Brassmonkey

iTrader: (2)

Hey guys,

I'm having some problems with my RX right now. All the problems find their way back to the individual who put my car together, but he is no longer in the picture. So I'm left to try to fix all the problems (he brought on) myself.

The car: It's an S4 86 base model, with a 91 TII S5 engine. I was under the impression that everything was changed to S5, but apparently that isn't the case!

I picked up an S5 throttle body from another forum member, to replace mine. I wanted to replace it because every time I would start the car, it would rev up to around 3000-3500 RPM and stay there till it warmed up. Once it was warm, it always idled at a solid 900.

Anyways, I uncovered the car today (it's been sitting all winter) and the S5 TB I bought is definitely not the same as the one I have in there right now. So, I figure it must be an S4. I've attached some pictures, just to confirm all this.

My question is... can I swap the S5 in for the S4? It would appear that there are certain sensors and connections on the S5 that I cannot find a mate to on my wiring harness (even though I was under the impression I had an S5 wiring harness?).

Any help would be greatly appreciated. If someone would like to talk, I will gladly call them, and if they want to do it online, I use MSN messenger.

Thanks in advance,

Dan

Hypertek

iTrader: (3)

all you probably needed was to re-adjust the tps sensor, that seems to cure some issues like that.

i cant help you on identifying it, but when i took off my s5 turbo tb to port it and put it back on = funky idle like yours, but once i readjusted the tps, back to perfect. Id try that first. Search the forums.

RotaryRocket88

iTrader: (7)

Don't try to use that S5 TB. The fact that your car is using the S4 TPS means you must be using both an S4 engine management harness and an S4 ECU. S5 electronics will not mix with S4 stuff.

Back to the issue you're having, it could be that the adjustment screw for the thermowax cam has been messed with. Typically, the BAC and AWS boost idle speed up to ~3k for about 17 seconds when cold starting, but it's supposed to drop to ~1.5k right after. So you could try unplugging both of those to see how it affects the idle. Maybe the BAC or AWS are staying open too long? Definitely test the TPS as well, as pointed out by hypertek. It can have all sorts of effects on idle too.

Brassmonkey

iTrader: (2)

Cool, thanks for the help so far.

Another problem I'm having as of recently, is that it wont start as well as it used to. I have a switch, which turns on the gas to the motor, to prevent flooding. I crank it over with the switch off, then when it starts to catch, I turn the switch on, and voila! Always has worked, no problems.

Beginning last fall however, I was having problems getting it to start. It would almost catch... but then die out right away. I also didn't like giving it too much gas, cause then the RPM's would shoot up to 3500 and the neighbours get pissed. It would take as much as 5 minutes to get it running sometimes. Now today (first time trying to run it since fall) it was doing the same thing. Would not start! Tried for at least 10 minutes. Every time it would almost catch, I would give it a little gas, and then it would die.

Perhaps the problems are related? I suggest this, because if I JUUUUST apply the gas, I can increase the RPM slightly. If I push it even slightly too far, then it "clicks" open a little bit, and that's when the RPM jacks up to 3500. When I say "clicks", what happens is the piece circled below in red snaps open slightly, and wont go back down unless you physically snap it back.

Hope this clarifies things a bit, and hope it can be fixed!

Thanks.

RandomHero

iTrader: (2)

When you have to start pulling your egi fuse or otherwise killing your fuel to prevent flooding when trying to start, its time for a compression test. If you have poor compression, then at least theres no sense investigating further.

But hopefully the plugs are just fouled up. As to your fast idle problem I cant help you there, I removed all the cold start stuff a long time ago.

Brassmonkey

iTrader: (2)

The engine is street ported, and has about 6000 KM on it, and has never been boosted past 14 PSI. From the day the swap was complete, I was told to use said switch. I did not know much about RX's then, and trusted the guy. The guy moved out west, and is nowhere to be found, and cannot be reached apparently. So, it wouldn't surprise me if he did some kind of hack-job on this.

If the compression is fine (which I'm quite sure it is), why would he ever have put this switch in??

Also, the plugs are brand new last fall.

RandomHero

iTrader: (2)

It certainly wouldn't hurt to check. I had similar starting issues with my first car when it started to lose compression and had to pull the egi fuse to keep it from flooding. After re-reading your post I saw you mention that it has been sitting up for a while.

You got fresh gas in it? Gas can go bad over a period of months and there are also different formulas for different seasons. Best to get the easy stuff out of the way before you start throwing parts at it.

Brassmonkey

iTrader: (2)

Gas was 91 octane, put in last fall, with the correct amount of fuel stabilizer. Also, it had a full tank, to prevent condensation from forming in the tank while it was sitting.

pfsantos

iTrader: (1)

Sometimes, when injectors start leaking, people install fuel cutoff switches to remedy (band-aid fix) the problem, without fixing the problem.

Is the car harder to start after warm?

Also, the clicking, where is it binding...maybe a closer shot? It's quite easy to mess adjustments and settings up with the TB and TPS and BAC AWS when you don't know what you're doing...you may have to correct what's binding, then look into the fast idle mechanism, look at the TB plates, adjust TPS ensuring you're at idle and fast idle is disengaged, etc.

arghx

iTrader: (3)

pull the manifold off and redo all the vacuum routing and double check all the wiring... you have no idea what you are dealing with here. start fresh. you need to figure out what series harness and ECU you have first, and what emissions equipment is on the car

alerx7

i have to pull the egi fuse when i turn my car off or trying to turn it on because it floods up and it doesnt start up after its warmed up and i turn it off thats wen i have to pull the egi fuse and crank it a few and then put the egi fuse back in for it to start , should i check compression ,change spark plugs,? anything would help

RandomHero

iTrader: (2)

^ yes and yes, if you still have starting problems then you may have a fuel system problem.

Brassmonkey

iTrader: (2)

I've attached a couple pictures, to show exactly where it is binding. In the first picture, the position is snapped shut, which allows me to start it and if I juuuust touch the gas, I can get it to increase idle. Second and third pictures are it snapped open, and that's when the RPM jumps up to 3500 ish. The fourth and fifth pictures show where I have to pull up, in order to get it to snap back shut again.

To answer your question, it was slightly more difficult to start hot, but it always started. I always cranked it with the switch off, then when it was about to catch, flicked it on and gave it a little gas.

I knew the whole idea of the switch was fishy from the start... but the guy assured me this is what was done on modified engines, etc. etc.

I have access to limited tools now, but my plan was to drive it to my father inlaws place, who has a huge garage, and countless tools. I would be able to get my hands on anything I needed (I think), in order to work on it at my place though. Also, I'm not an rotary mechanic, but I am also not an idiot. I can follow directions well, so I think I will be able to follow any instructions you guys give.

Thanks again.

Brassmonkey

iTrader: (2)

Well I got the car running, and here's a link to a video of what it does:

http://www.youtube.com/watch?v=N37io5qxSN4

Hope this helps. Once the car is warm, it does not snap open, it moves smoothly from closed to open.

RandomHero

iTrader: (2)

Man that could just be a mechanical bind, it looks pretty nasty in there. Its not too hard to take off the TB, that way you can clean it up and maybe get a better look at why that is binding up.

Hypertek

iTrader: (3)

Lube it up with some wd40 or any penetrating lube and move it around for a while.

Wouldnt be a bad idea to take if off and clean it real good with a soft wire brush and warm soapy water, than put it back on and lube it. Sounds like its just sticking. Than adjust the tps while your at it. Won't cost you anything but a lil time and could help.

WHen i did my TB mod, my throttle was sticking like that for a while, than i started lubing it and moving it til it eventually stopped sticking. No more problems for me.

Adjust the TPS https://www.rx7club.com/showthread.p...hreadid=235007

Brassmonkey

iTrader: (2)

Thanks for the primo link hypertek, I will borrow an Ohmmeter and try that out today!