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1985 GSLSE starts but won’t stay running efi issue?
Help needed. I have a 1985 gslse. Got it about a year ago I’ve looked through this sight hundreds of times but can’t seem to find anything that explains the issues.
the issues. I got the car let me mention it’s been modified. factory air box removed racing beat header and a somewhat recent rebuild.6 port actuators are non functional. It will run with the afm sensor not connected for a few seconds then shuts off with the sensor connected. nothing at all just cranks.
ive cleaned injectors, got a new fuel tank, cleaned fuel lines and repaired all vacume leaks.
my question is where to start? Also let me mention it will run until I hit the gas with the afm disconnected. It’s running Rich in my opinion
Wonder if it is stuck in cold start. Possibly disconnecting the AFM shuts off the injectors enough to start for a second. Have you tried the de-flood procedure to reset the ECU?
[QUOTE=13b Bro;12594469]Wonder if it is stuck in cold start. Possibly disconnecting the AFM shuts off the injectors enough to start for a second. Have you tried the de-flood procedure to reset the ECU?
i think I did a while back before I cleaned the gas tank and lines I’ll give it a shot again thanks for the input anything helps.
Efi nightmare again with more details that might help
So yesterday after fidgeting around with the gslse I got it to run for about a minute with the AFM disconnected. I noticed that the tach is not reading at all wondering if this could be a problem?
also when I got the car it did not have an o2 sensor so I put one on OEM equivalent I think.
dose that have an effect on this early EFI system?
im Not sure but I think all the adjustment screws have been played with befor I got it at least that’s the vibe I got from the seller. Ex: lean rich, idle and the other on the side of the tps. But everything I’ve read shouldn’t cause it to not start or run the way it dose? Unless y’all have any other thoughts.
are their any switches/controlling loops that I should replace or check that might cause my issues. Water temp sensor possibly or solenoids.
this is my first rotory and I don’t know much about early efi. I’m really close to throwing my hands up and putting a carb on the thing I just want to drive!!!
there's a link in post #2 that might also be helpful to you.
definitely don't give up on it. the whole point to having an SE is the fuel injection - at least, that's how i see it. i feel confident that the SE guys can get you straight with enough time. you just have to be patient, which i know is hard since you want to drive the car.
paging Dr. LongDuck ....
for your main problems, you can check the following:
1. if you have a leak between the AFM and the throttle body
2. the thermo sensor
3. TPS
as far as your tach not working, you'll want to give the trailing igniter a closer look. lastly, for your auxiliary ports, check if the exhaust pipe that activates them is connected, and it is, then check to see if the activator pots are seized.
there's a link in post #2 that might also be helpful to you.
definitely don't give up on it. the whole point to having an SE is the fuel injection - at least, that's how i see it. i feel confident that the SE guys can get you straight with enough time. you just have to be patient, which i know is hard since you want to drive the car.
paging Dr. LongDuck ....
for your main problems, you can check the following:
1. if you have a leak between the AFM and the throttle body
2. the thermo sensor
3. TPS
as far as your tach not working, you'll want to give the trailing igniter a closer look. lastly, for your auxiliary ports, check if the exhaust pipe that activates them is connected, and it is, then check to see if the activator pots are seized.
I appreciate the feedback. I don’t want to give up just yet I’m pretty determined to get this efi functional.
I’ll look into the trailing igniter soon.
no leaks on the intake side I’ve made sure of that.
As for the aux ports I think they are toast unless I get new parts. Just trying to get it running first then I’ll tackle that
I appreciate the links I’ve looked at both studied them pretty hard this will be easy access to use for next time I get to working on the car
First off, welcome board! Secondly, there's a lot of good in the Mazda Series3 Rx7 (*the GSL-SE); which was only offered during 84-85 model years. You mentioned getting it to run without the AFM hooked up, which is surprising as the ECU relies on many inputs to set Fuel Injection cycle, most importantly how much air is entering the system. You will need to troubleshoot ALL of the critical air, fuel, and spark systems to get this car to run properly and be driveable.
Start by searching on my Username (LongDuck) and search terms for what you're looking to learn about. I've been around here for almost 25 years, and everything you need to know is already covered in helping other members. There are also 2-3 active threads covering SE-specific troubleshooting related to fuel and air systems. Please read through those, and also the Factory Service Manual, section 4B, which covers the 13b engine in its entirety.
Basic information about your car can help with troubleshooting. Start with how many miles it has, what modifications have been done to it, what mods have YOU done to it, and what have you worked on most recently? All of these are important to know how best to help you get it up and running. Welcome aboard,
Yes very informative. Long duck I’ve looked through a lot of your post they are very helpful. For I’m a new rx7 owner. I’ve always loved the wankle engine and finally got one for myself.
so just some details no questions in this post input is appreciated if anyone has other thoughts I apologize in advance for the length of this post
My 1985 rx7 gslse with an original 13b has 210000 miles and has had a recent rebuild prior to me owning it maybe 7000 miles on this rebuild maybe that’s a shot in the dark.
car is in great shape for being 35+ YO. Recently befor I got the car it was running and driving just fine. It sat for about a year and the previous owner made some modifications. Racing beat header, intake piping removed and replaced with aftermarket rig up not a direct fit but it’s sealed good no vacuum leaks. Air pump removed. 6 port actuators are non functional. Air control valve removed and block off plate installed. Starting assist system removed. Aftermarket radiator and hoses from racing beat installed. All engine components are still there and hooked up except those of the air control valve and other items I’ve listed. Break booster removed. And the canister on the Passenger side I can’t remember the formal name that’s also removed.
let me mention I know this is a must check. But the fuel pump is aftermarket and I’m not sure on the operating pressure of this fuel pump but I’m able to get an intermittent run so I really haven’t looked much into it on I did change the pressure regulator on the fuel rail as well. The gas tank was an absolute mess and i repaired it myself so I know the fuel system is clean and in proper functioning form. Injection also cleaned I did not send them off and flow test but they are not leaking and they pulse and check out electronically. On all the throttle screws adjustments I’m sure they have all been adjusted in some form.
hears the kicker this is been my dilemma
for the past few months I’ve been chasing vacuum leaks and putting vacuum caps on out of service ports changing all vacuum lines just to be sure and still nothing has changed. I can get it to run with the AFM disconnected but it dose take some effort it doesn’t just start up I either have to push the gas a bit to get it to fire up then if I push the gas it will die if it already running. Now this is with the AFM Disconnected. With it connected it almost feels like it floods out instantly. So I disconnect fuel pump and it will start for a few seconds then die like it should right no fuel being pumped. Plug the fuel pump in start and it runs for a few seconds then Floods out. It’s been a viscous cycle.
NOW today this is really an embarrassing feeling for me. I go outside and look at this car open the hood and start expecting things to see if I’ve overlooked something simple. Long duck I’ve been following your help with someone having trouble with his thermal pellet on the throttle rod this is what I originally went to look at I did find a kink in the water hose going to it so that will definitely need to be fixed. But here’s where I really had an ahah moment I go around and look at the coils and distributor. I think I’m having a problem with my tach maybe it’s something here. I take off the newly installed cap and rotor from distributor. Let me mention I did not put this on its new from the looks of it.take a look at the cap and 1 of my prongs on the cap is bent about 1/8” to the right and about 2mm back that’s an estimate. I’m not really educated on the functional operation of what this could cause. And I’m not sure what this prong affects spark I know timing maybe tach issues? I didn’t look into it to thoroughly. If I can explain it’s the tab on the bottom or closest to the coils if that makes sense.
So got the part on order and also ordered a new water thermo sensor and a pressure tester so I can try and narrow down my troubleshooting direction.
Well that’s about all I hope this helps if anyone wanted to know more about my experience and what I’m working with.
Good description, and the more we know, the better we can help you. One thing that stands out in my mind is that last part about the Distributor Cap and Rotor; it shouldn't be bent in any way at all, and is a critical component of the ignition system. If you get a new Cap and Rotor in the mail, compare them closely and find out what happened with the older one. I once had a BAP Import Parts Distributor Cap that wasn't properly machined and had plastic covering the internal contacts. On attempted start, it bent up the Rotor and wouldn't run, as the timing wasn't anywhere near spec. The new parts should be obvious, and might move you in the right direction.
Also, know that the SE won't idle or run without the Air Flow Meter connected. This is the critical air measurement system which tells the ECU how much fuel should be injected and also has an Intake Air Temp Sensor installed which tells the computer how to manage the other emissions systems (*Cold Start, but you said that's been removed). It sounds like your vacuum leaks may be getting the best of you, but those only matter once your AFM and all associated air plumbing are sealed properly, so the ECU can tell exactly how much air is coming in.
On fuel, the Fuel Pump from Mazda is designed to provide ~38psi at idle and up to ~71psi at WOT. If your aftermarket fuel pump check provide this is anybody's guess, and the various fuel monitoring and Fuel Injection maps are designed for these specific pressures. The O2 sensor is only in play in 4th and 5th gear when cruising at steady state, so they will not adjust fuel injection mapping for pulse duration or timing at idle.
Do you have any of the original parts included with the car? These parts may be necessary to get your car running well,
Good description, and the more we know, the better we can help you. One thing that stands out in my mind is that last part about the Distributor Cap and Rotor; it shouldn't be bent in any way at all, and is a critical component of the ignition system. If you get a new Cap and Rotor in the mail, compare them closely and find out what happened with the older one. I once had a BAP Import Parts Distributor Cap that wasn't properly machined and had plastic covering the internal contacts. On attempted start, it bent up the Rotor and wouldn't run, as the timing wasn't anywhere near spec. The new parts should be obvious, and might move you in the right direction.
Also, know that the SE won't idle or run without the Air Flow Meter connected. This is the critical air measurement system which tells the ECU how much fuel should be injected and also has an Intake Air Temp Sensor installed which tells the computer how to manage the other emissions systems (*Cold Start, but you said that's been removed). It sounds like your vacuum leaks may be getting the best of you, but those only matter once your AFM and all associated air plumbing are sealed properly, so the ECU can tell exactly how much air is coming in.
On fuel, the Fuel Pump from Mazda is designed to provide ~38psi at idle and up to ~71psi at WOT. If your aftermarket fuel pump check provide this is anybody's guess, and the various fuel monitoring and Fuel Injection maps are designed for these specific pressures. The O2 sensor is only in play in 4th and 5th gear when cruising at steady state, so they will not adjust fuel injection mapping for pulse duration or timing at idle.
Do you have any of the original parts included with the car? These parts may be necessary to get your car running well,
okay thanks for all that.
no I don’t have any of the old parts sadly or I would try to restore to original condition.
okay this helps knowing when the o2 sensor comes into play with the efi and emissions
Long duck do you know what contact on the destructor cap I’m talking about the one closest to the coils. Towards the bottom inside of cap. What is this contact related to
is It possible this has been my issue all along bad or incorrect spark timing.
Also is this in any way related to tach issues possibly??
ohh and another thing is it possible that maybe I’m only thinking that it runs without the AFM connected due to fuel already in the housings aka flooding.
another possibility or thought you might know. What would cause it to run without the AFM if at all possible. Bad single from the magic gene box that’s supposed to portion the fuel or tell the injectors to fire or any other variable connected to the control unit telling the injectors to fire ?
Long duck do you know what contact on the destructor cap I’m talking about the one closest to the coils. Towards the bottom inside of cap. What is this contact related to
is It possible this has been my issue all along bad or incorrect spark timing.
Also is this in any way related to tach issues possibly??
it may be written on the cap. just look where the plug wire attaches and there may be a notation (something like L1, T1, L2, T2, etc.). if there is no notation, then see which wire connects there and you will know what the contact is for.
if something goes wrong with your cap/rotor it can affect your tach. when i experienced it, the tach bounced around near idle and low RPM. i don't think it can cause it to go totally dead though, but i'm not 100% certain.
it may be written on the cap. just look where the plug wire attaches and there may be a notation (something like L1, T1, L2, T2, etc.). if there is no notation, then see which wire connects there and you will know what the contact is for.
if something goes wrong with your cap/rotor it can affect your tach. when i experienced it, the tach bounced around near idle and low RPM. i don't think it can cause it to go totally dead though, but i'm not 100% certain.
yes if I’m not mistaken it’s around the trailing side of the cap. I haven’t been around to really look at it. I appreciate it
Point at it, take a picture, and attach it here. That'll help us to know what whether it's a factor or not. The tachometer gets it's signal from the Trailing Coil. When the Trailing Coil fires, the tach sees that signal; therefore, anything that affects the Trailing Coil might be seen as a temperamental tachometer (*coil, Ignitor, spark cables, spark plugs, and Distributor Cap and Rotor...).
Point at it, take a picture, and attach it here. That'll help us to know what whether it's a factor or not. The tachometer gets it's signal from the Trailing Coil. When the Trailing Coil fires, the tach sees that signal; therefore, anything that affects the Trailing Coil might be seen as a temperamental tachometer (*coil, Ignitor, spark cables, spark plugs, and Distributor Cap and Rotor...).
10-4 will do I’ll send one tomorrow. I’m almost 100% sure it’s the trailing side. If so that might explain my tach issues maybe even my starting issue.
hey long duck in your last reply you mentioned that if the AFM is disconnected it will not run or will in other words the injectors will not pulse attached is a video of the car running for a short period of time maybe five minutes with the AFM disconnected. This was after I fixed the gas tank issue. So In retrospect I’m wondering why it would run like this maybe leaking injectors but that would be a big leak but I’m not sure if it’s even possible. So maybe my issue goes beyond that and it’s something with the ecu. These are just thoughts not to ramble
I'm going to be very honest with you here because it will save a lot of time; whoever you bought the car from has hacked it up considerably. There are a lot of shade-tree mechanic "fixes" under your hood, and I'm not sure where to start to try and explain how the engine is running with A) a seemingly broken distributor cap (???), and B) a non-functional Air Flow Meter. In all respects, this car shouldn't be able to idle or run, and yet - it is.
Without trying to speculate as to how, I studied your video and took some screenshots just to see if anything stands out;
Some observations;
1) You have aftermarket Coils (*unknown manufacture) - factory coils were Mitsubishi and bullet-proof. I run ACCEL coils and see no benefit other than newer. Coil operation is required for Trailing signal to the ECU to tell it when to fire the Fuel Injectors.
2) Distributor Cap wiring looks okay from a distance, but I can't make out how the Ignitors are setup, and if wired correctly...
3) uhhh,... where's your radiator cooling fan...? Do you live in Northern Alaska?
4) The dual-sheave pulley on your Alternator is OVER-drive and is probably spinning that thing fast to get a battery charge rate up.
5) Power steering pump appears to be removed or inoperative (*belt missing)
6) Hey, A/C! Does it work?
7) Your brake fluid looks new, but your radiator cap looks canted.
And here; trying to see what's going on with your intake and AFM:
1) The AFM is plumbed in, but is it PLUGGED in? If you've unplugged it, this is where I wonder how the ECU knows how much air is coming in. How does it drive?
2) Where's your Air Filter? Highly recommend installing one, as rotary engines don't run for long when they ingest sand and road grit...
That's my initial observation, and still doesn't explain how this car is running without AFM signal, as the incoming air on the Air Door is what closes the Fuel Pump circuit, and if it's not connected, how is that running? I'm guessing the PO shunted across the Fuel Test Connector... but that still doesn't explain the Distributor Cap damage as you described. Send a pic of that, please.
I'm going to be very honest with you here because it will save a lot of time; whoever you bought the car from has hacked it up considerably. There are a lot of shade-tree mechanic "fixes" under your hood, and I'm not sure where to start to try and explain how the engine is running with A) a seemingly broken distributor cap (???), and B) a non-functional Air Flow Meter. In all respects, this car shouldn't be able to idle or run, and yet - it is.
Without trying to speculate as to how, I studied your video and took some screenshots just to see if anything stands out;
Some observations;
1) You have aftermarket Coils (*unknown manufacture) - factory coils were Mitsubishi and bullet-proof. I run ACCEL coils and see no benefit other than newer. Coil operation is required for Trailing signal to the ECU to tell it when to fire the Fuel Injectors.
2) Distributor Cap wiring looks okay from a distance, but I can't make out how the Ignitors are setup, and if wired correctly...
3) uhhh,... where's your radiator cooling fan...? Do you live in Northern Alaska?
4) The dual-sheave pulley on your Alternator is OVER-drive and is probably spinning that thing fast to get a battery charge rate up.
5) Power steering pump appears to be removed or inoperative (*belt missing)
6) Hey, A/C! Does it work?
7) Your brake fluid looks new, but your radiator cap looks canted.
And here; trying to see what's going on with your intake and AFM:
1) The AFM is plumbed in, but is it PLUGGED in? If you've unplugged it, this is where I wonder how the ECU knows how much air is coming in. How does it drive?
2) Where's your Air Filter? Highly recommend installing one, as rotary engines don't run for long when they ingest sand and road grit...
That's my initial observation, and still doesn't explain how this car is running without AFM signal, as the incoming air on the Air Door is what closes the Fuel Pump circuit, and if it's not connected, how is that running? I'm guessing the PO shunted across the Fuel Test Connector... but that still doesn't explain the Distributor Cap damage as you described. Send a pic of that, please.
okay yes I’ll look into getting different coils accel maybe like you mentioned. Yes power steering is removed I was not sure who removed it. Radiator fan is electrical I’ve removed it to simplify the engine bay at the moment it was winter time here in Texas definitely not Alaska but it doesn’t stay running for long. It will no move when the throttle is pressed in it does not run for long periods of time that video was the longer I’ve ever ran it about 3 maybe five minutes
ac works.
AFM plumed in but it’s not plugged in in this video.
air filter is removed just in the video I have one but like I said it’s stationary
attached is some pictures of coils and distributor yes the bent tabe is on trailing coil con
Yes long duck I have my hands full lol but I’m determined to work out the kinks I appreciate all the help and input don’t give up on me yet
Distributor Cap and Rotor look fine. Ignitors seem to be installed and have the connector boots intact, so they're probably fine as well. Tell us more about what happens when you try to drive it. Was it running and driving when you bought it?
Distributor Cap and Rotor look fine. Ignitors seem to be installed and have the connector boots intact, so they're probably fine as well. Tell us more about what happens when you try to drive it. Was it running and driving when you bought it?
yes indeed it was running when I got it. And it would stay running but as soon as a load was put on the engine it would bog out. ( start the car into first gear and then when gas is applied it would bog out. Now it’s anytime the throttle is pressed it dies out
anyway other than that here is a better picture of the inside of the cap pointing to the bent tab. On trailing lead
While it's a bit off-center, that's not enough to cause your engine to die when you put a load on it. The AFM will need to be plugged in for the ECU to map fuel delivery properly. You don't happen to have a stand-alone ECU or anything else going on, right?
Did the car actually DRIVE at any point that you've owned it? I'm trying to understand if something changed or you bought it this way. Also, the Throttle Position Sensor (TPS) tells the ECU where the driver wants the Throttle. If yours isn't set correctly, that could cause the engine to die. Search my username and "Setting TPS", then read a bit more.
P.S., no need to quote every post - it just lengthens the scroll and makes it difficult to read.
Long duck no there is not a stand-alone on my car just stock.
Next week when I get all my parts in I’m going to check all sensors with a multimeter
I’ve got lights coming to check tps
I’ve already got a compression tester (haven’t tested yet)
change water thermo sensor
change cap and rotor on distributor
test fuel pressure
and anything else I can find to check looking through your post and go thought the manual for troubleshooting. Hopefully I can find my issue. Or if nothing else give y’all a better understanding of my issues. And narrow down the possibilities.
Hey, man - finished up a few other threads and have come back to this one for more study. After rereading everything from Post#1, here are my recommendations, and in order, based on your descriptions and parts you have coming in;
1) Distributor Cap and Rotor - replace these with new parts. This removes the risk that something is bent or making physical contact with the rotor when it shouldn't. When you install the new parts, pay close attention to the embossed details on the top of the Distributor: L1 / L2 are on the bottom spark plugs, and #1 is the Front Rotor, while T1 / T2 are Trailing and are the top spark plugs. The L and T coil wires go to the Coils at the DS fender and Trailing is toward the FRONT of the car. By the way, your Coils are firing at idle, which rules out fuel, Air, and spark, telling me your Ignitors, Coils, and Spark Plugs are probably just fine. More on this later,...
2) Make sure than the car has 1/4 tank of Fuel or more in it (*about 4 gals or so). This will allow enough fuel volume for the pump and Injectors to work. We may end up coming back to the fuel system later, but there are more pressing items to connect and get running, so onto those,...
3) AFM - As mentioned above, the SE won't idle or run without the Air Flow Meter connected. This is the critical air measurement system which tells the ECU how much fuel should be injected and also has an Intake Air Temp Sensor installed which tells the computer how to manage the other emissions systems (*Cold Start, but you said that's been removed). Your Intake Air Temp Sensor within the AFM is compared against the one in the Dynamic Chamber for the ECU to determine fuel injection map, so you need both connected and running. These are robust sensors and don't typically fail, so don't replace them unless you're SURE it's a problem (*aka System Checker '83!). It's probably not, but you won't know until you get the engine to do anything more than idle. Connect the AFM. It won't drive without it.
4) Once all of the above have been done, start the car and see if it idles. If it does, you'll need to make your 2-Light TPS adjuster and use it to set the TPS. The TPS is just a carbon tape section with a slider that moves with the plunger and tells the ECU where the driver wants the Throttle to be. The ECU uses TPS signal to advance ignition, increase fuel injector pulse duration and speed up the engine. If your engine dies as soon as you move the TPS plunger with your finger, it's either not set correctly or is faulty and is sending a bad signal to the ECU, which then shuts down one of the above, killing the engine. It may or may not be flooding, but it is preventing the gradual increase of throttle to speed up the engine.
5) Once the TPS is set, try the following; take your finger and move the plunger in and out rapidly. The idle should change, but not die. As the engine accelerates, it's expecting more air to match the change in TPS, which is metered by the Air Flow METER (AFM). As yours is now plugged in, go over to that area of the engine bay and using a chopstick or wooden dowel, insert it into the AFM throat and push the meter door open. The engine should die. Reason being that you've told the ECU that more air is coming in, however the mechanical linkages at the Throttle Plates have not moved, because you're not pressing the gas pedal. This tests the TPS air metering signal to the ECU. Restart the car; does it restart easily? It may be slightly flooded, as the ECU called for more fuel, but no additional air came with it.
6) With the engine running again, you've demonstrated a hot restart. The ECU sets an air solenoid under the BACV to pull vacuum against the Fuel Pressure Regulator and steps up Fuel Pressure. If the engine restarted fine and idles fine, this system is working. Can you take a picture of the Air Solenoid valves in this area, from the DS of the engine bay? It should look like this;
...in the spotlight above, you should have 2 Air Solenoid valves to the left and a Vent and Vacuum Solenoid to the right. These are idle-related, but I want to be sure they're present on your car...
7) (*because every good list has 7 items!) What happens now when you push the gas pedal from inside the car? Be very specific. Tell us what the tachometer does, what the voltage meter does, what the Fuel level reads, etc.
Based on #7 above, it will set the direction of where we go next to get your car back on the road with you enjoying the ride. Take care, take your time, and we'll get this figured out,
Will do long duck I appreciate the details and steps.
step one complete. I put on the new cap and rotor yesterday afternoon. Plugged in the AFM and good news it started right up but only ran for a few seconds.
I did not do any thing more or check anything else. I just left it how it was. Need to check fuel level and make sure everything else is where it needs to be. I’ll get back with you on the beginning of next week with how everything went. Off to a good start with just step one.
02-26-24, 02:27 PM
