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lost
Posted: May 17th, 2013, 4:09 pm
by shawnxj
so i've been having a problem with rev limiting. it would run fine up to 3000 rpm then hit a wall. checked everything i could think of and ended up replacing the cam sensor and that moved the rev limit from 3000 to 2500. then i decided to change the crank sensor and that moved the rev limit from 2500 to 2200. i'm completely lost and don't have a clue what to do. going to recheck the distributor but i'm 99% certain it's dead on...any help would be appreciated
Re: lost
Posted: May 17th, 2013, 4:12 pm
by SilverXJ
Did you pull the distributor to replace the cam sensor? What cam and valve springs are you running? Have you checked fuel pressure while this condition happens?
Re: lost
Posted: May 17th, 2013, 4:30 pm
by shawnxj
bought a brand new distributor. was the same price as just the sensor
lunati 63501 ford 4.6 springs
fuel pressure is pegged at 50 psi running 19# injectors. the renix pump can't push anymore pressure. was doing the same thing with the 24# injectors i had in previously
Re: lost
Posted: May 17th, 2013, 4:31 pm
by shawnxj
would i need to reset the computer?
Re: lost
Posted: May 17th, 2013, 4:34 pm
by SilverXJ
I would make sure that the distributor is 100% indexed correctly.
Do you happen to know your open and closed spring loads?
Was the fuel pressure tested while driving and when that "rev limiter" kicked in? In this situation the idle or park and reving fuel pressure doesn't mean much.
Re: lost
Posted: May 17th, 2013, 4:38 pm
by shawnxj
open is 110# closed is 235#. lunati speced the springs
distributor is dead on. it can't get any better
it hits the limiter reving in park and the pressure was still 50#'s
Re: lost
Posted: May 17th, 2013, 5:00 pm
by SilverXJ
shawnxj wrote:distributor is dead on. it can't get any better
Was it necessary to cut the ears to get it align properly?
it hits the limiter reving in park and the pressure was still 50#'s
Doesn't prove anything in this type of situation. The engine will need more fuel when under load than in park.
Re: lost
Posted: May 17th, 2013, 5:03 pm
by shawnxj
nope just dropped it straight in
if it won't rev over 2200 in park how's it supposed to do it in drive?
Re: lost
Posted: May 17th, 2013, 5:07 pm
by SilverXJ
ohhh... it does it in park too. I missed that part, sorry.
So, the distributor dropped straight in and the rotor was pointing where it needed to point?
http://www.angelfire.com/my/fan/dist_index.html
So, fuel is good, distributor alignment is good... what about the coil?
Did it start doing this one day, or has it always done this?
Re: lost
Posted: May 17th, 2013, 5:09 pm
by shawnxj
it's done it ever since i put the new motor in. i honestly don't remember if i revved over 3000 the 1 time i drove it before i started building the new motor
Re: lost
Posted: May 17th, 2013, 5:11 pm
by shawnxj
if the rpm gauge is any indication it's cutting fuel and spark. when driving it pulls like a beast so there's definately not a power issue just an rpm limit issue
Re: lost
Posted: May 17th, 2013, 5:18 pm
by SilverXJ
What indication do you have that it is cutting both?
Where did you get the sensor from?
Re: lost
Posted: May 17th, 2013, 5:21 pm
by shawnxj
the wideband leans out and the tach starts jumping around like it's not getting signal. i can hold the rpm just before it starts limiting and everything's fine but soon as i hit the limiter everything goes screwy. and like i said it went from 3000 to 2500 to 2200 with each part i've changed
all parts came from orielly's
Re: lost
Posted: May 17th, 2013, 5:30 pm
by SilverXJ
A misfire can show lean. I've heard of problems with aftermarket CPS.. don't know if mopar still stocks them for the Renix, but it would be worth a check..
Re: lost
Posted: May 17th, 2013, 5:42 pm
by shawnxj
going to swap the distributor tomorrow and see if it goes back to normal