Can someone tell me what a pickup coil is and how it would make me run lean at high rpms.

Ive been trying to figure out what is going wrong with my truck 95350TBI mostly stock. Brian at tbichips told me I should probably change out my whole distributor becuase he said my pickup coil was probably bad causing me too run lean at high rpms.

It will pop a little and lose a lot of power at WOT above about 3700rpm. Sometimes it wont do it if its in first gear with not a lot of load. But hitting second at around 4000rpms it will just basicly stay there and pop, especially on a hill.

I though running lean like this will kill your engine very quickly?

Although I havent datalogged in a long time my DC is only about 54% at WOT at at4000.

Can I just turn my WOT afrs up at high revs or will it always run lean untill I find the problem?

 

The pick up coil is part of a generator that create an electrical pulse. This pulse is feed to the ignition module for SA timing.

RBob.

 

The pickup coil is the thing in the distributor that triggers your ignition. It has nothing to do DIRECTLY with your A/F ratio. However, if you are getting misfires becuase it's bad it can cause the O2 sensor to read lean (you're dumping unburnt oxygen and fuel into the exhaust with a misfire- the O2 reads the extra oxygen in the exhaust as "lean", even though it's not really). However, at WOT the ECM isn't looking at the O2 sensor- it's just reading the fuel tables in the chip and squirting in that amount of fuel.

If you've got an ignition problem, fix it. But don't assume that will necessarily fix a TRUE lean condition in the upper RPMs at WOT. Usually if you're lean wide open in the high RPMs you're just outrunning your fuel supply (inadequate fuel pump to keep up with demand) or the fuel maps in the chip are just too lean to meet your engine's needs.

 

Ok thanks and sorry I put it in this section wasnt paying attention.

It dosent look lean, but im reading with a stock nbo2. I might try to test it but I think I need something to measure resistance and plus im not that good with distributors so I might just set my shift pointsto about 3800 or 3850rpms its not like it makes any power above it.

 

Easy way to test a pick up is with a timing light. That is if you don't wanna pull the dizzy apart. You can test a pick up with a simple volt meter. [Get a reapir book] Though you must pull your dizzy and take it apart to change a pickup.


a bad ICM wont spark when fried. But a bad pick up can still work some what.
Put a timing light on the car and watch the strobe. All that light does is flash when said wire sparks. Put the timing light on each plug wire one at a time and watch the strobe. Should be a nice even constant flash on each wire. Any skip beats is the pick up not firing right, or even a bad plug wire.


Ask me how I know? I got a bad pick up right now. Coil got hooked up backwards, car ran fine for about a mile then started loadin up bad.
Still runs but on the timing light you can see it skip timing beats all over the place. Like its only firing 4 cylinders at random. So the car still run, just not well.

 

Yeah my truck runs good except for just like 3800 and up rpms. Sometimes it will pull thorough first gear but it always does it in second.

The feeling of it is like when you just started your motor up when its cold and you try to go WOT.

 

If it run fine to 3800 its not a pickup.

YOu need to do a full tune up. change everyrthing.
My V6 did similar.

Both 2nd and 3rd gens I have owned tend to eat up ign parts much quicker. And sometime they just need a full tune up, doesn't matter if you just change this or that. Full tune up will fix that. Doesn't matter if your plugs "look" good, change em. My 80 camaro did all that to me once. Changed everything. Last ditch effort was some 98 cent champion plugs. And it was fixed. 3 month old clean looking ACs were bad.

Back in the day folks did tune ups atleast twice a year. Before winter and before summer. That way you knew you were safe to go.

 

Sometimes at idel it seems like it misses just once every now and then when it does you can feel it shake for less than a second.
But why would my DC only be at like 54% I thought stock injectors where just enough to feed stock motor at 12psi?