302 Vacuum Mapping info
FlyingBrick
06-30-2004, 01:18 PM
Hey guys, I'm new here. just rebuilt a 5.0 HO from a Lincoln MK7. Upon removal did not map out vacuum system (no sticker left on old car). Just finished installation into a Volvo 740 wagon & it's beautiful!!..Just cannot get the engine to continue running. It will start great, then gets a shut-down message. No mass air on this engine. We did GT40 Aluminum heads/GT40 headers. No exhaust system yet. Did put O2 sensors into short collector pipes. Throwing flames right now. Need to get her to run to the muffler shop!! We suspect that something in the vacuum system isn't right..Or EGR...Any suggestions???
duplox
06-30-2004, 01:40 PM
Throwing flames? that aint right... check your timing, fuel curves, and cam timing. Specifically, timing excessively retarded, fuel too rich, and/or cam timing advanced too far.
Excessive retard will make your spark plugs fire later, and if its way too far the burn will not be complete by the time the exhaust valve opens, which will result in fuel burning in your headers... causing flames.
Too much fuel has a similar effect... too much fuel takes longer to burn, so burn isnt complete when exhaust valve opens.
Advanced cam will cause the exhaust valve to open early, therefore if the burn isn't complete when the valve opens, it will exit the exhaust.
If you fix it, you'll get more power. The idea behind tuning all of these is to get the most fuel burned during the power stroke of the motor, before the exhaust valve opens. The flames are most likely messing up your O2 sensors, making the computer freak out and stop the engine.
Excessive retard will make your spark plugs fire later, and if its way too far the burn will not be complete by the time the exhaust valve opens, which will result in fuel burning in your headers... causing flames.
Too much fuel has a similar effect... too much fuel takes longer to burn, so burn isnt complete when exhaust valve opens.
Advanced cam will cause the exhaust valve to open early, therefore if the burn isn't complete when the valve opens, it will exit the exhaust.
If you fix it, you'll get more power. The idea behind tuning all of these is to get the most fuel burned during the power stroke of the motor, before the exhaust valve opens. The flames are most likely messing up your O2 sensors, making the computer freak out and stop the engine.
thunderbird muscle
06-30-2004, 02:11 PM
Did you change the cam in it.
FlyingBrick
06-30-2004, 02:18 PM
Thanks for the quick reply!! Guys, I'll try dinking around with the timing..Since we cannot get it to run for long, static timing is the only option. This is the first time we have seen a roller cam..after 200K+, that cam was in beautiful condition, as were the lifters..We re-used all the stock cam gear. Starts, runs..Just won't continue..Our thinking is a bad sensor transferred from the old LSC...Or faulty plumbing..Will try the timing right away..Remember the collector pipes are onlt a foot long!!
FlyingBrick
06-30-2004, 05:29 PM
Hey, Duplox..You did me a giant favor..We'd have gotten around to it eventually but you saved us several hous of chasing...It runs now..We were able to get it to idle long ehough to put the timing lite on & everything got happy..WOW!! What a rush! now off to the muffler shop..I terrorized my neighbors enough for one day!!! Thanks again!! Flying Brick
duplox
06-30-2004, 07:18 PM
No prob.
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