308 GTSi Running on 4 cylinders!!!

1983 308 GTSi QV

We believe the problem is the cap and rotor. The cap is getting a spark, but nothing to any of the plugs. The rear bank is not running. The front 4 run fine. The rear rotor is turning though. When we put the rear bank coil on the front bank, it runs normally, so it appears the coil is ok. Any info on this problem would be helpful. If it is the cap and rotor, is there a link that details installation??? One question is the wires... they don't appear to be removable.

 

I just had this problem... check the crank/flywheel sensors.

 

You have to remove the distributor cap in order to remove the wires -- there are screws on the inside -- see jpeg.

But if the cap, rotor, and carbon button aren't obviously broken, and the electrical connection from the coil wire to the cap is OK, most likely is one of the TDC sensors per j b's point. When you say "the cap is getting spark" does this mean that you confirmed multiple spark discharges occur on the coil wire with a timing light, but no spark discharges occur on the individual plug wires?
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Boy, must be in the water or something...

This problem hit more that a few people since last summer, including me. It is a flywheel sensor (you have 3) Forget the coil and caps. Those were the first two things I checked too. The coil will not fire without a signal from the sensor.

T Rutlands has them and it is not that big of a deal

 

This part would be inconsistent with a reference sensor issue, if I am understanding the above statement. But to clarify: Have you verified that the wire going to the cap is actually sparking, or did you only get that by switching it to the other bank?

 

Thanks for the advice. Where are the sensors?? The coil wire to the cap and the "button" is definitely getting spark on the bad bank, so I would like to lok at the sensor issue. A quick tip on getting to them would be helpful... Thanks guys.

 

not sure on an 83 but on mine they are just below the distributors on the clutch/flywheel at 11 o' clock and 2 o' clock positions. Rutlands has a good price for them too so you won't have to shop around too much.

 

Here's a jpeg showing the TDC and RPM flywheel sensor locations, but, like Tony said, if you are getting spark on carbon button of the "bad" bank, the TDC sensor for that bank is working OK. Your problem must be either in the cap or the rotor (if the rotor is turning ) -- good hunting!
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I'll be hunting some more over the weekend...

 

Steve dude, you're the best.

brett

 

Thanks for that picture

 

Check the resistance of your coil wire . .. even when there's a lousy connection the spark will still arc and fire intermittently.

 

not sure about the coil wire, but resistance at the flywheel sensors should be 700mA - 725mA.

 

Good spec to know . .. on one of my 308's there's some other brand of pick up on there . . .one of these days I'll scope it and see if the signal looks the same as the stock pickup . . might be an inexpensive alternative.

 

depends on the brand but "roughly" 1k ohms/ft is what I've seen . . many times I thought I had a good connection and then I'd wiggle the wire with the ohm meter hooked up and see the resistance intermittenly go thru the roof . . made me not want to detail the engine . . . just another reason me luvs me coil on plugs .

 

last night we swapped the good bank cap, wires and rotor. It fired right up! So sensors are ok. I've seen recambi has a reproduction cap for 216.00. Any experience with this or tips on the most reasonable cost for these items would be greatly appreciated. The good bank cap didn't look all that great, so since it's off I'm thinking I'll just replace both sets of caps,wires,and the rotors. Who has the best quality/price deal???

 

www.allferrariparts.com shows a much better price (if the part you need is 115518)

 

i've checked some old threads and found many positive references to Dennis McCann. 130.00 ea for repro cap, 52.00 ea for rotors. Saw wires 60.00 for Taylors, 130.00 @ magnecor and 299.00 for a stock set @ t rutlands. Now to get my girl back on the road... I'll be calling on allFerrariparts tomorrow.

 

I still have a real funny feeling it is your sensor at the 11:00 position...

 

distributors and rotors just arrived from allferrariparts!! Trying to nail down some wires and will install this weekend. Fingers crossed...

 

The Rutlands set is OEM and pretty easy to install. I'd use them. Just did a set last week. Came with extendors, boots, etc. They should all be replaced at the same time IMHO

 

just ordered before i read your post. 24 1/2 feet of 7mm taylors for around 80.00 @ Scuderia

 

She's back!!! We put a cap, rotor, and new wires on each bank . She fired right up hitting on all 8!! Thanks everyone for your comments...

 

1983 Mondial QV euro. A slightly different situation but the same as the front bank is not firing. Cap, and all wires are good, but no fire out of the coil to the distributor. Tested by plugging a timing light between the coil and the distributor. The rear bank lights up fine and is firing. The yellow power leads are showing current into the coil when the switch is on and engine cranking. The coil is new and test good. So probably the sensor? Just checking if I am on the right track before jacking her up and pulling the left rear for inspection. Which is where I think the sensors are. Correct?

 

You can test the crank sensor and trigger signal from the digiplex at the diagnostic port.

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