 8psi and up it shows 0 volts every time it bucks.

I did the maps, but at 8 psi i'm not suppose to put any fuel anyway. Fuel pump doesn't run constant 12v as i haven't done that yet. It runs stock setting as it is stock.

What am i suppose to get on my fuel pressure gauge when i ground GND and F/P on that terminal box? Also what is the other option when i want to see my wot reading?

Amel

BoOsTin FD

Checked Fuel pump pressure. When GND and F/P are shorted i get 38psi. When Idling i get 32.

Also, for some reason I can't raise boost at all. If i use low or high boost and turn it up, no difference. I only get 7psi and when it spikes to 8 that's when bucking and crap occurs.

Amel

Hyperite

FPR? Clogged Cat? Time for new plugs/wires? If it was the stock ECU I'd say reset it, but...

edit: actually, you probably can't raise boost BECAUSE you can't spin the turbos enough because of the bucking.

BoOsTin FD

As i said Cat is brand new, and it's a hi-flo, I don't have any other cats. Wires and plugs are new as well. How do I check FPR?

Amel

Hyperite

I dunno how to check a FPR It *really* sounds like you need to be dumping more fuel in. You said that you "leaned it out" and it ran worse, did you try richening the mix? I'd be terrified to be running under boost with >12 A/F. Check the plug wires, make sure they're on the correct coils, and on tightly. Sounds like it could be timing thing as well. Lots and lots of possibilities

mad_7tist

you can check the fpr with a gague on the fuel line pull the vac line to the fpr and see if the press changes. also if there is fuel in the fpr vac line it is no good. they usually fail internaly and send gas through the vac line. have you unplugged the pms and seen how it runs?

BoOsTin FD

I tried running without pms and it was worse in a way that there was no bucking but there was no pull at all.

About leaning it out. I set it up to 10psi at 10psi i added some fuel, but it never reaches 10psi. the bucking and hesitation is anything above 7. No reason for me to add any fuel at 7 right?

I know it has enough fuel for 10psi but i can't get it up to 10 psi.

About FPR, does that mean i have to take rats nest to test it out? I can't see it nor can i come close to it if i remember correctly.

Amel

mad_7tist

if you have a dp you can see and get at it from under the car. are you sure it's boost pressure related and not rpm dependent?

BoOsTin FD

I think it's boost related, because in every gear depends where the boost spikes to 8psi. in 1-3 i rarely hit 8psi, but when i do it's usually around 3k or after 5k. In 4th or 5th gear it can happen at 2k rpms or any rpm.

Also, when i unplug the vacuum line from FPR how much is it suppose to change?

Amel

Hyperite

Can you rev to 7K in neutral?

BoOsTin FD

Yes I can, because, as i said, it never reaches over 7psi.

Amel

Mahjik

iTrader: (1)

Without load on the engine, the max boost should only be around 3-4 PSI.

jdhuegel1

MAP sensor? Not disconnected, but failing maybe?

BoOsTin FD

I know that, that's why i said it never reaches 7psi in neutral so why would it hesitate, which it doesn't.

Amel

BoOsTin FD

I don't know bud, i don't have another map sensor to test it out. But shouldn't it idle like crap and give me all those signs of blown engine if it was failing?

Amel

Hyperite

Not necessarilly. Check the PFC Commander versus your (mechanical?) boost guage. Do they match?

BoOsTin FD

I don't have PFC I have PFS, and I did try different boost gauge just for testing purposes. They both showed the same thing.

PFS Does have boost gauge but i never paid attention to it, as i heard that it's not that accurate. What are we shooting at here? Map sensor?

Amel

Hyperite

Bingo, we need to make sure the ECU is seeing the same thing as the boost guage (ie- ACTUAL boost)