I have a 94 which has stock turbos. When I boost the first turbo seems to build pressure fine but when I hit the 4500 rpm range the transition as the second turbo hits hesitates real bad. The second turbo will eventually hit and then things are fine, holds boost. After I have boosted with both turbos a few times the problem seems to get better. I also thing the problem got a bit better after I replaced the plugs, still stock NGK's but after only a few runs it seems to be the same.



I have the following mods:

HP Fuel pump

Intake

Exhaust

HP Cat

Downpipe

Y-pipe

PMS

PFS Intercooler

Radiator

Underdrive pulleys



Any suggestions? Should I run colder plugs? I don't know.

ever changed the spark plug wires or fuel filter ?

Fuel Filter yes, Wires no. Think that could be the issue?

hesitation is usually caused from lack of ignition or too much fuel. it could be a bad spark plug wire. you could be running way to rich in the top end also with the PMS. the PMS is hard to get running correctly unless you have PFS tune it on the their dyno

What would PFS charge to dyno tune it? Any idea?



I'll change the plug wires, looks like a pain. Any tips on changing these? Would running colder plugs be worth the $$?

you can try running all bur9eq's you don't need better plugs yet. try changing the easy stuff. if you can't get it running correct bring it to PFS if you are close and let them check it out.

For those who don't know

PFS 703-368-7959 Ask to talk to Peter directly. Your better off not wasting your time with that kid Jason who answers the phones anyway. He won't be there long rumor has it.

Dude try this!

The O2 sensor has a connector on the backside of the manifold. Dissconnect it and go for a drive. It should smooth her out quite a bit if not all the way. Also I have some nice maps I can help you with.



-Rikki

Get the PFC!!! :P

Well did you try the o2 sensor trick.

i had the same problem and it got worse and worse it ended up being vacume hoses and bad solonoid

Well if you havent upgraded top silicone vac hose I would do that right away.

I have replaced the O2 recently but I have not tried running it disconnected yet. I'll give it a try though.

I also have replaced all the hoses with silicon.



Thanks

heh, rx7s have never ending problems, now i'm getting hesitation in all the powerband, like i'm riding a bronco...



i'm gonna check the PFC and the plugs.. i had a couple vacuum leaks and fixed those, it might be running too rich now and messin everything up now

could it be a fuel cut? if it didnt have the pms thats what i would say it was.



mike

Are you sure that your clutch isn't slipping?

I have never heard of that much hesiataion. Could you give a better description?

i think my tps is out of range, it isn't reading correct voltage on the PFC, i'm going to adjust it and see what happens now...