Was running fine during routine shopping. When my wife came out of store the engine would not crank. Fuel is no problem it has new fuel pump. I have replaced crank and cam sensors, also plugged in new ASD relay to no avail. Changed coil pack. When I check the firing at plugs it hits ONE HEAVY SPARK and NO MORE at each try. Only hit's again after ignition is turned off and then back on. Please respond with any suggestion.
Does the starter turn the engine, or does it only crank a little, then stop turning ??
Keep in mind any newer vehicle from about 1985 on up, has an ON BOARD spark/fuel computer, with a variety of sensors- and the only way to effectively check them all, is with a special diagnostic computer- which the dealer has- or the better repair garages have. You have to "scan" the entire system first, to be sure all the sensors are working properly. Then also do a fuel pump pressure and volume test, and a fuel pump relay check- (all new cars are fuel injected- so they use an electric fuel pump usually) Once you eliminate the computer controls and sensors, THEN you can move on to the basic engine diagnosis.
95% of the time, it's in the computer controls and fuel system. Most of the time, the problem is electrical or sensors.
Finally, every car should be checked for EXHAUST BACKPRESSURE, by removing the O2 sensor, and running the car with a pressure tester screwed into the O2 tap. Many converters come up PLUGGED. My 2002 GM car with 75,000 miles on it, already had a plugged converter.
Drive with a plugged converter long enough, you burn all the heads off the exhaust valves- due to excessive engine heat- the exhaust cant' get out.
just a word to the wise.
my advice, take the car to a shop with diagnostic computer, the days of the home grown fixer is over for these new cars. The only thing the average guy can do, is brakes, change oil, trans fluid, filters. When it comes to a "no run" problem, forgettaboutit...
Now he mysteriously has a 2002 "GM car." When did this happen, Noodles? Raid another estate sale? Oh, BTW....a plugged converter usually results from BYPASSING EMISSIONS EQUIPMENT, such as EGR valves and air pumps, which you advocate doing elsewhere on Usenet...a Federal crime.
LMAO! The engine will quit running before that point, dumbbell.
For an idiot like you, Noodles, perhaps. For a smart tech with proper tools and knowledge, no way.
No it doesn't stop turning - no problem with battery or starter.
It does look like the PCM (Powertrain Control Module) is my next step and I may be forced to have it towed to a dealer for diagnosis. I just didn't want to be ripped off which none of us can afford.
Your word to the wise concerning EXHAUST BACKPRESSURE is well taken; I did NOT know that. I'm in agreement with you concerning "gone are the days". Thanks for all your input
goto dealer, ask them for the wiring diagram. try to locate all the sensors realted to the ignitiion system. Check all the connectors. Same books shows wehre the connectors are. Try to test all the sensors to be sure youhave working sensors. If you want you can bypass some relays.
Be sure you check all the fuses. Especailly ECM one.
PS: you c> I wasn't sure - was there any advise to me concerning my dilemma?
"Plugged" converters usually show up on car that are either prodigeous oil burners (ash then plugs the honycomb) or which have had their emssions systems tampered with (as all of Charlie Nudo's cars are) where the platinum substrate has been depleted by running a car too rich. Of course, old age kills converters, too, but I've seen them with 200K on them and still working satisfactorily enough to pass the most stringent smog testing regimen in the US. The key is good engine and system maintenance.
Not long ago, a doofus nearby in an older Ranger neatly melted his cat converter by simply unplugging the O² sensor, forcing the fuel system to run rich in open loop, saying that smog control was "government interference" with him running his car...about as convoluted a bit of thinking I've seen in awhile. When told he needed a new converter AND a smog check, he said not to worry, just put in a spacer and that "Joe Blow" across town would pass it by putting his car on the dyno/sniffer. "Joe Blow" is now serving a five year stint in one of our unluxurous and adventurous state prisons for multiple counts of fraud and clean air violations.
Besides the abusive, insulting style, what you post runs quite contrary to my experiences. Note: the following is case history, not conjecture.
I once had a converter plug up, and it ran, but without much power.
After determining the problem, the converter was changed, and I discovered a strange situation.
The car would run fine, then suddenly, it would lose power, then be back to normal. Sometimes it would be bad for a few miles, sometimes for many miles. After I cut the converter off and replaced it, I found that all of the contents of the catalytic converter had "melted", and re-solidified, as a perfect fitting plug against the outflow end. You could even see the indentations of the outflow screen in the plug.
As you drove around, the gas flow and bumps in the road would cause the plug to fit against the screen, withg an expected loss of performance. After the car was shut off, or hit the right bump, the plug would fall into the bottom of the case; not blocking the exhaust flow, and the engine would run normally.
As far as the damage to the engine, note that it did run, even with a near perfect plug, but the exhaust valves were pretty well cooked, although not "melted" off. The compression was low on 2 out of 6 cylinders, but higher RPM running was not too severely affected. Idle was not good, and there was some stumbling as the engine RPM came up.
So, perhaps what you seem to be so "sure" of, is not so "sure", after all. You might try to discuss and learn, rather than being a know-it-all.
Oh, I forgot to add that this vehicle with the melted converter had been in the family since new, and had never run leaded gas, or had any emissions controls or systems bypassed, or any other systems altered. It had been given excellent maintenance throughout it's life.
Not strange at all. That's caused by running too rich a mixture constantly and/or very retarded ignition timing. Both can be caused by a shot O² sensor, open/intermittant wiring to ECM sensors or a defective module. In the case of the O² sensor failure, most systems are designed to run way too rich if the system is in open loop mode.
The spark is not going to be there as long as you crank the engine. The ASD relay shuts down fuel and spark after 3 seconds of cranking. You say there is good pressure, what was the pressure reading?
Yes, they have been doing them in the largest cities for a few years, and have been adding more counties, especially the ones that are growing, or have industries that help to contribute to smog.
I don't know about the rules for the largest cities, but in my county, it applies to '96 and newer models.
They also add oxygenators to the gas in the largest cities, in selected months.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.