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This sure seems to be getting complicated. All you need to do is monitor your 02 reading, block learn, knock sensor and other sensor readings. A simple scanner will give you that information without the complexity of this gizmo. Sometimes simpler is better.
No doubt about that!
Can I do these tests at idle or do I need someone to watch the readings while driving?
The mechanic that drove with me last week said the knock sensor was working and the 02 sensor was normal. He only commented on those two things.
You need to see what is going one while driving with the engine under load. You should also do what makes it ping and see if you can get that recorded. With TTS Datamaster you can record and save a log, then go back and watch it so you dont have to keep an eye on it while driving.
Remove the spark plugs & look at the porcelain around the center electrode this is referred to as "reading the plugs" it will indicate what the engine is doing. Example: if white with black pepper spots the engine is lean. Google how to read plugs or post pix here a forum Guru will advise.
Engine hot & @ idle: Use WD40 with the supplied straw, spray along all intake gaskets, a change in rpm = a vacuum leak causing a lean condition. If the engine was not assembled correctly or incorrect gaskets were used the WD will indicate a problem area.
Brake booster make any noise when brakes applied? Brakes work ok & pedal height constant when applied? A bad booster = a vacuum leak.
Was the EST wire disconnected when the timing was set?
Check the TPS voltage it needs to be .54 V @ base idle. Procedure is on this forum.
Octane should not be an issue your owners manual states that the engine will run on regular fuel but performance will be reduced. You were advised to change the knock sensor.
Your 6sp Vette has a dual mass flywheel, if the engine does not idle perfectly smooth the flywheel can make a knocking noise.
91's are speed density check the IAT sensor ohms.
Engine should run ok when @ Pikes Peak or Death Valley.
Remove the spark plugs & look at the porcelain around the center electrode this is referred to as "reading the plugs" it will indicate what the engine is doing. Example: if white with black pepper spots the engine is lean. Google how to read plugs or post pix here a forum Guru will advise.
Engine hot & @ idle: Use WD40 with the supplied straw, spray along all intake gaskets, a change in rpm = a vacuum leak causing a lean condition. If the engine was not assembled correctly or incorrect gaskets were used the WD will indicate a problem area.
Check the TPS voltage it needs to be .54 V @ base idle. Procedure is on this forum.
Octane should not be an issue your owners manual states that the engine will run on regular fuel but performance will be reduced. You were advised to change the knock sensor.
91's are speed density check the IAT sensor ohms.
Unless it is really out of spec grossly, would you be able to read it? The ECM changes things so it might cloud the water some.
Why not brake cleaner or even starting fluid if you are careful? WD40 leaves a mess.
Procedure requires that everything but the Idle is I spec. I prefer to use IAC counts while would be more accurate and lets me know if there is a leak.
It will run but retard the timing till it can no longer do it when it hears pinging BEFORE you do.
I'd scan it and see what the ECM sees and hit the sensor with an infrared thermometer. Repeat with coolant temperature sensor
I need a new serial adapter the one that came with the scanner won't work with a printer so I'm out of the water on that till I can get to the store later today and then one of the first things I want to do is find out whether this pinging occurs when the engine is cold or hot that was recommended by one of the members so if it's cold and it does it that would indicate one thing and if it has to be hot only when it does it that would indicate something else according to this other member.
Took the car out today cool 70 outside. Car stayed cool for 30 minutes an no discernable pinging. Once it got hot even though it cooled down and got hot and cooled down it pinged no matter what the temp was.
Went to dinner let the car cool off for an hour got back in drove it home no pinging whatsoever.
Took the car out today cool 70 outside. Car stayed cool for 30 minutes an no discernable pinging. Once it got hot even though it cooled down and got hot and cooled down it pinged no matter what the temp was.
Went to dinner let the car cool off for an hour got back in drove it home no pinging whatsoever.
Took the car out today cool 70 outside. Car stayed cool for 30 minutes an no discernable pinging. Once it got hot even though it cooled down and got hot and cooled down it pinged no matter what the temp was.
Went to dinner let the car cool off for an hour got back in drove it home no pinging whatsoever.
Retard the timing 2 degrees and see if it goes away.
The above picture is what I have to deal with with the new printer all the cabling and connections and everything to the cigarette lighter and to serial adapters and to the MT2500 scanner itself you have to print from the car unless you have the super power pac which gives you constant power all the time. With that you can print inside the house with an AC adapter otherwise you're out in the car printing.
I need a cigarette lighter adapter and there's only a place for one in a Corvette so I ordered one tonight that has three you have to plug in the adapter for the connector to the OBD1 you have to plug in the other one to the printer so I can't do anything until I get that. Everything else is all working the printer prints out all of the dip switch settings that I set to make it work with the scanner everything looks good I just need a dual or triple cigarette lighter splitter adapter which will be here Tuesday. After much digging and research this particular scanner only prints when it's connected in the car to the scanner unless you have the super power pac which powers it all the time and lets you print off all of the movies and other saved information from within your house through an AC adapter. I can't find one on eBay currently the last one sold for about 30 bucks. So as it is now I'm stuck with having the printer and the scanner and both of those connected to two cigarette lighter receptacles in order to print off saved information frame by frame or movies but only in the car. I also need a serial adapter that I'm missing that I won't get till Tuesday or I can get it from the computer store.
The above picture is what I have to deal with with the new printer all the cabling and connections and everything to the cigarette lighter and to serial adapters and to the MT2500 scanner itself you have to print from the car unless you have the super power pac which gives you constant power all the time. With that you can print inside the house with an AC adapter otherwise you're out in the car printing.
I need a cigarette lighter adapter and there's only a place for one in a Corvette so I ordered one tonight that has three you have to plug in the adapter for the connector to the OBD1 you have to plug in the other one to the printer so I can't do anything until I get that. Everything else is all working the printer prints out all of the dip switch settings that I set to make it work with the scanner everything looks good I just need a dual or triple cigarette lighter splitter adapter which will be here Tuesday. After much digging and research this particular scanner only prints when it's connected in the car to the scanner unless you have the super power pac which powers it all the time and lets you print off all of the movies and other saved information from within your house through an AC adapter. I can't find one on eBay currently the last one sold for about 30 bucks. So as it is now I'm stuck with having the printer and the scanner and both of those connected to two cigarette lighter receptacles in order to print off saved information frame by frame or movies but only in the car. I also need a serial adapter that I'm missing that I won't get till Tuesday or I can get it from the computer store.
For now, will it scan? If it does, you can observe the knock counts. Sure, it will hear knock but if you go over a limit, it could be an issue. I'm not sure what to tell you since my car isn't stock by a long shot so whatever I tell you may not be accurate. OTOH, if you tell others what you have roughly, they might be able to help you.
Depending on what your temps are, you might be able to even dump something like "Motor Honey" or whatever they have to thicken the oil and see if you get reduced knocking. Or like someone said, lower the timing and test. But without a scanner on it, all we know is you say you have knocking and not what the ECM thinks.
Also get a scanner on the IAT and CTS to see if they are reporting correctly to the ECM. It has to agree with a thermometer. Best is an infra red thermometer.
For now, will it scan? If it does, you can observe the knock counts. Sure, it will hear knock but if you go over a limit, it could be an issue. I'm not sure what to tell you since my car isn't stock by a long shot so whatever I tell you may not be accurate. OTOH, if you tell others what you have roughly, they might be able to help you.
Depending on what your temps are, you might be able to even dump something like "Motor Honey" or whatever they have to thicken the oil and see if you get reduced knocking. Or like someone said, lower the timing and test. But without a scanner on it, all we know is you say you have knocking and not what the ECM thinks.
Also get a scanner on the IAT and CTS to see if they are reporting correctly to the ECM. It has to agree with a thermometer. Best is an infra red thermometer.
Until I get the rest of the connectors for the printer I can go ahead and drive around and record a movie on a road test and then go home and sit in the driveway and review the knock retard and knock counts and write down whatever ranges there are for that and then come into the house and then post that. Again to reiterate even though it's saves everything in memory you can't review it in the house unless you have a super power pac it has to be reviewed in the car or printed in the car.
Didn't get around to it today sometime hopefully Tuesday the 10th of October 2017.
Here are some figures while the engine was hot and gunning the engine. This will have to do for a start. See the bottom of this page for 7 frames of MT2500 data while driving(reply #136).
42 Electronic Spark Timing (EST) Problem
Exhaust Oxygen varied between Rich Lean back and forth
Block Learn 155 - 157
02 Ready Crosscount 10
RPM 725 (recommended 700)
Knock No then Yes when gunning the engine, mostly No
Knock Retard 0 - 5 when gunning the engine
Spark Advance 6 at idle, 6 - 34 when gunning the engine
Maybe recently timing the car cause the Code 42 when that connector is disconnected in order to time the car maybe I should reset it with the MT2500 there's a section that says reset codes and see if it returns.
Block learn indicates its lean. Cross counts are low but at least you have some. Fuel pressure? Does O2 sweep from below.100 to above .900? Tune may correct since this seems to centers around rebuilt engine.
Do not floor your car in 5th gear at 53mph. No wonder you hear knock. 2nd or 3rd is fine. Even 4th gear is too high a gear at that mph. Lugging the motor at wot is bad.
Here is an MT2500 recording with frames -10 0 5 10 15 20 and 25 I skipped some frames because this would rather be a long post otherwise but it gives you an idea on flooring this at about 50 miles an hour in 5th gear what the different readings are particularly the knock retard went from 1 to 4 during this test so you need to read everything left to right you'll have to expand it in order to read the text of course and then the last one underneath the single one is the last frame whick is frame 25.
Just bought a wireless endoscope with an adjustable led light attached for 30 bucks. I can tape it under the hood and focus it on the already there fuel pressure gauge and record the readings to see if I stay above 40 psi when I punch it on the entrance ramp. Will report back as soon as I record it this weekend.
Here is an MT2500 recording with frames -10 0 5 10 15 20 and 25 I skipped some frames because this would rather be a long post otherwise but it gives you an idea on flooring this at about 50 miles an hour in 5th gear what the different readings are particularly the knock retard went from 1 to 4 during this test so you need to read everything left to right you'll have to expand it in order to read the text of course and then the last one underneath the single one is the last frame whick is frame 25.
Without going through 135 older posts is the RPM really 2200, is it really closed loop at WOT? Did you ever check to see if TDC is marked correctly? Empty tank and run different fuel?
I was recently reading a TOMCO TECH TIPS and it was talking about how a faulty EGR can cause pinging on engines. It is issue #9 that talks about EGR problems making the engine ping more.
The first explains how the "Positive back-pressure" EGR valves operate.
The second mentions that the cars had carbon blocking vital passages to the EGR preventing it from working or in some cases working too much. This has important information regarding the pinging part.
Read the information on the links and it might help you come to a solution for your car.
On my 1988 Coupe the EGR passages were entirely blocked with carbon as was the little hole on the pintle. I had to remove the upper intake components to clear out the carbon blockage. I used a sand blaster with high pressure air to clean it out once and for all. After reinstalling the EGR, the EGR solenoid valve (Vacuum control) and the upper intake my EGR system is now fully functional again.
This might be a shot in the dark but it offers another plausible way for your car to be pinging as much as you say it does.
By the way, Tomco's TECH TIPS are a wonderful place to learn about how each part of our fuel injection system works with each other.
I wish you the very best of luck in solving your car's issues!
10-06-2017, 01:52 AM
