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Hi everyone, i've been reading everything online because usually when you ask a question you are told to use the search feature, but at this point I am kinda stuck.
I'll need to explain the whole story so you can understand better what the issue may be. The car was running fine 2 years ago, a bit of smoke on startup but goes away when its warm. I even drove it over 80kms from where I bought it to home. The previous owner had removed the emissions system and replaced the exhaust. It was not burning any coolant and would start up right away every time. Also I think the ignition cylinder (where the key goes) must have failed because he added 2 switches for ignition and a switch for the starter. It ran fine in this setup for a year.
The 2nd summer I owned it I added some fuel injector cleaner with a full tank of 94 octane and drove it for another few hours, but later that day it stopped holding idle and would die if you took your foot completely off the gas. it would still start and run, but wouldn't idle. it also started shooting flames out the exhaust when you started to coast and you'd hear popping. (straight piped) this lead me to think it was now running too rich, so I parked it and started the search for the issue.
First issue I found, there was no 02 sensor in the header. So I removed the exhaust and added a bung for a new sensor, and I found the white plug with a single prong near the passenger side on the 2nd rotor, which most sources online say is the right connector. When I went to start the car the fuel pump was not turning on anymore, and upon inspection it was found to only be getting 6v. So I wired up the pump myself(relay, fuse, etc) and added a switch so I could manually control the pump. I think it may have run a bit but it would flood out each time, so I started looking at the front of the fuel system. (fuel filter already replaced) and so knowing that the regulators often go bad I bought a new one and it was doing better but still not running. So I got the injectors rebuilt and I found out 1 was stuck open, and now they area all within 1cc of each other according to my rebuilder. Still no luck. at this point I was running out of ideas so I installed a new MAF just cause but it did nothing.
After moving and another winter I am trying to figure it out again. I replaced the temp sensor on the side of the block under the oil filter, and when I did I found it had actually come unplugged at some point. At this point I tested the throttle position sensor and set it to where it should be, checked the CAS was giving correct readings and it was. After doing this it was starting but not holding idle, and you could keep it on with your foot on the gas but it was rough and smokey. After playing with the idle speed and butterfly adjustments I can get it to start and run but its set to be as fast as the idle screw can be set and a few turns on the butterfly, but even with all that air it only idles at about 800-1000 rpm and it is rough and smokey. When I go to shut the car off by turning off the fuel pump, the RPMs quickly rise and the engine smoothes out, and when it gets to about 2200 rpm it will die from lack of fuel.
I had been noticing the leading plugs always came out wet, but clean. Started checking everything and I noticed that the leading spark was much weaker than the trailing spark, so I checked everything and found only 7.5v to the leading igniter. Temporarily running a 12v (fused) from the battery made the spark appear brighter and bluer to me, but it still runs the same way. While it was running at 1000 rpm I tried adjusting the timing, but either I didn't move it far enough or it was having no effect. Opening the butterfly valve more increased the idle speed but did nothing for the roughness. again turning off the pump caused rpms to rise and the engine to smooth out. I actually have a rheostat attached to the pump as 12v made it loud, so I had turned it down a bit since a stock NA isn't going to need that much gas. I turned the pump down to 8v and the car wouldn't start until I turned it back up. Leading plugs still clean but trailing plugs get dirty each time. I have like 4 sets of plugs and the only leading plugs I have that are dirty are the ones from when it was running properly. I have even had it running for 5-10 min and the plugs just get wet with fuel and oil, so it looks to me like they aren't doing their job, but when hooked up outside the engine and I turn the CAS I do get a spark, and with 12v hooked up it looks pretty strong.
at this point I know I have fuel, I have spark, and yes I have compression, a little less on the rear than the front but nothing is out of spec and they both make a loud chirp from the plug holes when rotating the motor by hand. When it is running, which takes a few cranks, there is a lot of smoke out the pipes. But for the few seconds when I cut the pump it sounds like its running properly the smoke goes away. I am thinking it still seems too rich, but my only remaining guess is that the ECU is failing. So I come now looking for someone who knows more than me about rotaries.
I have been wanting to get a adaptronic plug-n-play ECU, but I'm not certain if that will actually solve my problems at this point.
thanks for any input you guys have, I have been trying for 2 years now and I have also swapped the 4 lug hubs for 5lug, Tii brakes all around, coilovers and just been fixing things in general. I want to get it running so I can start replacing the interior.
I will record a video next time I am in the garage, currently took the plugs out to let it unflood.
edit: I have also used a smoke machine and determined there is no vacuum leaks.
i'm tempted to tell you to double check for vacuum leaks again, but i'll move on. out of curiosity, are the injectors and pump factory (or factory equivalent)? is the BAC still functional?
with regards to the Adaptronic, here's an opinion. considering the fact that there are so much of the emissions parts are missing (which helps with things like this overall), it might not be a bad idea. you will actually be able to tune the thing, so idle control and spark will literally be at your fingertips.
i'm tempted to tell you to double check for vacuum leaks again, but i'll move on. out of curiosity, are the injectors and pump factory (or factory equivalent)? is the BAC still functional?
with regards to the Adaptronic, here's an opinion. considering the fact that there are so much of the emissions parts are missing (which helps with things like this overall), it might not be a bad idea. you will actually be able to tune the thing, so idle control and spark will literally be at your fingertips.
well now that it runs I was going to get some starter fluid and try looking for vacuum leaks again. My injectors are stock NA, rebuilt (+all new seals etc.), and the pump is just a rockauto replacement. (although I think it was listed as 'high performance.') It doesn't have the BAC valve, previous owner removed it.
thanks for the opinion on the adaptronic, I've never dealt with aftermarket ECU's so I didn't know if it would help or hurt at this point.
I haven't had time to look for a few days but the fact that when I turn the pump off it runs like normal for a couple seconds is making me think I have a bad FPR. it was new but that doesn't mean its 100% functional.
Thanks for the help.
I checked the flow at the return line at the fuel pump and it was coming out like a garden hose, not a tonne of pressure but its not blocked,
Only other thing I can think of is the throttle position sensor, I set it to 1k to 5k ohms like the manual says but I'm wondering if thats what the ECU is getting. Tomorrow I think i have time I'm going to get the car out and started and play with the TPS a bit. if I can figure out which pin on the ECU is getting the TPS readout I will check that as well. I figure if its reading resistance it could be the wiring itself causing a higher reading at the ecu.
so today i pulled the car out and tried to get it going. I did manage to get it running for a minute, but it was hunting up and down from about 500rpm to 3000. Most of the time it would rev to about 2k and then die right away. when it was running I played with the idle speed and TPS adjustments, seemed to get better as I increased the idle speed but the TPS didn't seem to do anything half the time. I thought to check the resistance again, pretty sure it was 1k to 5k ohms but I couldn't get a reading off it at all, the pins looks pretty corroded. after taking it off and cleaning the pins a bit I was getting proper reading from the pins A and B, but the manual I found says that between the pins A and C you are supposed to get 5k ohms in both idle and wide open throttle, but it also changed like pins A and B. If this page is correct then maybe my TPS is bad?
have you checked the temperature sensor for the ECU (in the back of the water pump)? it might possibly cause what you're experiencing.
You know I have had the intake off in the last year but I never did that one. I even bought one a few weeks ago but never installed it because I couldn't get it out without removing something else. Thats on me if all my problems have been caused by being lazy and not doing a little sensor. It only took me 30 min to get the alternator off and swap it out just now!
so I can get it to start just about every time now. I'm fairly out of ideas so I made a video today. before taking the video I was playing with the timing while it was running but it seems the best place for it to be was right on the yellow and red marks like it should be, so all seems good in the timing department. The idle speed adjustment is roughly halfway, and the bypass air butterfly that I needed to have open to get the car to even start is now back in the stock position so I presume I did have a richness problem that seems to have been fixed by cleaning the contacts on the TPS and replacing the ECU temp sensor like Diabolical suggested.
first, i hate to sound like a broken record, but you need to make sure you have no vacuum leaks. what i hear in the video is definitely not just a vacuum leak, but if you have one, this will be a very long, bumpy road.
second, are you 100% sure the timing is correct? i'm interested more in the CAS gear position with respect to TDC.
once you've double and triple checked those things, then i think you ought to work on returning idle speed and idle mixture to somewhere in the neighborhood of the factory settings. (section 4A of the FSM). i wish i had more details on this, but i've never had to do this process on on a Gen 2 before.
gas on the plugs is either a rich condition and/or timing is too retarded, or perhaps a little of both.
also, you mentioned the front compression is better than the rear. what kind of numbers are we talking about?
also (again with the dead horse ) i know you mentioned removing injectors at one point. that's a possible leak source, that may not be easy to find because it's buried under so much other stuff. just spit-ballin' ....
also (again with the dead horse ) i know you mentioned removing injectors at one point. that's a possible leak source, that may not be easy to find because it's buried under so much other stuff. just spit-ballin' ....
thanks for the help. I did replace the injector seals last year but I bought some starting fluid and will try to do the vacuum leak check next time I get it to run. today was not that day. I did take a video showing the timing, and I did a compression check and got 75psi front rotor and 70 in the rear. its hard to do by yourself but all the pluses looked the same when cranking. and this is cold, so I assume it would be closer to proper numbers when warmed up. Its has been 2 years since it ran correctly (except for about 5 seconds one time last month, cut the fuel pump off and it smoothed out and went up in rpm until it ran out of gas)) but I rotated the engine by hand once a week to keep all the seals from drying out, and at one point I put a little ATF in each rotor housing.
Originally Posted by rxtasy3
kinda sounds like it's only running on one rotor.
it almost sounds that rough but the exhaust pipes are not connected and I'm getting smoke out of both of them, and smoke out of the plug holes on both rotors after running.
and the fix mentioned is that you need to set the TPS by voltage. Now I had it set via resistance when I had it unplugged and I was able to get it right in line with what the manual says. (1k ohms to 5k ohms) so my TPS works, at least the test says it does, however the voltage readings are way off.
I found a page about the S5 TPS (Cant find a guide to adjusting TPS rx7 fc S5 - AusRotary) and it mentioned it should be 4.5v to 1v when plugged in and ignition on, however I am getting only .2v (yes, point 2) at idle and 0 when full open. (it should be mentioned that I have 14v hooked up to battery for trickle charge so its not the batteries fault)
and when I checked at the connector itself I was only getting .12v.
the wires actually all look good on my car, I even opened the ECU the other day and it looked as new as the day it was made. But before I slice open the wiring harness I'm wondering if anyone has any info on the S4 TPS setting, or if this is caused by a bad ecu, or bad wiring, etc.
So I'm looking at the diagram in the haynes manual and I just wanted to ask some help reading it. 'BrB' is a brown/black wire, 'BrW' is a brown/white wire and 'GR' is green, coming from the throttle sensor. (i'm assuming since my wires are black, red and green that that is a difference in the 86 model)
so if anyone else can make sense of this I am looking at pins '2G' and '2C'? I guess the most important thing is where the 5v is coming from because thats what I have to track down.
after several hours of careful study... the arrows appear to indicate the direction of the current. 🤦♂️
but seriously, after looking at here and the car it looks like the pins on the ecu I have to measure are 2A (+) and 2G (-)
its also interesting to note I started looking up the 'boost sensor' or MAP (manifold absolute pressure) as it is connected to the TPS. This could cause problems if its bad but since it was hard to find anyone who even mentioned it I assume they don't do so very often. It was getting .6v on both the TPS side and the main relay side. This confused me more. diving deeper into the jungle of the forums past, I learned that the car will go into a standard map when the MAP is unplugged. This means I can unplug it and see if the car runs. however I fear that this is but a symptom of the real issue. the secret language of the Haynes manual beginning to come clearer to me, I was able to locate the alleged source of the signal I was searching for. Pin numbered '2A' should reveal the issue. Blast, the pins are not marked! This did not set me back long as the wires gave themselves away! the colour! then it was simple for me to trace the colour of the wire from the TPS, brown white, to the wire on the control module. Bolstered with confidence I then looked for a way to measure the wire, however the crafty creators of this device had affected an insular coating onto the wires, and there was not space enough for my instrument where the wire met the plug. As I understand it, the control unit must be plugged in and turned on in order to find the signal of 5v. Dare I cut the wire, only to inevitably resplice the wire later? I suppose I could shave away at the coating, but I decided I wanted to keep the integrity of my ship intact as possible. I must slice into the loom and look for corrosion. This is a job for tomorrow though, and I retreated to have some ale and relax on my favorite armchair.
anyways thats the plan, I may have been working too hard or maybe the ale but I guess I've read a lot of fantasy books, so there you go. Pretty sure lack of voltage on that line is my problem because essentially the ecu sees .1v and assumes wide open throttle. I also ran out of gas the other day, which would make sense if the car always thought it was 110% throttle.
well I was able to check the ECU and it was giving me the super low voltage readout like the sensor, Checked the wire and it had almost no resistance so it was fine. Decided to take a look at the EGI relay because that powers the ECU and it was not turning on at all. no voltage to the connector. there was voltage at the EGI fuse, so I checked the wire and there was no continuity. Currently running a new wire from the EGI fuse to the relay and I'll report back what that does when I try to start the car.
03-02-22, 04:51 PM
