DigitalSynthesis

Hey guys I've searched 'til I'm blue in the face but I can't find a straight answer to this problem:

I just upgraded my '89 ( S5 ) N/A with:

- Brand new NGK plug wires
- Brand new silicone vacuum hose almost everywhere
- Bonez Intake
- Bonez SuperFlo cat
- RP exhaust

I set the timing bang-on, idle seems to be okay (a little bumpy but decent), cleaned and checked the BAC, I've checked every point I can get at for a vacuum leak or something and found none, I've run a tank of FI cleaner, I set the TPS multiple times and its bang on now as far as I can tell, I don't have wierd electrical problems (so far)...

I still have emissions, etc... (I need them, and need A/C 'cause I'm in Hotlanta)...

The ONLY problems I now know of are

- 1 6-port actuator (the rear) is stuck open, the other appears to work as advertised.
- The ECU is sending a 4.8 V (AC) signal to the BAC (with the 10K ohm resistor to measure - 6-7 V was listed as good), but this should only affect idle
- When I connect a timing light to my T1 lead it blinks intermittently, instead of being smooth. This is usually corrected by pressing on the boot near the coil, but it doesn't seem to affect the engine any per se.
- I heavily flooded it right after putting in new spark plugs, but I cleaned the plugs very well afterwards and had to use ATF to get compression up. It starts OK now but needs a little bit of pedal-pushing when its hot.
- Idle quality goes down slightly when the engine is hot
- Slight backfiring which I am told is normal for an engine with these mods.

THE PROBLEM is that I have hardly any power in the low RPMS ( < 3.5k or so )... and the upper range ( > 4k ) is very good, but not as fast as I should think it would be compared to what you guys are posting with your mods. What else can I possibly check that would cause me to be running so poorly at low RPM? When I pulled the spark plugs (when the engine flooded) and cranked it over to get the gas out I heard the whooshing sound VERY clearly even from the driver's seat. It sounded even, but I haven't done a "true" compression check due to being VERY broke now.

Please help me get to the bottom of this mess!

Thanks a bunch guys... sorry if you end up repeating stuff to me but it seemed that nothing I was reading after literally 10+ hours of searching and reading was very applicable. So I *did* try!

BTW you have been SUPER helpful thus far... I hope someday to be able to give back in like kind...

Peace all and let me know what you think!

rx7power

My aux port by the firewall is open too, but I can close it by hand. When I pound the car it opens, but doesn't return to the closed position. Try closing that port by hand and drive it around not passing 4000rpm, you'll feel the lost lowend power.

My point is just get that sleeve that's stuck open, fixed (cleaning, etc.) so you won't be losing the lowend due to it being stuck open. I know how exactly how it sux, so when I get the time I will clean mine too and have it working the way it's supposed to be.

Shoot while you're down there cleaning everything replace the stock sleeves with the Pineapple Racing sleeves ( i will ).

Hope this helps.

88 SE

It's pretty normal for you to have low bottom end power with those mods. MY feels about that way, its pretty slow up till about 4k rpm. Once it hits 5k it pulls like a ****.

Your idle quality can be fixed alot by following these procedures:

https://www.rx7club.com/forum/showth...hreadid=155755

Even with those mods, a healthy running FC will idle near perfect.

See if you can get the idle smoothed out by messing with your idle mixture. If you can't, we can move on to further problems

Let me know what happens.

SureShot

It's probably the combination of a high mileage engine and the stuck aux port actuator.

I had a stuck aux port also. After pulling the whole intake, I discovered the sleeves were OK - only the actuator shaft was stuck. Penetrating oil would probably have fixed it!

(BTW nice clear description.)

Raymr

If you push on your plug wires and things change, that sounds questionable right there. How old are the wires? You might want to invest in a new set. The T1 and T2 plugs can cause major havoc if they are not firing when they should be. Did you try running with the trailing plugs disconnected?

RyosukeTakahashi

Hey a little OT but where did you get the silicone hoses and what size did you buy? I'm having a hell of a time finding a good size.


thanks

DigitalSynthesis

Thanks guys for the tips! Yeah I'm working on it now... my idle is getting really bad *again*... so, I'm dismantling the intake manifold to make sure its not a vacuum leak (heard a funky hissing sound at about 1000 RPM when it was surging)... also, I went ahead and did the BAC transistor modification just in case it was a bad BAC transistor... didn't help in the least. My idle still sucks when the car gets hot.

My TPS keeps going in and out of calibration too... wierd. Anyway, I'm doing a complete vacuum system check and then I'll let you know if I find anything there.

While I'm down there I'll take a look at that last 6 port actuator, see what its problem is....

RyosukeTakahashi: I got the hoses from NOPI (a local, but internet-capable, dealer). They are by Hose Techniques, and I only replaced the 4mm hoses, as that was all I was removing and messing with in the first place. I recommend them... they are good hoses. A lot softer than the hard, brittle, rubber hoses that come stock and way better looking. Just be careful not to kink them.

I'll let you know once I get this round of junk taken care of. . .

BTW, does anybody know what voltage you are supposed to get on an S5 across a 10 kOhm (10,000 Ohm) resistor in the BAC plug (instead of the BAC)? I got 4.88 and the TurboII Idle page said under 5 is bad, but when I replaced it with the recommended part, I got 4.08. Go figure. My idle still sucked, and unplugging the BAC still didn't do anything to it. But plugging in the test lead killed the engine almost immediately.