S4 - Warm Start issues...
07-14-2011, 06:02 PM
#32
Rennlist Member
Thread Starter
07-14-2011, 06:03 PM
#33
Official Bay Area Patriot
Fuse 24 Assassin
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Fuse 24 Assassin
Rennlist Member
Maybe the MAF is way out of spec? John Speake has mentioned that sometimes turning that screw can damage the electronic adjuster, throwing off the ohms.
07-14-2011, 07:03 PM
#34
Rennlist Member
Thread Starter
I just got the early 87 computer. Car started up and idled better than it ever has. I let it get half-warm, and then will let it sit for a partial-warm restart - which has been a problem previously.
I told the owner it was the LH about 4 months ago, but it needed the intake refresh anyway.
Who is the US person for LHs?
I told the owner it was the LH about 4 months ago, but it needed the intake refresh anyway.
Who is the US person for LHs?
07-14-2011, 07:11 PM
#35
Rennlist Member
Louie Ott is my US agent for my LH rebuilds... louie928 on RL
I just got the early 87 computer. Car started up and idled better than it ever has. I let it get half-warm, and then will let it sit for a partial-warm restart - which has been a problem previously.
I told the owner it was the LH about 4 months ago, but it needed the intake refresh anyway.
Who is the US person for LHs?
I told the owner it was the LH about 4 months ago, but it needed the intake refresh anyway.
Who is the US person for LHs?
07-14-2011, 07:47 PM
#36
Rennlist Member
Thread Starter
Louie? I know louie. Louie and I go way back. 
07-14-2011, 07:54 PM
#37
Rennlist Member
Thread Starter
I am 96% sure its the LH. I used the owner's non-rebuilt 87 computer and plugged it into the 91 without touching the EZK - I left the car's own ECU plugged in for that.
Previously, the car did not like idling at all after a warm start. Cold starts had some issues as well, but not so big.
There were other issues along the way, so I have replaced:
CPS
HALL
Knock Sensors (x)
FPR
TPS
Flappy was reconnected
Cleaned injectors
Caps
Rotors
Checked and rechecked coils
Cleaned all grounds.
Previously, the car did not like idling at all after a warm start. Cold starts had some issues as well, but not so big.
There were other issues along the way, so I have replaced:
CPS
HALL
Knock Sensors (x)
FPR
TPS
Flappy was reconnected
Cleaned injectors
Caps
Rotors
Checked and rechecked coils
Cleaned all grounds.
07-14-2011, 07:55 PM
#38
Rennlist Member
Thread Starter
07-15-2011, 12:27 AM
#39
Rennlist Member
Thread Starter
Strange - The 91 computers go into the 87 car and work fine.
07-15-2011, 01:59 AM
#40
Nordschleife Master
edit: nevermind the below - re-read your statement and realised which way round you're swapping brains and what you meant. Sounds like you have a harness issue in the 91 to me - possibly MAF harness connector.
Thats not strange.. they're the same engine and same basic maps. Although the '87 chips don't support the diagnostic tools.
The only major variations in ignition/fuelling chips are:
87-91 S4
89-91 GT & Clubsports & SE's
92-95 GTS
The computers themselves are interchangeable, and even the GT versus S4 chips aren't that radically different (i.e. a GT will start and be driveable on S4 chips.. although the idle is a little lumpy).
As an aside - adjusting the potentiometer on the MAF does nothing on LH2.3 (87+ model year) cars. The non-cat cars have a separate external pot, and the LH harness doesn't connect the pins for the pot in the MAF housing. (however 84-86 LH2.2 cars do use the MAF pot).
Thats not strange.. they're the same engine and same basic maps. Although the '87 chips don't support the diagnostic tools.
The only major variations in ignition/fuelling chips are:
87-91 S4
89-91 GT & Clubsports & SE's
92-95 GTS
The computers themselves are interchangeable, and even the GT versus S4 chips aren't that radically different (i.e. a GT will start and be driveable on S4 chips.. although the idle is a little lumpy).
As an aside - adjusting the potentiometer on the MAF does nothing on LH2.3 (87+ model year) cars. The non-cat cars have a separate external pot, and the LH harness doesn't connect the pins for the pot in the MAF housing. (however 84-86 LH2.2 cars do use the MAF pot).
