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Old 05-03-2008, 06:09 PM   #1
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hey guys, I have a bit of a problem with my car.

If I'm feathering the gas, it seems to run perfect, running at about 10psi, spooling at about 3-4k rpm, and it feels very strong

but at soon as I put my foot down, it falls on it's face and does't go anywhere past 4 or 5k rpm, with a loud popping out the exhaust. if I feather it past about 5500rpm, I can floor it and it'll go, but only at about 5psi.
I've tried messing with the RX-7 AFM I have on there, but it doesn't seem to help much, but from what I've recently researched, it doesn't sound like it would.

beyond what I've got in my sig, I have brand new NGK plug wires, and the stock vortec afpr with the 12:1 disk. Anyone have any ideas?
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Old 05-03-2008, 06:20 PM   #2
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too rich.
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Old 05-03-2008, 07:29 PM   #3
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figured. I know I'm running the ultimate 'band-aide' setup, but whats the best way to fix it? apparently adjusting the AFM won't help, I was thinking about trying to poke a small hole in the vacuum line to the vortec, see if that helps, and if it does I'll start looking for a new disc like 10:1 or 8:1
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Old 05-03-2008, 10:28 PM   #4
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Wait why are you running the Vortec if you already have a 190LPH fuel pump? Delete that ****.

And don't forget to take you your spark plugs out and clean them before you do your next test drive.
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Old 05-04-2008, 02:15 AM   #5
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figured. I know I'm running the ultimate 'band-aide' setup, but whats the best way to fix it? apparently adjusting the AFM won't help, I was thinking about trying to poke a small hole in the vacuum line to the vortec, see if that helps, and if it does I'll start looking for a new disc like 10:1 or 8:1
You're not running the ultimate band-aid setup yet. Get an adjustable fpr (i.e. begi 2025 can be had used for $100 or so) so you can get good control of your rise. There are guys that have ended up buying 4 discs before finally ditching the vortec.

You also won't know how rich (or how dangerous) you're running unless you get a wb02, which you will definitely need sooner or later.
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Old 05-04-2008, 05:25 AM   #6
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yeah I just got a godspeed radiator and two 12" slim fans. but after that the wb02 is next.

mike you're saying with the 190lph I don't need the vortec at all? I thought it'd have to go up somewhat as boost increases.

I saw the begi adjustable unit on FM's deal of the day the other day, really should've gotten it, only $120.
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Old 05-04-2008, 05:37 AM   #7
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Yes thats what im saying.
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Old 05-04-2008, 10:31 AM   #8
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PM me if you are interested in an extra begi I bought here just cause I like extras.
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Old 05-04-2008, 10:32 AM   #9
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You still need to increase fuel rail pressure with the 190hp.
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Old 05-04-2008, 07:17 PM   #10
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I checked the plugs, they looked fine, maybe even a little white. I removed the vortec, no change.
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Old 05-04-2008, 07:56 PM   #11
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Dam. Why dont you try putting the stock AFM back in.

Do you have a wideband?
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Old 05-04-2008, 08:00 PM   #12
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mike you're saying with the 190lph I don't need the vortec at all? I thought it'd have to go up somewhat as boost increases.
not completely no, but on the stock pump you couldnt see more than 70-80psi tops. the 190 can see much more than that, so when you max the vortech with teh 12:1, instead of being 75psi of fuel, you may be seeing 120psi.
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Old 05-04-2008, 08:16 PM   #13
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no wideband yet. its on my list of things to get. what's the cheapest option? so I know how many times I need to avoid going to starbucks.

I have another rx-7 afm and the stock, I'll try both of those, but I dunno if it'll do anything.
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Old 05-04-2008, 09:57 PM   #14
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Just try the stock AFM first. Iv seen alot of threads were people are having problems with there car after they install the RX-7 AFM, because there not adjusting the needle correctly. Im in the same boat as you with the wideband (its in my list too). For now i have a narrow band A/F guage (had one laying around) just to get some sort of idea if im rich or lean.
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Old 05-06-2008, 07:50 PM   #15
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so I put in the stock AFM and it didn't really help. I only went for a short ride, so its hard to tell, but the probably was definetly still there, I'm just not sure how much better/worse it was.

reading up on Olderguy's O2 clamp I have installed, since it cancels the ECU's signal at 4000rpm (where I'm having my problems) to lean out the mixture, would it be worth it to try disconnecting it?
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Old 05-08-2008, 12:56 AM   #16
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ok so apprently the white wire coming from olderguy's clamp had become disconnection from the NO terminal on the boost switch.

but since the clamp keeps the car from going lean, doesn't that mean, since it was unplugged, I was going lean? which means I wasn't rich? wtf?

anyways I love my freaking car now. except boost keeps dropping off from a peak of 8-9 to about 5. wtf.
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Old 05-08-2008, 04:07 AM   #17
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My car was dropping boost just like that last week, thought it was the Bipes taking timing, but checked the lights and it wasnt. Turned out to be a hairline crack in a coupler.
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Old 05-08-2008, 11:38 AM   #18
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Every time I have ever lost boost in any car, it was either a cracked coupler or a loose sensor causing a loss of power and hence, boost.
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Old 05-08-2008, 11:43 AM   #19
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Too lean will also cause choking and coughing, just not farting. Thats too much fuel, gasoline or burritos.
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Old 05-20-2008, 02:18 AM   #20
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ok so I'll revive this thread, and say that I've now installed my aem wideband, and in my fairly dead rpm range (3000-4500) I'm getting 17:1+. After that I'm getting around 13-14 till redline. any ideas? I took apart my vortech and the smaller rubber disc on the bottom was balloned out just a little bit, like it was stretched slightly from the piston?
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