Jigger - Intermittent Power Loss

[laimisl]

Hi Imadozol97 and other great folks, GM fans,

UPDATE: Throttle body was removed again, thoroughly cleaned. New TB gasket used.

In previous description/writeup it said that I should lubricate after cleaning with any oil but not WD40. I have lubricated the IAC after it was cleaned.
I have not lubricated the inside TB as I thought what was the reason of lubricating it as it was just cleaned and oil could burn stick to it making in similar to what it was before I cleaned it.
QUESTION: did I do right or did I need to lubricate the inside of TB as well with any oil but not WD40?

Yes TB and IAC really were black and needed cleaning. Now they are sparkling.

I have still to run it on highway and bleed the air out after coolant level adjusts.

On idle it runs well. Now I guess I have to watch for rough or Jigger and I really hope there will be none especially in winter as it seems I put some effort in summer to make it ready for the cold times.

Thanks,

Larry

[laimisl]

UPDATE: After TB cleaning, all runs great. No jigger, or rough idle. It uses bit much gas, but it is a not young puppy so that is ok. Thanks to all. Happy oncoming holidays! Larry

[justdave]

Hope-ing your engine is still running OK, Larry...but have some info for you, after reading through all the posts about this issue. 1. - The I.C.M. should not have anything placed between it and it's mounting bracket, by design. Using silver-bearing paste (PC heat-sink compound) in that 'huge' area would be expensive and not really help to 'cool' the Module; heat would flow from the engine TO the mounting bracket and into a (cold-start) Module sooner, that's all. Using grease between would slow the heat transfer from the Module into the bracket; NOT a good thing....think about the total energy being generated by the Module and Coils! They are "designed" to withstand high under-hood temperatures, but they also use the mounting bracket as a fail-safe heat-transfer component; maximum heat levels (idling at stoplights or in traffic in summer-time) within the Assembly are thereby the same as the engine's average heat-level; the cooling system limits heat to it's design level of around 195 degrees Fahrenheit. 2. - "Misfires" of Ignition Coils can be caused simply by 'loose' connections between the female connectors within a molded/enclosed Coil unit, and their male 'blade' counterparts which stick up from the I.C.M. The female connectors 'spread out' from heat/age/vibration combination, over time. They are not accessible, for the usual tightening procedure. Since the Primary winding resistance of most Coils is on the order of only 0.5 ohm, ANY extra resistance at these important connections (especially, intermittent changes in resistance due to vibration of loose connections) will cause trouble; the ICM's hybrid electronic parts are designed to switch electric current on-and-off at very fast rates into a Primary winding with a specific impedance.----The fix for such loose connections is to twist the "tips" (only) of the blades just 5 degrees, using "smooth-jaw" pliers (do not scratch the coating on the blades by using serrated-jaw pliers). Re-seat the Coil while wiggling it a bit, to get it onto the blades.
As for di-electric grease, it is supposed to be used only around metal electrical connections, to keep moisture OUT, and to keep the silicone-rubber insulator 'boots' from getting stuck on the Coil posts or stuck on the spark-plug ends especially (they get HOT). *Use of di-electric grease is especially important when the two contacting metals are dis-similar. Electrolytic corrosion will occur between any two dis-similar metals or even different alloys of the same base metal, given half a chance. Higher-quality (i.e. marine) di-electric grease will stand up better/longer when used on the high-voltage/spark connectors found atop the Coils and at the spark plugs, and, stand up better viscosity-wise to the heat levels the ICM is exposed-to. (People who skip the di-electric grease will soon find fine white powder all around the connector/tip of their spark plugs, and may get misfires.)

[laimisl]

Thanks Dave,

I hope have received your insights before I made the maintenance on the coils.

But all starts, works fine. Just my fuel consimption seems increasewd by 1 to 2 literd per 100 km.

Maybe this is the reason due to ICM plate actually sitting on the cussion of marine dielectric grease on the engine mounting surface.

The fuel increase is both felt in summer and in winter. On both seasons sconsumption is very similar though.

My engine has 380k kilometers on, so maybe injectors or anything else is not in the prime, thus fuel consumption is such.

Thanks,

Larry

[laimisl]

Hello all and HELP HELP.

Right after all was flawless and all worked, right after Christmas, here we have new surprise and new gift - the fixing project.

Unfortunately yesterday after snow storm we had lots of snow blown everywhere.

It all ran fine before and after snow storm.

But next morning I had again the same old problem:

"3. When driving over 50 MPH and after revs are LESS 2k, when gear is on Over Drive, and am maximizing the speed and slightly pushing the accelerator (gas pedal) the car engine makes intermittent jiggers and it feels as if: A-There is engine power loss; B- Loss of gasoline or not enough given to the system; C-loss of electrical current to the engine."

I suspect there is electrical problem.

As soon as gear switched to over drive gear, and REVs are low and I am softly accelerating the engine jiggers as soon as I push the accelerator just a little little too much or just a little more.

I am really pissed and disappointed.

Spark plugs are new ( 6 month max), TB cleaned, Coil plate cleaned, coils are all tested to perfection, all is nice and beautiful.

Hell, what else there can be?

Please help.

Thanks,

Larry

[laimisl]

UPDATE: Last night as it got dark I have sprayed the ignition wires with water mist, but I saw no sparks flying, so I guess it is not spark wire problem.

Anybody any ideas where to start troubleshooting?

Thanks,

Larry

[laimisl]

Went again under the hood. It sounds and feels like 1 cylinder is not working.

Removed one by one all wires off the coil posts and could not figure out which one.

I need this car to work, and would appreciate your kind advise and support.

Please help,

Larry

[J Wikoff]

Try this. Get a 194 size bulb, and one injector at a time, remove the connector from an injector at idle, plug the bulb into the wiring side connector, and see if it flashes. Remove the bulb, plug the connector back on to the injector, and move to the next. If one does not flash, that injector isn't getting a signal.

Another thing to try. Remove each spark plug. Does one look much different than the rest?

Another thing to try. Remove the fuel rail with everything still attached (wiring, fuel lines, regulator), put a small cup under each injector (rail sitting level, injectors pointing down), and crank the engine for several seconds. Do all the cups have a similar amount of fuel in them?

^^Not super likely, but be prepared in case of fire.

[laimisl]

Thanks a lot J Wikoff,

I appreciate your help. Will try to trouble shoot as soon as snow storm is over again, and will report back.

Happy 2013 New Year to all club!

Larry

[laimisl]

I have not played with injectors but.....

I have changed the spark plugs anyway. It did not help it.

Then I have changed the spark plugs. It helped but just 90%.

Still as I accelerate it is much better, but there are occasional jiggers, or misfires as i accelerate on low RPMS.

Could it be coils?

Could it be a computer or ICM?

Thanks a lot for your help,

Larry

[Krenzy]

My first thought with your symptoms when I was reading the first post were 1) Ignition Control Module/Coils, 2) Fuel Injectors or 3) Fuel Pump.

I think the write up on how to check your injectors is a very good idea, and although it may be a slight pain, I highly recommend checking them before your go through your ignition system again.

[laimisl]

Hi the weather permitted to do some more testing.

So I have tested secondaries and primaries of the coils. All tested fine.

Earlier in the post you can see that somewhere during summer I have cleaned all ICM, ICM plate it sits on, etc, so as I have removed now coils to test primaries, I have cleaned the engine block part ICM sits on and under ICM I cleaned too, as I have some dielectric grease between them. I thought that there can be ICM over heating issue or maybe not getting enough ground? SUGGESTIONS, IDEAS?

I will run the car on the highway today and will report if that had any improvements to do with the issues I currently experiencing as misfires.

However I am not sure if there are any ways to check ICM, but I took the liberty and tested with the tester the resistance OHM on the setting 2000K. This is what I got and maybe this would show anything that could help:

The two pins on which coil for cylinder 3 and 6 sits on: 957 (similar to coil for cylinders 1 and 4)
The two pins on which coil for cylinder 2 and 5 sits on: 820
The two pins on which coil for cylinder 1 and 4 sits on: 957 (similar to coil for cylinders 3 and 6)

Would this show to bad ICM not giving enough juice for coil of the cylinders 2 and 5?

Appreciate your inputs.

Of course when the weather will be better injectors are due to checking as Wikoff advised. Is this hear of that car with 382k km or 238k miles, have injectors that are gone bad?

As for the fuel pump, it is only 2009 September (it is Spectra).

Thanks a lot,

Larry

[laimisl]

UPDATE: Replaced coils from scrap yard and the problem is gone. It was Coils. As some say, if problem is intermittent at certain speed and certain RPM that are plugs, wires or coils. I problem is persistent during wide spectrum of RPMs and speed and maybe at idle, then it may by ICM. When ICM give up there is no way to run engine at all.

Cheers,

Larry