4) Checked the injector to see if it's working: Although I haven't done this trick in this instance, a few months ago I used the trick I learned here of pulling the fuel rail up and holding it, while the wife turns on the key...I got no dribbles or leaks. I had her turn the car over, and all of the injectors pulsed and sprayed fuel perfectly. Now, I haven't tried this test again since I've gotten the P0202, and I can do so, if you think it will help.

Thoughts?

Rob

I think if I where you Rob, I'd do this one again just to see IF the injector still works and if so, does it pulse or just open and spew fuel. The other option would be to use a noid light.

 

The noid would be a heckuva lot easier, because I can rent it for free...will this do the same thing as pulling the fuel rail, Ranger?

Rob

 

Well the noid light won't tell you if the injector itself is bad. Only a visual or listening to it with a stethoscope will. If you do a visual and don't see a fuel spray or listen and don't hear the injector pulsing, you know you have a dead injector, but is it the injector that is bad, or is it not getting the signal to pulse? The noid light replaces the injector and will tell you if the circuit is good and providing the proper pulsating current to the injector.

 

I guess I'll rent the noid to check the pulse, and then pull the rails to check for spray...I'll let you know what happens tomorrow.

Rob

 

Well, the noid set was already rented today, so I went with the spray test in the interim....I had the wife turn the key "on" first, and the injectors primed, but there was no leakage. Then, I had her turn over the engine while I held the injector ring up over the ports, and each of the injectors pulsed and sprayed fuel perfectly. I had her do it a few more times, to see if the atomization looked okay, and it looked to be fine, all across the injector loop.

I still have to perform the noid pulse test, but the No. 2 injector seems to be working okay....unless there is some sort of out-of-sync, pulse timing malfunction going on that I can't detect by a visual inspection...if that's even possible.

Rob

 

No need to perform the noid test. You have already verified that the injectors work and the circuits are good (unless it is intermittent).

 

....and the circuits are good (unless it is intermittent).

So...is there any way for me to determine this? Could any intermittent pulse be the result of bad wiring?

Rob

 

Yeah, I suppose it is possible you could have a wire that is chaffed or burnt and is very close the the block or manifold and vibration occasionally made it touch and ground out. The only way to find that is visual inspection.

 

Thanks, Ranger....I'll check the harness. Although I've never looked, I'm assuming the while injector circuit wiring loop just plugs into a harness clip, coming out of the PCM. I may take the whole thing out to make it easier to check along it's length (after labeling the connectors numerically); if that proves too much of a hassle, I'll just strip the front injector section back and look for damage there, including cutting, removing and reconnecting that 90-degree spot I spoke of earlier.

Rob

 

Hi, Rob. Many years ago I had an intermittent ignition problem in my 69 Corvette (3X2 427 400hp) equipped with the then "new" K88 transistorized ignition. Complete loss of fire to the coil was the symptom which occurred seemingly every few days of driving. Considered changing the expensive K88 module (all sealed of course. Couldn't verify a component failure) but first checked the harness with an ohmeter equipped with sharp ended test leads. Turned out a ground wire was opening up intermittently in the harness when I "bent" it a certain way. I thought at first I might have a mistaken "open" reading due to the probes or leads not making good contact but the indication reoccurred as I "bent" the harness. Replaced the one ground wire with new and never had the problem again. Point being, I like your idea of focusing on the 90-degree spot you mentioned..
Best,
Ron

 

Thanks for the encouragement and tip, Ron....I'm going to give it a go, probably this weekend, when I can have more daylight hours to fool with it.
Rob

 

Okay, fellas...did some monkeying around today, and traced the wires back (as best I could)...I didn't find anything out of the ordinary. I hooked up the OBDII reader again, and checked for new/recurring codes; after having cleared the P0202 code last week, and driving it all week to build the cycles, now I get a generic P0300 (but no 0202).

I started the car again, and pulled each injector plug to listen for a change in the idle; cylinder no. 2 was still dead (no change in idle), but now no. 1 is also not working (directly opposite of no. 2), so I'm effectively running on 6 cylinders. I could also hear the 'tick' of the injectors, using a long screwdriver to the ear trick, while the car was idling. :helpless:

I really can't figure this out, because I checked to see all injectors were firing (and they were--see post 6 above), and all of the injector voltages seemed to be within range...now, I'm wondering if this could be shifting back to the issue of actual ignition firing (coil packs, etc.). I just replaced the plugs, so I know it's not those; I am using a set of coil packs I picked up from a salvage yard, so I really can't be sure they are working 100%...they looked fine, and were clean, but unless there is a way to test them, I really can't be sure. I also kept my original ICM's, in case I needed to swap them out....not sure if they could be a culprit.

It seems like I'm just going in circles here, chasing these misfires...this is really driving me nuts! :banghead:

Rob

 

The ignition cassettes have nothing to do with the injectors. If you suspect the ICM, you might want to read up on in in the ICM sticky in the Northstar forum for a better idea of how it works (if you haven't already). If it's strictly an injector problem, might be an injector driver in the PCM (bad PCM).

 

I guess my logic is telling me that since I smell fuel from the exhaust pretty strong, and I have done the spray test, then the electronic part of the system must not be firing those plugs to burn the fuel being pumped into the cylinders and provide combustion; in other words, the injectors are working fine, but the plugs aren't sparking, for whatever reason...which I'm assuming could be the ICMs, the coil cassettes, or the PCM itself.

I'll read up on the ICM sticky you suggested, Ranger...thanks.

Rob

 

Hi, Rob. Apologies in advance for throwing a longshot possibility at you... Another corvette I owned many years ago (68 coupe, 1 X 4bbl 327) had a very slight miss only at idle and low RPM. Pulling spark plug wires one at a time only caused that one cylinder to quit firing but the idle miss really was the same. The skinny block chevy V-8's use dual valve springs and the problem turned out to be a cracked inner valve spring (not visible until removed) causing a slight compression loss which at low RPM happens to be "felt" across the plenum chambers on the intake manifold to the opposing cylinders!! Go ahead and throw rocks, guys. I'm just trying to help...

Best,
Ron

 

No one's gonna throw rocks. Never hurts to get another point of view or idea.

 

Ranger's right, Ron....right now, I'm just throwing parts and money at this Northstar, trying to see what might make a difference.

On the issue of a possible bad PCM, I've got a couple of questions: 1), is there any way to test it for problems to be sure, and 2), if I pick up a Y-code engine PCM from a salvage yard ESC Eldo, is it as simple as a "plug-n-play" installation, or do I have to take it to GM to be re-programmed?

Rob

 

Going through the diagnostic tree for the code would eventually tell you to replace the PCM by process of elimination.

Yes, a replacement PCM would need to have its original VIN cleared with a TECH II.

 

Going through the diagnostic tree for the code would eventually tell you to replace the PCM by process of elimination.

I assume you mean looking through the historical codes on the DIC?

Yes, a replacement PCM would need to have its original VIN cleared with a TECH II.

Thanks, MC.

Rob

 

No, not history codes. A diagnostic tree is what service manuals use to guide you through diagnostics, by testing each component that may be responsible for the fault.

Very basic example:

1. Test part A like so. Does it pass? Go to step 2. Does it fail? Go to step 5.

2. Test part B like so. Does it pass? Go to step 3. Does it fail? Replace part B.

 

Ah-ha, I see....where might I find one of those (other than a dealer)?
Rob

 

Ebay is your friend Rob.

 

Would this work?

http://factoryservicemanual.net/cadillac-eldorado-1996-2002-factory-service-repair-manual.html

Rob

 

Some of those aftermarket CD's or downloads have been known to not work or take up HUGE amounts of storage. Can't speak for which ones though.

The other option is a subscription to alldatadiy http://www.alldatadiy.com

 

Thanks, Ranger...I'll throw 10 bucks at the download first, but if it doesn't pan out, I'll try the Alldata subscription for a year.

Rob

 

Well, tried a 10 buck download, and although it's got a lot of other useful info, there's absolutely nothing about diagnosing a problem...no diagnostic tree whatsoever.

Looks like it's time for Alldata.

Rob

 

not sure if this will help, but here you go:
CIRCUIT DESCRIPTION
The fuel injector is a solenoid operated device. The fuel injectors receive 12 volts from the ignition switch through a fuse. The PCM provides the ground path for each injector through individual driver circuits. The PCM monitors the circuits for proper voltage levels. When an improper voltage level occurs, the driver signals the PCM. If the PCM detects an improper voltage level in the fuel injector circuit for cylinder #2, DTC P0202 will set.

CONDITIONS FOR RUNNING THE DTC

•System voltage DTCs are not set.
•System voltage between 11-16 volts.

CONDITIONS FOR SETTING THE DTC
The PCM detects an improper voltage level in the fuel injector circuit for cylinder #2.

ACTION TAKEN WHEN THE DTC SETS

•The PCM illuminates the Malfunction Indicator Lamp (MIL) the first time the malfunction is detected.
•The PCM will store the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC

•The PCM will turn the MIL OFF after three consecutive trips during which the diagnostic runs and passes.
•The History DTC clears after 40 consecutive warm-up cycles occur without a malfunction.
•The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers in the diagnostic table.

4.If DTCs P0203, P0205, and P0208 are not set, then the malfunction is isolated to fuel injector #1.
5.This determines if the circuit is shorted. An open ignition feed circuit or a faulty splice is indicated if the DTCs are set and the fuse is OK.
6.Checks whether the ignition teed or the fuel injector is shorted.
8.Checks for a short to voltage on the fuel injector control circuit.
9.Checks for an open or short to ground in the fuel injector control circuit.
10.Checks whether the fuel injector is open or if poor terminal contact exists.
17.This vehicle is equipped with a PCM which utilizes an electrically Erasable Programmable Read Only Memory (EEPROM) . When the PCM is replaced, the new PCM must be programmed

----------

not sure if this will help, but here you go:
CIRCUIT DESCRIPTION
The fuel injector is a solenoid operated device. The fuel injectors receive 12 volts from the ignition switch through a fuse. The PCM provides the ground path for each injector through individual driver circuits. The PCM monitors the circuits for proper voltage levels. When an improper voltage level occurs, the driver signals the PCM. If the PCM detects an improper voltage level in the fuel injector circuit for cylinder #2, DTC P0202 will set.

CONDITIONS FOR RUNNING THE DTC

•System voltage DTCs are not set.
•System voltage between 11-16 volts.

CONDITIONS FOR SETTING THE DTC
The PCM detects an improper voltage level in the fuel injector circuit for cylinder #2.

ACTION TAKEN WHEN THE DTC SETS

•The PCM illuminates the Malfunction Indicator Lamp (MIL) the first time the malfunction is detected.
•The PCM will store the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC

•The PCM will turn the MIL OFF after three consecutive trips during which the diagnostic runs and passes.
•The History DTC clears after 40 consecutive warm-up cycles occur without a malfunction.
•The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers in the diagnostic table.

4.If DTCs P0203, P0205, and P0208 are not set, then the malfunction is isolated to fuel injector #1.
5.This determines if the circuit is shorted. An open ignition feed circuit or a faulty splice is indicated if the DTCs are set and the fuse is OK.
6.Checks whether the ignition teed or the fuel injector is shorted.
8.Checks for a short to voltage on the fuel injector control circuit.
9.Checks for an open or short to ground in the fuel injector control circuit.
10.Checks whether the fuel injector is open or if poor terminal contact exists.
17.This vehicle is equipped with a PCM which utilizes an electrically Erasable Programmable Read Only Memory (EEPROM) . When the PCM is replaced, the new PCM must be programmed

----------sorry these aren't in order

http://i10.photobucket.com/albums/a148/DrEvil2005/p0202-2_zpsc1ed313d.gif
http://i10.photobucket.com/albums/a148/DrEvil2005/p0202-1_zps4b25464f.gif
http://i10.photobucket.com/albums/a148/DrEvil2005/p0202-3_zps7c42e265.gif

 

not sure if this will help, but here you go:

Hi, Matthew. Excellent post! I hope Rob sees this soon. Sure looks like what he may have been needing for more help. May I ask which from which manual are those three pages, is it applicable to the 2002 Eldo ETC (I suspect it is) and where can I obtain one? (The manual, not an ETC. LOL ) BTW, Can you tell me a little about the white SUV pictured in your photo album at a car show (page 2 IIRC). TIA!
Best,
Ron

 

Ron, that looks like a FSM from Helm Inc. (the official GM manual). Normally I would say Ebay is your friend, but I only see one set there for $235. After a little investigation I see why. Helm has them for $200, but is out of stock. You might be better off with a subscription to www.alldatadiy.com, which is basically an online version.

 

Thanks, Ranger! Much obliged.
Best,
Ron