supra hits a wall when boost kicks in

[86mk3]

I've searched and cant find a thread with my problem. Ok here it goes my car has 500 miles on the fresh build and ran real nice when first completed. About two weeks ago i started the car after work let it warm up and about 10 secs later my engine light goes on , while on the fwy i floored it and my car started back firing like crazy and started to slow down i checked boost and while it was slowing down and back firing boost was constant at 10psi. This only happens after half throttle. My ecu code was 52 and i fixed that one knock sensor wasnt plugged in. Also i have a at ecu because i conveted to r154 dont know if that could be a problem. Well i guess thats it please any help would be appreciated and thanks for any help in advance.

dont know if this helps but here are my mods list
-2.0 mhg
-arp studs
-3" ddp
-3" dp back
-light wieght flywheel and stage 3 clutch set
-bee*r
-was on hks fcon took it off thinking it was the fcon
-running 10psi no boost controller dont know if thats normal

 

[hvyman]

Have you checked codes since? Sounds like boost leak.

 

[spikesnstuff0905]

Stock boost is a little under 7psi. 10 with no boost controller is weird. Are you using an aftermarket gauge or the stocker? Is your wastegate shimmed?

 

[Devin LeBlanc]

With a down pipe and 3 inch free flowing exhaust, and after market intercooler/piping I was running 10PSI in the intake manifold with no boost controller or shimmed wastegate. Im running 14 now with a Halman controller..

Sounds like a boost leak, check your timing as long as no codes are present

 

[Poodles]

Sounds like the bee*r kicking in...

 

[Swifty]

Yea my supra ran 10 psi stock too.

 

[radiod]

Yeah, check codes. If your CEL came on at all it will have something stored at the least.

 

[goodhart]

I'd start with a boost leak test. Have you checked the gap on your spark plugs?

Yea my supra ran 10 psi stock too.

LOL

 

[86mk3]

thanks for all the support ... ok first i also think it might be a boost leak so thats gonna be done as soon as its atleast 0 degrees outside lol. second i checked the spark plug gaps and they seem to be fine , i tried timing it but when i jumped the diag. box my idle had no change (dont know if thats normal) and now im getting code 51 and 52 so thats a bad tps and knock sensor. im gonna replace the tps and knock sensors with working ones out of my other supra see if that works. oh and i have a aftermarket boost gauge and i do not have a shimmed wastegate.

 

[hvyman]

Where does the gauge get its reference? If its at the maanifold you should see 0 psi. If its at the turbo you should see full boost. But the 52 could be the whole problem.

 

[86mk3]

the guage is at the nipple in the back of the intake manifold it works fine, tested it in my buddys bone stock and hits 7psi so i think the gauge is good ..and the code 52 is the knock so im putting the new knocks in and see how that goes thanks ill let u guys know how its acting after i do some of these things

 

[ForcedTorque]

Code 52 refers to knock sensor wiring more often than it does for the sensors. Our cars are old, and therefor have deteriorating wires. I believe it is shaeff who makes the replacement kit for that. Simple wiring won't do it, because it is a sheilded wire. Try the other sensors first, then reset the ECU. If the code come back, you likely have bad wires.

 

[Poodles]

Sounds like the bee*r kicking in...

ahem...

 

[86mk3]

ahem...

oh sorry , ive run the car with 0 gain which shuts it off and i unplugged it also just to be sure and nothing man .....seems to not be the bee*r

---------- Post added at 08:12 PM ---------- Previous post was at 08:11 PM ----------

Code 52 refers to knock sensor wiring more often than it does for the sensors. Our cars are old, and therefor have deteriorating wires. I believe it is DrJones who makes the replacement kit for that. Simple wiring won't do it, because it is a sheilded wire. Try the other sensors first, then reset the ECU. If the code come back, you likely have bad wires.

im replacing the tps first and checking codes again after ..would unplugging the neg terminal for a while reset the ecu?

 

[hvyman]

Ya its easier to just pull efi fuse for 30 sec tho.

 

[86mk3]

Ya its easier to just pull efi fuse for 30 sec tho.

will do thanks

 

[86mk3]

sorry guys havent had any time to update, but as soon i do ill post with results

 

[86mk3]

i replaced the tps and rewired the the knock sensors checked my codes again and now im getting a 14 (coil or ignitor) and code 43 (starter signal) im stumped on how to even inspect let alone get rid of the 43 code please help me out with some advice

by the way im getting my info on the codes from this here
http://www.supramania.com/forums/showthread.php?97671-GUIDE-Reading-ECU-codes&highlight=engine codes

 

[turbojuiced]

I've searched and cant find a thread with my problem. Ok here it goes my car has 500 miles on the fresh build and ran real nice when first completed. About two weeks ago i started the car after work let it warm up and about 10 secs later my engine light goes on , while on the fwy i floored it and my car started back firing like crazy and started to slow down i checked boost and while it was slowing down and back firing boost was constant at 10psi. This only happens after half throttle. My ecu code was 52 and i fixed that one knock sensor wasnt plugged in. Also i have a at ecu because i conveted to r154 dont know if that could be a problem. Well i guess thats it please any help would be appreciated and thanks for any help in advance.

dont know if this helps but here are my mods list
-2.0 mhg
-arp studs
-3" ddp
-3" dp back
-light wieght flywheel and stage 3 clutch set
-bee*r
-was on hks fcon took it off thinking it was the fcon
-running 10psi no boost controller dont know if thats normal

Is it me or does this sound alot like an issue with the plugs? 90% of the time when I have had those same issues it was the plugs and this is on both my evo and supra especially if your boosting to 10psi on stock spec plugs. Its even worse when your running coppers. I highly doubt your having issues with all of those different parts. You sure they are the right plug, heat range, and gapping?

 

[shaeff]

Is it me or does this sound alot like an issue with the plugs? 90% of the time when I have had those same issues it was the plugs and this is on both my evo and supra

I'm not necessarily disagreeing with you about the plugs, I suppose it's a possibility, but this part:

especially if your boosting to 10psi on stock spec plugs. Its even worse when your running coppers. I highly doubt your having issues with all of those different parts. You sure they are the right plug, heat range, and gapping?

These cars LOVE copper plugs. 10psi isn't that much of a difference over stock, and most people here don't even bother to gap their plugs before installation, which means that they're running stock spec, and often times aftermarket NGK coppers to boot, all with no issues.