3SGTE: went rev past 6k in 1st and 2nd on 57 trim T3/T4

[farvaric]

"WONT REV" sorry for typo in title...

car will not rev past 6k in 1st and 2nd. It will run hard and fast till 6k in BOTH first and 2nd gear then it just seems to pull timing and essentially drops in rpm, however there is no check engine light when it does this or after....basically never got a cel at all.

the car however redlines just fine all thre way in 3rd and i preseume 4th and 5th (4th i have taken past 6k, not trying to go 120mph).

the turbo is a decent size...57 trim t3/t4 and i hit around 12psi top of 3rd, so not sure what is happening in 1st. not enough load to spool a turbo that size in 1st to pull timing is there???? I would say I may have another issue alongside of this which is the fact that my boost gauge reads that i am only making like 2-4psi around 1st however i have an 8psi spring in my wg and can hear my wg open...it vents to atmosphere, just some more info for you as you ponder (may be a break in my line or a leak some where in the sequence, have it tapped into the ic pipe on the hot side.

I have all typical mods (IC, tb inlet, intake, tublar mani, external wg, dp, full eshaust, and stock fueling.....and i am running it all with a jdm ECU in a 91t).

any help or things to try would be great.

thanks!

[mr3]

Is your tach accurate? I know nothing about the turbo cars so this was probably usless.

[farvaric]

yea, it is accurate. idles fine at 900rpm and redlines at 7000rpm (7300rpm actually)

[CJMR2T]

For starters, can you give all the exact specs on the turbo? We know its a 57trim t3/t4, but what is the turbine and what A/R is the turbine housing?

You say that you have a 8psi spring in the gate but you say that your getting 12psi in the top of 3rd gear. Is it spiking 12 or is it sustaining 12?

The wastgate will start to open well before 8psi. Most tend to start to open at about 1/2 of thier set pressure, So 4psi would be about right.

I would suspect that that is all that your actually getting but this would be more dependent on the specs of the turbine side of the turbo.

Also, how quick is it hitting the 2-4psi in first? You should be able to spool it more then that in first. The unit thats on my GEN3 is quite a bit bigger then that (62-1 compressor, with a T04 P-Trim turbine with a .96A/R housing) all of which is way to F'en big for the engine and I can still get 6psi in 1st with a 10psi spring. Granted this isn't till almost 6K RPM, but its still a lot bigger then yours and yet will still boost higher in 1st.

You didn't mention whether or not you have a way of monitoring EGT or AFR. Do you have a way? Without both, or a way to datalog ECU inputs and outputs, its kinda hard to tell what the ECU is actually doing.

What are other details about it like, "Has this setup been on the car for a while and was working fine but now its not?" Is the turbo a cheap off brand (china) unit that it might be too tight thus cant spool correctly? "Are you sure you have no Exh. leaks before the turbo?" and so on....

[farvaric]

.50 a/r comp and .63 a/r turbine

i took my boost controller out (had it set to around 12psi

had the kit on the car for a season now

it still creeps to 12psi by the time i get out of 3rd however that is where it holds (i know, not good).

running a 38mm wastegate that runs of the wg port of the turbo NOT a flange or converter (not the best place for a WG).

i have boost gauge and air fule sweeping meter (not wideband), it read in stoich to rich even before it pulls timing in 1st and 2nd at 6k rpm (if that is what it is doing.

replaced spakr plugs with gapped bkr7e's and new red trd plug wires.

dizzy cap and rotor are the ones that came with the car.

O2 sensor is what came with the car (changed most likely).

I have owned the car for 3.5 years.

basic history of the issue, back when i first put the kit on and was running 12psi, it pulled like a MF'er and it did not take this long to spool and did not have this issue.

It started to have the issue after i blew my lower IC pipe off. after doing some more talks on the board, folks said 12psi was the most to run on that turbo size with stock fueling, hence why i wanted to run off the WG, that is when i noticed the WG would not hold 8psi and it would creep slowly to 10-12 depending on gear and load.

this "choke/timing" issue happened right before or around the time i switched to WG (remember i blew the pipe off). the car was doing this ar originally 5500rpm till i changed plugs and wires, now it is 6k.

Keep in mind that it was fine till i blew of the pipe. now this would naturally lead to possibly a leak, well i am pulling 20-23 vac at idle and idles at 900rpm and drops to 800rpm with clutch or brake boost engaged.

I guess i may have a few issues of a possible boost leak and timing issue?

but what i dont get is how the car will pull timing or whatever the hell it is doing (no CEL EVER, not when it happens, not off then on, ever, and yes the CEL works). Again, keep in mind the following when this happens:

1. car stops revvng (declines in revs as if pulling timing) at 6k in 1st and 2nd only
2. caris only boosting around 2-4psi when this happens
3. was doing this at 5500 till i changed plugs and wires
4. the low boost and slow creep (2-4 psit on 8psi spring is really really really slow) started when i blew a pipe, but i did pull my MBC as well to run just off of WG
5. vac sits at 20-23
6. idles at 900rpm or 800rpm with clutch and/or brake booster engaged

so there is the info for now, let me know what more you may need. i will do my best to supply info.

UPDATE: one more thing to consider, i remember a conversation on here or the OTHER board a few years ago about what could affect knock sensors, the possibily of a knock on a engine component at the right frequency or interval could set it off. well, something to consider is that my IC pipes do rattle against my engine strut bar in 1st and 2nd (like rat a tat tat). ok, i think that is enough for you guys to ponder for now i think.

Thanks guys!

[MR210]

change the cap and rotor

[farvaric]

i will order it and change it, just wondering if there are anything else to look into as i dont want to troubleshoot with spending naturally, but it cant be helped i am sure.

Keep any other ideas coming guys and do please provide any additional insight or concerns if any.

thanks!

[farvaric]

ordered them just now.

will put them in once they are in, keep ideas coming if anything else you find interesting about my thread.

thanks guys!

[MR210]

It sounds about right, my ignition system had been neglected I am sad to say. When I hit boost my car would pop and not create power, which I found was due to too hot of plugs (iridiums). Then It had problems reaching certain rpms in certain gears, mainly first and second. Mine wouldn't go past 2k rpms in first and 3k in second. If I could get it past that it would run fine.

I'll be surprised if it is anything else seeing you say they are 3 and a half years old.

We can only hope, right?

Edit: another sign is the lack of CEL, typical with these engine components going out.

GL!

[sabing]

If its not doing it in higher gears it probably isnt a problem, but maybe just for kicks, try wrapping the pipe that wiggles around and dings in something heat resistant and take a little drive around and see if it still happens when it doesnt knock together.

[Bak@EMSPowered]

are you sure you're not hittnig fuel cut?

[farvaric]

Not slamming into a wall and no CEL.

Forgot to mention I have HKS FCD set for 17.3psi or whatever it is for the appropriate setting for the MR2, the next setting of resistance will set it at around 21 psi or so, but I currently have the tvsv capped.

Oh, and I can rev it all hte way to redline in neutral or while parked.

Looking on youtube, it does seem to be cap and rotor.

Also, when I wash my car at times, if i drive it hard, it would choke, something to do with water in the dizzy from what i read as a possibility, which could also point in that direction.

[Bak@EMSPowered]

* Check for boost leaks

* Check for leaks between the AFM & turbo inlet

* If you still have the catalytic converter(s) they could be clogged, and that causes similar issues sometimes as well

[farvaric]

running full exhaust, no cats.

i will look for leaks again. vac is around 20-23 or so at idle.

[Bak@EMSPowered]

what mods/maintenance or removal and reinstallation of items have you done recently?

[farvaric]

the turbo kit would be the most recent. however problem started when i blew my lower IC pipe off.

i have checked and re-checked all my pipes. i would say the car does boost slower then it should though, it certainly doesnt just shoot up to 8psi and it doesnt even just shoor tup to 4psi it walks up to it in 1st and 2nd, naturally in every gear is rises faster.higher since it is spooled.

[Bak@EMSPowered]

what intercooler kit do you have? If you have one of the ebay intercoolers, your clamps/hoses are probably not the right sizes. Sounds like a boost leak to me.

[farvaric]

using tension clamps on the IC. i think i may have a boost leak somewhere, could possibly be my boost line to my gaige, not sure (which explains slow rising boost possibly), however this does not explain the drop in revs once i hit 6k in 1st and 2nd does it?

Keep in mind that this used to happen at 5500rpm till i hcanged the pugs and wires, actually just remembered that it really improved with the swap of a new few filter.

cant do any testing or checking right now, car is at the shop getting a new master cylinder in for the clutch...im a lazy bastard...took the pedal apart, wnet on a three month business trip, now it is cold, so i put it all back together and will just have the shop do it lol.

[Bak@EMSPowered]

If its a big enough boost leak it will cause you to run so rich that the engine may not want to rev and may even bog and want to die. Which BOV do you have, a lot of people end up with boost leaks at the BOV sometimes too.

[farvaric]

running recirc stock BPV/diverter valve.

iirc i am in the stoich zone according to my sweep gauage.

EDIT: I DO NOT HAVE THE VTV in, just running a straight line into the T for the boost/vac source to the top of the valve.