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Old 08-01-2006, 02:57 AM
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Bang Head About to break something

This is my first post so bear with me. I have had my 87 Regal Limited for about 2 weeks. It has a stock rebuild w/ about 8,000 miles, green stripes, 93 chip, TH dwn pipe, 3" all the way, k&n, adjustable wastgate, greddy blow off valve, new fuel pump, rebuilt factory turbo. I have receipts for every thing and it appears that everything was done right. ( $12,000 in receipts with the car) I even have a dyno sheet. (270/375 at the wheels) the car has a strange hiccup thing. It sounds like a missfire but it's not all the time. The idle suffers sometimes but then it clears up. I unplugged the maf and it still idled bad. I checked for vacuum leaks and saw nothing. The fuel pressure gauge is broken on the rail (from before the rebuild). It ran great when I got it up until about a week ago. I have full gauges and my egt is reading about 1,000 at cruise. It will get really bad sometimes and I swear its back fired through the intake a few times. It doesn't just miss, it seems like it actually slows the car down when it does this. My tranny seems fine/lock up is working properly. I traded a "cherry" 500 hp el camino for this and I could use some help. This is my first fuel injected performance car so I have no scan tool yet but in a few weeks I will get a turbo link for my laptop..................thanks. Plus I checked the coils and they ohmed out ok.

Last edited by Josh Watson; 08-01-2006 at 03:04 AM.
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Old 08-01-2006, 09:30 AM
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Default Re: About to break something

Some likely culprits:
  • Chip improperly seated in the ECM (I've seen this a LOT as they get older)
  • Loose grounds on the back of the pass. side head
  • Positive battery cable under the header grounding to frame
  • Loose connection of ground to turbo bracket
  • Corrosion on ECM terminals in the kick panel (water runs down if the drain holes are plugged)
  • Loose connector on ignition module
  • Failing crank sensor
  • Failing ignition module
  • Weak coil pack
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Old 08-01-2006, 02:05 PM
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Default Re: About to break something

Thanks for the info........I check for trouble codes (manual method) and am reading a 34........I'm friends with the guy I got the car from and he has replaced the maf 2 times in the last 10,000 miles (over a 6 year period). Is this normal? btw I appreciate this site.............I'm lost already but it would be o-so-much worse without this resource.....thanks
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Old 08-01-2006, 03:18 PM
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Default Re: About to break something

Not really "normal", but not surprising either ... especially if they were remanned units.
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1987 GN original owner 650+ HP Black
2015 BMW 328xi XDrive wagon
2012 Volkswagen Tiguan (the Tig!) Night Blue Met (sold)
2006 Trailblazer SS Red Jewel Tint 395 HP AWD (sold)
2014 Silverado LTZ Crew 4WD
2012 Honda VFR 1200F Tahitian Blue (sold)
2015 BMW S1000R Racing Red
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Old 08-01-2006, 04:37 PM
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Default Re: About to break something

The HP numbers seem low, how much boost are u running ?
With scan tool data like "direct scan" we can nip this in bud. I also recomend upgrading to a MAF translator with a LT1 or LS1 maf
did you make sure the blow off valve is leaking or stuck open?
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Old 08-02-2006, 04:13 AM
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Default Re: About to break something

I checked the positive cable by the exhaust and it was stuck to it and burned about half way through. I fixed this and I thought it cleared up everything for a while. It still is sputtering but very little and not nearly as violent. I am SUPPOSED to be running 15lbs of boost but it is not holding (I've seen it try to overboost so I never give it full throttle). I can hold it for as long as I want but when the peddle is on the floor I can see it try to overboost and I can feel the car slow down (I think the computer is pulling timing). I suspect something is up with the blow off valve, it is supposed to be adjustable but even on the "quiet" setting it is very loud. What kind of numbers should I be looking for on the dyno? I have access to one and when I get things cleared up I'll be going.Thanks for the help. I know we are getting off subject and I am re-posting parts of this in the turbo area.
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Old 08-02-2006, 06:07 AM
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Lightbulb Re: About to break something

Quote:
Originally Posted by Josh Watson
I suspect something is up with the blow off valve, it is supposed to be adjustable but even on the "quiet" setting it is very loud.
Certain people here know how I feel about blow off valves. Where is this one mounted? IMHO, they are not needed on these cars. Especially a stock car. People add them as a noisemaker. (ala 18 second Hondas) Then when they stick open, they cause problems. I say cut out a piece of thick aluminum, remove the valve, leave the gasket, and use it to cap the hole. Voila! No more blow off worries!

No telling what your power/torque should be. Depends on how well it is tuned. See the 'Performance Recipes' on the web pages for some buildup ideas and tuning combinations.
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Old 08-02-2006, 07:57 AM
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Default Re: About to break something

Quote:
Originally Posted by Keller
Certain people here know how I feel about blow off valves. Where is this one mounted? IMHO, they are not needed on these cars. Especially a stock car. People add them as a noisemaker. (ala 18 second Hondas) Then when they stick open, they cause problems. I say cut out a piece of thick aluminum, remove the valve, leave the gasket, and use it to cap the hole. Voila! No more blow off worries!

No telling what your power/torque should be. Depends on how well it is tuned. See the 'Performance Recipes' on the web pages for some buildup ideas and tuning combinations.
Or just replace the blow-off valve with a bypass valve. Much more usable on auto car that a blow valve.

Blow off valves best purpose would be on a manual gearbox vehicle to hold boost in between shifts.
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Old 08-02-2006, 08:35 AM
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Thumbs up Re: About to break something

I agree.

But not having it at all means it can't fail.
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Old 08-02-2006, 08:40 AM
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Default Re: About to break something

i agree. Im not running one anymore. It cause more problems then they are worth on the turbo buick
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