I aquired an '84 gsl-se that didn't run. It is a very clean car and is complete. It would blow the 20a fuse under the dash every time I turned the key and wouldn't run. I traced the short back the the choke and check relay. I fixed the relay and the car started right up. I can't get it to run for long. It is hard to get it to stay running at all untill it is warmed up. After it is warmed up, it will idle great for 5-10 min but than sputter and die after a while. It will always start right back up. The car did sit for about 2 years.

The car had 5 galons of bad gas in it that I drained. I changed the fuel filter, spark plugs, and cap and rotor. I also cleaned the air flow meter and Throttle Body. I also ran fuel injector cleaner and seafoam through the car. I did find that the TPS is sticking ( I have a good one I will install tonight).

It almost feels like the car is starving for fuel. I have not tested the fuel pressure yet but the I can hear the pump running and feel the fuel flowing. The car does have a home made fuel pressure bleed-off made out of two brass t's and section of 5/16" line. Could the bleed off cause fuel pressure drop?

I still need to test the AFM and temp sender. I also have not tried running codes. Anything else I should look for?

I'm completely new to fuel injection.

 

pics of the car: https://www.rx7club.com/build-threads-293/my-light-beige-gsl-se-restomod-build-924632/

 

Check the fuel filters again, including the little screen prior to the fuel pump. If you're finding junk in them, especially the screen, that's your issue. If you clean them out and they plug up again, it probably indicates that your tank is rusting from the inside -- most likely due to the bad gas rotting it out.

You can have it reconditioned to save it (there's amazing stuff to make it better than new) or drop in a new tank.

 

you're talking about the screen in the tank right? I can get to that through the access panel in the hatch area right?

 

He's referring to the little cone filter on the input side of the fuel pump. To access the in tank screen on the fuel pick up line you'll need to drop the tank.

Post a pic of this bleed off thingy. The FPR is on rearward end of the fuel rail, the Pulsation Dampener is on the front.

 

also the rich/lean screw was turned all the way to lean. How much should I turn it to get a good starting point.

Here is the bleed-off:

 

Yep.... thx trochoid!

 

also there is a wire conector with two wires coming out of it that look cut and frayed. They are just exposed wires. it sits to the rear of the oil filler and the conector is laying on the block with the wires sticking out twards the fender. I don't see anything else with frayed wires for these to conect to. the conector looks just like the one in the pic above to the left of the filler.

I will take a pic of this tonight, I will also see what the wire colors are.

 

Ididn't know there was another filter besides the large one.
I changed this one: http://www.mazdatrix.com/c-1.htm 13-4800-N304

 

The fuel pressure seems to be good.

The frayed wires turned out to be the intake air temp sensor. I'm going to try and solder the wires back on.
Where can I find a new one?
Does the FC use the same one?
Could that cause the car to not want to idle?

I cleaned the BAC and the air supply valve. I also changed out the ait flow meter (I had an extra).

I'm going to test the Water Temp Sensor as well.

 

Air temp sensor not really important. It'll run fine without it.

Set L-R screw to around the middle. It is really more of a fine adjustment, so the actual position is not too critical

The fuel bleed thing is something the Mazdatrix sells as a band-aid for leaking injectors. There is a pin hole between the two tees that allows the pressure to bleed back to the tank after you turn the car off. You can take them off.

Water temp sensor in the back of the water pump is an important one. The sensor can go bad, but also the connector tends to get brittle with age/heat and you may not be making good contact.

Throw a fuel pressure tester on the car when starting the car and letting it run. If the fuel pump is weak or cutting out, then you'll know it.

If it is lacking fuel, it could be several possibilities. Fuel pump relay, trailing ignitor (would cause the ECU to lose signal to fire injectors), fuel pump could be getting too hot, etc.

Also make sure to do a fuel volume test. Take off the feed line in the engine bay and put it into a gallon jug. Turn the key to 'ON' and prop the AFM door open. The fuel should start flowing. Time for 1 minute and then cut the key off. If the pump is working well and the lines are not clogged, the jug should be half full or more after 1 minute. If not, you probably have a blockage somewhere.

There is also a thread in the archives that'll tell you how to check codes if you haven't done that yet.

 

I'm wondering if the injectors aren't leaking and that's why the bleed off is there, to prevent flooding when shut off. The FC AIT is the same as the SE. To set the fuel mix, you really need a wide band.

 

-First I'm going to check the TPS to make sure it is set right.
-test water temp sensor.
-set the L-R screw to the middle.
-try the fuel volume test.
-do a code check (I did see the archive and I bought 2 LEDs to check it)

I have a friend with a better bleed-off setup I'm going to install. I have an extra set of injectors that I'm going to have cleaned in the near future than I will loose the bleed-off completely.

Thanks for all the help.

 

I'm starting to think that it isn't runing lean but rich. It is very frustrating because the car will start right up and rev to 2-3k and drop back to idle. It will than stay at ide for a minute or two but than starts to sputter. It doesn't make a difference once the car is warmed up. Adjusting the idle speed doesn't seen to change anything. The car will not rev smoothly and it will not go very high. Sometimes it will smooth out for a few minutes but than it goes back to sputtering.

Any thoughts?

 

I soldered the intake air temp sensor back together although I don't know how good of a job I did. I will test it tonight with the meter. If it doesn't work I will pull one out of the junk yard.

 

Made a bunch of progress. I did end up pulling the tank and I also bought a new fuel pump because the old one died.

Where can I get a new tank pickup screen?

 

The car is back together and running good. I have a few more questions.

When I first start the car it sends out a plume of oil smoke out the tail pipe, what could cause this? After the inicial plume it stops and runs great. I do still need to change the oil. I will probably change the oil again after 500 miles because I don't know how bad it really is.

Once the car warms up it will idle at 800rpm but if I drive it it drops to 500-600 rpm (no sputtering or stalling). Is this normal?

 

Since you have that bleed off thing, I would say its a leaky injector dripping a little fuel when the cars off. When you start it off, its burning that puddle of gas and making some extra smoke.

 

Good Idea, I don't know why I wasn't thinking about that.

 

The car is running good. I'm having a problem with rust in the tank but I'm getting that worked out.

The problem I'm having now is an oil leak at the oil cooler. I removed the oil cooler and found that the cooler was cracked where the lower line comes in. I had it fixed at a welding shop and he did a great job. You almost can't even tell that it was ever cracked. I replaced the crush washers with new ones. I was able to get sone to work from the parts store. They are copper crush washers. I ordered some through Mazdatrix that will be here hopefully this weekend. THe leak is worse than it was when I started. I can see the oil coming out around the crush washers.

What could I be doing wrong? Should I not have used copper crush washers (mazdatrix's don't look copper)?

 

Depends on how the crack was tigged.. When I have them tigged, I cut a groove in the crack on the side and top of the bung. That gives a spot for the tigged aluminum to bite into and fill. The top of the bung then needs to be finished perfectly flat for the crush washer to seal. If the bead didn't penetrate the crack deep enough or the sealing face of the bung isn't perfectly flat, it will leak.

The other problem is torquing the hose to the just right ft/lbs. Tighten the fitting finger tight, then turn 1/4 turn with a wrench, start the engine, then gently torque until any leaking stops. Crush washers are not re-usable, have extras on hand.

 

When I dropped the cooler at the welder I asked him if he would put a v groove in the crack. He did and he also finished the top of the bung so it would be perfectly flat. He told me he specialized in auto welding and did oil coolers all the time.

I think my problem is I didn't torque the hose right. I have new crush washers on there way from mazdatrix that should be here later in the week.

 

Good luck, keep us posted.

 

Thanks. I will be working on it this weekend.

 

i'm interested to see how this goes....to bad i don't have my car in the springs...i could show you the work that my friend did, putting an fc oil cooler on my car....