n8dawg

So I am completely new to actually working on a vehicle. Only thing I have ever done is change oil and spark plugs, thats about it. SO I decided to jump head first into an 84 GSL-SE. I needed to drive it 90 miles to get it from the original owner and I only got 22 miles........ luckily he paid to have it towed to my buddys shop where I could work on it a little in the parking lot before I just hand it over to them to fix. The car would not accerate more than a crawl. If you got on it at all it would simply just bog down until it finally just died. You can start it up and it will idle for about 30 seconds unless you give it some gas. As of right now I have a fuel filter on order as well as spark plug wires, I already replaced the spark plugs (even though the old ones didnt look that bad) from here where should I go? Maybe replace the cat converter? I bought a manual and am looking through it. I am just a total nub when it comes to cars and need a little direction from those who had had similar problems. The car did sit for quite some time before being drivin a few weeks ago for about 250 miles.

25yrfan

If it has been sitting for awhile, I would look for rust in the tank. If you have a rust problem there are 3 filters in the SE. The first filter is a screen filter that slides over the pickup tube in the tank. The second is a cone filter, about 1 inch in length, that slides into the inlet of the fuel pump. The third is an extenal fuel filter that is connected to the high pressure side of the fuel pump. If you have rust in the tank, they are going to clog. I found that the screen filter in the tank is the first one to clog, if you pour some new gas in it or shake the tank, it can temporarily clear the filter. So the car will run for a few minutes and then clog again.

LongDuck

First off, welcome aboard.

I don't know how much you know about 1st Gen RX7's, but the one you picked is the most complicated and technically advanced 1st Gen RX7 out of model years 79-85, as the SE's were fuel injected with a larger engine compared to the 12a carb'ed cars in the earlier years. That said, if you're mechanically inclined at all, this isn't the space shuttle, and you can learn.

Recommendation; get that car out of your mechanics parking lot and over to your house unless you're made out of money.

Most mechanics have never worked on rotary engines, and outside of what they've read or seen back in trade school - they won't know how to work on them. Basics aside (like fuel/air/spark), they'll be guessing at what they think is wrong, and you'll end up paying a lot of money for diagnostic work. So, get it to your house, and then work with us here to get you up to speed.

The upside is that there are plenty of SE owners here (SE's were only sold in 84/85) that have done troubleshooting on just about every issue you can have in a fuel-injected SE, so you have that support network going for you.

On your initial description, it sounds to me like fuel pressure or fuel pump related problems, so replacement of the high pressure fuel filter should tell you something. Google up 'Black Dragon Auto' and get their latest catalog - you're going to need it, and they're about the best place around to find parts. Also check into Mazdatrix, who I've had good luck with on SE parts over the years.

If there's a mechanic that can help you diagnose issues, get them to loan you a fuel INJECTION fuel pressure regulator, and that will tell you a lot, as well. The Factory Service Manual will be valuable for fixing stuff like this, and most of the SE guys here can help you with specs and what to do. If you're getting good pressure, then look at fuel volume, which is a long test procedure that I won't go in to just yet.

Start by replacing the fuel filter (the big heavy metal one by the pump), and reply back. If the car has sat for any length of time, that's your likely culprit to fix the issue - and be aware, you may need to change it twice, as the new filter will allow for greater flow, sucking up more stuff from the tank, and quickly clogging IT, requireing another replacement. Two filters will pretty much clear all the loose junk, but if it's rust - it'll happen again down the road.

Okay - so there you go.

djs2571

Bad plug wires are something to concider, and if you put your new plugs on - did you get the wires mixed up? I think the cap is labeled and the block is as well. There's an L&T which is leading and trailing, though also lower and top if you're wiring the plugs.
If the air flow meter is stuck it'll be hard to start and die / backfire - the meter is easy to get at, just make sure the door in it moves smoothly. I had a wire break that led to the air meter, it was a ground splice from one wire to three wires at about midway between the meter and engine. You may want to flex some wires to see if it starts working better or stalls out.
If the 6-port is stuck open (search the forum) it may run bad, though i never had mine stick open, they can stick closed though.
the TPS (throttle position sensor) can cause issues here as well, don't replace it unless you're sure it's the problem, but there's a test procedure on the forum somewhere for that too.

Good luck debugging, they are fun cars to learn on.

n8dawg

Thanks for the help guys. I wil be putting new plug wires, changing the fuel filter, and doing an oil change Sunday. I will report back with what I find after doing this.

gsl-se addict

iTrader: (3)

I would also do a fuel volume test (and pressure too if you have a tester). For the volume test, remove the fuel feed in the engine bay. Stick the hose into an old 1 gallon jug. Turn the key to 'ON'. Remove the cover on the air filter and remove the air filter itself. Reach into the opening and push the AFM door open. Fuel should now be flowing into the jug. Time the filling for 1 minute and release the AFM door to stop the flow. If the pump is good and your lines are clear, the jug should be at least half full. If it is much less, you either have a weak pump or a clog somewhere in the line.

If flow is low at the engine bay, I will usually repeat this test before the fuel filter (under the car). If the flow is low there too, I know the problem is not in the filter of anywhere past that point. Besides the filter, the most common places for things to get clogged up is either the screen in the tank or the hardlines that go into the tank or at the pump. My friend's hardlines were so clogged, that the car would only idle. Even driving a few feet on flat ground would cause it to die due to lack of fuel.

n8dawg

Went this morning to put the new wires on and OH MY what a difference it made. Before it would feather idle from 900-1300 RPMs. Now it just simply idles at about 900 perfectly. I acutally drove it about 3 miles. And while it still bogs down a great deal when you try to give it more than just a little bit of gas, I was about to get up to 45 MPH. When there is no more traffic on the road, I am going to drive it the 5 miles to my house and start working on it as much as I can.

LongDuck

Good to hear - report back when you get it home, and we'll try to help out with the remaining fuel issues. The car should have no difficulty getting past 45mph (haha).

widz

iTrader: (1)

does it sound anything like this? that's my car by the way, this happened to me 4 days after i bought the gsl-se -__- not a good first impression on rotaries but i stuck it through and i'm glad i did

http://www.youtube.com/watch?v=8F5y8P_8jeM

we've all been down the "new at cars" road before so don't trip, your're in good hands on this forum..what my problem was is that the gas tank, like 25yrfan has mentioned, was filled with 25 year old gunk that his been there from sitting too long, try to check the gas tank yourself, then if its dirty, which im sure it is, go to a radiator shop and have them professionally steam clean the tank or whatever and line it up again...its gonna be a lot cheaper if you drop the tank yourself, don't be intimidated...realistically, it's only four bolts, you just gotta get down and dirty... haynes manual is like an elementary text book for the newbs

this is what i did to fix my problem
-professionally clean gas tank
-new spark plug wires (cap and rotors is recommended too even though i haven't changed mine)
-new fuel pump
-definitely new fuel filters (all of em if you can), the strainer inside the gas tank can be bought at mazda for about 30 bucks

I recommend that you DO ALL THIS AT ONCE while everything is out...no point in replacing the fuel pump and filter if your gas tank is dirty, its just gonna clog up again

don't forget that your car is almost 30 years old, so don't skimp out on buying new parts to save a few bucks (i did, so i ended up doing more work than i should have).. all of this stuff is routine maintenance anyway for its mileage, if any questions, pm me, i'd reply faster..lemme know if i was any help, i'm always glad to help another gsl-se stay on the road

djs2571

If you do drop the tank, that's when to put the fuel gauge sender unit in the correct orientation. I think they were installed improperly from the factory causing some erratic fuel measurements - both of my GSL-SE's had them turned 1 bolt away from vertical. I could only get one of them out and reinstalling it pointing the correct direction (so the float moves vertically) the fuel gauge was dead on accurate.

n8dawg

Got it home yesterday. Was able to put the fule filter on. When it was pulled off the liquid was dark brown. It didnt really help my issue. I am thinking that the best course of action would be to drain the tank and clean it out. I might as well just start with the tank and go from there. After dropping it down, what do i need to do to clean it? What about the filter inside the tank? What is it called so I know what to order. THanks guys.

gryhll5

i have to drop my tank again,i think the screen is clogging as well.

widz

iTrader: (1)

i highly suggest that you let professionals clean it, they use special chemicals and steam cleaning and all that, u dont wanna contaminate your tank and end up messing your car even more, but thats just my opinion

trochoid

iTrader: (6)

When you get the tank out, buy an impact screw driver to remove the fuel pickup/return and sender units. I replace the screws with allen head ones, preferably SS. Then take it to a radiator shop that boils out tanks. Also ask if it needs resealed. I do that at home with Red Coat tank sealer. 1 qt will do the entire tank.

gryhll5

have the sealed tank,i will take it to the pros.

n8dawg

So check this out. I had syphoned about all of the gas out of the tank when I decided to star it up, let it idle for a few minutes and take it for a spin since the next step would be to take the tank off. WOW DID IT RUN WELL. I drive it around the neighborhood and side roads for about 6 miles and did not have a single issue with it. SO perhaps the fuel filter that I changed just needed a little breaking in? Maybe I syphoned out some bad gas? Could there be any possible reason while it would run better on a near empty instead of a full one?

widz

iTrader: (1)

its the gunk in there that is clogging your fuel system...maybe at low the tank is clean?

gryhll5

anyone know how to unclog the fuel pickup tube? i will have to cut it open if i cant unclog it with a fish tape or something else

trochoid

iTrader: (6)

There is a filter at the end of the pickup tube. I had a tube that was so plugged by gunk that the engine would idle perfect but as soon as it was given any throttle, it died. Pulled the pickup unit, sand blasted the inside of the tube, good as gold after that. It's possible that you drained some of the gunk out that was clogging the pickup. That's usually an indication that the inside of the tank is due for cleaning and sealing.

n8dawg

I am happy to say that I was able to get the tank off today by myself. I know this is simple to alot of you but I am new at all of this so I am happy. I took the part off that hold the 3 fuel lines and saw alot of nasty rust in the tank I took a water hose and filled it all the way and just watched the stuff float around in there. Once it is dry I am going to take it to a shop to get it cleaned out. Anyone tell me how much this is? I just dont wanna be screwed over. Also, the small little filter at the end of the lines looked really nasty too. Anyone have any I idea what it is called? OR have a part number so I can get a new one to put on there?