But how are you actually setting such timing on the stock ECU?

 

I think you need to take the car to someone who knows what they are doing.

 

i know what im doing im the one who rebuilt the motor an ported it. im not taking it to a shop so they can screw me outa my money an tell me something like well you dont have any emission sensors or any of the throttle body stuff were going to have to put them back on. That could be the problem then its all back on an still the same thing

 

using a timing light with a dial for degrees an turning the cas. is there another way? an jumping the green plug like in the book

 

There's your problem!! Set the timing BACK TO STOCK BEFORE YOU BLOW IT UP!

 

turbos fuxored

 

and/or timing is way out

 

i did set it back to stock and it still did the same thing i changed my iat sensor today it made a little differnence but i found my manifold was crcked its weird cause there wasnt really a exhaust leak. but im going to changed my tps see if that fixes anythin if not im putting my ms in

 

There's your problem.

 

The problem could very well be the turbo but it is unfair to just jump to that conclusion just because it is an eBay turbo. Now, one question about the turbo...Is it the T4B with the big hotside (1.15 I think) that says "13B turbo" on it or something to that effect? If so, then the compressor is in fact quite small.

Too small a turbo doesn't explain why the car sputters under boost. The TPS likely isn't the issue, but try checking the pressure sensor.

And I think you're spinning your wheels with the stock ECU...If you have a standalone sitting around, install it.

Also, know that you can't just turn the CAS to some ridiculous angle and expect the timing to be correct. Are you sure that it is stabbed correctly and that you checked the timing under 1000 RPM? After 1000 RPM, the ECU begins advancing...

 

What BOV do you have? I havnt seen anyone mention your BOV. This could be leaking. I actually had a buddy with a greddy type -s leaking under boost. Would only make 5 psi and it took days to figure it out.. We cut out a soda can and used it as a gasket to block of the BOV mounting plate and bolted the BOV ontop of it. I dont know if I explained that right but, thats how we found it. Granted there was back spin on the turbo but dont just let off the trottle let the boost disipate.

Also, its totaly possiblt to have a boost leak but not a vacuume leak. I personally had a coupling that would leak under boost, but seal under vacuume. I would double check you clamps and hoses, even triple check. Sorry I'm **** when it comes to them..bad expericanes lol XD

 

Aaron,

And if the turbo was assembled improperly? It could be holding boost at 5psi but the computer is still seeing it as WOT load. So everything isn't working together ... to much back pressure in the engine, to much fuel coming in, etc etc. Sounds more of a turbo issue to me then anything else.

I've seen quite a few turbos only hold around 5psi or how much, and be able to SPIKE a couple psi higher, but never hold. In fact I'm going through that right now with my "upgraded hybrid turbo" from a shady shop. They built it so poorly that I couldn't make more then 10psi at 5000 and it would just sink up to redline (that's with the gain set to 75!!).

Your compressor may be garbage.

So my candidates = 1. Turbo = byby 2. Timing is somehow not coming up right 3. You have a leak somewhere.

 

MaczPayne
the turbos fine before i rebuild the engine it boosted 12 psi perfectly fine. I dont see how taking it off putting it under a table. Then putting it back on a rebuilt motor is going to cause it to all of a sudden be assembled incorrectly. WHO CARE IF ITS A DAMN EBAY TURBO. I knew someone would bring it up. Ive never had a single problem with a ebay turbo its been on my car for over two rebuild street port an half bridge. AN never had a single problem with it.

Mr.AARON lol
SO anyway aaron im going to put my ms in today i lost my db9 cable lol i need to tear my house apart an find it. Also i need to go get the correct iat sensor i took mine off a saturn cause they are made with the same motor as the cavilier. But im going to go get it. I ended up cracking my manifold through this whole problem. SO i need to get it fixed an renforced with some brackets. But Ill write you if i cant figure something out offf you site for the ms install..

hurleysurf24
IM taking my turbo an stuff off today an ill look into it see if maybe something is goofy. Also im going to check see if maybe my cat might be clogged i did relized when i rebuilt this motor it sounded a little quiter. DIdnt much think of it cause i use new seals

 

ok im getting closer. today i got the manifold welded. i found one of my fittings on my wastegate was barely on i hit it on accendent an it popped right off.. so i screwed it back in. Put it all back together. The popping an studdering it gone but still that five psi i might try changing my boost controller an im going to change my pressure sensor agian an my tps

 

Retard your timing a few degrees. Like someone said earlier, setting the timing is more less easy. Set your timing light to just 0 and of course put a jumper wire in the green initial set coupler, then point the light down to the crank and set your timing, then give your self 2 more degree's of retard timing. You can also make a mark on your CAS where stock timing is and then another mark where your retarded timing is. I'm saying retard your timing in order to achieve a little more boost and there is no harm done or worry about detonation by retarding timing. My rule is to retard my timing a few degree per psi of over stock boost. You're aiming for 10 ish? retard your timing 4 or so degrees. If you had something to program your ECU with like an Rtek 2.1 I would say set timing to stock and set a parameter that would change the ignition based on the boost like I said. But if you're turbo is fine, your exhaust is free flowing, you're not running lean or heavy rich, and you're certain there's no leaks, then just try this and if I'm wrong set your CAS back to stock and find another idea.

 

Chris i blame the tps too its ok. LOL but thanks man ill give that a shot i still wanna check an see if maybe my cat its clogging up a little bit. but ill give this a shot tomorrow am an check it out. i wanted to get a rtek but i like not have a maf so i went an bought a megasquirt about 6 months ago. Never got the time to put it in cause i live in colorado an snow its gay. so im going to try to get that in asap. Rtek is probaly a little more user friendly but ill give this ms a shot see what i can come up with.

 

Could it be a pre-turbo exhaust leak? I assume you're running a cdm manifold along with this turbo. If that's the case, maybe the flanges need a good resurfacing and proper gaskets.

That's really the only thing i can think of. Dunno about the hesitation but you should be able to make more than 5 psi with that turbo. Check your wastegate again with somethign that can measure the pressure it opens at. I know you already tore it apart and **** but check it again.

 

so its not my boost controller i had my friend check it on his s5. im thinking maybe i have something stuck in my intercooler so tomorrow im going to pull all my piping off an look through it maybe something could have fell in there during the time i had the motor out. if not im thinking it could be my wastegate maybe there was a little tear in it an i didnt see it ill have to check in the morning

 

ok so today i took my wastegate off an completley torn it down cleaned an rebuilt it. Still 5psi went over all my vac lines shot starter fluid around the engine found one vaccum leak. it was one of my block off plates. Fixed it was happen hoping for the best an still 5psi. Even checked my line going to my boost gauge for anything holes kinks. im starting to lean tord my turbo but i dont see how it could go bad just sitting there for a week. between rebuilds

 

to much shaft play, some fins are bent, maybe the plunger isn't opening enough in the turbo ?

 

At this point, I'm going to say try another turbo.

 

yeah im going to go through it one more time look at my intercooler take everything off see if maybe something is stuck in there an if not. im going with my turbo so ill let you all know thanks for helping me guys. an aaron what year can i get a iat sensor for my ms ill just go to the junk yard an grab a pig tail to

 

I believe the air intake temp sensor or AIT or IAT intake air temp sensor (at least thats what I think you're refering to) is the same for both S4 and S5 turbo and non turbo engines. For some reason I can't remember where on the NA's its located at the moment... on a turbo its easy just right at the throttle body intake triangle pipe. ... That question was for Aaron though, disregard this info ^ haha

Anyways,
So there's no exhaust restriction, you've disabled the wastegate once already, the BOV or recirc valve is holding the pressure, there's no leaks, timing changed nothing, no turbine leaks, the twin scroll valve isn't causing problems (if you have a TII manifold) and no vac leaks.... Check shaft play, consider rebuild... again. Even I'm out of ideas and I don't understand why too because I've had beaten stock turbo's with shaft play and chipped fins and all still boost up to 8 with their wastegate turned off. Nothing else could be wrong but the turbo unfortunately

 

oh no i know were it is on the turbo engine i was asking about what year i should get a gm iat for my megasquirt. But no its not the stock turbo. its a t4 t04b with 50mm wastegate. but i did tear my wastegate apart nothin wrong. my turbo does have shaft play its not like omg but theres no in an out. so im thinking it could be that. as for my exhaust i havnt really got a chance to check it. so i will have to look

 

I did a turbo swap on an NA once and the owner told me to leave the stock mufflers because they were new. We then completed the swap and all was well but he was only hitting 5 psi like you were. We went through everything and the engine was rather stock and the turbo was near new and we couldn't figure it out. Finally I dropped the exhaust one day at the first coupler off the turbine before the cats and the downpipe aimed down at the road. I put a set of ear plugs in and took it for a quick spin and then I gave it some boosting throttle and before 3500 rpms I was hitting 6 psi and by 4K rpms it had jumped to 8 and bounced off the fuel cut. Not to mention it was boost creeping like crazy. Then after I had him take it to an exhaust shop and get 3in straight to turbo spec mufflers. Problem solved. For some reason it was real sensitive to the exhaust it had on it, perhaps yours is too. Of course I have to caution you about opening the exhaust, the exhaust can get 3 times hotter than a piston engine car, is very very loud, and of course if an rx7 isn't leaking oil somethings wrong, so heat plus oily substance = fire. Be careful, but you'll know if thats your problem immediately when you get into something like 3rd and floor it, either it will stay at your 5psi, or it'll jump up to the wastegate pressure and most likely boost creep past and hit your fuel cut.