hat.paradox

When I first bought my 82 RX7 GSL, it really didn't have any problems and idled at the right 750rpm, something that was read on the factory hood stickers indicating the normal idle speed.

I just added a quart of Castrol GTX 10W-30, which was one of the recommended motor oils to get on a different factory sticker on the hood. I was deciding between 10W-30 and 10W-40 which were within temp ranges, and I figured it really didn't matter (10W-30 is -10F and 85F, 10W-40 is just 1-10F and above). So I add just a quart, I didn't want to add too much (I was severely low according to my dipstick and the low oil light came up in the car), so I was running with that fine yesterday.

Today while leaving work, my car died while waiting to turn with the clutch pushed in, while I was waiting at a stop light, and while I was coasting down a hill. The engine runs absolutely fine while in gear and moving forward or backward.

I'm not sure what's happening - didn't hear a vacuum leak which was what a tech told me over the phone when I told him about the normal symptoms of running a rotary, when I first got the car (a month ago) - LOL, air filter in carb is brand new and I've been running it fine for a week now, and it only just started after I added new oil in. Perhaps it's the new oil? Now that I think about it, I had no idea what the previous owner put in, oil wise, so perhaps he got a different weight than what I got. If that's the case I might just bite the bullet and just go get an oil change instead of doing it myself (not much time on my hands).

It really isn't electrical, I don't think, although I did notice the battery gauge did dip up and down a tiny tiny bit every time the turn signal actuated itself, and it would move up as if it was getting charged every time I revved the engine. Perhaps I didn't notice it at first, I'm not sure.

Any ideas will be entertained, it isn't an exactly serious problem as I only have to drive twenty minutes to work and it's cruising the large majority of the way, I'd just like to hear from anyone and see if it's something I can do before I decide to take it to a garage.

Thank you all!!

1982 RX-7 GSL, 137k miles, bone stock

Qingdao

iTrader: (3)

Sometimes you can't hear a vacuum leak. Look for it with a can of wd-40. If you spray the wd-40 around the intake the oil in the wd-40 will temporarily seal a vac leak and the engine rpms will surge. wd-40 is safer than ether or carb cleaner but I've used all manner of things to find vacuum leaks.

Oil isn't gonna affect your idle speed. If it does it means you have NONE and your engine is seized; I don't think that's the case.

Was the car daily drivin before you bought it? How clean is the fuel tank, lines, fuel filters?

hat.paradox

See, that's what I thought about the oil. But that was the only change I could think of before it started to do all this

And I'll try the WD40 tomorrow at work when I get a chance.

The car was a weekender car, a cruising car, and was kept up to date by a retired Naval Mechanic from the day it rolled off the lot back in 1982 up until last year, so it was pretty well maintained. It definitely wasn't a daily.

Thank you

t_g_farrell

iTrader: (1)

How long ago did you buy it and start DD it? I suspect its just a coincidence with your oil
addition. Adding that oil isn't going to affect the idle at all.

My guess is you have been driving it regularly now and something popped or cracked from age
and/or heat with the recent activity. You should replace all the rubber vacuum tubes now and
suspect any other rubber hoses as being bad until replaced. I mean all, brakes, radiator, heater, bushings, window seals etc.

hat.paradox

t_g,

I just started driving it a month ago. However, it should have been in pretty tip top condition as it was kept up to date by a navy mechanic but, he could have never touched the hoses at all, and something cracking or popping from my recent daily usage seems like a viable candidate for my idle problem.

Will inspect on the weekend, maybe just get it looked at real quick and see if I can do anything myself before I take it in to the garage.

t_g_farrell

iTrader: (1)

Yeah, he may have kept it in good shape but I'll bet he stopped driving it often a year or two
before the sale. Thats a prescription for rubber dry rot to set in all over the place.

Always do the obvious first, make sure the fuel is filtered and clean coming into the carb. Make
sure nothing came unplugged etc.

hat.paradox

Holy heck, you must be a psychic the last bit of maintenance done was back in Dec 2015 I believe, the guy kept track of everything he did in his "Ship's Log". Funny, a car upkept by a Navy mechanic and sold by an Air Force systems/computer operator to a future flyboy (well, more Navy than (ch)Air Force lmao).

I'll go about and buy a new filter, I might as well just change it out.. I'll see about it. Thank you. Might as well use the oil filter I bought too, I might also just change that out as well.

Skurge

i'm going through almost the same thing myself, just started chugging at idle about a week ago, so far i've cleaned out the carb, swapped out plugs.

next step will be checking for vac leaks.

dmc83RX

Mine did this last summer. I discovered that 2 of the 3 valves in the air control valve were stuck.