No power through RPM's

[Mk3 SuPrA]

Hey guys, I have an 87 7M turbo and it doesn't seem to produce any power trough higher RPM's. From a stop or just cruising it'll pull a bit but then it's like complete power loss and it'll start kinda like bucking here and there till about 5K and power will hit out of nowhere. Also tonight it wouldn't want to go passed 4500RPM on 4th or 5th gear at WOT for a good 5 seconds. I have no idea what the hell is going on with this thing. Stock turbo, bigger intercooler, HKS BOV, 3in turbo back exhaust and thats about it no major upgrades.

 

[atmperformance]

not giving us much to work on. go do a boost leak test? is your CEL on and are you just not mentioning it because it's "always been on"?

 

[hvyman]

Any codes?

 

[IndigoMKII]

Bet its either a boost leak or code 52..

 

[BryanDyer]

Code 52 did that exact same thing to me I'm guessing because of the richened fuel mixture you don't have enough spark to burn the fuel until a higher rpm so it bucks until you can burn it correctly. Used to do that for me at about 4k rpms until I fixed code 52. But anyways check codes first.

 

[IndigoMKII]

Code 52 did that exact same thing to me I'm guessing because of the richened fuel mixture you don't have enough spark to burn the fuel until a higher rpm so it bucks until you can burn it correctly. Used to do that for me at about 4k rpms until I fixed code 52. But anyways check codes first.

Code 52 also pulls a lot of timing to prevent knock.

 

[Mk3 SuPrA]

not giving us much to work on. go do a boost leak test? is your CEL on and are you just not mentioning it because it's "always been on"?

CEL is not on. Ok i'll try doing a boost leak test

 

[7M4EVR]

CEL is not on. Ok i'll try doing a boost leak test

So you're saying that when you jumper T and E1 in the diagnostic terminal you get steady and consistant rapid flashes (no stored codes)? But based on your limited info, I would say boost leak as well. Did you do any mods before this started happening or did it just start to happen out of nowehere?

 

[Mk3 SuPrA]

I checked for codes again and i get codes 42 and 43. I don't think those would affect how the car drives or am i wrong?

 

[BryanDyer]

I checked for codes again and i get codes 42 and 43. I don't think those would affect how the car drives or am i wrong?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=28

 

[Mk3 SuPrA]

Yea I read what the codes were but I'm saying I don't understand how that would affect the cars performance. For the code 42, does the car NEED to know how fast it's going? For code 43 it says no starter signal until it reaches 800RPM while it's NOT moving so it shouldn't affect the car while it is moving right? Or am I wrong?

 

[7M4EVR]

You will need one of the old timer gurus to help you out on this one, which means you might have to show some more proof of time invested on things you have tried/tested to narrow down your problem.

Admittedly not really knowing what I am talking about, I would venture to guess that your problem lies in the code 42 considering that RPM signal has a direct relation to ignitor operation.

 

[hvyman]

Sure it's not 24 and 34?

 

[Mk3 SuPrA]

You will need one of the old timer gurus to help you out on this one, which means you might have to show some more proof of time invested on things you have tried/tested to narrow down your problem.

Admittedly not really knowing what I am talking about, I would venture to guess that your problem lies in the code 42 considering that RPM signal has a direct relation to ignitor operation.

Alright sounds good man I'll keep trying to figure this out thanks for the help so far .

 

[Mk3 SuPrA]

Sure it's not 24 and 34?

Yea I'm sure man

 

[IndigoMKII]

Have you roll started your car?

if not, look a little into the STA signal.

 

[Mk3 SuPrA]

Have you roll started your car?

if not, look a little into the STA signal.

Yea I have. Is that why I get that STA code?

 

[Mk3 SuPrA]

Ok finally did a boost leak test and found a leak. The intercooler seems to have a crack but can't exactly see where it's at, the cooling fins are in the way. I hope after getting it fixed or replacing it it'll fix the cars boosting problem.