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The computer on these cars are slow .If you get a knock or 2 after stabbing the throttle you are probably chasing something that will never be fixed.If you stay in the throttle from 2500 to 5000 rpm and it knocks the whole time you have a problem.Still sounds like some basic functions have been missed and you went straight for the computer.
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?
According to the scanner at 62 miles an hour in 5th gear floored it was 2200 RPM. I started acceleration at approximately 51 miles per hour in 5th gear on the highway and with a warm engine and took it up to 73 miles per hour before ending the recording of the scanner movie. The timing was just adjusted from 9 before top dead center to 6 before top dead center and the tests have been with it at 6 below top dead center. Someone who burns chips for high performance cars told me to test it to see whether it's occurring when the engine is cold or warm and it's positively when the engine is warm/hot and has gotten up to 105 to 109 Celsius mark. When it's cool no ping. I plan on putting in a cooler thermostat and having the PCM chip burned to turn the fans on below 200 degrees so the engine never gets hot at all I can always afford to buy new fans.
Collectively the other few tests that I'm supposed to do here according to people that performance tune cars for a living is I'm supposed to record the fuel pressure when I floor it I'm supposed to get the number off the oversized injectors somebody put in there and I'm supposed to pull out the piggyback chip and send it in to see what's actually on it since somebody probably or most definitely had to have a PCM chip burned when they put in oversized injectors. Otherwise the engine is supposedly stock and just recently in the last Thousand Miles had a upper rebuild in regards to valves and the Rebuilder thought that the bottom half of the engine or the short block looked good the cylinder walls had hash marks in them etcetera so they didn't bother with that but they put all new top quality gaskets and seals throughout.
The knock isn't bad at all but it definitely pings it doesn't lug at all just pings when the engine gets hot up around 228 degrees f and then it doesn't matter even if it cools off it still pains after that until you let it have a complete rest of an hour or so but I'm doing a lot of this for fun in that I've been talking to a couple of PCM chip burners and they have their own ideas about what to do I think I really want to keep the engine cooler by turning the fans on under 200 degrees I'd say I wanted to that first and I think maybe putting in a cooler thermostat the one particular chip burner says from the readings that showed him so far he thinks the engine is running lean and he doesn't know what's causing that it will be fun to get the endoscope and be able to see what the actual fuel pressure is since the gauge is already sitting under the hood attached to the fuel rails it's just how do you see a gauge under the hood when you're driving.
I'm slow it implementing some of the suggestions I'm getting I'm not mechanical I do have two mechanical friends who assist me and with the help of the Forum and the friends I've gotten the corner of my hood which stuck up three quarters of an inch fixed the driver's door door locks and the passenger side door door locks didn't work those are fixed cruise control is fixed drivers power seat is fixed 1 inch play in the steering wheel vertically so the brights didn't come on and wouldn't pass inspection is fixed leaky grommet on the valve cover is fixed.
So really a lot of this I could not have done without Forum suggestions that I passed on to the two mechanic friends as they're not interested in Reading anything on the Forum as they don't have Corvettes so I'm making progress I bought the car back in March and I've had a number of things fixed and understand more about how the car is working so I want to continue on I have a list of about 5 more things that I want to address and it's fun dialoging this out because of it makes you think more of things that you wouldn't think of otherwise and plus valuable information that you can apply to the actual fix or repair.
The knock isn't bad at all but it definitely pings it doesn't lug at all just pings when the engine gets hot up around 228 degrees f and then it doesn't matter even if it cools off it still pains after that until you let it have a complete rest of an hour or so but I'm doing a lot of this for fun in that I've been talking to a couple of PCM chip burners and they have their own ideas about what to do I think I really want to keep the engine cooler by turning the fans on under 200 degrees I'd say I wanted to that first and I think maybe putting in a cooler thermostat the one particular chip burner says from the readings that showed him so far he thinks the engine is running lean and he doesn't know what's causing that it will be fun to get the endoscope and be able to see what the actual fuel pressure is since the gauge is already sitting under the hood attached to the fuel rails it's just how do you see a gauge under the hood when you're driving.
I have a gauge with a hose taped to the glass. I don't have much experience with the gauges on the rail. I had a few that sucked on my diesel and gave up on them. Even the expensive ones didn't hold.
I have a gauge with a hose taped to the glass. I don't have much experience with the gauges on the rail. I had a few that sucked on my diesel and gave up on them. Even the expensive ones didn't hold.
Have you figured out what the injector size is?
If the readings off the fuel pressure gauge don't seem good I'll do what you have as that's what the other person recommended was that I get a Harbor Freight fuel pressure gauge and attach a 4 foot hose to it and then duct tape it to the front windshield of the Corvette.
No I haven't figured the injector size out I I don't know how to take the injector out of the car and haven't researched it I must do that though and I won't forget I follow through on these posts and go back to them even months later to correct and update things so people that read them in the future we'll get some value out of our discussions rather than leaving them half finished with no resolution.
I'm not sure whether I should take the injector out or have my friend take it out I need to watch a YouTube video on it.
I guess we'll find out what fuel pressure readings I'm getting I don't know how good the gauge is it screwed right into where I supposed to be screwed into according to videos I've seen and it normally reads about 40 with the engine idling but the guy that burns chips wants me to punch it in maybe 3rd gear and take it up maybe 20 miles an hour or so higher than what I start at and give him the readings off of the fuel pressure gauge.
The computer on these cars are slow .If you get a knock or 2 after stabbing the throttle you are probably chasing something that will never be fixed.If you stay in the throttle from 2500 to 5000 rpm and it knocks the whole time you have a problem.Still sounds like some basic functions have been missed and you went straight for the computer.
One reason that we gone straight for the computer on this instead of addressing some basic functions is that the engine and whole drivetrain has recently been out of the car in the last thousand miles sitting on a rack with the upper part of it being rebuilt with new seals and gaskets new valve parts person I bought it from said the heads are straight as an arrow there still hash marks inside the cylinder wall so we didn't touch the lower half and he put on new fuel pump new distributor all kinds of tune up parts throughout so the basic functions I think have been covered by the previous owner hopefully he's a line mechanic in a dealership for the last 30 years or 20 years and did an adequate job hopefully.
Picture of my fuel gauge that is permanently attached to the engine that I'm going to use the borescope endoscope on to get the readings from it when I floor it off the entrance to the highway.
Might be easier to disconnect the gauge and use a gauge with a hose taped to the glass. Why go through all that for one simple WOT test? I don't even think you need the gauge for much to bother with reinstall other than it looks like it does something since you can't read it while driving and we need to see if the pressure holds up under load.
Might be easier to disconnect the gauge and use a gauge with a hose taped to the glass. Why go through all that for one simple WOT test? I don't even think you need the gauge for much to bother with reinstall other than it looks like it does something since you can't read it while driving and we need to see if the pressure holds up under load.
I already ordered the borescope that's wireless so I can see on my phone what's happening with the pressure gauge, the mechanic friend of mine wants to use it for all kinds of things so I'll keep it just for different kinds of things you can look in walls and down drains and all kinds of things to see what's happening because it's a lighted borescope other than that I was wondering if you get a Harbor Freight fuel pressure gauge and you put a 4 ft hose on it and connect it where the existing gauge is will it fit under the front of the Hood by the windshield without crimping?
Here's an external fuel pressure gauge hooked up checking pressure under load from someone else on YouTube:
I already ordered the borescope that's wireless so I can see on my phone what's happening with the pressure gauge, the mechanic friend of mine wants to use it for all kinds of things so I'll keep it just for different kinds of things you can look in walls and down drains and all kinds of things to see what's happening because it's a lighted borescope other than that I was wondering if you get a Harbor Freight fuel pressure gauge and you put a 4 ft hose on it and connect it where the existing gauge is will it fit under the front of the Hood by the windshield without crimping?
Those looking like 30 pph which are not stock. What fuel pressure? ECM has to be adjusted CORRECTLY for that.
end of aklim comments
I need to get the number off of one of the oversized injectors for the guy who burns PCMS is there one injector that's easier to remove and do I have to remove the injector or is there anyway I can stick any kind of a mirror around it to get the number off of it?
I ordered and tried out the wireless borescope to capture the fuel pressure under the hood while I was driving and it freeze framed on me so I sent it back and I opted for one that had 30 frames I guess per second they said that most of the other ones were 10 frames and they would freeze but their's would not freeze frame so I have to wait till tomorrow and then I'll try the whole thing over again.
I ordered and tried out the wireless borescope to capture the fuel pressure under the hood while I was driving and it freeze framed on me so I sent it back and I opted for one that had 30 frames I guess per second they said that most of the other ones were 10 frames and they would freeze but their's would not freeze frame so I have to wait till tomorrow and then I'll try the whole thing over again.
Just get a fuel pressure monitor gauge with a hose. Screw it onto the schrader valve. Drive around with it sticking out the back of the hood at the base of the windshield. You are really making harder than it needs to be. Focus on the task instead of going off onto these tangents. This one should work.
Just get a fuel pressure monitor gauge with a hose. Screw it onto the schrader valve. Drive around with it sticking out the back of the hood at the base of the windshield. You are really making harder than it needs to be. Focus on the task instead of going off onto these tangents. This one should work.
The second one I ordered came today and it also froze up on me so I'm back to what you guys suggested an external one taped to the windshield the only question I still have is when I close the hood is it going to crimp the hose?
The second one I ordered came today and it also froze up on me so I'm back to what you guys suggested an external one taped to the windshield the only question I still have is when I close the hood is it going to crimp the hose?
Do you have to have the hood closed for a WOT run? If it sits on the hood temporarily, it won't do any harm. I wouldn't drive like that but just one run in a straight line won't hurt.
I've accidently made a number of passes over the years at the track with my hood closed, but not latched, reaching 130mph. I can verify it doesn't fly open. Just close the hood, don't slam it. The hood will hold the hose in place without crimping it.
10-26-2017, 12:27 PM
