Low boost

hotcobra03

Active Member
Nov 29, 1999
969
4
39
poteet,tx
My 03 is low on boost.i have installed a new bypass solenoid and new vaccum harness.the boost will only go up to the t in boost,it does respond when you hit it and i hear whine.UM mentioned adjusting the actuator.other than this piece can a blower wear out inside?
 
My luck its gonna need rebuilding.how tight should belt be?the ac belt was new and very hard to get on,blower belt is fairly new but during that engine nightmare was removed several times,would that be noticable .
 
Can u school me on actuator?manual shows adjusting tool but isnt very clear on fine details.with tool on turn something till rod touches reinstall actuator than remove tool.have you or anyone else done this.
 
I've never done this adjustment personally. I read that the bolts on the actuator can be loosened and then the actuator can move up or down which adjusts when the boost bypass valve opens/closes. Try moving the actuator down and see if you get an increase in boost, if not slide it the other direction.

I wish I still had my '03 Service manual.... I could have posted the adjustment instructions for ya.

U.M.
 
It says the tool comes with a new actuator,has picture of tool on actuator, looks like it clamps onto actuator rod,than u rotate the actuator into position until the rod engages the lever.guess those steps might work.my actuator wiggles,hoses were pulled many times during this.um i also had blower rotors out to clean off black buildup,those rotors were cool very heavy
 
It says the tool comes with a new actuator,has picture of tool on actuator, looks like it clamps onto actuator rod,than u rotate the actuator into position until the rod engages the lever.guess those steps might work.my actuator wiggles,hoses were pulled many times during this.um i also had blower rotors out to clean off black buildup,those rotors were cool very heavy

You removed the coating from the blower rotors?
 
Ok moved actuator.got boost to go up and down,i will go c if my local dealer can lend me a tool.What do u think about what earl said with coating on rotors?didnt seem to me like it was part of it but i know jack about blowers.the car to me is still not right.it will buck when you nail it,in 4th at 20mph nail it and it studders,no ping heard and it will accelerate any thoughts?when cel lites its 455 and 457 sometimes 453.when checking those i was led to an intermitting problem.457 will stall engine any tie thier
 
The Lightning blowers came with Teflon coated rortors, but I don't believe the Eaton's on the Cobra had any special coating on them. Superchargers and turbos in general have extremely tight tolerances and over time they wear like anything else. Your rotor to case clearance, or rotor to rotor clearance may be excessive due to the age/mileage of your car and this is causing it to not make as much boost as before.

Now punching the car in 4th gear at 20mph sounds like a recipe for disaster to me! That's WAY too low and puts unnecessary strain on the motor when you lug it like that.


U.M.
 
Um with the service manual i brought it came with a 2nd disc.it has 46thru93 trucks and all mustang ,all production numbers how many colors ,who had what ect...on cobra it says it uses the same model as lightning .with a cast aluminum case, machined aluminum internal rotors.7.5to8.0psi. I thought the cobra was set at 10?maybe i should try another gauge.how much would you trust a vac/pressure gauge?it use to go to 10 and 12 if done right. Thats on stock gauge and the t in boost is as hi as it goes,it it had numbers t would b 8.i lowered gap on plugs to 35 looking 4 miss,works been slow havent drove it yet.wife is driving it and is to easy on it to feel it.sorry im bored