QV backfiring on start up

2066 Views 9 Replies 0 Participants Last post by Eric Eiland, Jan 12, 2004

Discussion Starter · Jan 12, 2004

Hey guys I made it over here.

Hey guys I made it over here. My 85' running rough at and not starting well at all. After it is started it will fart around and have slight backfires if given gas. I am thinking ignition as the car always ran great since I have owned it and it all started after I left it for some paint work on the front spoiler. Here is my ideas on what to check and if anyone has something better to start with or do let me know. Check/clean coil wire connections to coils, clean dist. cap contacts, clean rotors, clean connections on flywheel sensors, and the large white harness on the drivers side rear by the shock tower. Then get the car to idle and check for spark with a timing light. How does this sound? After that not sure. Maybe check resistance for flywheel sensors but I have heard that this can be misleading and not show if one is bad so if anyone knows the best way to test them chime in. I like this site, questions and answers on topic, doesn't get much better than that.

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Discussion Starter · #2 · Jan 12, 2004

Hi RF, welcome to Ferrari-Tal

Hi RF, welcome to Ferrari-Talk.

If you really think it's body shop related I'd first pull the plugs and clean/replace, then look for water from the usual body shop drenching the engine car wash. At the same time make sure the Frequency Valve is humming.

Regards, JRV

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Discussion Starter · #3 · Jan 12, 2004

Ok thanks. I am on it. To ch

Ok thanks. I am on it. To check the FV just pull the harness on the back behind the fuel distributor and turn the key to pos. II right? I should hear it buzz.
I am sure it is related to them but I am not sure how many times they tried to start the car and if they plugged the coil wires in the wrong coil, or it could just be lots of water in the engine with whatever soap they used. It still had some soap on it when I picked it up.

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Discussion Starter · #4 · Jan 12, 2004

Hi,

don't unplug anythi

Hi,

don't unplug anything, just start the engine or turn the key to position II and put your hand on the FV, located on the left side of the Fuel Distributor, you should feel it vibrating. This is just a quikie test of the Lambda System, which wil cause very poor running if in-op.

If the coil wires were reversed it wouldn't start at all.

Regards, JRV

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Discussion Starter · #5 · Jan 12, 2004

Would it hurt anything in the

Would it hurt anything in the system if they plugged the coil wires into the wrong coils? Sensor, Digiplex?

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Discussion Starter · #6 · Jan 12, 2004

No it wouldn't hurt anythi

No it wouldn't hurt anything if the crossed coil wires. That's definately not the problem.

I'm thinking:

1- water
2- fouled plugs
3- loose connections

Regards, JRV

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Discussion Starter · #7 · Jan 12, 2004

Great. I was worried it could

Great. I was worried it could be some electrical damage. Thanks for the help. Great Site!!!!

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Discussion Starter · #8 · Jan 12, 2004

Sorry to "horn in" on

Sorry to "horn in" on this thread here, but I had a quick question for JRV regarding a past glitch that I was having on the TR that seems to be related to the topic here....

You mentioned the frequency valves "humming", and poor running conditions due to Lambda System glitch. Do you think that the intermittent humming I was hearing was from these valves? I'm assuming that the K-jetronic (Euro) would have this setup. The problem with mine was that the humming would happen at odd times with the ignition off. Initially, I suspected the warm up regulators -- here's the thread: http://www.ferrari-talk.com/discus/messages/5/634.html?1062705546
Problem started after having the car detailed (including thorough wash of engine bay). Haven't noticed it recently though.

Odd thing is that the engine would idle rough, and surge, as well as die out when coming to a stop (revs drop too low). Found myself having to feather the throttle and brake at the same time while engaging the clutch when stopping -- a real trick I might add.

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Discussion Starter · #9 · Jan 12, 2004

Eric,

the humming of the FV

Eric,

the humming of the FV's is almost inaudible even with the engine off which is why it's always suggested to feel them for vibration or listen to them with a mechanics stetescope.

are you sure your TR has the Lambda System with FV's ?

Regards, JRV

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Discussion Starter · #10 · Jan 12, 2004

Thanks, JRV, for the clarifica

Thanks, JRV, for the clarification on the FV's.

Not sure if it has this system or not -- it is a Euro model (DOT converted on import).

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