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The mkiv Supra Owners Club

Rough running NA Headache


Richie_k83

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I did, engine stalled straight away.

 

I used an old number plate to blank off the throttle inlet. It held the plate there for a few seconds after the engine stalled too.

 

No point getting new gaskets then. At least your problem isn't a leak after the TB.

 

If I were you I'd borrow a working manual ECU from a member and rule that out as a starting point. If issue persists with other ECU then start diagnosing the ignition system, coolant ecu temp sensor etc.

 

Did you get a vacuum gauge hooked up yet?

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N/A's seem FAR more prone to head gasket failure than TT's. They don't blow out as such, rather that one of the inner laminations cracks. The head and block and both gasket surfaces can look perfect, but if you split the gasket up into its constituent shims you find one is cracked. I have seen this several times. Why N/A's do this i don't know.

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No point getting new gaskets then. At least your problem isn't a leak after the TB.

 

If I were you I'd borrow a working manual ECU from a member and rule that out as a starting point. If issue persists with other ECU then start diagnosing the ignition system, coolant ecu temp sensor etc.

 

Did you get a vacuum gauge hooked up yet?

 

I'm thinking this to be honest, will get hold of one and keep my fingers crossed lol.

 

Vacuum Gauge i have ordered from eBay, so can add that to my tool collection lol

 

N/A's seem FAR more prone to head gasket failure than TT's. They don't blow out as such, rather that one of the inner laminations cracks. The head and block and both gasket surfaces can look perfect, but if you split the gasket up into its constituent shims you find one is cracked. I have seen this several times. Why N/A's do this i don't know.

 

Ahh righty, good to know.

 

Its pushing the miles out a bit now (136,000 mile), so may be overdue...

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BTW, many vacuum gauges come with a damper in the port to dampen needle movement. it's usually an insert with a VERY small bore hole in it. You DO NOT want a dampened movement when looking for bad valves or vacuum leaks, you need to look for needle pulsation, so remove it. Good luck.

 

No worries, cheers Chris, will take a look when it arrives :)

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