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e23 and e27

15K views 65 replies 5 participants last post by  the recluse 
#1 ·
E23 - EST Signal Problem

E27 - Open Throttle Switch Signal

what is est? how do i check to find the faults of these problems?
 
#3 ·
i have cleared the codes many times. the car has never ran right the 8 years ive owned it. when cold it runs great but when it gets warmed up it lugs down between shifts and you have to floor the gas pedal to get anywhere.timing is correct, cap , rotor , plugs and wires were all replaced with new parts. also when coming to a stop, it seems to be idling too high causing the motor to almost die out before it finally downshifts. it was owned by a funeral home and only has around 75,000 on it.
 
#22 ·
when cold it runs great but when it gets warmed up it lugs down between shifts and you have to floor the gas pedal to get anywhere... it seems to be idling too high causing the motor to almost die out before it finally downshifts.
Right, this is why the E23 code shows up. In computer controlled vehicles you have two separate "modes" in which the engine runs. In open loop the engine runs with most of the sensors shut off and dumps a lot of fuel through the engine to get it to warm up (dumbed down explanation). Once it reaches operating temps, it goes into closed loop operation where it pools information from the various sensors to get the engine to run its best.

The problem you seem to be having is in closed loop operation. One of the sensors that the engine is calling on is faulty, whether it's a lose connection or a bad sensor or what not, and is not letting the engine run optimally.

The computer is indicating an Electronic Spark Timing fault (E23). This variable is configured by compiling info from a variety of sources such as the pick up coil, the ICM, ignition coil, etc, and relaying that back to the ECM. If any of the information received falls outside of the parameters encoded into the ECM, the ECM throws a "fault" code.

So, with the fault code in mind, you try to deduce all the possible sensors/parts that are controlled by or feed information to the computer that have to do with motor timing and spark. You already replaced the basics such as cap, rotor, plugs, and wires; so in cases where the problem is not fully evident I usually like to start from least expensive to most expensive, like pulling the ICM and having it tested (free to do).

You can probably rule out the ignition coil because the car runs good in open loop. I say this because if the coil was bad, the possibility remains that the car would run crappy from the start.

The ICM moderates the current from the coil, like points did back in the day, and is the next logical step in progression. It just so happens to be the cheapest also.

Pickup coils work with a vehicle's ignition system to regulate spark and communicate to fuel injectors. When one fails, it can have adverse effects on multiple vehicle systems including the engine and fuel system regulators. A pickup coil that has failed, or is about to, may also cause engine stalling and an inability to accelerate smoothly because the fuel injectors are not firing properly or on time with rest of the engine. Unfortunately, this one is a little tricky to tell without just replacing it and is the most expensive/time consuming item on the list for a novice mechanic.

I know it's long winded, but that is the nutshell of my thought process concerning your symptoms in your vehicle and why I'm telling you where to look :yup:

Good luck and report back...
 
#9 ·
The EST controls spark advance and the like. It's part of the entire circuit which includes, among other things, the knock sensor, the pick up coil, the ignition control module, and the ignition coil. All must be in working order for the circuit to run properly. IIRC it is actually IN the ECM...

When was the last time you replaced any of these parts?

Seeing as how it it runs crappy in closed loop operation, the pick up coil or the ICM (ignition control module) may be your culprit.
 
#23 ·
thanks for the detailed reply. your thought process is nearly identical to mine, i just didnt know where to begin. today i pulled the ICM and had it tested at a local parts store. it tested bad twice and good once. i bought a replacement. however i have a 84 seville that runs flawlessly , but is wrecked. when i looked at the pickup coil on my hearse, i saw rusty cruddy crap below it. i pulled both distributors , and will be swapping them tomorrow . the original dist on the hearse seems to have a lot of vertical play where the seville one has a very small amount of play. since the ICM is a non returnable part once installed , im going to hold off on installing it into the replacement distributor . ive got a day to do this before halloween, and will be busting my backside to see that it happens. thanks for all the help given so far, it is much more than i have been able to get locally. and much more than my chiltons books and my limited knowledge of vehicle electrical systems... ill let you know what happens...
 
#28 ·
Make sure you have the power wire (pink) fully pressed into the cap and the clip is not broken. Did you change the coil over from the old cap? Did you install the new ICM?

Somewhere the power signal to the distributor is getting cut and/or dropping off. This can either be the power wire or the dreaded pick up coil :ill:

Check those 2 items and get back
 
#29 ·
power wire is fully pressed into the cap, and i used my new cap . i did not replace the ICM because i didnt see a need , since it was pulled from a perfectly tuned engine. codes 23 and 29 have showed up today. i saw a bit of crud in the flat weatherproof connector for the distributor, but we cleaned it with contact cleaner and a wire brush before reinstallation. i am getting the feeling its time for a 350 swap , or maybe my spare 425.....
 
#32 ·
Screw it , I'm done. I'd rather burn the stupid thing before I spend another dime on it. Today while driving , the car shut off and would not restart. I had fuel pressure , but no spark. When i removed the coil cover the wire to the positive side was burned . I replaced the coil with a brand new one , but still have no spark . It cranks over fine and has plenty of fuel . Not even a weak spark though .
 
#33 · (Edited)
Screw it , I'm done. I'd rather burn the stupid thing before I spend another dime on it.
I hear this a lot when people talk about their Cadillac :lildevil:

Been there, said that myself :annoyed:

CODE 23...this still points to the pickup coil...

and the spark is controlled by the ICM...

What people fail to understand is that car parts that sit are failures waiting to happen. You've still not changed the parts that effected you from the beginning, only another distributor from a car that sat, which (by the way) made the car run right at first. Change all the parts listed, if nothing works, then burn the car.
 
#35 ·
pulled the distributor again today. tested the pick up coil as per my service book , with a reading of infinity, meaning it is indeed good. im going to go ahead and replace it on payday however, along with the ICM ,and that other part that looks like a condenser. i really dont know what else could be causing the problems im having , so i figure ill start completely fresh....
 
#36 ·
pulled the distributor again today. tested the pick up coil as per my service book , with a reading of infinity, meaning it is indeed good.
Did you spin the distributor while testing? The pick up coil breaks a magnetic field which relays info to the ICM and fuel system as to cam positioning and timing. Sometimes a bench test with a meter doesn't tell the whole story. If a resistor is burned up yet is dependent upon current to be active, then again, the bench test would say "good" to problem that would not show itself until electrified.

Like I said before, this one is not as easy to detect and can be a little tricky....
 
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