YnOhTnANaYrB

I'm not sure if my 5th and 6th ports are opening...I think they are supposed to after 3500 RPM's...when I start in first flooring it...wait till 7000...then shift to 2nd...between 5000 and 7000 it bogs down...I know the fuel filter needs to be replaced and same with air filter...but it bogs down alot...I am wondering if it is the 5th and 6th ports...any ideas anyone...?


84' GSL-SE

Streetported, Full RB exhaust...thats all for the engine...

GavinJuice

fuel filter will affect you at higher RPM's as will your actuators. actuators won't feel like it's bogging down ALOT like you said, but a combination of the 2 would probably be what your feeling.

BigJim

just start ur car go to the passenger side grab the throttle linkages and rev it up. U will se them move and oepn, at least mine do. it doesnt have to be under load like i previously thought

hornbm

Dont know what your car is doing. But yes the car needs to be underload to generate the 2PSI of exhaust backpressure needed to open the AUX ports. THey will not do this unless its under load

YnOhTnANaYrB

so how would I check it...cause I have pulled on the linkage and I didnt see the actuators do anything...I thought something was wrong with them...

Felgar

We have no consenus on whether it needs to be under load. But given that BigJim's open with no load I'm inclined to say that they don't need load. This thread indicates that they open with no load also. https://www.rx7club.com/1st-generation-specific-1979-1985-18/5th-6th-ports-356428/

I think maybe the secondaries on carb setups require load and that's where the confusion comes in.

Brianhsval

The ports NOT opening has nothing to do with your bogging though. I ran mine closed for almost a year. All it did is take away some of the exceleration at the higher RPM's. Took 2 wire ties and tied them open. As for your bogging it may be running 2 rich, or the timing could be off. But I am just guessing. Also check your TPS.

YnOhTnANaYrB

okay how do I check the TPS...I know what and where it is...thanks for the help so far...fuel and air filters have been changed...I havent ran it high RPM's yet but if I feel diff then I guess it was just the fuel filter...thanks again...

Unsupa

iTrader: (2)

https://www.rx7club.com/showthread.p...postid=1335894

RotorJoe

Sorry to disagree with you on this one HornbM. But if they are working properly (not binding or stuck) and you have fairly stock exhaust they will slap open at 3500 or so.

On my beat up GSL-SE I have a RB header, no emmisions crap, bonez cat with stock exhaust from there back. I was able to stand over the car and rev the engine. I could watch the ports slap open rather quickly and low in the RPM range. I was alone and out side of the car so I do not know the exact RPMs.

But now my ports do not open and need a good cleaning. Hence how I found this.

bizarro

iTrader: (1)

no load needed for checking your actuators...so if they don't move when you rev it they are stuck...

basically either the actuators are stuck or the actuator rods are stuck

first take out your actuators and see if you can pump the little arms down...if not then use some grease to loosen them up enough so they pump up and down freely without getting stuck. i used silicone spray, wd40, pb blaster, grease...etc

next check your actuator rods...best way to do this is take out the upper and lower mani, pull them CAREFULLY and clean out built up crap that is in there...
i would follow BROWNMOUND'S website in order to do this...it's really involved and you will be out of a car until you are done...

or

you could go my way...i didn't want to take out the lower mani...it was too much work for someone so inexperienced...so i just took out the actuators and with some pb spray and a needle nose plier i sprayed and turned and sprayed and turned the actuator rods...slowly after about 4-6 hours of playing around the actuator rods came loose and now both of them turn freely...

get new gaskets for the actuators, bolt it all back in and test them by revving the car upto 4000rpm...they should open right up...

this is also dependant on the backpressure hose coming out of your head catalytic...if that isn't hooked up and without leaks then they won't turn at all...

hope this helps...

let me clear it up cuz i see this alot in the forum...

if you have a stock GSL-SE you do not need load to check your actuators...

(where is longduck when you need him???)

serious...anyone know what happened to him? he's been quiet lately...and he is way better at explaining things than i am...

LongDuck

Hey, guys, saw the post here and thought I'd chime in - glad to see that I was missed! Was in Germany (Austria/Switzerland) for the past several weeks and obviously away from the computer...

On the '6'-port operation, in my experience, no load is necessary to check proper functioning AS LONG AS the port actuators can rotate smoothly. If there's any stickiness at all, the additional backpressure generated through load may help to open them up, but then you already have a problem.

The actuators only operate between 2.6 and 4.5 psi (IIRC), which isn't much at all, so any leaks that you have in the backpressure sensing tube or the gaskets (as mentioned above) will be felt almost immediately. Be sure that you don't have any cracks in the tubing on the lower intake manifold or the gaskets themselves, and you should be good for pressure. A good low-pressure gauge can also help with diagnosing lost pressure in this system.

It may be a lot of work to remove the lower intake manifold for the eventual 'fix' to this problem, but the overall performance increase is well worth the effort. It's been about a year since I had mine apart, but the pictures from 160k miles of daily driving tell a graphic story of how much carbon can be built up. HTH,

YnOhTnANaYrB

Thanks alot guys for all the info...appreciate it...