stranded again what gives? ideas

[atsronnyats]

took the na s4 fc vert out last night for late night drivethru withdrawal, so as per usual i turn the car off to talk to the clown while waiting 4-5 mins i try to crank back up.....miss it (i have to wait for stater to stop) then try again once engine is once again turning over she decides thats all she will do. i cant remember exactly (rough night towed the fc home) but i do think there was a intermitent start there for a couple seconds not sure this is the point where i tried to restart. so yeah im pushing the 7 thru the drive thru get my drink and by a simple math error im only charged for what my girl ordered lol that did help at the time. got the (Free) food and attempt to push start it. it does start but has no ablity to accelerate i e no throttle responce at all. a dies and soon as the rpms die with it. i thinking flooded? i always think that lmao. so i pull the plugs they are dry of oil gas nada... with so black discoloration no ash or carbon deposits but black ya know. i went thru the rigoris deflood procedure with no luck it just turns over. so im thinking i wasnt getting fuel.
OK here is the kicker after driving the minivan to work i get home and for shitz and giggles decide to try and start it. she offers no problems at all , first attempt fires right up to the 3k warmup.... i cant fix when i do have a problem only trouble is there is a problem? the 7 is messing with me ideas neone
btw i am a noob to this forum, came from rx7club recently ATL based

[Phoenix7]

that's a lot going on in one post.

RIght away sounds like a hotstart issue and severe flooding...

1. What's the mileage on the car? How old are your fuel injectors? Have they ever been replaced?
2. When was the last tune up (i.e. plugs, wires, make sure the TPS is set right and no flatspots, timing is dead on)?
3. the way you described the car dying when you give it throttle input makes me think you may have some sort of vacuum leak...have you checked for vaccum leaks?


I recommend you videotape the next time this happens so we can see it...your posting style is difficult to read.

[RETed]

Fuel filter?


-Ted

[atsronnyats]

1.yea all have been changed as of late in miles... as for miles 110k on the car

2. i have replaced all vacuum hoses

3. reconditioned the injectors not long ago (2 & 3 done at same same time)

4. i do have replacement wires and plugs ready to go havent changed bc dont think its neccesary but i am asking yes

5. i guess i could replace the fuel filter i work at advance auto parts will pick one up today

6. changed the fuel pump the first time i had problem like 2k miles ago

7. i had extra coils changed them under the belief it was a spark issue

[atsronnyats]

i just got this car back from when it stranded me in florida luckily at my parents house.
the same moved the car to load my stuff up switched car off. then no restart and failed attempts to push start parked it had it "fixed" got it back a couple weeks ago

since then a idle has never been established... got it to where i can drive it... stopped with the ac running does present a problem also cold starts car will stall

-if any of that information helps

[13brewrx3]

I had pretty much the same problem. would start cold and drive fine but seemed very sluggish till I shut it off. changed all the things mentioned above and nothing helped. I had the compression checked and found out I had low compression in both rotors. The only difference I guess is I was able to pop start mine(i dont know if this matters). From what Im reading you arent able to do this? I may be way off but have the compression checked

[atsronnyats]

i dunno what checking the compression would help honestly only because it "works" fine but has a mysterious hot start issue...definately something i would think to check....and honestly something ive never checked on a rotary...will check fsm

[atsronnyats]

i love the fact the fsm always uses special Mazda specialty tools i give my left nut for i.e. the compression tester as seen in the fsm anyway its mentions checking all THREE combustion chambers(gotta love it)NOTE: should read 85psi or 588kPa consistantly @250 rpm and list a variance ceiling (limit) of 21psi or 147kPa although it does vary with rpm it mentions has a cool XY chart

just a fsm rant thought id mention it

still wish i had the tool lol

[LunchboxCritter]

Have you checked your fuel pump wiring?

You can check your compression with a standard compression tester. Here is an example, you can search youtube for other examples.

http://www.youtube.com/watch?v=DMflTrwgKss

[atsronnyats]

there you go lunchbox....got the stethoscope out no sounds up front when inspecting the fuel pump in back again nothing....so yes a fuel issue definatly changed the filter anyway...

it got dark on me didnt have time to get the multimeter out will break it out tomorrow

btw it did the same thing...cranked right up but died out because it wasnt warm due to bad idle....it did this two more times before it ran and just died out and yeah the final time as if it abruptly lost fuel, trying to start from this point yielded the same results as before

the car was low on oil theres no fail safe is there cutting out out power to the pump?

[LunchboxCritter]

there you go lunchbox....got the stethoscope out no sounds up front when inspecting the fuel pump in back again nothing....so yes a fuel issue definatly changed the filter anyway...

it got dark on me didnt have time to get the multimeter out will break it out tomorrow

btw it did the same thing...cranked right up but died out because it wasnt warm due to bad idle....it did this two more times before it ran and just died out and yeah the final time as if it abruptly lost fuel, trying to start from this point yielded the same results as before

the car was low on oil theres no fail safe is there cutting out out power to the pump?

I do not believe that there is a fail-safe based on the oil level.

The pick up screen in the tank could be getting clogged up, so you might check that while you're checking the internal wiring to the pump.

I would recommend running new wires to your fuel pump, and definately make sure that you have a good ground for your fuel pump. There are some pretty good write-ups about how to do it; however, I'm fairly sure it's pretty straight forward as you're just replacing old wire with new, and securing a better ground.

[atsronnyats]

Good stuff man this stuff is old as I am any way will check the stickies and go from there....

[My5ABaby]

the car was low on oil theres no fail safe is there cutting out out power to the pump?
The only "fail safe" it has is that the idiot cluster will light up for low oil and the buzzer will go off. The same buzzer for redline/low coolant.

i dunno what checking the compression would help honestly only because it "works" fine but has a mysterious hot start issue...definately something i would think to check....and honestly something ive never checked on a rotary...will check fsm
A car with low compression will still "work" very well, it just won't pull as hard, but you'd probably never notice that. Low compression really begins to cause issues with things like hot start and idle.

[atsronnyats]

[comments removed]

[atsronnyats]

A car with low compression will still "work" very well, it just won't pull as hard, but you'd probably never notice that. Low compression really begins to cause issues with things like hot start and idle.

1. all good to know. will check into i have a friend in mind with tool

2. still have the rewire (fuel Pump) to do im reading up on the for NA. also decided to change the fuel hoses/clamps didnt like the condition

[atsronnyats]

so if my attachments work you will see from the fsm what im talking about....remember NA

1. on position no voltage at pump wiring harness (R0-3)...in yellow
note: i know two top supply voltage--- bottom two fuel level sensor

2. From FSM section 4A-74 **NA** when checking voltage at fuel pump relay...
a. ON position checked out
b. ig sw Starting no voltage from Fc which is "fuel pump switch"
c. failed to check (no time) with measuring plate open

until this point i was going to as you know rewire the fuel pump i have the materials and im in a holding pattern suggestions guys based on 1-2 info above

[My5ABaby]

Your fuel pump won't have power unless that car is running or you jumper a connector in the engine bay.

To run the pump, you will need to jump the diagnostic connector at the passenger front shock tower. It's a yellow plug with two connections and you can jump it with as small jumper lead or even a paper clip.

Do that, you'll hear it running if it is. I still vote check the compression.

[NoDOHC]

Actually, I had similar symptoms to this except for a completely different setup. It turned out to be the fuel pressure regulator. I checked compression and had 75psi bounces front and rear, so I knew that I needed to check fuel pressure.

I agree with My5ABaby, you should look at compression. I know for a fact that bad compression will cause the symptoms that you describe. So will bad coolant seals.

If I was helping you I would do the following in the following order:

Get long-hosed compression gauge, remove check valve, install in front rotor leading plug hole. Get friend to crank engine - verify consistent bounces at at least 50 psi. If you have a low face, it will misfire, but will still start. Re-verify compression with engine hot.

If compression is good, install fuel pressure gauge in the supply line to the engine.
Verify about 32-35 psi at idle and 42 psi at WOT. With engine warm, floor gas pedal and verify that fuel pressure maintains 42 psi at rev limiter.

If fuel pressure is good, check for vacuum leaks by starting a spraying starting fluid, pressurizing intake with shopvac and towel and checking for leaks with soap or any other means of testing for vacuum leaks that your mind can imagine.

If no vacuum leaks, verify ignition timing with timing light.

Verify all sensors per fsm.

Check for pressure in coolant system, no strange symptoms with temp gauge, etc. Attempt removing radiator cap while running (using a rag and being careful) before shutting off to verify that the restart issue is still present).

Scratch my head.

[My5ABaby]

75psi is pretty low. I'd expect hot start issues at that point.

[atsronnyats]

Your fuel pump won't have power unless that car is running or you jumper a connector in the engine bay.
using this procedure was able to get the voltage no problem there....
pulled pump replaced works well.... turns out i still had the original one i pulled the screen looked good

[My5ABaby]

using this procedure was able to get the voltage no problem there....
pulled pump replaced works well.... turns out i still had the original one i pulled the screen looked good
Btw, it may help to make your sentences a bit more coherent.

If I'm understanding correctly you're saying your car still had the original pump and the in tank filter looks good.

It's normal to still have the original pump. They're pretty reliable. The in tank filter could look good and still be clogged. I still say check the compression...

[NoDOHC]

75psi is pretty low. I'd expect hot start issues at that point.


I should clarify, this is with a long-hose piston engine compression gauge with the check valve out. it runs about 135-140psi with the check valve in - this is the highest compression that I have seen from an 8.2:1 rotary.

With an in-port compression gauge I get 125 psi bounces (9.2 bar).

If you turn the front pulley partway through a compression stroke and release it, the engine will rotate backwards.

The long hose compression gauge adds enough volume that the compression reading does not match the engine compression, it is still a decent estimate though.

45 - 50 psi bounces with a long hose gauge is adequate to start the engine.

[atsronnyats]

Btw, it may help to make your sentences a bit more coherent.

If I'm understanding correctly you're saying your car still had the original pump and the in tank filter looks good.

It's normal to still have the original pump. They're pretty reliable. The in tank filter could look good and still be clogged. I still say check the compression...

nah sir...

I'm saying that I replayed the second pump with the original one. When I had the problem the first time I purchased and installed an aftermarket pump. It became defective and I have now reinstalled the original pump and its working.

btw checked compression checked out. I now own a compression tester. lol

[atsronnyats]

1. Alright guys, got the car running better by setting the timing as per procedure from FSM.

2. I also adjusted the TPS sensor using multimeter and this also helped alot.

3.. I wanted to go threw threw with the idle speed mixture setting procedure but i have two questions/comments
a. i have no response from variable resistor what so ever (when adjusting) and would like to know if you all had any ideas about the reason for that. Just so you all know i did take it off and verified the resistance across both circuits and it checks out.
b. My second question also pertains the FSM procedure. The first step in the procedure is to attach a jumper wire to the "initial coupler set." My question is where is it. upon searching the issue some people post its next to the coolant reservoir. According to the FSM photo this would seam correct but the photo also shows the battery inches away. I haven't seen and fc3s with a coolant reservoir in this position and there is no coupler to speak of in this suggested position (next to accumulator/drier). having said that, I have to assume the "initial coupler set" is the green plug next the dianostic plug and the leading coils. thanks for clearing this up in advance