Finished Recent Top end work, few issues remain

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Sgtduckyboy

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I just went back and re-read your original post and noticed you talk about a "dimple on the larger of the two gears"- please explain. Are you talking about your timing gears? That's the only thing I can think of that matches what you're talking about, since there's nothing on the oil pump itself that you can turn around backwards. And if so, I don't see how you could have got the timing correct if you didn't have dots to line up on the upper and lower timing gears. But... if you did install the upper timing gear inside out, that's most likely your problem. My Cloyes timing set came with a camshaft thrust washer and it needed to be installed correctly or "it will cause a severe wear issue". I'm not sure of what would happen if you reinstalled the stock upper timing gear inside out but I don't think it's a good thing at all.

It was the oil pump I was referring to. If you look it up, on the gerotors, there are dimples, you dont really see them, at least I didnt at first, there is no reference to them in the instructions I found while doing this work. I found it while looking for reasons why my oil pressure is low at running temperature AFTER doing all this work. the timing chain was fine, inspected by a neighbor who has rebuilt many small blocks.
 
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Sgtduckyboy

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UPDATE: went in saturday and removed the intake manifold and injectors. Since my gasket kit had injector seals, I went ahead and removed the rail, removed injectors, cleaned them, remplaced seals, put them on the rail and let them soak in some carb cleaner. they all looked clean inside, nothing seemed to be in any of them, which is what you would think! The gasked for the manifold looked fine, nothing pinched or out of place. the stock type I bought to put back on, just didnt look as good as the Fel-pro that came with the gasket kit and we took it off, cleaned it up, inspected and put it back on. I double checked the gap on two of the spark plugs from each side, they were .004. I did find one thing odd, on the back of the intake manifold, there is a 'blow off' type of gizmo. We werent sure what position it was in, but we closed it and it was sticking open easily when opening and closing it. So we put a drop of WD-40 on it and it seemed to work better. Our guess was this was some sort of 'gate' in case a backfire occured, it could release pressure out that way and then close when normal operation occured. I am not a car genius but that is all that made sense, see the pictures yourself. Car runs great except once really warm. Put in fresh 5w40, hoping to get better oil pressure at warm idle. I still got it to set off 'oil pressure low' after sitting for 20 minutes once warmed up. If i raise the rpm about 100 rpms, its fine, OP goes up a few pounds and light goes off. I thought about raising the RPM with my diablo tuner. thats great, but it would still idle rough,even with the extra 100 rpm's. Remember, this is only at normal operating temperature. Cold is fine, warming up is fine, once warm, OP goes down to trip the light and idle starts going down, then up, and you can see it in the car lights dimming and increasing. My thoughts, tune is most likely since I do not have any DTC's. I wonder if the car is running to rich or lean. Not familiar with Fuel Injected closed loops systems to know what is the effect of being to lean/rich at idle. I was giong to try one of the two other tunes in the Diablo sport tuner. there is one that is 87 octane, better power/economy than the stock , then there is another one that is for 91 octane, I was going to save that for last. My question, is there an actual 'learn' process once the tune is reset/installed? Whether or not, is a tank of gas enough to see if it works after the tune is changed? I thought the cold weather might have something to do with it, but that is more about poor MPG's in this bitter cold. Also, remember, i have changed my MAP sensor, Cam position sensor, Engine coolant sensor and oil pressure sensor (which didnt work before i did all this and never had 'loping' at warm idle issue before.IMG_20171230_155657.jpg IMG_20171230_155702.jpg
 

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It was the oil pump I was referring to. If you look it up, on the gerotors, there are dimples, you dont really see them, at least I didnt at first, there is no reference to them in the instructions I found while doing this work. I found it while looking for reasons why my oil pressure is low at running temperature AFTER doing all this work. the timing chain was fine, inspected by a neighbor who has rebuilt many small blocks.
Here's what you said about the oil pump, which has me baffled:" i put in the melling 295HV pump. i didnt however, realize there was a 'dimple' on the larger of the two gears and not sure if that is facing in or out. I dont feel this would be an issue since it is working, but I figure, i have a 50% chance its correct. I can not find out if having it in wrong changes anything with the oil pressure or performance of the pump". Now you just said there are 'gerotors" with dimples. I don't understand. Here's a picture of the pump and as you see, there's no gears that you can put inside out, nothing with dimples. You can't remove the gear from inside the oil pump and put it in inside out, and you can't install the oil pump inside out so that's what's got me confused. The second picture is the timing gears and chain, which have dimples for timing. Those need to be lined up when you install the timing chain, and if you get either gear installed inside out you might lose oil pressure. As for that "blow off type of gizmo" on your intake manifold, that's where the vacuum hose goes for the brake master cylinder which isn't used if you have hydroboost brakes, which you must have. With hydroboost brakes, that hose is replaced with that funny-looking thing which is actually a plug for the hole in the manifold. The reason it moves in and out is because it has a quick-connect fitting that works like that. It does nothing except plug the hole, and if it was leaking you'd have a massive vacuum leak.

mel-m295hv_mh_xl.jpg
M-L03-1.jpg
 
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Sgtduckyboy

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Here's what you said about the oil pump, which has me baffled:" i put in the melling 295HV pump. i didnt however, realize there was a 'dimple' on the larger of the two gears and not sure if that is facing in or out. I dont feel this would be an issue since it is working, but I figure, i have a 50% chance its correct. I can not find out if having it in wrong changes anything with the oil pressure or performance of the pump". Now you just said there are 'gerotors" with dimples. I don't understand. Here's a picture of the pump and as you see, there's no gears that you can put inside out, nothing with dimples. You can't remove the gear from inside the oil pump and put it in inside out, and you can't install the oil pump inside out so that's what's got me confused. The second picture is the timing gears and chain, which have dimples for timing. Those need to be lined up when you install the timing chain, and if you get either gear installed inside out you might lose oil pressure. As for that "blow off type of gizmo" on your intake manifold, that's where the vacuum hose goes for the brake master cylinder which isn't used if you have hydroboost brakes, which you must have. With hydroboost brakes, that hose is replaced with that funny-looking thing which is actually a plug for the hole in the manifold. The reason it moves in and out is because it has a quick-connect fitting that works like that. It does nothing except plug the hole, and if it was leaking you'd have a massive vacuum leak.

mel-m295hv_mh_xl.jpg
M-L03-1.jpg

sorry, but your picture of the pump is the back side of the pump. the process i am referring to, when installing the pump is here
 

Rocket Man

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I've never seen anyone disassemble an oil pump to install it like in that video. That's a new one on me. I love how they say disassembling the pump voids the warranty. There is a simpler way to center the pump, and I've never heard of a problem doing it the normal way. But now I see what you were talking about. Thanks. Your problem is worrisome to me though since the NBS GMT 800's normally have 40 psi at idle and 60 at higher RPM's. Mine had about 150k when I replaced the pump with a Melling standard volume and it has nearly 50 psi idle now and 65 at higher RPM's. The pressure you're reporting is closer to what the NNBS GMT 900's have but I'm not sure why.
 
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Sgtduckyboy

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I've never seen anyone disassemble an oil pump to install it like in that video. That's a new one on me. I love how they say disassembling the pump voids the warranty. There is a simpler way to center the pump, and I've never heard of a problem doing it the normal way. But now I see what you were talking about. Thanks. Your problem is worrisome to me though since the NBS GMT 800's normally have 40 psi at idle and 60 at higher RPM's. Mine had about 150k when I replaced the pump with a Melling standard volume and it has nearly 50 psi idle now and 65 at higher RPM's. The pressure you're reporting is closer to what the NNBS GMT 900's have but I'm not sure why.

Glad we got through that!
since its not that hard to do, but I'll wait until its warmer out, I'll pull the front open again and check that oil pump. And the way in the video is how you have to do it, if you dont drop the oil pan. Because you have to remove the rotors in the pump in order to rotate the pump off of the oil sump tube and likewise, to install the pump, rotating it around the oil tube. you sound like you have way more experience than I do with these, this is my first. Not sure if you had done this without removing the oil pan.
 

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I removed my oil pan but others have done it with the pan on and without disassembling the pump. It's a bit harder for sure but all the instructions I've seen do it with the pump together. That's a good idea though. Some have pinched the O-ring doing it which leads to loss of pressure too. I had a piece of the oil dipstick tube in the oil pan ( long story) which I wanted out so I dropped the pan which led to replacing the rear main seal while it was off. One thing leads to another ya know.
 

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