LT1 Problem... High RPMS BOGGING!!
#22
Staging Lane
iTrader: (1)
Join Date: Dec 2001
Location: Detroit MI
Posts: 92
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Fuel pressure: base pressure is the key on-engine off pressure. Watch the gauge during the prime (first couple seconds after key on).
Double check: engine idling, pull the vacuum hose off the regulator and watch the fuel pressure, It should read the same as step 1.
Manifold vacuum: with the engine idling put the vacuum hose back on the regulator, the fuel pressure should drop 7-10 lbs depending on idle vacuum (depends on camshaft)
WOT test: since the engine manifold vacuum is very close to 0 at WOT, your WOT fuel pressure should be very close to the base pressure. Make a WOT pull from lower RPMs (50% of redline or so) in a higher gear and watch the fuel pressure. The pressure needs to stay close to the baseline pressure or you have a fuel pump, fuel filter, or similar issue.
If you can't measure your fuel pressure while driving at WOT (or on a dyno) then you have no way of knowing that your fuel supply is adequate.
Just my .02
Bob
Double check: engine idling, pull the vacuum hose off the regulator and watch the fuel pressure, It should read the same as step 1.
Manifold vacuum: with the engine idling put the vacuum hose back on the regulator, the fuel pressure should drop 7-10 lbs depending on idle vacuum (depends on camshaft)
WOT test: since the engine manifold vacuum is very close to 0 at WOT, your WOT fuel pressure should be very close to the base pressure. Make a WOT pull from lower RPMs (50% of redline or so) in a higher gear and watch the fuel pressure. The pressure needs to stay close to the baseline pressure or you have a fuel pump, fuel filter, or similar issue.
If you can't measure your fuel pressure while driving at WOT (or on a dyno) then you have no way of knowing that your fuel supply is adequate.
Just my .02
Bob
#23
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Did you get your Opti replaced yet? did it fix your hesitation?