[Matts99Sierra]

anybody have any ways of checking to see if a computers fried?

[segge]

What do you mean by fried exactly, are we talking about a car computer or what?

[Matts99Sierra]

uh... no my shops computer, kid. yes a car computer. lol, oh my... i was just curious to see if there were any ways of checking to see if a CARs ECM was bad

[1931 steve]

Originally Posted by Matts99Sierra

anybody have any ways of checking to see if a computers fried?

What kind of problems are you having that makes you think it a computer (PCM) problem.

Steve

[Siggy_Freud]

In my experience you usually have to deal with the problem as if it were sensor related. Once those means are exhausted, I start looking at the computer or wiring as fault. I havent come across any ways to test the computer itself.

[Matts99Sierra]

it'll idle fine then all of a sudden it'll start buckin, missing and rockin like crazy. and when i hit the gas it'll miss like crazy and has no power, umm, every once in a while the check engine light will stay on, and the fan come on like i have the code scanner hooked up when i dont and when that happens i cant even pull the codes from it. and when i am able to pull a code i get 44 which says its running lean. when this first started i checked all the sensors which were all fine. i even replaces a few... O2, MAP, TPS, IAC and crank position sensor. i just got done tearing this engine down to nothing but the rotating assembly and replacing all the gaskets, tearing the head apart checking the valves and cleanin g all the carbon out of it. i checked the cam timing which the marks were dead on... lifters looked almost perfect. what i could see of the cam was perfect. valves were all fine, rods were fine, valve springs were good and so were the valve seals and guides. none of the valves were sticking. oh, the ignition module and coils checked out ok, spark knock sensor was fine... nothing was blocking the fuel system, i was getting good pressure. new fuel filter, i ran injector cleaner through it. dude, im stuck, i dont know what else it could be but for the computer. im about ready to junk the car. i been working on it for a week straight. i dunno... if i missed something let me know

[1931 steve]

What kind of car is it your working on? what engine? what year? Why did you do the tear down?

Steve

[segge]

Originally Posted by Matts99Sierra

uh... no my shops computer, kid. yes a car computer. lol, oh my... i was just curious to see if there were any ways of checking to see if a CARs ECM was bad

No need to get sarcastic. Not like you gave a whole lot of info...

[Matts99Sierra]

i guess that'd help, sorry.. its a 90 chevy cavalier, 2.2L I4 TBI, 5 speed...

Sorry segge... lol... you left it open i had to. didnt mean to piss ya off :-P

i did the tear down to check the cam timing. i had to take most everything off to do that anyway so i just figured i'd tear it all the way down and check for flaws

[segge]

Heh yea I guess i knida set myself up for that one.

[1931 steve]

What is the service # on the ECM? Could be a known bad ECM. Did all of this start after assembly of the engine? Can you read a data stream or is your reader just a code reader? If so how are the values? Silly but need to ask, are the spark plug wires on in the right order? How about the injectors are the all firering?

Steve

[Matts99Sierra]

it started before assembly of the engine thats why i tore it down. i have a $500 computer scanner and it wont work on the car. keeps telling me to plug it in.the code that keeps popping up is 44... lean fuel mixture. the plugs are newer and so are the wires. the wires are all on the right way and the injector is firing and i can see a fuel cone come out of the injector

[1931 steve]

How are you retrieving the code # 44 flashing it on the check engine light? Have you checked the basics such as compression, spark on ALL cylinders AT the PLUGS? Does the check engine light pass the bulb check at start up? Does your scanner read data or is it just a code reader? (this is a long shot) Have you tapped on the ECM to see what it does?

Steve

[Siggy_Freud]

First verify that your scanner does work (like on another GM). If you still cant get info through the OBD port, Id replace the computer. I've had a similar problem of my GM ECM not sending out data (it was running a bit funny as well). A new ECM cured this.

[docvette]

Doc here,

Those Computers are pretty Well buffered from the real world...(you really have to work to smoke one..) My Brother in law's Nephew was driving Tow Truck in Barstow Ca. And picked up a Car in a lightning storm...Lightning Struck the truck...and the vehicle being towed...

Killed the owner of the towed Vehicle..and sent my Bro in Law's Nephew to the Hospital for a month..to learn how to walk again..eat without drooling...and not having metal eating utensils stuck to his forehead..

Anyway, The end of the story is BOTH computers survived unscathed and both vehicles started the next day and ran...(Did better than the Motorola radio and MDT did in the Truck..they died) after MILLIONS of Volts struck them..

I would Check and Clean your Computer Harness Plugs and pins at the computer and component end both. Be sure you have no collapsed Pins on the computer edge card connector...and all make good Clean contact.

Next check the Computer grounds (Very Important) If you have Errant grounding at the computer you will throw codes sporadically, and get Check engine lights when you least expect them..I had the Very Same problem with one of the Vettes, and to cure it, I installed a Hard ground to the Computer case, and the main ground wire to the computer..It would Give a check engine, and misfire, and hesitate off the bottom end of the throttle, and the A.I.R. pump would run like crazy....that cured that problem.

Worst Case Scenario, will be the Mem Cal prom Will be shot...Thats usually about $50., and usually an "Order" only item.

Hope it helps!
Doc