lgoodson@pacbell.net

I changed the fuel pump 3 times and the noise persisted. Don't think it is the pump. Adding the rubber fuel hose made a big difference but I will re install the cumulator and see what happens.

So David, when and where us the meet a Brooklyn Pizza, so that we all might know

For those of you that have read my posts as to the noise problem, I want to give you some resolution. I first noticed that if I replaced my steel braided pressure fuel line with a long rubber one, the noise was almost all the gone. I then had one made the correct length , about 9", and the noise came back a little but not bad so I was happy. BUT while re-reading the JTR "TPI" manual for the tenth time I noticed a small section in the fuel pump section. 2 1/2 lines to be exact. It talked about a fuel "damper or pulsator". The purpose of which is to "quiet" the noise made by the injectors due to fuel pump pulsations. Imagine that!. The LT1 fuel rail comes with a device called an "acumulator" which I believe does the same thing. One fine fellow (not on this site) told me to discard that device, everyone does he said. Imagine that!!. There must be a lot of noisy LT1's running around. I haven't reinstalled it yet, it will take some doing but I will let you know. I don't know about you but my car, at 70 mph, has a lot of noise in it, Can't hardly hear the radio so Injector noise and fuel pump noise can't be allowed. I have told you all that I switched to a BMW fuel pump which is soooo much quieter. I am also gong to insulate the doors and floor boards with a product called DynaMat so that should make a big difference. By the way, the BMW fuel pump I installed appeared to be a OEM pump so I bought a nother one that looked newer, They both work but the OEM one is quieter but it is old so I carry a spare. I should maybe have it installed and wired seperatly. Just in case. The one I have in it now, you can barely hear before start up and not at all after start. AS I said, this kind of noise can't be allowed. Larry

My LT1 /T56 is getting 11 to 14 on the road and off mostly on. I will pull a plug and see what they look like. It is turning 2000RPM's at 70 MPH. Still trying to verify the speedo calibration. Using a Cable X converter. This could be a problem and also the rear diff ratio.

JTR makes a T-56 mount which I used with my 240Z. Worked fine but I did bend the ears at each end to conform to the floor boards. Used a 8 lb mallet and a concrete curb. Drive line angles were checked and found to be correct.

After I fixed the exhaust leak I still had the poping until I changed back to the NGK sensors. At 70 MPH the tach reads 2000 RPM. Does that sound like a 3.90 or 3.36? Replaced my intake gasket today following everyone's instructions leaving it sit for a hour before torqueing the bolts. Change the TB gasket as well and a couple of the injector "O" rings. Leaving it sit a couple of days before starting it up to make sure the RTV is good and cured but a fuel pressure check revealed no leaks so it shold be ready to run. Looking into the TB, it looked really dirty and I know I cleaned it a couple of hundred miles ago so I wonder why this is. It was dirt and what felt like oil mixed in. Where could all this be coming from? The air cleaner I have is one I bought at Kragen or Autozone for $30 bucks but it should work better that this. 200 miles???? My fan belt is starting to look worn. On both edges I can see the cords in the belt showing in places. This, I can't seem to get a handle on. Every thing looks fine and the pulleys look all lined up so I don't know. Thanks to everyone Larry

8 Pm. Kind of dark Any Idea of how many cars that will show? How about an address for those of us not familiar with Mission Viejo

In a 75Z the fuel pump is turned on by the AFM. Turn the key on and manually open the AFM butterfly and you should hear the pump come on. If not run 12Volts to the power wire on the pump and see if it comes on. If not replace pump. $20 at Pick A Part or $220 at the dealer. I made that mistake. You can also use a pump out of a BMW and a few other cars that have a external pump. I am using one out of a BMW 633 to run my LT1 because it is strong and QUIET. And cheap!

Yea I am using gaskets also. Lost one nut and the rest were loose. No leak now even with RTV sealing the headers but that will probably change.

Z48LT-1. Almost everyone I talk says that they use the breather instead of the PVC valve without any problems. These LT1s leak at the rear intake. I have been told that it is a common problem. Pulling it again tomorrow. deja. Put the original O2 sensors back in. No more poping out the exhaust. With the Delphi sensors I went 102 miles on 10.2 gallons. That's 10 MPG. Worse yet. What I am thinking is that I have a 3.90 rear end and therefore I have the poor milage. Would a 3.90 do that? I am going to spin the tire and count the drive line rotations and get a clue as to the ratio.

There is a link here about the front diff mount. I believe it is call the RT mount used for holding doun the diff under a lot of torque. Can anyone point me to that link. I have searching for hours trying to find it. There are several posts on this subject. Thanks Larry

Turned out to be loose collector bolts

I have the stethoscope also but what do you do with it. Run it around the manifolds and collectors and do what? Listen for exhaust noise? I think that these devices work by vibration, not noise.

I plan to find someone who can do the Data logging for me to see exactly what is going on. I am looking around here when I have time to find someone. Don't really know what type of person or service that I should be looking for. And yes. I an going to pull the intake again and re seal it one more time. I hope!

Thanks Greg

Well I took pains to do a good job with the install. Torqued the bolts per the manual but I think they are leaking. Not sure yet because it could be the collector. Kind of waiting untill it gets worse so I can tell where it's coming from.

Yes, he has been a lot of help so I listen and follow his directions closely. He has not mentioned the bolt sealant though. Couldn't hurt. He also has told me that difficulty shifting this T-56 into reverse could be a sign of a bad clutch. Does any one know what else could cause this problem. I have to slam the shift lever all the way to the right to get it to go in. I have a B&M Ripper shifter that I bought from Jody also. He said that he never had this problem when it was in his car so what else could it be. If the shift lever was not inserted into the trany correctly, I wouldn't think that I could shift at all but the other 6 gears shift fine.

Well it's tomorrow and after driving 20 miles I rechecked and the leak is coming out the back on the right side of center of the engine, I looks like it is leaking from between the RTV and the intake manifold. Jody, on this site, says to install the manifold and let it set for an hour before tightening the bolts. Has anyone else done it this way? And also, don't trim the excess RTV off which I did trying to be neat. I did it days later though.

yea I know, The RTV seemed a little too easy but that is what Sanderson said to do. I will be installing some gaskets if that is where the leak is coming from.

Ok, I installed the new Delphi 02 sensors. Today I had the car out for about 20 miles. As I was driving it I noticed that the fuel gage was sinking like a rock so I don't believe I solved the mileage problem. I also noticed that I now have backfire through the exhaust. Loud poping when I let off the gas at a high RPM to slow down. It never poped and backfired before with the other 02 sensors. What is causing this, Too rich or too poor?? or is this normal with no back pressure. Remember I have a 2 1/2" exhaust to the Y pipe and 3" out to a 3" magnaflow. Do I have the correct sensors now or what??

Did all of that except the thread sealer but it looks like th oil is coming out along the back of the block. I cleaned it all off and I'll see what it looks like tomorrow. thanks, Larry

Well here is the final finding. After many weeks of trying to figure it out I found that the braided steel line from the fuel rail to the chassis line was the problem, I changed it to a rubber line to insulate the noise and bingo, no more noise. Keep that in mind.

Another question; I have Sanderson Headers on this LT1 and a brand spanking new exhaust system. The headers were installed per Sandersons Instructions using RTV instad of the normal gasket The head pipes are installed with a gasket at the collectors. But I can hear a leak and when I put my head over the engine, my eyes burn so there is definately a leak. Is there a trick to determining where the leak is coming from, Header at the head or the collectors. If it aint one thing it's another. Thanks, Larry

I replaced the intake gasket about a 150 miles ago and it has started leaking again. I used the strongest RTV I could find and was very careful not the disturb the RTV when installing the intake, I carefully torqued the bolts to factory spec and pattern but still I get a leak. I read in a datsun racing engine building book that to seal oil pans, you should use "weather strip adhesive". Maybe that would work. Anybody have any good ideas. I undestand that LT1's have a sealing problem, GM didn't design a rear seal, just use RTV so they leak. Thanks, Larry

I had the PVc hose from the pasenger side valve cove hooked to the top port on the throttle body but have sense removed it. Couldn't see a difference so I have put the breather back in and pluged the port. I had no vacum at this port.. Haven't checked the other port yet. I thought that it was the head vent passage so no vacum would be there. As far as the fuel problem, I just insatlled another set of O2 sensors, GM/Delphi ES10966 purchase from http://store.getgmparts.com/. I can't be sure that they are the right ones though because that site does not provide any way to search various models to determiine what they might take so I took the guys word for it on the phone when I ordered. Today I ran the engine for a while and after a while the "check engine" light came on. It has never done that before but I thought that it might be because I changed something and the computer needed to be updated or cleared which I understand that all that is required is to diconnect the power to the car and the memery will get cleared. I did that and so far, no check engine light. We shall see and we shall see if the milage improves. Another problem I have been asking for help with is the Injector noise that could be plainly heard sitting in the car. Today I replaced the braided steel line running from the chassis fuel line to the fuel rail steel lines. I replaced it with a rubber hose -6 fuel line and the noise in the cabin went away. I can still hear it but I have to listen hard to hear it. Just Insulating the engine fuel line on the engine from the chassis line helped a big amount. I also notice today that my intake gasket at the rear is leaking again. After only a 150 miles or so it is leaking. I took pains when I replaced it before making sure that all bolts were torqed to spec and still I get a leak. I used the strongest RTV I could find but still it leaks. Any Ideas??? One more thing. I went around the car with a can of starter fluid spaying everything and listening for increases in RPM. Couldn't find any but I did see the intake leaking, Could this be also a vacum leak. I would think that the oil would keep it pretty sealed as far as the vacum is concerned