Rough idle, die on gas. No problem if rev.
 

Ok let's start....

I have a '01 S8 FD3S with around 80000 KM and a rebuilt from less then 700KM

Went on a little trip (around 60 KM) and encountered various very slow car.... temp reached around 100-105 C. not more.

After i reached my destination i stopped the car for around 30 minutes.

Restarded the car with no problem and made other 20 KM and stopped.

After this car sitted for around 50 minutes and when i tried to restart it here the problem....


Difficult to fire and very roug idle (under 500 rpm) when i tried to push gas a little car stall.....

tried 2 times with same result.....at the 4th try i succed in overcoming 1000 rpm and moved the car.

I do again the same 60KM without problem, good power good boost and no rough driving.

When i arrived at home and release the gas the rough idle come back....(but this time if i press gas car don't stall but go over 1000 rpm "without problem".

Idle is rough but car don't stall this time if i let it idling.

Ah forgot......

Addition Blitz Boost gauge is perfectly stable at idle or low rev but shake a little when moving....

BUT

BOOST and power are perfect..no esitation...full and perfect smooth acceleration with first and second turbo (with good PSI value)



Here a vid of rough idle and boost gauge shaking a little

BTW when car boost i have no boost problem and no power problem....

Like I say fresh rebuild on this car.


http://www.youtube.com/watch?v=umEbB...ature=youtu.be

Re: Rough idle, die on gas. No problem if rev.
 

I'm no expert on rx7's but maybe check the t-valve or whatever where the boost gauge is connected to see if there's any vacuum leaks?

Re: Rough idle, die on gas. No problem if rev.
 

100C = 212F
You may have cooked the engine.
(1) compression check
(2) plug check, pug wire check, primary ign. coil check

Re: Rough idle, die on gas. No problem if rev.
 

mmmh from what I know 100 C is an acceptable operating temp for a turbo rotary engine....(150-230F is middle of stock temp gauge 250F is high and over)

230 is when you need to start being worried and 240 you MUST stop...

Btw i have replaced plug wire and spark plug...coil are ok...

I found a faulty primary injectors and i'm waiting for a new one....

The primary faulty inj (to me) can explain why car show problem at idle and not over 3000 rpm (with no lack of power at all)

let's see what happen (in this time i have renewed all vacuum system)

Re: Rough idle, die on gas. No problem if rev.
 

Sounds like it is running on one rotor or only firing on trailing plugs.
The leading coil is known to go bad. Pull leading plug wires and have them fire to
ground through spare plugs. See if they spark and engine runs worse or no spark and engine runs the same.

Re: Rough idle, die on gas. No problem if rev.
 

Yea I was going to say sounds like a misfire issue.
I'd second the ideas to check your coils.

105 Celsius is little hot but not a death nail. You'll want to do done work to get your temps down to 80-90 Celsius or your coolant seals won't last long.

A good tip I'll share, remove the rubber weather stripping on the top edge if the fire wall. It helps air escape without much effort on your part.