I have a tire pump with a pressure gauge built in, so I used the conical nipple that came with it for blowing up air mattresses, put a vacuum hose over that (maybe with a hose clamp, it's been a while), and put the other end of the hose on the fuel pressure regulator. Attached the fuel pressure gauge to the rail, used a clip lead to apply power to the fuel pump test lead behind the alternator (which is where my hot wire setup gets the trigger signal for relay), and then just slowly pumped it up while watching both gauges with the fuel pump running. If you have a compressor and a regulator that would be much nicer.
Cant Figure Out the Knock
- Thread starter GNBeswick
- Start date
Ok, first I checked the EGR. I pressed the diaphragm in almost all the way for about a second. Definitely dropped the rpms a bit but I wouldnt say it made it stumble.
Now as far as testing the regulator, I made a new pump contraption with a gauge on it and hooked it up to the AFPR. Pumped about 15 psi into it and still was losing psi at a fairly quick rate. Still stumped me because I checked and double checked the "pump" and lines I made for leaks. They all held 100+psi of pressure. So I took out the soap spray and went searching for the leak. I found it at the top of the AFPR where the screw comes out, under the tightening nut. Now my question concerning this, is it normal? At this point Im a bit frustrated because Ive gone through 3 different contraptions trying to hold pressure. So I decide to see if I cant get a test out of it even with a pressure leak.
I turned the ignition on and heard the fuel pump prime, it pushed 12 psi of pressure to the rail. I waited about a minute max and the pressure in the rail dropped to 0. Turned the ignition off and on again, heard the pump again, checked the rail psi and it was now 25psi. Started the car after about 4 cranks. Tried raising the pressure to the AFPR with my pump with the car running and while there was a pressure leak to the AFPR, the fuel pressure looked like it rose according to the pressure I pumped. Went up to about 70 psi.
I was expecting to see it drop off around 50 psi, so I was surprised. Shut the car off and checked out the rail gauge. It was 42 psi. Went inside to get something, came back out maybe 4 minutes later and it had dropped to 35psi. So I decided to stand by and watch it. Another 5 or so minutes and it was at 30 psi or so. A few minutes later its in the high 20 psi range and I went to go look at something in my cabinet (which is 5 feet from the car), turned around and the gauge was at 0. Now my sense of time may not be perfect, but I can say with confidence that the psi went from 42 to 0 in a MAX of 15 minutes. So that seems like a problem to me. I've heard that the rail psi should hold for hours. If it doesnt its a leaky injector problem. Is there any way it could be a regulator problem? My injectors are brand new and have 600 miles on them tops. When I had my old 42lb injectors I remember I checked to see how long the rail held psi and it was only about 45 minutes or so, it was at least 2 years ago I checked that. (same AFPR)
Once again sorry for another essay, but maybe someone can make sense of this because Im just confused
Now as far as testing the regulator, I made a new pump contraption with a gauge on it and hooked it up to the AFPR. Pumped about 15 psi into it and still was losing psi at a fairly quick rate. Still stumped me because I checked and double checked the "pump" and lines I made for leaks. They all held 100+psi of pressure. So I took out the soap spray and went searching for the leak. I found it at the top of the AFPR where the screw comes out, under the tightening nut. Now my question concerning this, is it normal? At this point Im a bit frustrated because Ive gone through 3 different contraptions trying to hold pressure. So I decide to see if I cant get a test out of it even with a pressure leak.
I turned the ignition on and heard the fuel pump prime, it pushed 12 psi of pressure to the rail. I waited about a minute max and the pressure in the rail dropped to 0. Turned the ignition off and on again, heard the pump again, checked the rail psi and it was now 25psi. Started the car after about 4 cranks. Tried raising the pressure to the AFPR with my pump with the car running and while there was a pressure leak to the AFPR, the fuel pressure looked like it rose according to the pressure I pumped. Went up to about 70 psi.
I was expecting to see it drop off around 50 psi, so I was surprised. Shut the car off and checked out the rail gauge. It was 42 psi. Went inside to get something, came back out maybe 4 minutes later and it had dropped to 35psi. So I decided to stand by and watch it. Another 5 or so minutes and it was at 30 psi or so. A few minutes later its in the high 20 psi range and I went to go look at something in my cabinet (which is 5 feet from the car), turned around and the gauge was at 0. Now my sense of time may not be perfect, but I can say with confidence that the psi went from 42 to 0 in a MAX of 15 minutes. So that seems like a problem to me. I've heard that the rail psi should hold for hours. If it doesnt its a leaky injector problem. Is there any way it could be a regulator problem? My injectors are brand new and have 600 miles on them tops. When I had my old 42lb injectors I remember I checked to see how long the rail held psi and it was only about 45 minutes or so, it was at least 2 years ago I checked that. (same AFPR)
Once again sorry for another essay, but maybe someone can make sense of this because Im just confused
Blown&Injected
Active Member
- Joined
- May 31, 2001
Could be a leaky injector or regulator or more likely the fuel pump is letting the pressure bleed back.
It looks like there may be some issues with the fuel system but your AFR looks good. Your plugs look OK too
It looks like there may be some issues with the fuel system but your AFR looks good. Your plugs look OK too
meanmachine
Member
- Joined
- Feb 9, 2002
Have you checked the injector timing ? Could be an issue if its that hard to start.
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Ok, first I checked the EGR. I pressed the diaphragm in almost all the way for about a second. Definitely dropped the rpms a bit but I wouldnt say it made it stumble.
Now as far as testing the regulator, I made a new pump contraption with a gauge on it and hooked it up to the AFPR. Pumped about 15 psi into it and still was losing psi at a fairly quick rate. Still stumped me because I checked and double checked the "pump" and lines I made for leaks. They all held 100+psi of pressure. So I took out the soap spray and went searching for the leak. I found it at the top of the AFPR where the screw comes out, under the tightening nut. Now my question concerning this, is it normal? At this point Im a bit frustrated because Ive gone through 3 different contraptions trying to hold pressure. So I decide to see if I cant get a test out of it even with a pressure leak.
I turned the ignition on and heard the fuel pump prime, it pushed 12 psi of pressure to the rail. I waited about a minute max and the pressure in the rail dropped to 0. Turned the ignition off and on again, heard the pump again, checked the rail psi and it was now 25psi. Started the car after about 4 cranks. Tried raising the pressure to the AFPR with my pump with the car running and while there was a pressure leak to the AFPR, the fuel pressure looked like it rose according to the pressure I pumped. Went up to about 70 psi.
I was expecting to see it drop off around 50 psi, so I was surprised. Shut the car off and checked out the rail gauge. It was 42 psi. Went inside to get something, came back out maybe 4 minutes later and it had dropped to 35psi. So I decided to stand by and watch it. Another 5 or so minutes and it was at 30 psi or so. A few minutes later its in the high 20 psi range and I went to go look at something in my cabinet (which is 5 feet from the car), turned around and the gauge was at 0. Now my sense of time may not be perfect, but I can say with confidence that the psi went from 42 to 0 in a MAX of 15 minutes. So that seems like a problem to me. I've heard that the rail psi should hold for hours. If it doesnt its a leaky injector problem. Is there any way it could be a regulator problem? My injectors are brand new and have 600 miles on them tops. When I had my old 42lb injectors I remember I checked to see how long the rail held psi and it was only about 45 minutes or so, it was at least 2 years ago I checked that. (same AFPR)
Once again sorry for another essay, but maybe someone can make sense of this because Im just confused
This may help.
Fuel System Check Up
Thanks for the link Jerryl, I forgot about that article on gnttype.org. I tried the test for the fuel regulator. Mine failed horribly. As soon as I put the ignition on and the fuel pump engaged, the AFPR started spewing fuel from the brim and under the tiny screws. It then preceded to drop psi at a very quick rate with the line clamped. So Im going to order a rebuild kit and see if that doe anything.
I have not checked the injector timing, honestly thats not something Im familiar with doing. I did however realize why the starting issue came into play right after I installed my 60lb injectors. I installed my wideband 02 sensor at the same time, and the wb 02 has to heat up before you can start the car. So Im guessing whats happening is the pump sends pressure to the rail and in the 30 seconds Im waiting for the wb sensor to heat up, the fuel has drained back to the tank.
As for the chip being burned for alky, mine is not. But even if it was I would be able to adjust the timing and fuel accordingly.
Now onto another question I have related to valve springs. In this period of about 6 months chasing the knock Ive tried to think of other issues that could cause knock. One that was brought to my attention was valve float. When parts were being gathered for my build my engine builder told me he was having trouble finding springs to match my cam (comp 218/212 roller). Eventually he found some that he said were right and I trusted him. Out of curiosity I checked the part number of the springs yesterday and compared them to what Comp suggests for Grand National roller cams. I noticed there was a slight difference in the springs I had and the springs suggested. (I also noticed the springs suggested are the ones Full Throttle sells with their roller kits)
My spring part number is: 26915 and the suggested is 26918. You can see a comparison of the two here (Scroll to the bottom for comparison) My spring seems to be a little bit weaker. My question is if the difference from the recommended spring and mine is big enough to cause a problem, or create valve float.
I have not checked the injector timing, honestly thats not something Im familiar with doing. I did however realize why the starting issue came into play right after I installed my 60lb injectors. I installed my wideband 02 sensor at the same time, and the wb 02 has to heat up before you can start the car. So Im guessing whats happening is the pump sends pressure to the rail and in the 30 seconds Im waiting for the wb sensor to heat up, the fuel has drained back to the tank.
As for the chip being burned for alky, mine is not. But even if it was I would be able to adjust the timing and fuel accordingly.
Now onto another question I have related to valve springs. In this period of about 6 months chasing the knock Ive tried to think of other issues that could cause knock. One that was brought to my attention was valve float. When parts were being gathered for my build my engine builder told me he was having trouble finding springs to match my cam (comp 218/212 roller). Eventually he found some that he said were right and I trusted him. Out of curiosity I checked the part number of the springs yesterday and compared them to what Comp suggests for Grand National roller cams. I noticed there was a slight difference in the springs I had and the springs suggested. (I also noticed the springs suggested are the ones Full Throttle sells with their roller kits)
My spring part number is: 26915 and the suggested is 26918. You can see a comparison of the two here (Scroll to the bottom for comparison) My spring seems to be a little bit weaker. My question is if the difference from the recommended spring and mine is big enough to cause a problem, or create valve float.
- Joined
- Feb 18, 2006
Have you changed the plugs?
Contrary to what I used to think, it's better to start the car right up and let the wideband warm up with the engine running. Supposedly less temperature shock. Now for the first year I had my lc1, I would let it warm up first and never had problems so take it for what it is. I would say either way is fine.
My fuel pump will not hold key on engine off fuel pressure either but does not give me any issues starting. Even if I wait for wb to warm up and fuel pressure drop. Starts up on about 3-4 turns every time.
I would look into the springs for sure. Does it seem to loose power past 4000 rpm? On your recordings, somthing is going on up there.
Wish you were closer, I could help out alot better with some hands on.
Rick
Contrary to what I used to think, it's better to start the car right up and let the wideband warm up with the engine running. Supposedly less temperature shock. Now for the first year I had my lc1, I would let it warm up first and never had problems so take it for what it is. I would say either way is fine.
My fuel pump will not hold key on engine off fuel pressure either but does not give me any issues starting. Even if I wait for wb to warm up and fuel pressure drop. Starts up on about 3-4 turns every time.
I would look into the springs for sure. Does it seem to loose power past 4000 rpm? On your recordings, somthing is going on up there.
Wish you were closer, I could help out alot better with some hands on.
Rick
- Joined
- Feb 18, 2006
You maybe on to somthing. After looking over those spring specs, the spring pressures are quite different. 105 verses 130 seat load?
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
Looking back to March you had this problem back then as well as a noisy valve train. Someone asked about the spring pressure. Bet you are floating the valves with boost pushing on them after seeing 105 as the spring pressure. I've seen 135 and up seat pressure mentioned for rollers.
Im going to give Accufab a call Monday and order a rebuild kit for the AFPR.
While thats on the way Im going to continue looking into the spring issue. Done a bit of research already and found that desired seat load is around 140lbs. My springs are rated at 105lbs at 1.800 install height. I unfortunately do not know what height they are at right now, so Im going to have to measure it. For all I know its possible for them to be set at 130lbs seat load. Depending where it is (if its off at all), I should just be able to add a shim or two to get the desired 140lbs seat load. Im hoping if its off at all I wont have to change the valve locks to maintain the .060 clearance between coils.
I have not changed the plugs
While thats on the way Im going to continue looking into the spring issue. Done a bit of research already and found that desired seat load is around 140lbs. My springs are rated at 105lbs at 1.800 install height. I unfortunately do not know what height they are at right now, so Im going to have to measure it. For all I know its possible for them to be set at 130lbs seat load. Depending where it is (if its off at all), I should just be able to add a shim or two to get the desired 140lbs seat load. Im hoping if its off at all I wont have to change the valve locks to maintain the .060 clearance between coils.
I have not changed the plugs
Well I sent my AFPR to Accufab to get it rebuilt and got it back a few days ago. Installed it and checked to see if it leaked any more; not one drop of fuel leaked and it held pressure for about 45 minutes. So I took the car for a spin, and of course the knock is still there, doing the same thing it's been doing. In the time that I sent the AFPR away I also checked the height of my springs. Intake was 1.730 and exhaust was 1.690. Those numbers match up pretty well to what they should be if I wanted to hit the 140lb seat pressure. So that rules out insufficient seat pressure and the AFPR as culprits of the knock.
Back to square one. Dont know what the hell to check now, but im fairly confident my fueling is ok at this point.
Tried researching to see if a coil pack could cause knock. Every post mentions things about popping or loss of power. My car does not pop at all and has no loss of power. The intermittent jumpy nature of my knock makes me wonder if its possibly spark related if not fuel, maybe an issue of the spark being erratic and not consistent or something of that nature. However I dont know if that kind of spark behavior causes knock or just popping and loss of power.
When I get time Im going to gap my plugs at .35 as well. They are at .32 now. Dont know if that gap could be causing the knock.
Back to square one. Dont know what the hell to check now, but im fairly confident my fueling is ok at this point.
Tried researching to see if a coil pack could cause knock. Every post mentions things about popping or loss of power. My car does not pop at all and has no loss of power. The intermittent jumpy nature of my knock makes me wonder if its possibly spark related if not fuel, maybe an issue of the spark being erratic and not consistent or something of that nature. However I dont know if that kind of spark behavior causes knock or just popping and loss of power.
When I get time Im going to gap my plugs at .35 as well. They are at .32 now. Dont know if that gap could be causing the knock.
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
Sounds like the KR ignore feature is activated in the chip.
Well, at least yo know now you are getting fuel.
Did you verify the cam sensor timing yet?
Unplug it and see ..... it will go batch fire, but if you no longer see KR, you have narrowed the search down.
Get a chance yet to go through the KR list?
http://www.turbobuick.com/forums/ge.../182571-false-knock-so-seems.html#post1282715
Also, verify the grounds and look fcor corrosion at the ECM connectors.
I have read in your posts, both "Audible" and "intermittent jumpy nature".
Can you clarify which one you have now?
If it KR still spikes, it is most likely false KR.
If it is still "audible", try something real unconventional, like leaning it out to about 11.0-11.5 on pump ,one decimal at a time and see what happens, as you could be seeing "rich KR".
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
You also might try disabling the O2 correction feature in the chip and let the nb do it's thing just to see if something in that area is out of sync. It's also possible you have something going on with your wiring. A friend of mine has a strange issue and could not resolve it until he replace his injector harness. Did any of this happen before you built the engine or did it just start after you put the engine back in?
Hmm...I didnt request the KR ignore feature in my chip, I dont know if thats something that Eric just programs in though. Im also not sure exactly what it does? Im guessing its supposed to just not retard the timing, but if thats the case, I dont know why I would see it on the scanmaster.
I have tried to verify timing with a timing light and putting the computer in diagnostic mode. It looked pretty close to what it should be, maybe 1 degree retarded at most if anything. I have not unpluged the cam sensor, I didnt think the car would run with it unplugged.
I have gone through most of the list, but there are a few things I have not gotten to yet, the .35 spark plug gap being one of them.
I am confident in most all the grounds and connections. I looked at everything when I installed the engine and plugged it all in. The bunch of grounds that come off the wiring harness at the back of the intake are grounded to one of the back intake bolts.
Knock is most of the time audible as well as jumpy. Sometimes I have to really listen for it, other times its very clear. Its most loud and severe when I boost from a roll.
I will try disabling the wideband correction and see what it does. I had lots of trouble with knock before I replaced the engine. But I also had a blown headgasket near the end of my hotair engines life. it was barely blown and was leaking coolant into the #1 cylinder. Everything on my new engine is new except the fuel pump and maf sensor/translator.
I have tried to verify timing with a timing light and putting the computer in diagnostic mode. It looked pretty close to what it should be, maybe 1 degree retarded at most if anything. I have not unpluged the cam sensor, I didnt think the car would run with it unplugged.
I have gone through most of the list, but there are a few things I have not gotten to yet, the .35 spark plug gap being one of them.
I am confident in most all the grounds and connections. I looked at everything when I installed the engine and plugged it all in. The bunch of grounds that come off the wiring harness at the back of the intake are grounded to one of the back intake bolts.
Knock is most of the time audible as well as jumpy. Sometimes I have to really listen for it, other times its very clear. Its most loud and severe when I boost from a roll.
I will try disabling the wideband correction and see what it does. I had lots of trouble with knock before I replaced the engine. But I also had a blown headgasket near the end of my hotair engines life. it was barely blown and was leaking coolant into the #1 cylinder. Everything on my new engine is new except the fuel pump and maf sensor/translator.
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
Well I guess the next question is did the old hot air engine pop the head gasket from detonation? It may be that your problem is not the new engine or parts on it although you have found a few issues which is good that they got fixed anyway. If that detonation keeps going though you'll back to square one. I assume the translator/LT1 maf is new? I would double check that wiring and swap out the ECM if you know someone with an extra to see if that has any issues. What exactly do you mean by the knock is "jumpy"? Do you mean the car bucks or skips?
