Hey guys, there's definitely something wrong with my car and I'm trying to figure out what it could be. It feels like it has less go than a civic. I guess I'll start with my mods list and then go into the symptoms.

Mods: Full catback exhaust, downpipe, midpipe, rebuilt engine with mild street port at around 9,000 miles.

The car used to be automatic but I had a full conversion done to manual. I only had the car for a few weeks before the conversion was done, so it's hard for me to remember what it was like when the car was automatic. I don't remember it having any of these problems, but at the same time the tranny was slipping so bad I could hardly drive it to see.

Now for the symptoms...

1. I guess for starters, my car runs super super super rich. On a full tank of gas I can get maybe 120 miles around town. On the highway though like going down the interstate where I'm contstantly in 5th, gas mileage is normal and fine. And of course a ton of black smoke coming out the exhaust when I'm in boost/WOT.

2. I can boost as high as I want, all the way up to 30 (highest my gauge goes). Now, I don't make a practice of doing this since I know it's bad, but just letting you know that It won't stop boosting. I can make it stay at a certain boost level, like 5 or 8 psi, but if I go WOT the boost will just keep climbing.

3. When I get around 8-9 psi the car doesn't respond...as in I can have the pedal pressed hard down and the car won't go any faster, it just feels like fuel and air and everything is going in, but the car won't put down the power. It doesn't really stutter, but it just doesn't go anywhere.

4. Also my check engine light comes on around 3200 RPMs when I'm getting on it passing someone or whatnot. It doesn't always, just usually when I accelerate for long periods of time, and I don't even boost over 8psi. It goes right off when I restart the car.

I'm thinking maybe the wastegate is stuck shut or something. But could it be anything else? Vacuum line out of place? Something the shop forgot to hook back up after the tranny swap or rebuild? I know I need a Power FC to control the midpipe and all, could the problem go away when I get that installed and tuned?

Any feedback is greatly appreciated. Thanks guys!
Erica

 

What ECU? If you are or having been running that on stock ECU you are really pushing your luck.

Also, do you have a boost controller in there? Have you gone over 14psi quite a bit?

 

stock manual

 

Sounds like you don't have a boost controller either? Did you actually hit 30psi?

 

Yeah no boost controller. When I first got the car and didn't know it could, yes I hit 30psi...or the gauge says I did.

I forgot to mention, my vacuum is only at 11, it won't go go down any further unless I hit the higher boost numbers and even then it will only go down to 18 and creep back up to 11 in a few seconds. At idle, my car only vacuums at around 1-2

 

First things I would do would be a compression check, followed by checking the vacuum hoses. After hitting 30psi, I'd be curious to see your compression results.

Also, your wastegate wouldn't cause 1-2 psi at idle.

 

stock turbos?

 

does it sound like a helicopter at idle?

 

Maybe stock turbos.... It's still twin turbo, but I think they were rebuilt and/or upgraded when the engine was rebuilt. They sound like an 18-wheeler's turbos they're so loud spooling up. A friend of mine with an RX-7 said they were probably sent to a diesel truck place to be rebuilt.

And whether it sounds like a helicopter....I guess you mean choppy-sounding. Yeah...I kinda say lawn mower lol

 

your motor is probably blown, and you can't do 30psi on the stock turbos...it just isn't going to happen, they max at 18psi

get a better gauge

 

hahahahah 30 psi!!!

sorry...

anyway, there is def something wrong, have you replaced your stock ecu?

 

does it feel like the secondary turbo is kicking in?
ill bet its a bad actuator or maybe a solinoid that causing the over boost.

 

Yeah, the secondary turbo kicks in around 3100 RPMs.

The only time the stock ecu was replaced was with the manual tranny swap and it was swapped to the manual ecu.

And if it is a bad actuator or solenoid, how tough is it to get to the wastegate to check/replace it? Would you upgrade the wastegate at this point or wait to go single turbo?

 

By the way, what's good compression numbers so I can check it tonight?

 

Wow! Your boost gauge said 30psi on stock twins & stock ECU. Your killing me, Your gonna break it... And it actually idles at 1-2 vacuum...! What the hell...!?

 

LOL I told you I never let it go over 8, that 30 psi was when I first got it and didn't know it had this problem.

But, I just checked my compression. The rear is 105 and the front is 117. Are those numbers good? What's the ideal number?

 

they're good, 120 is considered perfect

sounds like your boost gauge is bad, and you might have other issues

 

WTF? 30lbs of boost at one time? full exhaust on stock ecu is asking for trouble...keep that up and you'll have to get another rebuild

 

lol 30 psi.. i beleive you hit it but the effciency in it was prolly like blowing through a straw. Anyway make sure you have good spark. your vaccum is low as ****, check for vaccum leaks, spray carb cleaner on everything past the TB ( everything as in anything that uses a gasket) if the idle changes then you found the leak.. what rpm you idling at?

 

you are going to blow your engine realy quick... if it is not already blown...

first, go to the stickies and read the newbie stickies. many of your questions will be answered there and you will learn how to go about making your car run correctly. its a lot of reading, but nobody is actually going to take the time to tell you everything that is wrong right now. and trust me that the list is long give what you have already told us - midpipe and stock ecu is bad...

second, put in a stock cat.

third, buy a decent boost gauge and take it for a spin. come back here and tell us what your boost pattern was or search if it is anything other than a 10-8-10 boost pattern. actually, after reading the newbie stickers, you might not need us to diagnose the problems since you might already understand the issues.

 

i am going to look at her car

 

its actually prob your actuator, i dont think its a solinoid unless you got a boost controller.
you cant upgrade your wastegate on a stock turbo set up.
to replace the actuator is not that hard as long as you got the manual. but i want to hear other people suggetions on what else it could be or if someone else agrees w/ me.

how many miles do your turbos got? if its already been said sorry but im too lazy to re-read.

ian

 

what is the gauge at when the car is off?

 

You could do 30 psi if the flow was restricted. Either way, sounds funky. Bring that car to a dedicated RX mechanic and get it checked out.

 

does anyone else agree w/. me that its the actuator?