Hey guys, had a recent rebuild with large streetport, removed secondary throttle plates in UIM, free flow exhaust, etc. Car is not broken in yet but I am disappointed in the way it runs. Kinda shitty idle, idles high sometimes, pops and backfires when shifting or going off throttle. Not what I would expect. Car has yet to be tuned. Will this get better or is this what I should expect from a large streetport with mods. I realize it will have a loping idle but I expect it to idle consistently and transition into smooth open throttle. Someone tell me I didn't make a mistake going away from stock.

 

This in itself should tell you to wait until the car is in top running condition before you make any judgements. You'd be surprised to see what a tune can do.

 

if you have a stock ecu it will run like crap if you have a stand alone that was tuned to the old engine it will run like crap. I would expect the engine builder to have put in some break in settings if you have a stand alone and if he didnt then you may want to look into it.

Be very patient as break in is EXTREMELY IMPORTANT. It is not for tuners to use an excuse to waste warranty time. Once you have finished the slow painful break in go get it tuned and you will be smiles for miles!!!

 

Can somone list what must be done during break in to make the engine run its best later on?

What steps should i take when i first get a re build?

What sort of tune am i looking at getting when i get the car rebuilt?

 

Everything you have explained is tuning related and will be fixed when you tune the car.

thewird

 

if all else fails.. just make sure to make a valid complaint to the shop before your warranty expires. its just your tuning tho. my buddy has his motor rebuilt and his idle started to die out, he called and they said "sounds like its blown" but walked him through some tests. the idle just needed to be adjusted. car is having a gt35r put in on it now. so jealous. lol

 

Sounds like you need to do some troubleshooting/tuning of your own right now. The idle can be adjusted following some simple steps outlined in this forum ( search ).

You could have a vacuum leak somewhere, again covered extensively in this forum.

If everything is sound and as it should be, then wait until the 1k mile breakin is performed, and perform it as you should.


LAter

 

I checked for vacuum leak. I'm gonna try and adjust the idle again when I have time. Check the TPS and all. Just in a hurray to have this thing purring. It's got a Power FC and I put a tune on it that I downloaded from BDC motorsports webpage. Brian, the guy that is gonna tune it, suggested this as it was running really rich on the Power FC base MAP. The tune was for a car that very closely matched my own. I guess I'll do some troubleshooting and wait for the full tune.

 

Check the TPS. But your car motor could still be building compression. The reason you're getting the popping though is from a rich condition on decel. It's perfectly normal. I use to dump 4 foot flames due to a REALLY rich map. You could also be running rich at idle, this will surely cause a erratic idle. Unless your idle is high I wouldn't suspect a vacuume leak.

 

if you have larger primaries it will run like *** until it is tuned.

i've yet to see any streetported motor that idled anything less than smooth. you simply can't cut away enough metal on the stock irons to make it idle rough unless you do something drastic like a J-port.

 

As was already stated, you are in DESPERATE need of a good tune. Just be patient in the meantime, and break the motor in properly.

The tune should fix all of your issues, unless of course you do have a vac leak. I'd be willing to bet you just need a tune though.

 

My tuner is the one that gave me the map because the Power FC base mod MAP was WAY to rich and the cat converter was running red hot at idle. Therefore I could not drive it to break it in. The MAP that is currently in is almost identical to base mod MAP except it is leaner at idle and I no longer have the red hot cat.

I realize that it is not broken in and need some major tuning. My main problem is that I can't stand the popping and backfiring when shifting and coming off throttle. Some people say it's normal but there is no reason for any car to do that especially with a cat converter. Makes the car sound like a POS.

 

It's popping and backfiring because it's running pig rich...There's raw fuel getting into the exhaust. It's as simple as that.

Once you get it tuned it will alleviate most of that problem.

 

popping is actually associated with running lean, the pfc has a fuel cut feature same as the stock ECU except that the transition are often not as smooth as the stock ECU until the maps are tuned out to get rid of the lean condition until it goes into full fuel cut on decel.

basically what i'm saying is you're actually running too lean on decel not too rich like many people here are saying.

 

[QUOTE=chemicool;8677136] Car has yet to be tuned. Will this get better or is this what I should expect from a large streetport with mods.QUOTE]


Key words, untill its tuned it will be crappy..... why would you spend thousands of $$$ without knowing what you were getting into. did you builder have any similar setups so you could see the final results?

 

Make sure your MAP sensor, TPS and O2 sensor are all within specs. Attach a VAC and VOM meter to the MAP to see if it responds in the proper readings. It seems like the PFC is still "hunting" for the correct idle.

A quick tune will clear up some of the smoking, but will not be correct until the engine is properly broken in. The apex seals are still "adjusting" to the rotor housings. Have patience in breaking it in, its tough not to boost that baby, but it'll be worth the time. Good luck on your machine.

 

the idle hunting is the most common problem with the PFC and is often corrected by cutting the 4 wires on the harness (see the Apex'i installation instructions) and by adjusting the screw recessed between the lower studs for the throttlebody elbow. do a search in the PFC subforums.

 

I appreciate all the feedback. I did spend thousands and knew what I am getting into. Just sucks to have to drive it to break it in when it is running kinda crappy. Kinda takes the fun out of it and is embarassing. As far as it being too rich or too lean it popped and backfired a bit when it was running pig rich too. So lean or rich I don't know. In a couple days I will be installing my wideband and we'll see.
I checked my TPS on the PFC Commander last night and it was mostly in range. The VTA2 was at 1.33. A little high so I will adjust but I wouldn't think that would cause problems.

OK so here is my question to the RX7 masses. How many of you have had a rebuild with large streetport and have "tuned" cars that still have the popping and backfiring? I asked cause some people on the forum say that "backfiring" is normal for these cars and I don't think it would ever be normal.

 

My FD never backfired with either the stock catback, or the PFS catback I had after that (even with the DP installed). With the RB Dual-tip CB, I do often get backfires while shifting, etc. I think the lower restriction (free-flow) CB's are more prone to backfiring.

 

If tuned correctly it should not be backfiring.

Also if you TPS is out of range it will cause problems. Usually though, i would not mess with the tps until your engine is broken in. Otherwise you will just keep messing with it the whole time of break in.

I am almost done breaking in my 1/2 bridge and yes it is frustrating but once you start getting into the upper miles of the break in, it is a lot nicer.

If the car is giving you the most problems while it is warming up and driving that can be taken care of. It is just your water temp correction table. You can adjust it so that you are not running pig rich or too lean during warm up driving. Once again though these values will change since your compression is changing.

Just take your time and be patient.

 

lean out the cells in the P1 and P2 rows

 

Man I got problems. I started it up again tonight and was letting it warm up so I could double check the TPS settings again and maybe adjust the idle. I let it warm up. Idled at about 1400 and would not go back down even with idle bleed screw under the throttle body all the way in and all idle adjusters completely slack. Then I happen to go on the turbo side and the section of the turbo I could see was bright red!! This was after idling at 1400rpm for about 10-15 min. I shut it off and could hear gurgling and metal creaking. The water temp never got past 85C. WTF! Am I screwed?

 

You need to relax. When I was breaking in my last motor, I had a lot of symptoms similar to yours. But before I got the car back, and before I broke it in, I knew enough about the condition of the tune and also the motor to judge that everything was, at least as far as the motor goes, OK. After the 1k mile mark, AFTER I TUNED IT (which means repeated adjustments... I've changed the maps at least a dozen times), I started giving it hell, and it's been great since. About 15k miles now on the engine. Idle quality, off boost engine behavior seems to get better after the "break in" period.

Gurgling and metal creaking happens in my 2001 honda, why should you be worried about it on your car? About the turbos glowing, I've never seen that happen...

 

Turbos glowing...are you sure it wasnt the manifold and not the turbos? otherwise that would be a lean condition if its the manifold.

 

I'm new to rotaries, but on 4cylinders, retarded ignition timing can cause glowing manifold and turbo at idle.