capacitor?

[whcherman]

88 b2 2.9 L i found what appears to be a capacitor near the coil associated with the distributor. what is this never seen in wiring schematics before.

 

[Robert_1967]

Got one on my 88 Ranger 2.3, well had one, the Engine is gone right now, and I have one on my 89 BII with a 2.9.

it use to be in the Dizzy when there was points in the Dizzy.




Robert

 

[adsm08]

It's a capacitor. The coil produces a lot of EM and RF noise. That capacitor is there to catch it and keep it out of the engine control wires and radio. The engine will run, usually just fine, without it, but there will be all sorts of noise in the radio.

 

[whcherman]

thanks to all, that is what i thought but haven't seen them for some time. even searched advanced auto for a replacement but there were none. dont think it has anything to do with my current problems of no spark.

 

[adsm08]

No, a bad capacitor won't cause no spark.

I'd be looking at the TFI module.

 

[whcherman]

replaced tfi, rotor and cap. white wire jumped coil and sparked. cranking engine with spark plug attached to coil wire no spark?

 

[kimcrwbr1]

With the plug in the coil wire plug sitting on a good ground with the key on, jump the neg side of the coil to ground quick touches you should get a brite blue spark. if so coil is good, then you need to troubleshoot the module and the pickup coil in the dizzy. Check all the wires and connectors first. The tech library under TFI diagnostics and a volt meter will get you there just print it out and have at it. I always read it through a couple times so you know how it works to help the diagnostic.

 

[whcherman]

yes, thank you. I have looked at the tfi sheet in the library. the only unclear pt to me is the diagnosis of the pick up coil. can this be done through the spout connector (used for checking timming)? or how? I have tested the tfi's new and old and there connectors for voltage. but the pick up coil is still the gray area in my mind. again thanks oh and how do you replace the pickup coil, been looking all day.

 

[kimcrwbr1]

You have to pull the dizzy to replace the coil. You can test it with jumper leads attach male spade connectors to some jumper wires and push them up into the coil using the module as a guide for which one is which. That is also how you can put the remote module setup just jumper wire the coil to the module and mount it on a heat sink similar to one you would find on a computer processor always use heat sink grease when mounting the module. To change the coil you have to remove the cam gear and pull out the shaft easy enough to do with a drift pin and a block of wood tap out the roll pin and if the cam gear is worn this is the time to replace it also. Check the bushings in the dizzy for slop first if there is any slop side to side it can affect the spark and end play can affect the timing and replace the o-ring when putting the dizzy back in. A rebuilt dizzy is a good option and in general the more expensive the module the better it is.

 

[kimcrwbr1]

Turn the rotor to where you have a point to reference when you take it out to put it back the same place.

 

[whcherman]

Thanks, alot. that is what i thought had to be done. will rediagnose the coil. before pulling the dizzy.

 

[n_grimm]

As mentioned above, there is a lot of good info in the TFI Diagnostics section. From the diagrams there, it appears that the PIP signal (hall sensor) is passed thru the TFI module to it's external connector so it seems like you could use a pin and a volt meter to probe that wire to check for some kind of pulsing when you crank it over. You could also check for power to the TFI module as well. Do you know if the distributor is turning? Just throwing it out there.

 

[whcherman]

i tested the tfi new and old. compared the resistance values from motorcraft to bwd. and also spoke to bwd engineer, about the differences. i have tested the power in the connector to the tfi as suggested in the library. but can you collect any information comming from the external spout connector?
thanks in advance.

 

[kimcrwbr1]

Good question there are three wires comunicating with the computer, the pip out #6 is the same as the camshaft position sensor signal to the computer. the spout in #5 is how the computer tells it when to spark unplugged the timing is fixed. I am guessing the pip voltage is different coming from the computer telling the hall sensor when to switch the coil #2 coil neg. The other three are power run/start and ground. I was just reading my chilton the leading edge of the vane turns on the coil and the trailing edge switches it off creating spark in run mode or dwell, on start mode or push start mode it only uses the leading edge for spark or base timing. If the computer or spout it interrupted it always reverts to base timing no dwell (limp mode) If the engine runs without the spout connected and the dizzy and ICM test good it is likely the computer or a wire that is bad. I find it amazing this all happens at 3 times the rpm or at 2000 rpm the coil switches on and off 6000 times per minute plut it controls the dwell angle and injector pulse length according to engine temp, rpm, air temp, barometric pressure, O-2 and throttle position did I miss something.

 

[whcherman]

nope, got it all, thanks.