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grumpyvette

grumpyvette

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Staff member
I had a guy in the shop recently with a fairly new looking c5 corvette who had purchased a new set of fuel injectors as he was convinced that he had several that were not functioning, he had pulled several spark plugs and two showed much darker electrodes, and porcelain that the others , leaving him to conclude that the fuel injectors were malfunctioning, he was very insistent that I should replace those fuel injectors, I brought out my infrared temp gun and confirmed those two cylinders were running far cooler, than the others, but that did not necessarily lead me to conclude it was a faulty injector
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viewtopic.php?f=44&t=579&p=743&hilit=+infrared+tuning#p743

viewtopic.php?f=50&t=5726&p=17448#p17448

I swapped those two spark plugs out and during the process verified the spark at the plug, from the ignition wire, and verified that it was significantly weaker in appearance, so I pulled trouble codes

viewtopic.php?f=32&t=2697

the short version is that the trouble codes indicated an ignition fault and replacing two coil packs cleared up the problem

http://www.car-stuff.com/carparts/chevr ... t+Page%3A2

http://www.autopartswarehouse.com/detai ... 82478.html
 
heres a different deal, my friend calls up with a problem, it seems the car won,t start like the battery's dead, a quick check with a volt meter shows the battery has 7-9 volts,(meter keeps changing) when he jump starts the car it shows 13.6 volts but it jumps between 12 volts and 13.5 volts so hes 100% convinced the alternators at fault, so he buys an alternator, for $180, and asked me to help install it, a quick check shows his whole problem is corrosion on the battery terminals , a quick clean up on both the cables and connectors and the car runs like new.
 
Kudos to ya Grumpyvette!
I can relate, alot of times faulty thinking or going with a gut feel will take you where you dont want to be, while all the time there is a way out of the woods. its called a compass, Just joined the forum after reading many posts that you have started and they all had good knowledge backed by experience and fact.
I just learned while starting my first engine rebuild after a twenty year hiatus how much has changed.
A lot of us are still thinking 1970,s and not realizing how much has changed in this digital world!
After buying some truck rods and buying ARP bolts and having them reworked I have a nice set of connecting rods with an unknown amount of cycles and cost more than a superior rod from so many manufacturers out there.
Also a point getting a thirty year old set of head castings and reworking them will probably also be a no go concerning how many newer fresher castings are out there. Thanks Again GrumpyVette!
 
one of my freinds calls me up and asks my help replacing the oil pan gasket and rear seal on his 1985 corvette, it seems hes been living with a slow oil leak at the rear of his engine for a few months and its been progressively but slowly getting worse to the point hes now using a quart of oil about every 400 miles and its leaking not burning.
I say, sure, it will cost you paying for lunch , but where else do you get nearly free skilled help for a $7 sub sandwich and a few cold beers?
we putt the car up on the lift and he wants to start dropping the oil pan and replacing the oil pan gasket, but I tell him to slow down, for 2 seconds and I spray the lower engine clean and de-greased it with carb cleaner and a few shop rags and get him to start the engine and let it idle, within seconds its rather obvious that the oil leaks there but not from the oil pan gasket or lower rear seal area.
It turns out a close inspection reveals its the oil pressure switch, located next to the drivers side of the distributor base (naturally a P.I.T.A. to access) thats cracked and leaking oil.
http://www.ecklers.com/corvette-oil-pre ... -1987.html

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Oilpressureswitchearly.jpg
 
I don't want to sound like a know-it-all, but those sending units have been a problem for years, maybe even since day ONE. When is GM going to change to a something better !!!
I wish you had a picture of his face when he realized what the real problem was !!!
 
I recently got a panicked call from a friend, it seems he "RIPPED HIS OIL PAN 1/2 OFF" when he hit a newly installed speed bump at about 35 mph
when he went to visit some relative and since he knew I had a trailer and lived only a few miles away "could I PLEASE come get the corvette with your trailer and put it up on your lift,and help with repairs?
because he
"obviously could not drive the car with it pissing oil out at about a quart every 100 feet"
well I told him Id be glad to help, but I had to call my son who had the truck with the tow ball connector to use the trailer,
and it would be several hours until he got off work,.... so he had a local tow company pick up and deliver the car,to my house, we manually pushed it into the shop,and got it on my lift, he was convinced he had done major damage, to the oil pan and possibly the engine and transmission, that would cost him hundreds or even thousands of dollars... but when we got the car up on the lift the oil pan had a rather obvious scrape, but it was only minimally dented the oil leak was from a cracked and ripped oil filter.
I happened to have a spare oil pan that I sold him dirt cheap along with a new oil filter and oil pan gasket and we had the car running as good as ever in about 2 hours.
 
heres a classic, a friend calls up and says his 1967 bbc corvette was running great, but now its recently lost a great deal of hp,the engine seems to run smoothly enough at idle, but its got far less hp as the rpms build, hes got a long list of suspected causes....putting it up on a lift he locates the cause, seem his wife forgot to tell him she left the lights on in her car, killing the battery,....no problem, she just jumps in her husbands corvette, for a short couple block trip to the store, and makes the short 15 minute round trip,... and conveniently forgets to mention pulling into a parking space a bit too far and too fast (not being really familiar with the cars driving characteristics and running over a concrete bumper block, at the end of the parking space, and crushing one of the exhaust pipes about 70% closed, then driving it home, parking the car and never mentioning it!
luckily he had a spare section of exhaust pipe, and within a couple hours time and having a welder in his shop,he could correct the problem.
he never mentioned the discussion Im sure that occurred with the wife about not running over curbs, speed bumps and concrete parking space bumpers
 
I had a friend call me up recently , asking for help to diagnose a cooling problem, he was having on his Pontiac v8 engine he had recently rebuilt and installed, he was scratching his head and confused as there was no water flowing thru the brand NEW radiator and he had just installed, as he had recently replaced the water pump, and T-stat, and radiator hoses, less than 2000 miles ago and less than 3-4 months ago,.with all brand new parts,..yeah! it turned out to be the water pump impeller had come loose from the main shaft in the water pump,, it was spinning at far less than shaft speeds, and barely moving coolant, he had assumed it could not be the water pump as it was almost new..


thats why when isolating and verifying the source of a problem its better to assume nothing and check the function of each component,
you can,t assume just because a components new or recently installed that its functioning exactly as its designed, you might be amazed at how ofter a logical step -bye-step ,check list approach, to problem location,isolation and solving the problem, with a shop manual and a few test tools is frequently how problems are located and cured ...you just can,t assume a component can,t be the cause, because its new, unless you test it, and prove it functions , Ive seen parts right out of the sealed box they came in fail to function at times.
I had a brake master cylinder that was rusted solid internally, water pumps that would not turn, wheel bearings that fell apart as they were removed from the packaging, and brake shoes with the correct part numbers that didn,t fit the brake drums surface, and brake calipers that had pistons that would not retract...new doesn,t mean it functions correctly as most people assume, especially with electrical components, and you sure won,t be the first guy to have a auto parts store sell you the wrong part and swear its correct either.
 
JACK brought his corvette over with an ignition problem,about two months ago, he was all intent on upgrading the current HEI with an MSD ignition box and I helped him, do so,at the time and it helped but it was not the cure for the cars seeming lack of upper rpm power, a quick check showed the ignition spark was not all that impressive and the battery was not fully charged, I suggested he get a new battery as the current one was 5 years old, and upgrade his alternator, as it was original and would only put out 13 volts, but he still had a few other electrical issues , and he said he was basically low on cash(WHO ISN,T) so I did a few quick checks,on the electrical system with the multi-meter , I think most of his problem could be traced back to an alternator that was not putting out the correct current, and I said so at the time
.he calls me today to tell me he installed the new 200 amp alternator, a new battery and larger gauge battery connections and the car seems to have a far smoother idle and seems to no longer have the poor throttle response it used to have.
I know from experience that many times cooling or ignition issues result from a battery or ground connections or alternator output issues, and while its not always obvious, you need to have those checked , before assuming the cooling fans,not running at full speed, sensors, fuses, or ignitions a problem.
 
If you get a chance to buy a muscle car at a good price that's got a defective drive train, you may want to jump on it if the price is good!
no sense worrying about the cars past, history, Id suggest testing and isolating the problem to the engine or transmission,then once you know which it is at fault, Id simply pull , disassemble and inspect the engine or transmission components......"


you certainly would not be the first guy to find a deal on a car with a defective drive train or the first guy to pull an engine apart thinking it was busted, because of the noise coming from under the hood, when it was in fact the transmission or torque converter.
and you certainly would not be the first guy to mis-diagnose the source of a noise until you got well into the research of the cause either.
I purchased a 1969 camaro back in 1975 that had a (BLOWN-UP ENGINE) at a good price, a bit of research showed the (ROD KNOCK) ) was mostly burn rocker balls,and a bad cam and lifters, once the rockers, cam and lifters and timing set were replaced the engine ran fine and had good oil pressure.
my friend BOB bought a ford van with a (BLOWN UP ENGINE) that turned out to be a busted flex plate that had chewed a hole in the rear of the oil pan , a weekends work on jack stands, one new flex plate and a bit of welding resulted in a running van purchased for several thousand dollars less than average retail price.
the fact is that more than one guys just dumped a project when "one last straw broke the camels back" and that problem, under fresh eyes turned out to be a minor inconvenience at most not a huge catastrophe the previous owner thought it was.
 
I was talking with one of my old high school friends (damn that was like 50 years ago)
he reminded me that , even back then guys panicked and failed to research problems,
I had a friend sell a 396 1967 chevelle back in about 1970 when the (ENGINE BLEW UP) no noise,
just tons of oil smoke out the exhaust and it ran like crap, all the plugs oily...
the other friend bought it for $1800 diagnosed the problem and replaced a transmission modulator valve that was leaking trans fluid into a vacuum line for under $40

COA-22650_1.jpg


http://www.summitracing.com/parts/tci-350001/overview/

http://www.summitracing.com/parts/bmm-20234/overview/
 
I had a local single mom come over asking me to look at her cars brakes, she had recently (4 months ago) had rebuilt,with a $500 plus brake job and she says the brakes are making a grinding noise and she really just can,t afford another $500 plus that the shop quoted her do do the brakes again....so I grab my son, who is visiting at the time to do the bending and lifting stuff, and put the car on my lift,the car goes up on the lift and I see theres a short section of palm frond stuck between the disc brake backing plate and the caliper, I grab some vice grips, and pull it out and bend the flimsy aluminum backing plate out so its no longer dragging on the rotor, spin the disc...the noise is miraculously all gone! I inspect the brake fluid levels, caliper pads, and lines, and everything looks to be in great shape so I lower the car, re-install the tires (with my sons help, doing the lifting ), drive the car up to the house and walk in,... I look serious.....I tell her its going to be expensive!....she starts to get that panicked look.....I tell her she owes me a cup of coffee ,next time I see her, (she works at a coffee shop)I tell her, it was just a bit of road trash stuck in the brakes backing plate!, its all fixed and everything looks just fine!
 

That's got to feel real good for both of you ! It's nice when it turns out to be so easy and
they don't have to spend any more money. Certainly a win-win situation !
 
frank came by to have some coffee and B.S. about cars and I suspect get some help...he said the rear main seal on his 383 sbc must have failed as the lower 1/3 of his bell housings covered in black oil and the cars leaking a good amount of oil......I got in the car and drove over to franks and we put the car up on his 12 ton jack stands with his floor jack
(WHAT A P.I.T.A. when your floor jack is a crappy cheap auto parts $35 1.5 ton that is to do)
he had purchased a new one piece oil pan gasket and rear main seal, but before we started pulling the oil pan , looked things over carefully and found the oil leak source which saved him from several hours work, careful inspection showed that he had somehow installed the new oil filter with out removing the old oil filter gasket so he had TWO oil filter gaskets clamped between the oil filter and block surface and they were not providing a complete seal, so oil was dripping out, simply re-placing the oil filter and gasket correctly cured the oil leak

lubegasket.jpg




you should carefully verify the old gasket came off with the oil oil filter and put a bit of oil on the new o-ring seal before its installed on any spin on oil filter
 
JACK, stopped by, his problem was diagnosed by a tire dealer, who does tune-ups, minor repairs etc. as bad injectors, and it was going to cost about $880 for them to be replaced,
he drove his 1993 Pontiac, over here and it was running like crap,
a few checks indicated the fuel filter was partly clogged and there was about 1 quart of water in the fuel tank, replacing the injectors was not necessary, a new fuel filter, a tune-up, new spark plugs, cap, rotor, wires, and draining the fuel tank and fresh fuel and two cans of injector cleaner and one can of dry gas had him up and running like new for under $200
 
RON, called me today, all pissed off because the new demon 750 cfm carburetor he bought caused the car to continue to dump fuel into the cars engine after he shut it off, he said it reeks of gas fumes and its hard to start and the exhaust burns your eyes.
I asked RON to verify the fuel pressure and float levels , but he stated they should be correct because its a brand new carburetor, and the fuel pressure never caused an issue with his old Holley carburetor!
its that type of (LOGIC) that causes most problems,
well I drive on over and get out a few test gauges
and hes got 7 psi on the carb feed line
(RON has an adjustable return style fuel pressure regulator but he doesn,t have a gauge)
so I adjusted it using my fuel pressure test gauge,
I have no idea why you would not have a adjustable fuel pressure regulator, or not have a fuel pressure gauge and no way to check the fuel pressure its set at???
and when I pull out the IR temp gun ,
T504-4254_product.jpg

and use it and find his intakes at about 180f, temp.
(because he forgot to block the intake exhaust heat cross over which here in Florida is a totally useless feature) so I suggested using a 1" Phenolic carb spacer , which I happen to have in my tool kit
(he had to buy a couple carb gaskets, and 4 stainless longer carb mount studs and matching nyloc nuts and washers of course of course)
and once I adjusted his carburetor float levels ,"which were WAY OUT OF SPEC, and too high out of the box." and swapped in the heat barrier 1" thick Phenolic carb spacer, and the two required gaskets...
things started running so much better he could not believe it
its usually the simple stuff that makes you crazy and its having a few tools and understanding how things are supposed to work and what may be wrong that cause problems and how to recognize the symptoms that helps
in this case it was mostly a faulty install not faulty equipment
sum-g1404.jpg

http://www.summitracing.com/parts/SUM-G1404/

HEAT BARRIER TYPE SPACER

QUESTION How do I adjust the fuel level on my carburetor?
ANSWER Setting the fuel level should be the first thing you do before attempting to make any further adjustments.The float level should put the fuel level just below the bottom of sight plug hole. You will make the adjustment with the vehicle on a level surface and the engine idling. You will first remove the sight plug, then to make your adjustment you will need to loosen the lock screw on the needle and seat. This will allow you to turn the adjusting nut to raise or lower the float level. Each hex flat on the nut will change the float level approximately 1/32". When you have the fuel level just below sight plug hole you will then tighten the lock screw and reinstall the sight hole plug. Make sure you have a shop towel handy in case you have any fuel leaks from the Sight plug or needle and seat adjusting nut.
scrp_0809_04_z+holley_carburetor+plug_removal.jpg


scrp_0809_06_z+holley_carburetor+lock_screw_removal.jpg




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one of my friends kids calls me up last night to ask for advise, he was doing some parking lot burn-out to impress his racing buddies and a few chicks when the engine " STARTED RUNNING BADLY AND MAKING A CLACKING NOISE"
he was convinced he "threw a rod or spun a bearing"
well I ask him a few questions , and I don,t think he fully understood all the questions or what I was suggesting he look at or test for,and when I ask him to do a few tests and inspect a few things, he said it was a waste of time, as he was sure he "BLEW THE ENGINE" and after awhile his dad gets on the phone and I discuss some basic tests...they are both convinced the engines toast! but agree to humor me and do some tests and inspect a few parts.....well they do a few tests and inspect a few things as I instructed and things don,t look quite as bad as they first thought...he threw a section of a fan belt, and the lower radiator hose got a minor slice from the fan belt whipping around and he busted a valve spring ,and a rocker was flopping around under the valve cover but so far that the extent of the "COMPLETE ENGINE FAILURE"
now lifes tough and most of us are far from rich, but I,m always amazed at the people who assume just because the engines making some noise they never heard before that its a total waste to test , isolate and inspect, look it could easily be a engine failure but before you go trading the car or buying a new engine it only makes sense to find out whats failed and what it costs to fix.

My good friend JACK thought he blew up an engine once,it made a terrible noise and the car would barely move, it turned out to be a catastrophic flex plate failure,(the center hub sherd and the starter/ ring gear split) that we corrected with a new flex-plate and about 4 hours work for under $120
 
bob went to look at a old 1970 something, motor home recently as it has a 454 chevy engine and its being sold very reasonably.
we pulled the dip-stick and the oils slightly silver grey tint, in color It might be because its been sitting for several years and theres condensation, moisture in the oil, it might be because theres micro debris in the oil or a bad head gasket or just old dirty oil, I strongly suggested we start the engine and get it running and change the oil for the guy for free before he places a bid on the engine. but at the price the guys asking for the whole motor home ($500) bob may just take his chances, buy the motor home and pull the engine and check it out as its well worth the time and effort if it runs and just most of the block and heads and rotating assembly are salvageable , as it comes with a th400 and a decent differential also.
most motor home engines have very low mileage because even when gas was cheap owners were not big on paying gas bills when you typically got 4-8 miles per gallon on trips, so most motor home engines are low mileage cores where corrosion and lack of frequent oil changes, and occasionally overheating issues are far more of an issue to look into than wear from excess mileage or abuse from excessive high rpm driving
 
youll love this one!
bobs wife mentioned his cars just not running right, he jumps in and drives it , looks at the gauges, notices, it sounds funny and seems to lack power, so he brings it over , we get it up on the lift and one tail pipes squished about 70% flat........its only then that bobs wife vaguely remembers putting the car in drive not reverse and suddenly jumping over a parking curb,stone

parking_block.jpg


then backing out with a "THUMP/BANG SOUND!...but it could not have been anything she did because the problem didn,t start till she was well on the way home" I feel for bob but he is hardly alone, it seems like most wifes just don,t think of cars like most guys do....

45 minutes with a torch and a short welding job later everything's fine...
but I remember back to 40 years ago when my wife mentioned
"honey the OIL LIGHTS been on all day, does that mean anything?"
she has no clues why I stare at her, at times like shes lost all her marbles
about twice a month I get some guy driving a early corvette or muscle car thats badly out of tune or one that needs minor repairs because the engine runs like crap, now in many cases the owner is CLUELESS as to how to locate the cause OR he assumes its just in need of a tune up, which can of course be true, but its surprising the number of mechanical issues like busted valve springs , worn cam lobe,or leaking vacuum hoses, or badly adjusted coils, etc. that come up, so learning to isolate and test is a critical skill.
I know some guys would rather be boiled in oil than read links, and SUB LINKS but for those that would rather get the car running correctly, heres a few very useful links
now keep in mind missing can be from 3 general areas in your engine , and yes ITS THE SUB LINKS WITH 90% OF THE INFO YOU NEED TO READ
mechanical,
like badly adjusted valves, broken rings,worn cam lobes, busted valve springs ,leaking gaskets, leaking vacuum lines etc.
electrical
badly adjusted timing, cracked insulators, defective connections, wires or ignotion, defective plugs or wires or bad grounds defective coils, bad battery, bad grounds
fuel/induction
low fuel pressure, badly adjusted floats, defective injectors or fuel pressure regulators, clogged filters,etc. youll need to isolate and correct the source but without knowing how to test your screwed

read the links AND SUB LINKS

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sometimes the answers so obvious we don,t want to see it!
Im always amazed at the guys that don,t break out the shop manual and multi meter when things don,t run correctly and the guys that don,t pull the trouble codes.
my neighbors kid just purchased a 1987 camaro from some other kid, the car runs like crap,hard to start,ran rough, stalled, cut out frequently, etc. and after a few tests we get down to measuring the sensors, and I find the manifold temp sensor is reading off the scale open,the fuel filter looks like its 10 years old minimum as its well rusted, and 5 if the 8 fuel injectors don,t read anyplace close to the ohms range they should, 2 are dead open reading off the scale open, and 1 reads 57 ohms two read in the 25-30 ohms range
I also find the intake has vacuum leaks, I point those things out and strongly suggest he buy new intake gaskets, a manifold temp sensor and a new set of 24 lb injectors, naturally the kid wants to try some injector cleaner as hes on a limited budget, I tell him it can,t hurt but its also unlikely to help.
I tell him to get on the internet and start shopping and look for a new set for under $350, but don,t buy anything until I check it out!
he will need to check all the sensors and the O2 sensor is suspect


GOOD RELATED TESTING INFO, IF YOUVE GOT SIMILAR ISSUES

http://www.thirdgen.org/service-engine- ... rror-codes

http://www.iroczone.com/2009/10/1982-19 ... -firebird/

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IF YOU STILL CAN,T LOCATE THE PROBLEM

always drop back to basics
whats the compression test read on all cylinders?
WHAT cam are you running?(did you degree it in)
whats your ignition timing curve?
whats your fuel air ratio every 1000rpm?
whats the exhaust back pressure at every 1000rpms?
Have you tested for vacuum leaks?
what the intake vacuum reading in the plenum at every 1000rpms?
where in the rpm range does the power seem to start and drop off?
how did you adjust the valve pre-load?
whats your battery voltage?
what colors the ignition spark?
have you CAREFULLY VERIFIED the firing order?
WHATS the ignition wire resistance?
Whats the spark plug gap?
can you post CLEAR CYLINDER LABELED PICTURES of your spark plugs?

without facts, you're verified from current testing, to work from, your spinning your metal wheels and wasting time guessing
once you know the basics theres more than likely more tests, that will need to be done, changes to ets,power valves accelerator pump cams ignition timing etc. but with a firm basis of facts, and eliminating areas that prove to be operating correctly, its simply a matter of testing, verification,isolation, and tracking down the cause and correcting the flaw, in the combo or tuning.
btw you do realize that the cam might require a different rear gear ratio to perform at peak potential?

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