So I got my FD a couple of weeks ago and the previous owner said it has a BRAND NEW stock motor installed with only 50 miles on it so far. Well I have only put 3 miles on her since and already noticed alot of weird things. At start up idle goes to 3k for about 4 seconds and then idles at a whopping 1500 rpms. The exhaust gets VERY hot. I can't put my hand 2 feet behind my exhaust for 2 seconds without it burning the **** out of me. The check engine light is also on. I've emailed the seller (out of state) many times with no response. Is there a reason why my idle would be set so high? Is the exhaust supposed to be this hot? I haven't had her over 3k rpms and 50mph yet but she also stutters a little sometimes. Please lead me in the right direction! thanks

 

idol sounds like a boost leak, but thats shouldnt be the case on a new motor with new hoses...was it cold when it was started? if so, thats just the aws heating up the car. do you have a boost gauge? if you do..wat are you reading vac wise?

is your pre-cat still on the car, or does it have a downpipe? do you have an a/f gauge? if so, wat is it reading?

this will help diagnose your problem

 

It's not a boost leak, that was the first thing I checked. Yeah it was cold but even after she ran for 3 miles and I parked she was idling at 1500. It does have a downpipe and no to the a/f gauge.

 

The reason the idle was that high at start up was because of the accelerated warmup deal. (Can't remember the exact name). From the factory they do this to help get them warmed up when the engine is cold. Even on mine I would notice even after the warmup it would idle down to around 1200-1500 for a while. Should be normal, however, once it's to full operating engine temp it should drop to 600-750. You checked for boost leaks, great first start. What it might be, and I hope others will back me on this one, is your thermostat. Does it have the factory thermostat? If your thermostat is a lower temp than the factory one, it will open allowing coolant to flow and never really giving your car a chance to get fully warm. I had a hotter thermostat in my rx7 during the summer and I forgot to change it in the winter and mine would do the same as yours. After installing a factory (higher temp) thermostat it fixed the problem.

^It's been a while since this has happened, and I might of said part of that wrong, but I do remember my idle being high due to the degree of thermostat I had in the car.

 

The hot exhaust is likely a result of the high idle. The first thing to look for is a vacuum leak. If it's not that, then there are several devices that feed air into the engine (ACV, PCV valve, etc.) that could cause the high idle if they malfunction.



I'd guess that if you solve the idle, the extremely-hot exhaust will go away.

 

Great! Thanks guys. I'll take her out when I'm off of work and run her for a 5-10 mile trip and see if her idle drops after that. I'll also record exactly what the vacuum is reading and let you know.

 

Just thought of a few more things to check: air bleed screw adjustment (in the throttle body below the intake elbow) and throttle linkage (idle adj screw and cable adjustment).

 

If you start the car in gear, that will disable the AWS (accelerated warmup system).

Btw, good to see you posting, marshall

 

hmmm I do start the car in gear but it still did it. I don't know, I will report back later today. btw, not sure if you were thinking I was "marshall" but I am not. If you weren't talking to me, sorry.

 

IIRC, my exhaust used to get VERY hot when my main cat was still on the car....I found it slightly melted and gummed up when I removed it. Now I can practically hold my finger to the muffler less than 2 mins after shut down

 

He was talking about me; my name is Marshall. Any luck?

 

Thanks, man. I chime in ever once in a while when I think I might have a some-what plausible or intellegent answer.

 

I would assume the idol is set that high due to the new engine and breakin. A lot of builders/installers will set the idle high. I always set it at about 12-1300 for the first couple hundreds miles. What mods do you have, what codes is the ecu pulling? This is stuff we need to know to help you out. I would adjust the idle bleed screw which is located on the TB beneath the intake elbow right inside the lower rear nut that tightens the elbow down. You will need a short flathead screw driver to adjust it. Turn it clockwise and the idle should start dropping. That is just a start. Give us more info and we will try to help more.

 

the only performance mods right now are intake downpipe and exhaust. I haven't gotten off of work yet but as soon as I do I will update you guys. Thanks again for the expert advice.

 

well it ended up just being the idle screw. I guess that they did set the idle high since it is a brand new motor. I'm going to leave it where it is for a few hundred miles. Thanks for the help and info!

 

your high idle could also be a gap in your spark plugs or some wiring is loose in your throttle body ... might want to check that out happened to me

 

i thought in an earlier post you said you "didnt" have a downpipe. if so i, highly recommend getting one put on. the pre-cat's like a ticking time bomb straped to your engine

 

If I said I didn't have one, I don't know why. I don't think I said that tho. It does have one.

 

Naw, it was just the idle screw. I turned it down a little bit and the idle went down. I turned it back up tho.

 

hey what part of va beach r u in?

 

I just moved from Great Neck to near Strawbridge.

 

oh sweet man...yeah i work over here at oceana base.

 

hey if u don't know about our club yet, we have another meet on the 1st. check it out here: http://rx7.meetup.com/55/

 

Yeah I know about it. We have sent some shouts to eachother before recently. I hope I get to see your rex rolling around, I saw the pics on rx7.meetup and that thing looks naaaasty!