RX7 Vert FC TII - Misfire/popping from exhaust ad idle with A/C on
02-25-17, 06:16 AM
#1
Full Member
Thread Starter
RX7 Vert FC TII - Misfire/popping from exhaust ad idle with A/C on
Hello everybody.
I discovered a silly problem on my European FC Turbo 2 after i adjusted idle rpm: ONLY WITH A/C ON i have misfire and popping sound from exaust when engine is hot every 20 seconds.
With A/C disengaged the idle is perfect.
I have adjusted the idle because when i bought the car, with engine fully warmed up it was at 1050/1100rpm!
As service manual and Haynes Manual says i turned the screw on the BAC Valve after jumpering the connector in the hood. The idle lowered correctly at 750rpm with engine hot. And when i turn on AC the idle rises 50 to 100rpm.
But i discovered that with AC on now i get this misfires and ONLY AT IDLE (when cruising the engine is perfect).
What can be the problem?
Thank you very much
I discovered a silly problem on my European FC Turbo 2 after i adjusted idle rpm: ONLY WITH A/C ON i have misfire and popping sound from exaust when engine is hot every 20 seconds.
With A/C disengaged the idle is perfect.
I have adjusted the idle because when i bought the car, with engine fully warmed up it was at 1050/1100rpm!
As service manual and Haynes Manual says i turned the screw on the BAC Valve after jumpering the connector in the hood. The idle lowered correctly at 750rpm with engine hot. And when i turn on AC the idle rises 50 to 100rpm.
But i discovered that with AC on now i get this misfires and ONLY AT IDLE (when cruising the engine is perfect).
What can be the problem?
Thank you very much
02-25-17, 07:22 AM
#2
Year? See it's a '91
I would first ground the test connector:
Adjust the TPS just to be certain it's correct, use the 3 pin green check connector.
Disconnect the BAC and adjust idle with screw on throttle body.
Connect BAC and fine tune adjustment.
Don't forget to remove the ground wire from the test connector.
I would first ground the test connector:
Adjust the TPS just to be certain it's correct, use the 3 pin green check connector.
Disconnect the BAC and adjust idle with screw on throttle body.
Connect BAC and fine tune adjustment.
Don't forget to remove the ground wire from the test connector.
Last edited by Turbonut; 02-25-17 at 07:26 AM.
02-25-17, 07:34 AM
#3
Full Member
Thread Starter
It's a 91' indeed.
Vert 91' Turbo 2 European version without airbag!
Why are you asking me if it's a 91'? Do the 91' have some hidden problems?
However with A/C disengaged idle is perfect.
Also when idle was at 1000/1100rpm there weren't no misfire or engine esitations at idle with A/C turned on.
I didn't touch the TPS sensor when i adjsted the idle, only BAC.
And i don't understand why idle was setted so high!
Any explanations for the stock high idle?
Engine has 64.000 km (kilometers) and has never been rebuilt. Compression is perfect.
Vert 91' Turbo 2 European version without airbag!
Why are you asking me if it's a 91'? Do the 91' have some hidden problems?
However with A/C disengaged idle is perfect.
Also when idle was at 1000/1100rpm there weren't no misfire or engine esitations at idle with A/C turned on.
I didn't touch the TPS sensor when i adjsted the idle, only BAC.
And i don't understand why idle was setted so high!
Any explanations for the stock high idle?
Engine has 64.000 km (kilometers) and has never been rebuilt. Compression is perfect.
Last edited by Venturer; 02-25-17 at 07:41 AM.
02-25-17, 07:45 AM
#4
Full Member
Thread Starter
One more detail. With 64.000 original kilometers since the production of my Vert in 1991 i'm pretty sure "fuel filter" has never been changed!
I think it's the original factory filter!
Next week i should get the replacement for the fuel filter.
Is it possibile that a worn and old fuel filter causes misfires at idle under A/C load?
Is it a crazy idea?
I think it's the original factory filter!
Next week i should get the replacement for the fuel filter.
Is it possibile that a worn and old fuel filter causes misfires at idle under A/C load?
Is it a crazy idea?
02-25-17, 07:51 AM
#5
I first asked the year as it wasn't in the thread, but after looking up some of your
other posts, saw it was a '91. The FC convert was manufactured '88-'91 and the '88
has different diagnostic procedures from the '89/'91.
Have no idea why the previous owner would have such a high idle, but am assuming
there was no mechanical problem, e.g thermowax, blocked coolant, binding cable, etc.
Did not say that there was a problem with the TPS, but just wanted to make certain that
it was adjusted properly as it can cause some hiccups if out slightly.
If no TPS check, ground test connector, disconnect BAC, adjust idle using the idle screw
on the TB, connect BAC, adjust, remove the ground wire from the test connector.
other posts, saw it was a '91. The FC convert was manufactured '88-'91 and the '88
has different diagnostic procedures from the '89/'91.
Have no idea why the previous owner would have such a high idle, but am assuming
there was no mechanical problem, e.g thermowax, blocked coolant, binding cable, etc.
Did not say that there was a problem with the TPS, but just wanted to make certain that
it was adjusted properly as it can cause some hiccups if out slightly.
If no TPS check, ground test connector, disconnect BAC, adjust idle using the idle screw
on the TB, connect BAC, adjust, remove the ground wire from the test connector.
02-25-17, 09:04 AM
#7
It won't cause the problem you have, but when in doubt as to when it was changed last,
it's an inexpensive maintenance item. To reduce fuel pressure, just make certain you either
remove fuel pump fuse, idle the car until it runs out of fuel, or let the car sit overnight
and then do the change the next day.
Same as plugs, air filter, etc
it's an inexpensive maintenance item. To reduce fuel pressure, just make certain you either
remove fuel pump fuse, idle the car until it runs out of fuel, or let the car sit overnight
and then do the change the next day.
Same as plugs, air filter, etc