DBLTKE

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So I'm working on a car with a speed density LB9 and and having an issue with a code 32 (EGR), 42 (ICM), and 43 (ESC). It's also having drivability issues. It will run fine when everything is cold, however in hot weather or when the car gets hot it will lose nearly all power for a second or two, then pick back up again. It's not a misfire but it completely loses power. If I push in the clutch while this happens the car will die. It will start back up the first 2 or 3 times but eventually it won't start and will just crank. I have to let it sit for 20 minutes or so until everything is cool for it to start again.

Obviously this is not EGR related, so it has to do with code 42 and 43. It has a new knock sensor, yet the code still stays. I checked all the wiring and connectors for the ignition and everything looks ok, even has a brand new Ignition control module. I just put a new distributor in yet the problem persists. What else could cause this? Bad ECU/memcal? Bad coil?

lunaticinaZ

If the knock code stays I would double check the sensor part number. they are YEAR and ENGINE specific. maybe they gave you the wrong one. But the drivability sounds like a fuel problem to me. maybe the fuel pump is going bad. Or the tps is going bad causing it to dump to much fuel or not enough when it gets warmed up and the sensors take over (can't remember if thats closed or open loop lol)
Oh also make sure you plugged in the connectors good at the dizzy. The SD cars esc is in the dizzy

DBLTKE

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Replaces the ECU with a new AC Delco unit and no improvement. I'll be hooking up a fuel pressure gauge and see what's going on there.

DBLTKE

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Checked TPS operation via DVOM, readings were steady and within spec for both idle and full throttle. Checked Fuel pump relay by swapping with the fan relay, no change there. I pulled a spark plug wire when I cant get it to start and it was getting spark. I also checked fuel pressure at the fuel rail and its getting a full 50psi during the crank/no start, straight to 50psi with key on and while cranking. I'm baffled, it's getting fuel and spark yet wont start.

DBLTKE

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I pulled the codes again after I put in the new ECU and the only code present is the 43 (Electronic Spark Control circuit), in other words, the knock sensor. I followed the diagnostics flow chart from ALLDATA and i get 4.88V at the ECU side of the circuit and 4.88V at the connector, so theres no wiring issue there. I then checked the ohm reading for the knock sensor by connecting the ohmmeter between the sensor terminal and the engine block and got .0003 ohms, which is definitely a far cry from the proper operating range of between 3300 and 4500 ohms. This leads me to believe that the knock sensor is bad. Can a faulty knock sensor cause a no start issue? I was under the impression that it only caused drivability problems.

DBLTKE

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So I replaced the knock sensor and torques it to 14 ft/lbs, reset the codes and fired it up. SES light still came on after a few seconds and died shortly after. So I decided to install a new ignition coil, cleared the codes again and started it up. This time the SES light did not come on until after a few minutes of idling the. Went out a few minutes later. Car never died and I've been sparingly driving it for two days now. The SES light has been on and off intermittently and now only shows a code 43. I'm going to double check the part number and do an ohm reading on this sensor but I don't know what else could be causing this, a bad MEMCAL?

DENN_SHAH

iTrader: (1)

im working from memory so i may be thinking of another brand of car here.

make sure the ignition timing is right.
i know the ECM looks at the voltage on the knock sensor wire to set a 43.
but i believe the ECM also advances the timing up to a certain point where there the sensor should pick up some knock counts.
if it doesn't see any knock counts, then the ECM thinks there is a problem with the knock sensor circuit and sets code 43 and fixes the ignition timing.
also, it seems like it can kick the code if it sees knock counts for too long after the ECM has pulled all the timing it can.

DBLTKE

iTrader: (1)

Interesting, I did not get a chance to set the base timing after I replaced the distributed because I stabbed it so close to where it was, however I can tell that it's a little retarded because it's not as responsive as before. I'll time it tomorrow and see what happens.

DBLTKE

iTrader: (1)

Checked the timing, it was dead on at the factory spec of 6* BTDC with the EST wire disconnected. I got some insight from another tech at my dealership and he brought up the fact that had gotten an EGR code too. I haven't looked into that yet simply because it isn't causing any drivabily problems which leads me to believe that the EGR is stuck open. However that also means that this is essentially a vacuum leak, causing the engine to run leaner than what the computer thinks it's at, possibly inducing a little detonation resulting in the knock sensor code (43). So I'm going to cap off the vacuum line at the EGR to see if maybe that's causing an issue.

DBLTKE

iTrader: (1)

So I capped off the EGR and reset the ECU, yet the code 43 persists. The only thing that I can be is the MEMCAL itself. I'm going to get into tuning this car in a few weeks so we'll see if the code goes away once the adapter and new chip are installed.

DENN_SHAH

iTrader: (1)

problems with the MEMCAL is a possibility.
years ago i had a chevy astro van that wouldn't start. turn the key on with a scanner hooked up to it, the injectors would sit there and fire about 2~3 times a second. then look at the data and it showed an RPM reading. if you pushed the gas petal, the RPM reading would climb and the injectors would fire faster. with the petal on the floor, the injectors buzzed they were firing so fast. if you cranked it over, the RPM would go to 0 and the injectors stopped firing.
it was all caused by the MEMCAL.

if the motor is getting EGR the wrong times, it wouldn't be lean. being there isn't much O2 left in the exhaust it maybe a little rich.
EGR at the wrong time would be a dilution problem.
because exhaust gas won't burn, it doesn't take much EGR at the wrong time to cause a misfire because of the dilution, especially at idle.
i've never seen excessive EGR cause ping and i don't think it can.
but it could cause no ping. but usually you'll see some type of driveability problem if you get either too much EGR or get it at the wrong time. ruff or won't idle, a sag or hesitation under acceleration and a little power loss under WOT.

is it still dying with a no start?

you may try hooking up a DVOM or a scope and monitor the voltage on the knock sensor wire to see what happens during an event/kicks the code.

DBLTKE

iTrader: (1)

No, the ignition coil took care of the engine dying/no start issue. It idles and drives just fine however Ive noticed that it sometimes feels a bit sluggish in the 1200-1800 rpm range. Like as if it were pulling a lot of timing or running really lean. The problem is that I just picked this car up so it's hard for me to tell how it really should feel.

DBLTKE

iTrader: (1)

Recently my car had started running worse and worse. To the point were it always felt like it had a lack of power and at times would hardly accelerate, similar to when you've run out of gas. Well I already knew that my knock sensor was bad so I just double checked and threw in an AC Delco replacement and cleared the codes (32, 43). After installation, my car ran like a champ. Full power and not a hiccup. However, twice now in the past three days, I've had a little episode where it almost felt like the car was going to die under acceleration throughout first, second, and third gear. The feeling was again similar to running out of gas. The biggest issue is that this is intermittent, so it makes it hard to do any tests because this only happens under acceleration. Now I've checked and adjusted fuel pressure at idle with the vaccuum line disconnected and took the fuel pressure down from 55psi to 45psi (stock: 43.5psi). I've tested the connector at the knock sensor and it's getting 5 volts which is perfectly in spec.

Another thing I should throw in here is that I've been having a undercharging issue (10-11volts) ever since I got the car. It's never caused any issues (dead batteries, etc) so I've been brushing it off. But I wonder if it can screw with the fuel pump if it's not getting the full 12 volts? I really need to find a way to be able to see what happens with my fuel pressure when this happens. I'm also beginning to wonder if maybe I have a loose connector for the knock sensor or a broken wire.

P-ROC

iTrader: (2)

I have the exact same issue going on. I am about to start troubleshooting mine. I did not have that problem until I put in a new dizzy. I was reading your posts to see what you came up with but I am about to throw parts at it. Did you try to replace the ESC module? I was going to test that and my knock sensor. I am positive that I don't have a wiring problem so I will post if I find the fix for it.