soru81

Hi!

I've had my car rebuilt, so lot's of stuff was replaced. New turbos with two actuators, new tranny, new shortblock engine, new y pipe, some ney check valves and solenoids that got broken, injectors cleaned, new wires, new plugs, new belts, new o2 sensor and other stuff. In the current moment, the car has stock ecu, no boost pills (it's irrelevant since I don't boost it yet), stock ic, m2 intake, no a/c, 3inch dp, mp and catback.

Now the car is pretty much completed, so I'm breaking it in. I've done about 250 miles with it. After 150 miles I have taken off the cat and I saw some blue smoking at idle, especially with the car cold. I think it's almost gone now, at least at idle. I didn't seem to consume any oil so I contribute it to the engine being new and oiled. What do you think?

Since I'm breaking it in, I never WOT it, nor boost it (occassionally it reaches up to 2 psi, but I'm avoiding it), nor rev it past 4000 rpms. I've never driven the FD before, so I don't know what's exactly normal, so I have some question. Altough, I think there's a lot of potential to make it running better. This are my findings:

1.) I think by the exhaust smoke, it's running rich.

2.) It does rev nicely, but if I bounce it in neutral with quick WOT, I get b-br-rrrrrr. It responds quickly, just not as fast as with part throttle.

3.) When driving, it sometimes bucks a little with part (very light) throttle at aroung 2500 rpm. I think it only happens when engine isn't hot yet. Or it doesn't happen if my airpump is on, I'm not sure about that yet.

4.) It misfires a bit with airpump off, when I rev it neutral and rpms drop down. I have the idle set at around 850 (with tas). It drops fast to about 1300, then it drops slowly to 1100 or 1050 and then very slowly towards 850... usually it sticks around 1000rpms.

5.) Yesterday I've noticed my airpump wasn't working so far, because my connector was making troubles. If I twist it, it starts working... So I have tried how it handles with that. The result is (it blows in the athomsphere, since it isn't connected with exhaust):
A lot more backfiring when I rev in neutral. Really pops very much. But doesn't seem to be increased with normal driving. The idle is now at 1300rpms. When I rev it in neutral, it drops faster than before to about 1250 and goes back to 1300. Also, if I drive it at idle with no throttle (rev are around 1000) in 2nd gear, it's smoother and almost doesn't buck, as without airpump connector on. I think that increased idle is the reason for this.


So, quite some gremlins even before boosted gremlins

So, I'm asking you to comment this observations, what could be causing it, if you have it too or had it too, what did you do to go away, etc... I'd also like to know if there is any driveability troubleshooting guide, I could use to improve my car. I now it has the potential to run good and it will one day.

So far I have checked TPS which seems to be working fine. I have also used the TAS to lower my idle a bit. I couldn't find AAS yet. I did locate the dashpot and it goes in and out smoothly, just didn't have someone to help me with throttle so I can check if it engages right at 2800rpms.

What is the correct order of adjustments for the idle? I didn't find it in the workshop manual, it's just barely mentioned somewhere, not really detailed procedure. Can someone point me to the workshop manual section where I can find it?

Thanks very much for everyone's answers.

soru81

Also, some relevant info. I had my battery moved in the rear bins. The + is connected right to the starter (where the stock + wire comes from the battery), and - is connected to the chassis at rear bins and to the trannsmission. One of the grounds has been replaced, others looked fine. Do you think grounds could be the problem?

And one more question. Does error code always results in check engine light? I don't get check engine light, but I'm wondering whether to check for codes. Is it even possible to get some fault codes without the check engine light?

Thanks!

soru81

C'mon, I know there are plenty people that had similar problems and had to go trough it. Speak up to help another forum member!

skunks

if you have no cats, just get rid of the airpump or just disconnect it. you might wanna also try to reset the ecu. it might be running rich, just keep breaking it in and changing your oil (make sure its always full). check the codes if you want to, i mean it takes like 20 secs only.

as for bucking, if you dont give it enough gas, it will buck at low rpm.

as for "It does rev nicely, but if I bounce it in neutral with quick WOT, I get b-br-rrrrrr. It responds quickly, just not as fast as with part throttle." idk, perhaps your flooding your engine a bit? perhaps your ignition needs some help or perhaps your sparkplugs are kinda crappy, wirebrush them clean or replace them perhaps?

cewrx7r1

iTrader: (2)

The RX-7 is a complex piece of machinerey when it comes to the engine and it's controls.

If you really live in Slovenia; I suggest you:
(1) run a straight through exhaust (you did memntion the cat was removed).
(2) convert the turbos to non-seq or better yet get a single turbo kit.
(3) get an Apexi PFC and Commander. You need this even now if you want to properly tune out the richness of your current situation. With your straight through exhaust, you need it anyway to properly tune.

#2 above removes a lot of the troublesome controls that just mess things up in this car.

Anyway, make sure the map sensor , and fuel pressure regulator are hooked up properly.

Did you replace the engine harness? Should have with these old cars, unless you have a newer Jap version..

soru81

Thanks guys for responding!

skunks:
I have just reset the ecu. I drove and it didn't buck while revs climbed. Overall, I think it droves pretty well. It's just the driveability in the lower rpm, where the car bucks a bit. For example, I let it on idle in 2nd gear, and it started bucking... it didn't happen in fourth gear my revs weren't low enough.

Maybe I'm just little picky and used to the bmw's, which have great driveability (for a daily driver). Even the s2000 was bucking at low rpms and driveability wasn't that great. Similarily rx7 does it. But I don't know if it's normal or not. So it really isn't a big problem, just a glitch and I would like to have my engine running as perfect as possible. That's why I'm bugging you.

So you say it is completely normal to buck a bit in low rpms when decelerating or when trying to maintain speed at idle with no throttle?

The part about the reving at neutral isn't that bad either. It's just a glitch in the tenth of the second when you quickly wot in neutral. After that tenth it revs really nicely...

But thanks for the suggestion, I will check my plugs to see what's happening. They were new from the start (500km back), but b/c aftermarket alarm issue we were cranking it quite some time before we managed to start it. But I don't think it did some harm to the plugs, because if it flooded we wouldn't be able to start it so easily...


cewrx7r1:
I agree. I've gotten awared of it's complexity long time ago, when doing vacuum job when replacing an engine... which is actually simple

I do live in Slovenia, there are two fds here and no mechanics who would know anything about it. That's why I'm learning about the car constantly, and I have already learned a great deal of it. I've realized that here, there's no chance for me but to learn about the car and understand it - the only way for it to run as it should. So I plan to do some work on my own...

I did the #1. The #2 doesn't come to my wishlist since I want a little more in the lower band. I do consider sequential simplification or just some minor simplifications - I already cut pcv, might also AWS, double throttle, airpump... The #3 might come in the future, when I learn more about the car and the tuning itself.

Map sensor is hooked up, I will check the fpr, but it actually isn't much chance of popping the hose since I attached them with plastic clamps.

No, I didn't replace, but I really regret it... I maybe will during the winter, if the car proves troublesome and I will need to dig into it... After reading here how many problems there is with it, I trully regret it.

cruiser

Liar

I guess my FD doesn't count

cruiser

YES. The other Slovenian FD does it also, lol
FDs arent meant to be driven in low RPMs, that is below 2k RPM. I tried driving it like my daily civic and it was horrible. Now I usually drive in one gear lower, trying to keep revs past 2.5k RPM all the time. 5th gear is only good over 110kmh or something like that.

Good grounds helped resolve/minimize some of these problems though.

soru81

Hehe, sorry, my mistake... Well, I drove it for so short time and everything was new to me so the last thing I remembered was driveability in low range )

When need to meet and compare the beasts sometime. Just another 1000km for mine to start boostin her

cruiser

You have time until Saturday when we have a track event. Now go drive those 1000km so you can show up in your FD

soru81

I guess M3 will have to do on saturday... but till next event...

soru81

One new finding: If I rev it in neutral and stay above 2000, there is no backfire. But if I let it fall under 1500 and quickly blip the throttle, I get some backfire. If I do this few times in a row it wil eventually get very loud backfire (sounds like a small bomb).

I'm questioning, whether this means my ignition isn't at it's best at those low revs? Does that makes sense? I have always tought ignition problems reveal in the upper range....

Anyways, do you have any suggestions what's causing it? I cannot be related to the engine not being fully broken in, right? It happens with airpump on or off...Otherwise the car drives nicely... if I stay above 2000 it's smooth. Just if I add throttle at 2000 or under, I get little bucking - not hesitation or something, car accelerates, just some bucking is felt a moment or two, after that acceleration smoothens..

I appreciate all the help, thanks.

soru81

ttt


Please someone comment my backfiring issues... Thanks!

cruiser

Stop worrying about driveability unker 2k RPMS. Its a race engine and expect it to behave accordingly