05-15-2016 | #41 |
Join Date: Aug 2014
Location: Trois-Rivieres (QC)
Posts: 473
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Re: Low RPMs bucking
Update:
Removed fuel pumps assembly and visually inspected it. Everything seems to be fine. Went under the car to double-check the fuel filter (without success), I found something interesting instead. https://www.youtube.com/watch?v=fHqLdS43baU One of the wire in the o2 sensor connector is loose, as you can see in the video. I'm going to fix it tomorrow morning (will replace the connector). It is the passenger side o2 sensor, it probably explains why I got code 64 showing up (and why I had the code only since I replaced the fuel filter. The connector is fixed to the fuel line... I probably broke it while working on the fuel filter). But I'm still scared about the knocking noise. Started the car this morning to park it in and out of the garage and I didn't hear the noise, but it is still a concern. |
05-15-2016 | #42 |
Join Date: Aug 2010
Location: ottawa canada
Posts: 156
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Re: Low RPMs bucking
Monitoring your situation & progress/ frustration! I'm closer than T.O. being in Ottawa area so if I can help in anyway.
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05-15-2016 | #43 |
Join Date: Aug 2014
Location: Trois-Rivieres (QC)
Posts: 473
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Re: Low RPMs bucking
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05-15-2016 | #44 |
Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
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Re: Low RPMs bucking
I'm back. See additional info on my earlier post.
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Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry |
05-15-2016 | #45 |
Join Date: May 2016
Location: Whangarei New Zealand
Posts: 29
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Re: Low RPMs bucking
I just logged into this forum. After reading the site for the last year Ive just joined.
Ok, the knocking sound you have is the clutch unit on the AC compressor. Not a biggie, its just rattling around as you will see if you get closer and have a look. Thats why the sound will come and go. I had the same thing on mine, and I just replaced the clutch unit and its sweet as now. |
05-15-2016 | #46 | ||
Join Date: Aug 2014
Location: Trois-Rivieres (QC)
Posts: 473
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Re: Low RPMs bucking
Quote:
I changed the fuel filter (which is behind the front passenger wheel housing). I'll try to find a fuel pressure gauge extension to run a dynamic test. Or, even easier would be to buy 2 new pumps at RockAuto... I can't tell you at which temperature I tested the resistance of the injectors, I don't remember. I add this to my todo list (after changing the o2 sensor connector). I tested the resistance using this diagram: For the TPS: can't I unplug it and hook a multimeter in the TPS plug to see the voltage fluctuation? What's a VOM? For the o2 sensor test, to be honest if I have to remove them I'll simply change them. Coil packs: they'll be in my todo list as well as the spark plug wires, but pretty low on the list at the moment. "Waste spark design", I think they are just like a 3.4 2000 Grand Am. And I'm pretty sure they even fit in there... Quote:
Knocking sound is irregular, so I hope I can assume it is more a rattle than a knocking sound. Actual todo list: 1. Fix o2 sensor connector. 2. Change spark plugs (I'm receiving my BKR7EIX11 plugs tomorrow, it can't hurt). I'll ask a mechanic nearby what he thinks of my old plugs. 3. Test the resistance on the fuel injectors (car hot). 4. Dynamic test fuel pressure. |
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05-15-2016 | #47 |
Join Date: Aug 2009
Location: South Dakota/California
Posts: 3,799
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Re: Low RPMs bucking
VOM is a Volt Ohm Meter among other uses of the abbreviation VOM
One of the first tests I always do is a Compression Test on Zs which does not have much to do with your issue but just saying. A compression test says a lot about the valves, Cylinders, and general wear of the engine. A compression test also says a lot about the uniformity of the wear among cylinders and uniform compression assures uniform work done by each cylinder. Your first post suggests "Severe Buckings". You have since suggested Knock. You suggested the LT5 has behaved like this for 3,000 miles. Also you suggested total power loss for a revolution or more but immediately returns to normal. I have some ideas but what I do on ALL LT5s/ZR-1s is do my typical Top End after the Compression Test (The Compression Test is conducted to make sure I do not have Bottom End Issues). Once my Top End Restorations are complete the LT5s run perfectly with NO Codes for a very long time. Part of that Top End of the LT5 includes the INFL REST restoration (the Air Bag Sensors re-grounded each side) including the Internal Wire each side. And part of that Restoration includes complete Brake Restoration and/or Installation of C5 Z06 Calipers and Rotors. Some more also but you get the idea Oh....and my favorite Modification to ALL LT5s (Block TB Coolant at the Injector Housing).
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Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 05-15-2016 at 08:31 PM. |
05-15-2016 | #48 | |
Join Date: Aug 2014
Location: Trois-Rivieres (QC)
Posts: 473
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Re: Low RPMs bucking
Quote:
I always hated doing a compression test. It's like inspecting your girlfriend while she's asleep. Not sure I want to know the numbers. But I'll do it soon... I've seen your (more than complete) threads. I like modding my cars, but I want to fix the initial problems before, or the car becomes garbage pretty quickly. |
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05-16-2016 | #49 |
Join Date: Aug 2006
Location: McLean, VA
Posts: 3,725
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Re: Low RPMs bucking
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05-17-2016 | #50 |
Join Date: Aug 2014
Location: Trois-Rivieres (QC)
Posts: 473
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Re: Low RPMs bucking
secondchance I just looked at it and it's pretty much the same for a 1991. Thanks for the reference...
Updated todo list: 1. Finally, I do not need to fix my o2 sensor connector. I went to the scrapyard to find the connector on another vehicle and they all had the same problem. Local electric shop told me it's normal, there's no problem there. 2. Changed spark plugs. To do: 3. Test the resistance on the fuel injectors (car hot). 4. Dynamic test fuel pressure. Here's a picture of the plugs. Driver's side to the left, passenger's side to the right. All the plugs from the right side (passenger side) are pitch black, it's a bit better on the left side (driver side). Why the code says that I'm running lean on the right bank? Pitch black means too much fuel, no? |
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