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My 1982 23000 miles all original runs with no knocking when driving engine cold. When the engine nears operating temperature it knocks when accelerating and have to back off the gas to reduce the knocking. Any ideas.
Spark knock?? Like pinging? Rod knock??. Perhaps a little better description might help. were not there. Not hearing it.
Rod knock could be very bad. That low of miles on that age of car says its done a lot of sitting. That's potentially very bad for any machine.
Spark knock?? Like pinging? Rod knock??. Perhaps a little better description might help. were not there. Not hearing it.
Rod knock could be very bad. That low of miles on that age of car says its done a lot of sitting. That's potentially very bad for any machine.
My 1982 23000 miles all original runs with no knocking when driving engine cold. When the engine nears operating temperature it knocks when accelerating and have to back off the gas to reduce the knocking. Any ideas.
For starters, if your engine’s timing has been advanced too far (did you recently have a Technician tune it up?) it can cause knocking, especially on acceleration. Earlier this summer I also experienced a mild but noticeable predetonation knock when I forgot to use 93 octane gas. While the engine is designed for standard octane fuel, I installed a Hypertech “Streetrunner” ECM chip a few years ago to help optimize its performance/shifting that was constrained due to the CAFE/technology limits of the day. The Streetrunner chip’s strategy uses more advanced timing, and requires me to burn 93 octane fuel to avoid knocking. It is not a big deal (although I silently curse Biden everytime I get gas).
As an aside, in the unlikely case that it is caused by a defective knock sensor, I understand that, that particular, normally reliable sensor can be challenging to find.
Suspect a knock sensor, poor gas quality and/or a firing issue. Start with the simple stuff - add some gas treatment and high octane fuel. Then I'd pull the plugs and look for signs of unburned fuel or low spark (bad wire). Agree with others on timing advance. Check to ensure the wire (brown in color - see picture below - the one with a quick disconnect) is connected. Has to do with spark advance.
You car has a 9:1 compression ratio. This should be okay on 91 octane.
You may be experiencing carbon build up in the cylinders acting like 'hot-spot' which contribute mightily to pre-ignition (pinging).
As Lakeside said (minus the Biden comment) The old 82 knock sensors are an ANCIENT analog to digital design. They use a pendulum tuning fork design to induce a current as they pendulum weights vibrate due to knock.
These are currently the most 'unobtainium' part for the 82.
Both Buccy and I have done exhaustive research into this part.
This is a DELCO part and cannot be brought back into production. (We tried).
I have a cross-check list and the closest you'll find is the LG-4 305 Camaros/firebirds.
Timing +Octane + knock sensing+ de-carbonizing the cylinders.
Are you seeing a Check Engine Light (CEL) on the dash? Does the CEL indicator still work? The OBD system should cause the CEL to illuminate if 'pinging' is detected. You might want to check for any trouble codes thrown by your ECM.
Your problem could be as simple as some 'cheapo' gas station accidentally (or intentionally) put regular fuel in their mid/high grade fuel tank; or a sensor in your engine is faulty; or the ECM has a corroded ground connection. Lots of possible faults....but they all point to an ignition timing problem caused by the ECM getting faulty data, a mechanical issue with the ignition system, or the ECM being the issue.
Set the timing per the GM manual.......if you pan on keeping this car, get a GM service manual for it......
If someone tried to set the timing like a non-computer Vette.....it will be very advanced......the computer can only "pull" so much timing......too far advance puts it out of its window.
Start with checking base timing with the single wire connector un-connected near the distributor , this puts it in base timing , plug the connector back in when done , if timing is good then the EGR tube needs checked for blockage , you will need a scan tool more than likely to determine if knock sensor works or not but those two things can be checked easily with out scan tool
I'll say it again, start with the simple fix before moving to the complex. You may eventually determine you need to pull the throttle bodies, but you need to know what you're getting into when doing that. For example, you'll have to balance/synchronize them when reinstalling them. I've never had to do that but its a complex procedure. Going on 25 years with 2Tone82 and the most I've had to do was pull the top-plate to repalce the gasket that had gone bad near the EGR mount. Fairly common I later discovered but I chased the issue for some time before finding the problem. Take your time and good luck on getting her running right. Great color choice by the way!
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
If you do decide to pull the TBs, the balancing procedure is rather simple actually. There is no Voodoo magic in this stuff. Here is the "down and dirty" on how to do it. Watch both vids. These are taken from my site. Enjoy and learn.
You car has a 9:1 compression ratio. This should be okay on 91 octane.
You may be experiencing carbon build up in the cylinders acting like 'hot-spot' which contribute mightily to pre-ignition (pinging).
As Lakeside said (minus the Biden comment) The old 82 knock sensors are an ANCIENT analog to digital design. They use a pendulum tuning fork design to induce a current as they pendulum weights vibrate due to knock.
These are currently the most 'unobtainium' part for the 82.
Both Buccy and I have done exhaustive research into this part.
This is a DELCO part and cannot be brought back into production. (We tried).
I have a cross-check list and the closest you'll find is the LG-4 305 Camaros/firebirds.
Timing +Octane + knock sensing+ de-carbonizing the cylinders.
Unkahal
Good info. In your own experience will an LG-4 (Delco) satisfactorily function? Any trade-offs/side-effects? Thanks in advance.
A little more information. The CEL works fine. A complete tune up was done recently. I only use Shell 91. I had to replace the faulty O2 sensor which was causing the engine to dump extra fuel and blackened the plugs severely. A ton of black carbon was burned off and plugs replaced . No smoking at all now. Car runs well otherwise except when stopped and in gear it runs rough like it has an upgraded cam, which it doesn't. Intake gasket replaced a year ago.
Crossfire knocking when accelerating
