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Running too rich?

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Old 06-06-09, 09:36 PM
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Running too rich?

So I'm going to check out this Turbo II tomorrow. The owner said the car has a rebuilt motor & turbo. But the car runs reallllllllly rich, shoots flames & he said that you can pull it up to speed slowly, but if you try to accelerate too hard then the car bogs out...any ideas on what's wrong? It was rebuilt by the owner before him, so he doesn't know what the problem is.
Old 06-06-09, 09:50 PM
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Likely TPS or boost sensor related. There's no way to know without pulling codes and testing components.
Old 06-06-09, 09:52 PM
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Well this is gonna be my first 7. How do I pull the code? I've only owned honda's prior to this...so bear with me.
Old 06-06-09, 10:01 PM
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What year is it?

S4s ('86-'88): http://www.teamfc3s.org/info/article...odes/main.html

S5s ('89-'91): http://www.johnr.com/cpucodes.html

For the S4, you will need to make a little tester with 2 LEDs.

As for testing components, you can download the FSM from the FAQ. The fuel and emissions section will have tests you can perform for all the sensors.

You can probably use the whole 'not running properly' thing to get the car for cheap. Then worry about correcting the issues later.
Old 06-06-09, 10:08 PM
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You think it's anything serious? Or definitely worth lowballing for? lol. I can't afford a new motor...so that's why I ask.
Old 06-06-09, 10:26 PM
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they all run rich compared to a piston engine. Does it have aftermarket exhaust or any leaks? any certain rpm it dies at? its probably cutting fuel because its overboosting or it thinks it is. list the mods on the car
Old 06-06-09, 10:34 PM
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I know they run rich, but it shouldn't be popping & back firing like it's goin outta style...and boggin out...lol. The guy didn't tell me that much in detail, but I'll let you know tomorrow. I'll try to rig up that connector before I go to pull the code. And I guess the problem with it thinking it's overboosting would be the boost sensor?
Old 06-06-09, 10:35 PM
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does it only happen when you floor it? can you, say, use half throttle and it will do fine?
does it have aftermarket exhaust and intake? sounds like it might be hitting boost cut.
Old 06-07-09, 12:28 AM
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If the car has a free-flowing exhaust (ie no cats) & an aftermarket intake, then fuel cut due to overboosting is very likely. The stock ECU cuts fuel when boost hits 8.6psi. This is would be somewhere at the top of the stock boost gauge if an aftermarket gauge is not installed.

If the exhaust & the intake are mostly stock, overboosting is not as likely. In that case, I would suspect an electronic problem. It's not going to be an internal engine problem. That would typically result in poor idle & huge loss of power.

When you test drive the car, see if you can accelerate without issue at around half throttle. And keep an eye on the boost gauge. Also try upshifting to a tall gear, so you can be below about 2500 rpm. Go to WOT, then see if the problem happens before you build much boost. If it doesn't, you know it's boost related.
Old 06-07-09, 01:20 AM
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Thanks a bunch guys. I'm gonna hit up radio shack in the morning, rig up my device to pull the code...and hopefully soon I'll finally be an FC owner :P
Old 06-07-09, 12:09 PM
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make sure you check vacuum diagrams to make sure no lines are swapped around I mistakenly did this i and got similar problems with bogging.
Old 06-08-09, 12:09 AM
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Well I went and checked her out today, and I'm quite certain the motor is a goner...those apex seals are probably gone. VERY sluggish at low rpm, had to slowly raise the rpm to like 3,000rpm & then drop the clutch just to get her to climb the driveway. It was depressing to see. And the guy said it was running rich, but it's not running rich at all, the pipes were dry...only thing comin outta the pipes was blue smoke...she was burning oil like it was goin outta style, especially when I finally managed to reach like 3,500rpm & she started popping like crazy.
Old 06-08-09, 01:05 AM
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if it takes an *** load of time to get up to 3000 then ya, it's pooched.
Old 06-08-09, 01:55 AM
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tell him you'll buy it for $500 cause it has a bad motor.

you can then get the motor rebuilt for as little as $1500 if the housings are in decent shape.
Old 06-08-09, 01:12 PM
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Running on 1 rotor. It's done.

If you still buy it, and get the engine rebuilt, don't leave it set up like it was. If the engine blew, It's likely there was either not enough fuel, too much boost, or a combination of the two. Or the rebuild was crap to begin with.
Old 06-08-09, 08:55 PM
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Ya I figured so much. He said you could still drive the car...but there's no way in hell that that's possible. oh well...prolly jus gonna save up for an FD now...lol. how much do s4 & s5 turbo motors go for anyway?
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