ShadeTree Mechanics

[crazy4offroad]

My truck would be in a junkyard if weren't for my ability, and willingness, to jump into the motor swap with both feet. I had never taken on a project of that magnitiude before. And now that i have, I realize I can pretty much do whatever I set my mind to. And you can't get that feeling any other way.

Right on.

 

[HotRodPC]

that was low...

I didn't think so for as many times as he slapped me. And when I was married, I wished the wife would have worn the pants for a change. I got sick of wearing the pants. Actaully I don't beleive either should have to wear that pants, its supposed to be a mutual thing, but she didn't see it that way.

 

[Old77]

that was low...

Hence the 'no comment'. Not worth acknowledging....

 

[RetroC10Sport]

Well, there's always me. I have more dresses than my wife.

 

[RetroC10Sport]

Hence the 'no comment'. Not worth acknowledging....

I stand up for the Big O.

 

[Old77]

 

[HotRodPC]

that was low...

Hence the 'no comment'. Not worth acknowledging....

I stand up for the Big O.

Woweee !!! I didn't mean to make you cry. Was it really that bad??? C'mere buddy. I didn't mean to hurt your fittings.
Now you're gonna make me cry. Didn't think you'd take it that personal.

 

[oneluckypops]

OK OK I know I am new here but I read a few of the posts in here and cant help it. I gotta give ya my 2 cents.
First let me say I am an automotive technician, some have said that techs would rather NOT work on the older autos which is true. BUT some have also said that the reason is they cant just plug a computer to it to find out whats wrong which is totally WRONG. The biggest reason why a Tech doesnt like to work on older vehcles is that they are Carbeurated, most of the time those vehcles are brought in is because of drivablity issues (running rough) which 9 out of 10 times is due to carbration. Which we all know are tediouse to set CORRECTLY, Hell for that matter alot of people think you set them by ear and thats good enough, well IMO that is FALSE there is no better substitute for setting a carb with a vaccume gauge and pressure gauge. TAKES ALOT OF TRIAL AND ERROR which most are paid from book times which means they dont make as much money.

Now onto a little about the computered vehcles. Theres alot of misconception about computer controlled cars. First the computers that we have DO NOT tell us what is wrong with your cars, they simply give us data and point us in the right direction. For instence a P0300 code is a random cylinder misfire, If you were to take your car to an autoparts store there going to pull that code and tell you you need a tune up, then there going to sell you plugs, wire, cap, rotor, air and fuell filter ect. ect. 9/10 times that will correct the problem BUT a technitions job is to DIAGNOSE the problem. Meaning first thing there going to do is pull the code, Ok we have a P0300 (random cylinder misfire) which means 1 or more cylinder are either firing at the wrong time, weak fire, or not firing at all. Then the Technition is going to pull up misfire data in his computer. Looking at the counts they will determine 1 3 4 cylinders are misfiring. Then its time to hook a fuel pressure gauge to it to rule out the possabilities of it being a fuel system problem. Ok looks like pressures are normal with KOEO and KOER so they have eliminated the possabilites of a plugged filter or weak pump, still possable to have faulty injectors, so the next step is to skip to the easy steps verify "good" spark at the plugs, there are a number of different ways to test this. My favorite and IMO the most reliable is NOT with fancy spark checkers but to simply switch the faulty cylinder plugs with known good cylinders plugs, but before we switch them we can run a compression check to rule out a mechanical issue, then start the car again and check for misfire counts on 1 3 4 cylinder. If the misfires are still on those cylinders you have ruled out the PLugs. next you can on SOME cars switch the wires to test each cylinder. ALL of this is with OUT buying any parts. Next we are going to visually look at your Distributor cap and rotor, Ok there a little corroded but not bad enough to cause a misfire, so we will polish the terminals a little and reinstall, then start the car and check the misfire data again, welp still misfiring. So now we can do an injector balance test. Well guess what it looks like all cylinders are testing good EXCEPT 1 3 4 so we have now discovered we have an injector problem. So what do we do now Replace the 1 3 and 4 injectors at 30-200 dollars a peice? NOPE well I dont anyhow, it is still not fully diagnosed YET. Next step is to verify that the computer is even sending the injector pulse. We do this either with noid lights or test lights depending on the vehcle. Ok we have done the pulse test with noid lights and confirmed that numbers 1 3 and 4 are NOT receiving communication from the VCM or PCM. Which means if we would have replaced the injectors it would have been a waste of your money. Now comes the part I REALLY ENJOY. Time to go to the computer and pull up the schmatics of the fuel delivery system. We look them over and determine that all 8 injectors are receiving constant power from the # 11 fuse in the underhood fuse panel according to the diagram. So we check to verify power is supplied, Yep we have power on all 8 injectors. Next we are going to look at the diagram and snd determine that number 1 3 and 4 cylinders pulse from a ground signal from the computer, we then determine the pin locations of those signal ground wires at the PCM and test for ground with engine running at the computer. UTOH the computer is not sending the ground signal to those 3 injectors, Is the PCM bad in the car? Usually yes but to DIAGNOSE we are going to double check our ecm fuses, yep they are good so the PCM is faulty. now we get to R&R a PCM then REFLASH for your VIN number.

NOW I ASK YOU THIS DID THE COMPUTER TELL ME WHAT WAS WRONG WITH THIS VEHCLE? Absolutly NOT it simply pointed me in the right direction, constitant and proper diagnostics told me what was wrong with the car. Which is my point DONT EVER think that a computer is telling a technition what is wrong there is so much more to diagnosing these cars today. I have personally seen alot if instances like these where people have bought parts that a parts store said they needed when they trully did NOT. When we checked for power at the injectors we could have very easilly had no power at those injectors due to a broken splice pack from the fuse flock which would be an "open" circuit.

 

[Irishman999]

Your spot on Pops, Besides carburetors being the main reason to avoid older vehicles... there is a fine line between repair and restoration. Chasing those small problems suck and cost money if your working out of the book. If there is certain conditions that cause a problem a computer is not much help, for example.... I screwed around working on a 90 something chevy truck trying to figure out why it would shut off randomly if it was warm. While working on the books I had to drive it around until the thing would die so I could see if it was fuel or spark. I had the obd2 snap on scanner plugged in but it never gave me any usefull information. After my boss sold this guy a new computer (first thing people replace when they dont have a clue) We figured out it was a problem in the distributor. I really lost my ass on that job, the guy got his truck fixed though.

 

[HotRodPC]

Ahhhhhh hell !!! And just to think I wasnted to do an LS conversion or even SFI Vortec convesion just to have OBD ll so my truck would fix itself. SOB, now you're telling me it won't fix itself??? Sumbish !!! Actually I just want to install SFI so I can have remore start. No, not that either, but as you mentioned, I hate cold weather starts with a carbed vehicle and having to let them warm up. With anything OBD ll, its turn the key and go. Of course remote start isn't that bad either but its way overrated. I also like the old school non computer carbed trucks for the simplicity and cheap to build. But, you also lose hp, torque and mpg, so no matter which way you choose there is trade offs in either direction.

 

[89Suburban]

OK OK I know I am new here but I read a few of the posts in here and cant help it. I gotta give ya my 2 cents.
First let me say I am an automotive technician, some have said that techs would rather NOT work on the older autos which is true. BUT some have also said that the reason is they cant just plug a computer to it to find out whats wrong which is totally WRONG. The biggest reason why a Tech doesnt like to work on older vehcles is that they are Carbeurated, most of the time those vehcles are brought in is because of drivablity issues (running rough) which 9 out of 10 times is due to carbration. Which we all know are tediouse to set CORRECTLY, Hell for that matter alot of people think you set them by ear and thats good enough, well IMO that is FALSE there is no better substitute for setting a carb with a vaccume gauge and pressure gauge. TAKES ALOT OF TRIAL AND ERROR which most are paid from book times which means they dont make as much money.

Now onto a little about the computered vehcles. Theres alot of misconception about computer controlled cars. First the computers that we have DO NOT tell us what is wrong with your cars, they simply give us data and point us in the right direction. For instence a P0300 code is a random cylinder misfire, If you were to take your car to an autoparts store there going to pull that code and tell you you need a tune up, then there going to sell you plugs, wire, cap, rotor, air and fuell filter ect. ect. 9/10 times that will correct the problem BUT a technitions job is to DIAGNOSE the problem. Meaning first thing there going to do is pull the code, Ok we have a P0300 (random cylinder misfire) which means 1 or more cylinder are either firing at the wrong time, weak fire, or not firing at all. Then the Technition is going to pull up misfire data in his computer. Looking at the counts they will determine 1 3 4 cylinders are misfiring. Then its time to hook a fuel pressure gauge to it to rule out the possabilities of it being a fuel system problem. Ok looks like pressures are normal with KOEO and KOER so they have eliminated the possabilites of a plugged filter or weak pump, still possable to have faulty injectors, so the next step is to skip to the easy steps verify "good" spark at the plugs, there are a number of different ways to test this. My favorite and IMO the most reliable is NOT with fancy spark checkers but to simply switch the faulty cylinder plugs with known good cylinders plugs, but before we switch them we can run a compression check to rule out a mechanical issue, then start the car again and check for misfire counts on 1 3 4 cylinder. If the misfires are still on those cylinders you have ruled out the PLugs. next you can on SOME cars switch the wires to test each cylinder. ALL of this is with OUT buying any parts. Next we are going to visually look at your Distributor cap and rotor, Ok there a little corroded but not bad enough to cause a misfire, so we will polish the terminals a little and reinstall, then start the car and check the misfire data again, welp still misfiring. So now we can do an injector balance test. Well guess what it looks like all cylinders are testing good EXCEPT 1 3 4 so we have now discovered we have an injector problem. So what do we do now Replace the 1 3 and 4 injectors at 30-200 dollars a peice? NOPE well I dont anyhow, it is still not fully diagnosed YET. Next step is to verify that the computer is even sending the injector pulse. We do this either with noid lights or test lights depending on the vehcle. Ok we have done the pulse test with noid lights and confirmed that numbers 1 3 and 4 are NOT receiving communication from the VCM or PCM. Which means if we would have replaced the injectors it would have been a waste of your money. Now comes the part I REALLY ENJOY. Time to go to the computer and pull up the schmatics of the fuel delivery system. We look them over and determine that all 8 injectors are receiving constant power from the # 11 fuse in the underhood fuse panel according to the diagram. So we check to verify power is supplied, Yep we have power on all 8 injectors. Next we are going to look at the diagram and snd determine that number 1 3 and 4 cylinders pulse from a ground signal from the computer, we then determine the pin locations of those signal ground wires at the PCM and test for ground with engine running at the computer. UTOH the computer is not sending the ground signal to those 3 injectors, Is the PCM bad in the car? Usually yes but to DIAGNOSE we are going to double check our ecm fuses, yep they are good so the PCM is faulty. now we get to R&R a PCM then REFLASH for your VIN number.

NOW I ASK YOU THIS DID THE COMPUTER TELL ME WHAT WAS WRONG WITH THIS VEHCLE? Absolutly NOT it simply pointed me in the right direction, constitant and proper diagnostics told me what was wrong with the car. Which is my point DONT EVER think that a computer is telling a technition what is wrong there is so much more to diagnosing these cars today. I have personally seen alot if instances like these where people have bought parts that a parts store said they needed when they trully did NOT. When we checked for power at the injectors we could have very easilly had no power at those injectors due to a broken splice pack from the fuse flock which would be an "open" circuit.

I like this guy, Hey, can ya come over and fix my POS?