timing annoyance
 

87, na with tii swap. was running pretty damn good but...

was idleing funny. i knew my timing was a lil off befor, so i went ahead and took off the CAS. lined it up better (it was one tooth off) and placed it back on where the lil dot on the tooth spindle matches up with the pointer on the cas case, and verified it by the way the 2 pointers looked near the pick ups...
the main pully is on the red mark ( i also even tried it with the yellow mark) i start up my car. and now my idle is at 2k. and the yellow and red marks are about 12oclock or 11:30oclock away from the pointer . so i turn the CAS counter clock wise to bring them closer to the pointer at the pully. and it brings idle down but i run out of space to turn the CAS. and the idle is then at 1500.

the idle speed screw (tiny flat head scew behind TB) is all the way backed out as well as the TPS screw . i cant lower the idle manualy any where. i tried skipping a tooth on the CAS but that made it rev funny and back fire. :scratch:

the timing is SPOT on when i put the CAS back in but when i turn on car and its idleing at 2-1500, its 10degree off or so. advanced

You can't set the timing if the engine is over 1000 RPM.

You need to bring the idle down first. Probably a vacuum leak or stuck throttle body component. Sometimes the cable is too tight as well.

ya so i got it below 1000, it was the throtle cable, it was to tight. i adjusted timing. but it still isnt spot on. it requres a lil bit of advancing to run right.
well at least thats taken care of. i hope.

if this has anything to do with it. my rx7 idles at 10 a/f ratio.

Can you adjust the fuel at idle via some type of fuel controller. I idle at ~11.9 afr.

ya but.... if i use my SAFC to do that. then i have to bring down the throtle % and then i'll loose my tuning for 0-5 lb boost and 5-10 lb boost like i have it set to.

why would i want to do that though . i wanna fix the problem not bandaid.



though i did try doing that with the safc. and it wound up just killing the car once i got to 12 a/f. maybe cuz my timming and throtle adjustment is set to be running her at the rich idle

i think the main issue with this idle problem i tried fixing earlier. is nothing to do with the timing. but instead. probably the reason my idle is at 10-9 a/f ratio.
after 1/8 throtle it seems to go to 14 while driving but if i have throtle out at all but not coasting. its as low as 8 a/f ratio. and closer to 10 on idle. also when i take foot off gas, the rpm raise up a tiny bit befor falling. when i use my fuel cut switch to turn off car. for 4 seconds the car runs better cuz its not so rich on idle. and its only on idle. my idle air mix screw doesnt do SQUAT. do you think its that screw over near pressure sensor. or more likely the tps. or both.
everything else seems to be doing great!

Hmmmm...ok lets try this. Re-stab the CAS the way you did before, then adjust the SAFC much leaner at idle end of the graph. Try and turn the car on and see if it will idle. Try and see if you can register a high 11, low 12 AFR during idle. If the car will still not idle correctly, I could only imagine there would be some type of intake leak somewhere. Hope that helps.

You can adjust the idle mixture via the variable resistor, its by the pressure sensor. There is a idle set procedure in the FSM that will tell you how to do that.

yeah thats what i did but it doesnt show anything happening on my a/f meter (wide band)


again. why would i want to do that . i'd eliminate one of the 2 settings my safc can do when i am driving.
that means i'll have one (low throtle) for my idle only and then high throtle for higher boost. it just wont work. it'll be way to screwed up to deal with

my boost is what controles my hi/lo map. not throtle. i tapped into boost sensor for SAFC. at 43% throtle is 0 lb of boost. above 65% is above 5lb of boost.

if i set the lo throtle at 20% which is typicaly around what idle is. then well. that would just be annoying to tune for.
unless some one can recomend a better map for my safc to tune to. my map is pretty good right now..

Do you still have your stock O2 inplace, or are you using your wideband 0-1volt signal for the ecu?

No no no...I'm not saying to change and save your settings. I'm saying to mess with the SAFC just to see if its possible to get the car to idle at an ~12 AFR, and if it doesn't then go back to what it was set to. If it does work, still go back to your previous settings to keep the car tuned as is. I'm suggesting manipulating the idle ARF, but after testing, returning to your previous settings. Sorry about the mix up.

Did you tune it or did you have someone else tune it?

OOOOOOOOOOOOOOOO oh yeah. i've done that but not to the extent of messing with the timing AND safc. i gotcha though.

i said some where above i am using a wide band.
i have an lc-1 with analog out and such. and of cource confermed the numbers with a lap top. still rich as crap :-P

maybe new spark plugs could help. i've had these for 2500 miles. since we first started the rebuilt engine..:scratch:

The variable resistor should have done the trick. If your afr at idle does nothing when you turn it's screw one way or the other, then go to the variable resistors wire at the ECU, with the plugs still connected to the ECU, and monitor the voltage on that wire as someone turns the screw one way or the other.

If no rise and fall of the voltage happens, ring out the wire to the variable resistor or try another variable resistor.

I can turn mine and it'll change the afr quite a bit when turning it.

After fixing the throttle cable, did you then readjust the TPS?

That is insanely rich. My bridgeport idles at 13.5:1.

Do you have any of your emissions equipment in tact? If the airpump/ACV is removed, then the A/F ratio will be far to rich. The factory tune runs the car rich at idle and injects air into the exhaust ports to continue combustion which helps keep the cats hot and decreases HC.

Idle mixture screw...

Sure you don't have any vacuum leaks?

Rebuilds are hard on plugs as they break in. Check the plugs and see if they are fouled.

i have one intake leak that JUST happen infront of the turbo. other then that. i've taken that intake off and put it back on many times. i shouldnt have an intake. idle is very steady.

ALL emissions have been removed.

no i havent messed with the tps since the throtle cable was asjusted as of 2 days ago. but i didnt have to mess with it much. it was just the cause of my ilde being 2300. once i moved it from behind my oil filler spout where it was not causing tention. idle went back down... DOH!

i am most positive the "variable resistor" is the issue. it was all gunky and i couldnt see the screw till i cleaned that lil thing out.
and i did go from n/a to tii with out adjusting that? maybe that is why? i did keep n/a harness when i went from n/a to tii ecu and engine. :scratch:

The TPS will need to be readjusted after the throttle cable change.

A leak before the turbo but after the AFM is a vacuum leak.

The rich idle is due to the lack of emissions equipment and in this case is normal. The variable resistor (if its working) should be able to clean most of this up with slight adjustment.

Aaron, an idle in the 10's is normal for no emissions equipment??? I don't have amy emissions equipment either, and I idle at ~12 A/F.