07-04-2016 | #1 |
Join Date: Mar 2013
Location: Roswell, GA
Posts: 233
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1992 ZR1 Seems Sluggish
Car was running fine the last time I dove it. It has been about 6 weeks since then. I usually disconnect the battery as well. When I went to start it the battery was about dead, not enough juice to turn it over. I hooked up my remote charger and she fire right up with the usually guide chain rattle for a few seconds but this time she barked out a bit or smoke momentarily but that cleared up. When I drove it, it seemed to lack power, it idles fine but when I give it some gas, it is unresponsive. It feels like i am driving on 4 cylinders. The idle is smooth, there has always been a slight vacuum leak, the pump runs once every 2.5 seconds with engine off and when running maintains a steady 17" of vacuum. There is spark on all 8 cylinders. The car is drivable with no engine codes. The only thing left I can think of is bad or fowled fuel injector....or the fact I have been driving my 700 HP 434 cuin C3 around all week....
Any thoughts?
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1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp |
07-04-2016 | #2 |
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,193
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Re: 1992 ZR1 Seems Sluggish
Is that a 454 C3 ?
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07-04-2016 | #3 |
Join Date: Mar 2013
Location: Roswell, GA
Posts: 233
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Re: 1992 ZR1 Seems Sluggish
Yes, it is a 434 small block.
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1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp |
07-04-2016 | #4 |
Join Date: Jan 2015
Location: Marietta, GA USA
Posts: 1,160
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Re: 1992 ZR1 Seems Sluggish
A guess (I think I've heard other people mention this) - The small backfire pushed the vacuum tube off the back of the plenum, and the fix is to simply slip it back on.
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07-04-2016 | #5 |
Join Date: Feb 2012
Location: Ledyard,CT
Posts: 8,193
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Re: 1992 ZR1 Seems Sluggish
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07-05-2016 | #6 |
Join Date: Mar 2013
Location: Roswell, GA
Posts: 233
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Re: 1992 ZR1 Seems Sluggish
Hello Russ, I checked all the tubes that can be seen.... my vacuum pump test with the car off runs at the same frequency it always has and my vacuum at idle is steady at 17". I am thinking the vacuum is likely not the culprit here. I guess I will just run the car some more maybe put in a can of injector cleaner and check the plugs before I pull the plenum and have a look around. Also going to pull the plastic intake and take a look at the throttle blades. I guess that is the best way to describe how it feels.... like I am pushing the pedal but the throttle blades are not opening up in a proportional manner.
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1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp |
07-05-2016 | #7 |
Join Date: Nov 2011
Location: Dunbarton NH
Posts: 7,418
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Re: 1992 ZR1 Seems Sluggish
The vacuum line Russ is refering to is right at the back of the plenum. It tends to blow off with a backfire. Unrelated to the vacuum pump.
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07-05-2016 | #8 |
Join Date: Mar 2013
Location: Roswell, GA
Posts: 233
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Re: 1992 ZR1 Seems Sluggish
Understood, the line is definitely still connected.
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1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp |
07-07-2016 | #9 |
Join Date: Mar 2013
Location: Roswell, GA
Posts: 233
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Re: 1992 ZR1 Seems Sluggish
Took it out for another drive yesterday. Ran better but still hesitates at times.
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1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp |
07-07-2016 | #10 |
Join Date: Aug 2012
Location: Ellicott City, MD
Posts: 1,688
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Re: 1992 ZR1 Seems Sluggish
I have a 92 and same except that it starts to stumble badly around 3000 RPM. Think it is the common fuel pump issue. Just purchased a pair from RockAuto and hope to install them this weekend. Will let you know if this is the cure, I hope so.
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Charlie __________ Dredgeguy WAZOO Member 1992 Bright Red/Black ZR1 #246 Dana 4:10 gears Polished LT5 by Haibeck Polished Fikse FM5's with Michelin Pilot Sport 2 Stainless Works headers and cats with Corsa |
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