Quote:
Originally Posted by eldorado1  Were you running a vin 9 calibration on a vin y? That would allow you to pass 500 rpms above the rev limiter. |
PM me your Email address and I will show you a portion of the software I use.
.
.
.
The engine had 4557 miles on it when I pulled it out for a bad casting. I patched welded it. The coolant in between the layers was contaminating the weld. I was using a alloy product from my local supplier. The small leak soon spread to a 6" long Fish Scale like area. Ever time I thought I had it good some coolant residue would come up. I thought I had it good and so I installed it in the car. I was being rushed. The f****** idiot across from me wanted the engine support that I had the powertrain unit on. I installed the engine to give him the support table and had never pressure tested the block. It leaked at the head gasket. I dropped the powertrain out Pulled the head off and found that the layers of casting split all the way to the deck surface. I head back to the welding supplier to get some type of cleaner or flux. He called the manufacturer and they told him I should not use this product on this alloy block. I dig all my wire feed crap out to weld aluminum and get a some old alloy wire I had. I cut about half the wire off the roll and grind all the crap off the block. Reinstalled the head and pressure test it
. Good to go. I had never driven the car off the lot with the coolant leak. I changed the oil and had everything taped off when I was grinding and welding.
I had just ran the engine a couple of time with the leak.
After I Reinstalled the engine It sounded like it may have a misfire. I ran it to the Exhaust shop to have two little mufflers put on it so I could hear the car run. I had a Misfire in #7. Pulled the plug, then swapped it with #5, checked the wires, swapped out the coil assembly, and checked the injector. I found nothing, but when it missed I could hear an exhaust change. The miss slowly went away. If I would drive the car it would come and go. I cleaned the injectors twice. The more I drove it the less it happened. If it did miss it would stop if I let it idle. If the Torque Management kicked in it would misfire about 80% of the time immediately following that and I would let it idle about 15 second and it would be fine. Sound like a poor connection
. If I make a sharp turn or U turn it would misfire about the same. I would just let it idle and it would clear out.
.
Last night I was collecting more data on the program and about 100 MPH it shift back into 2nd for 1 second I let off the gas and then replanted my foot. ran it to 136 MPH and backed it down I over shot the first drive way so I drove down to the second drive way. I was at a cruise of about 35MPH. I did my U turn and it started to misfire.
.
This is a 96 to 99 replacement engine. I have been wondering what could be the cause. Loose wire in my custom built harness? How about oil in the intake? The oil build up in the intake is cause by two thing first is high RPM ( I have that) the second is a baffle problem in the rear valve cover. The valve cover only has 5000 miles on it. You have to have both to get that much oil in the intake that it would slosh to one side and then misfire.
.
This time the misfire did not clear up and it started to knock like a spun bearing or something in a cylinder. I limped it back home about 1 mile and it did not get better.
.
I think it stuck a valve open and if I had to guess it is #7 cylinder. I do not understand why a U turn would cause a valve to stick.
.
I pulled the power to the coil and cranked it this morning and it has a cylinder with low compression.
.
I am headed back to the dealership this morning to check it out.
.
In the snapshot I got it showed the PCM shifting 1st, ...... 2nd, ........ 3rd, ...2nd, 3rd............
.
I had taken someone for a ride yesterday just before 5pm. Nice customer. I had mad a comment that I thought I heard some type of exhaust note difference from side to side, but I did not have a miss and it was very smooth.
.
I am selling it at the end of the month and was realy pushing that deadline.
Welcome to the world of tuning, building, and racing. That's not your last burnt/cracked piston on the road to reliable performance. I'm not knocking your efforts to outguess GM - but there are more engines to go before you can market a performance increase with reasonable assurance someone else's engine won't blow. Is there a knock sensor code? It would be interesting to know the engine operating conditions when the piston let go......probably too much advance with too little octane.
