68falcon

iTrader: (2)

when my 1981 rx7 gsl, gets to about 3000 rpm i have to shift or it will start sputtering or act like its running out of gas, the problems gets terrilbly worse during the winter months when its cold outside, any one know why?

brap brap

fuel filter?

Aviator 902S

Fuel filter. <$10 at Napa and others, and takes ten minutes to change including the time it takes to don cover-alls and clean up the fuel spill. Located under the car, just ahead of the fuel tank on the drivers' side. You'll need a screwdriver, a pair of vise grips (to pinch the fuel line from the tank closed during the swap) and a container to catch as much of the inevitable fuel spill as possible.

vipernicus42

iTrader: (4)

And shop towels. The $1.50 blue papertowels on a roll kind.

If you haven't changed the fuel filter, start there and report back. I do mine every year. I've learned through experience that fuel filters should be kept clean. It makes sure your car is getting enough gas when it needs it and doesn't put strain on the fuel pump.

Jon

68falcon

iTrader: (2)

already changed the fuel filter right after we got it and it apears to be clean, so it must be something else. another quick question, what is a good vin decoder for my car that will tell me everything about it, i tried searching but all i could find is for miatas

brap brap

possible bad fuel pump. how many fuel filters are in the line? do you have fuel pressure in the engine bay?

ray green

iTrader: (14)

I'd change the fuel filter again. I was clogging them up every few weeks, probably because of water and rust in the tank. I changed it five times before the problem finally went away. The symptoms sound just like yours, loses power at high speed. Try it, it takes a couple dollars and about five minutes. If things get better for awhile, then return after a few hundred miles, you are probably clogging fuel filters.

Ray

Aviator 902S

Start here:

www.rotorhead.ca

There is a very descriptive VIN de-code page on this site, as well as more info on 1st gens, history, related items for sale and photos of a pristine GSL-SE formerly piloted by none other than Pamela Anderson--- before she turned into a super-skank.

Unfortunately the car is now deceased, but you can still see Pam on old **** videos made and indirectly (but intentionally, no matter what she would have you believe) exposed by her and ex-hubby, Tommy "Tri-pod" Lee.

68falcon

iTrader: (2)

i dont think it is the pump cause the pressure is fine, i think it may be the carburator but i know nothing about cars. Ill give some background on the car and maybe that will help your diagnostics.
a guy my dad works with had it and he got a brand new black paint job on it. then he started having the problem i described. he took it too the shop (not specialized in rotary engines) and thought the carburator was the culprit. the guy at the shop gave it back and said it was fixed but it wasnt so he took it back. this time the guy at the shop set it in a field in the sun for about a year and didnt do a thing to it. so the owner said he would give it to me for nothing, but i didnt want to just take it from him so i gave him 50 bucks for it. i drove it on the trailer so i figured it was worth it. the paint is faded (gonna try some of that nu-finish stuff for now) the window channels have disintergrated and the dash is crack all to pieces. me and my dad have been working on it some (him more than me). im only 17 and so my dad taught me how to drive a manual with it. i dont know a thing about cars by the way. so my dad thinks its the carb but is afraid to touch it cause its a rotary. got any guides with pics on who to clean it out?

68falcon

iTrader: (2)

however the shop guy rebuilt the carburater and the problem persists so maybe its not it

Zyrano

well, if it is the carb, a rotary carb is the same as any other carb, so he shouldn't have problems with it, though it doesn't sound like a carb deal, have you actually measured the fuel pressure from the pump?

alvin

Suparslinc

bad gas, got some builup in sending line on the carb. This happened to me, I had to take the fuel line off, remove the little steel in/out lines, and clean out that wire screen in there.
I had to do this about 3 times, should have drained the tank. After that, I put a filter in the engine bay.

Aviator 902S

It definitely sounds fuel-related judging by the symptoms but just for grins, check your spark plugs. When these wear out one of the symptoms is bogging down at higher revs under acceleration and even at cruise. The only plugs to use are NGK BR8EQ14. Accept no substitutes because others may damage (or ruin) the engine.

These plugs have four side electrodes on the business end that converge on a center electrode. Take a close look at the center electrode. Is the end of it still round? If so, and if the plug isn't oil-fouled it's ok. But if this center electrode is taking on a more square appearance it is worn and causing weak and intermittent sparking.

A new set of four of these costs upwards of $30 but is well worth it. If you haven't replaced the spark plugs yet they're probably due for a change.

As for your dad having concerns about working on a rotary, everything about the fuel delivery system is pretty conventional. The only major maintenance tips exclusive to rotaries vs. pistons are a) Never let a rotary overheat. If you burst a rad hose pull over and shut the engine down immediately until the hose and coolant are replaced, and b) top up the engine oil with each fuel fill-up. It is normal for rotaries to use approx. one quart of oil every 1000 miles or so because a small portion of engine oil is metered into the intakes to lube the apex seals.

txredneckmedic

Id say it would have to be either your fuel filter or fuel pump

ray green

iTrader: (14)

Couldn't be the fuel filter, they put a new one in back when they got the car, sometime before last winter. It must be the fuel pump, I'd put one of those in (about $90 and some labor). Then when that doesn't work, I'd take the carb off and rebuild it (another $90 and a bunch more labor). Then when that doesn't work, out of frustration and just for the hell of it, I'd replace all the ignition parts (about $120-$200, not that much work though). Then, when it still chokes out over 3000 rpm, I'd replace the fuel filter again (about $2.95, 15 minutes) and hope all my work and new parts haven't caused too much damage. That's how I handled the problem, anyway.

Ray

Aviator 902S

LOL. Yeah, that seems to be the way many of us go about such things--- the first time around. Then we learn to start at the least expensive problem first and work our way up. For example, I'd change my plugs, high-tension leads, distributor cap/ rotor before touching the carb.

As for the fuel pump, there's an eisier way to test this: Just after replacing the fuel filter, disconnect the incoming fuel line from the carb and insert it into a metered container. Now turn the key to the "ON" position, ie: when the warning lights illuminate. (Do not crank the engine). You should hear the pump running and there should be a steady gush of fuel filling the container. I'm not sure what the ideal volume per time frame is, but if you have a properly-running RX7 to compare it to, do the same test on it. If the time to fill the same container is similar your fuel pump is ok.

What may not be ok is the wiring to the pump. The most common culprit is an plastic connector in the wiring harness that supplies power to all electrical components in the rear of the car: tail lights, licence plate lights--- and the electric fuel pump. This connector is located under the carpeting under the drivers' side rear storage bin--- exactly the location where hidden rust from the rear wheel well devours the metal, allowing water to enter and short out the wiring in the connector.

The symptoms of this will range from intermittent bogging down to steady bogging at higher revs to complete failure and being stranded at the side of the road. The fix is to go to a wrecking yard and scavenge a good connector, then splice it in where the old one was, one wire at a time. Be sure to water-proof this junction and seal off the rust holes that allowed the water to enter in the first place. Better yet, bead-blast ALL of this rust out from both inside and out, then prime and coat with sealant. Once this rust is too far gone it completely weakens the body and will be BER--- "Beyond Economic Repair."

68falcon

iTrader: (2)

while driving it ive been paying more attention and when i let it get to around 3000 and it starts acting up it blows black smoke out the back, which makes me think its flooding out. or at least something with the carberator, but i dont know

Rx7Kidd

if it was sitting for awhile, maybe u should check the catty converter.

i kinda have the same problem with mine, i get to a certain speed it sputters out, change the fuel filter a few more times. i guess alot of these rx's have rust n stuff in the tank.

68falcon

iTrader: (2)

how do you check the catalytic converter, if i go to change the fuel filter and its clean then i know thats not the problem, right?

Aviator 902S

If the fuel filter is absolutely clean the problem is elsewhere, maybe the fuel pump or wiring to it. As for the cat, there's a warning light on the instrument panel that sez "overheat exhaust system." If the cat is plugged this light will alluminate. If it does, do not ignore it because plugged exhausts cause local over-heating of the engine core that can warp housings and necessitate an engine teardown.

ray green

iTrader: (14)

Concerning the fuel filters, you would think a visual and blow through inspection would do it, but unless its absolutely clean, as Aviator says, I'd go ahead and replace it anyway. The reality is that fuel filters are almost never absolutely clean and it's hard to predict how they are functioning when the car is at speed and requiring the most gas.

A filter that looks OK and passes the blow through test in your garage may be collecting crap when the fuel flow is high, reducing the volume just enough to cause your symptoms at 3000 rpm under load. The crap can be particles suspended in water, rust and other debris that 20 year old gas tanks tend to produce. When you slow down or stop the car, the fuel flow is reduced and the crap comes off the filter, so it seems to be working OK.

Besides, it's a whole lot easier to just replace the filter than to sit around and wonder about if it's working right. If the car runs better, even for a short while, you've probably found your problem. But expect it to come back again when the new filter gets dirty. So you might want to pick up a spare filter or two at the parts store.

Once you're sure it's not the filter, you can move on to more expensive options.

Ray

Kentetsu

Verify that you have spark on both leading and trailing ignition.

Also, for bringing the paint back to life, I recommend McGuire's paint cleaner. Works wonders....

68falcon

iTrader: (2)

i got a new fuel filter and am putting it on when i get time (schools about to start back so schedule is kinda full). whats causing the smoke though, no lights about anything

68falcon

iTrader: (2)

hopefully ill get some pics for you guys, any thing you need to see?

txredneckmedic

what color smoke is it?
oh and pics of everything...preferably with a nice looking girl in the pics...hehe