koolcat

Hi All,

I am very new to rotary engine and looking to buy a FD Rx7 vr that I see locally. I went to check it out and it seems "fine" as I really don't know. One thing that bothered me was this plug for the air pump (did some research to figure this out) control the idle of the car? This is also my question for you fd gurus here.

So the seller said the motor was swapped out with a 68k km engine from a RHD front clip he purchased in Florida. Both rpms & speedometer seem to be reading just fine. The car has a full cat back with the cat deleted. When I attempted to crank the car it turned over but will not idled. I tried this several time with same result. The seller then asked me to popped the hood and he unplugged said plug and requested that I crank it again, this time it turned over and idled. So should I walk away from this vehicle or is this common? I test drove and it boosted just fine other than the crappy suspension.

Attached is the shot of the bay with the plug location circled. Thanks in advance.

PS - should I specifically check any other things? I usually check for any code or pending code with obd2 but this is obd1 and have no clue.

koolcat

200+ views and nobody here knows about this "issue"?

lduley

iTrader: (1)

Well i know little about FDs, but i do know what you circled is the air pump, and that should have nothing to do with it idleing, if anything, if it was unhooked it would not let it idle due to and air leak. But i read it as he unhooked it? Something doesn't jive here. Did he tell you what he did? Or just do it and smile? If he didn't tell you or wouldn't tell you, i'd walk away

Especially without any compression #'s

koolcat

Well he said it's for emission mainly since I really didn't know what the heck that was atm so I was like ok but it's weird it idle when he unhooked it and then we let it idle for like a good 2-3 mins and I said I wanted a test drive and he hooked it back it was idling fine. So I just want to know if that is normal. Since I read that it helps with the excessive gas in the CAT when it is plugged so I thought it was because with the CAT deleted it and it had to do with the idle somehow. But it just doesn't make sense and I guess you guys don't know or haven't stumble on this before?

lduley

iTrader: (1)

Alot of 3rd gen guys don't make it through here often, Sgtblue will make his way, and be able to probably give you a better answer

But, from my standing, no matter WHAT the car, no, it isn't normal and something is wrong

koolcat

I see, thanks for the reply. I'll just hold off on it probably looking for someone to trade my e60 550i for rx7

armans

iTrader: (2)

Actually air pump along with other systems like Air Control Valve, O2 sensor, AWS (accelerated warmup system) etc control the idling directly or indirectly. The thing that the car has no cat means most emission control stuff is useless there and can be removed from the engine bay.
I'm not quite sure about the mechanics of what's going on with that hose when unplugged and plugged back, but pretty sure it's not yet a sign you should walk away.

In fact you should check other more important stuff like the state of the engine (i.e. compression check), how well turbos work/make boost. Fixing either of them in the future will cost you thousands. But of course it all depends on the asking price too. Good luck

HadaVette

iTrader: (3)

What you circled looks like the input to the air pump. You want it getting cool air from the intake so it lives longer. I believe the output of the air pump goes to the main cat. Does this car have the main cat deleted (not so common) or the pre-cat in the downpipe deleted (quite common)?

The input to the air pump should make no difference on how the car runs. Hooking it up may have been a coincidence, or something else got hooked up at the same time.

Before buying, getting a pre-purchase inspection by an expert is much advised, especially if you are new to the FD. Nice cars!