why is it that "isolate and test" seems to be a FORGOTTEN ART FORM

Grumpy · Nov 29, 2015

I got a call early this morning from a guy that I helped build a rather nice Pontiac engine,(admittedly mostly in the planing and component selection and parts acquisition phases)
http://garage.grumpysperformance.co...ck-butt-pontiac-engine-combo.1472/#post-48277
well he calls me rather excited, his cars been running great recently , until yesterday when he was doing a few burn-outs and suddenly the car starts missing badly and quits dead, it won,t start , and he starts to assume the worst ,
he just "KNOWS" he blew it up"OR SOMETHING"
I ask a few questions and we rather quickly isolate the issue to a fuel delivery related problem.
now I ask him if he has fuel in the tank and he assures me that theres several gallons ,and yes the fuel gauge does occasionally show fuel even when its very low, and I remind him that pontiacs are well known for the fuel pump eccentric that actuates the fuel pump , coming loose , so I start thinking that might be the cause but before we go diving into the engine to repair or replace the eccentric I suggest we do a few tests.
hes already to start tearing into the engine once we find the engines not getting any fuel but I suggest we verify there fuel in the tank, and sure as I suspected its bone dry, so he grabs a full 5 gallon can of gas that hes had sitting in the garage for his lawn mower and pours it in the tank,
guessing is a waste of time
think logically, isolate and test
I rarely want to jump blindly ,into projects simply because,
I know all too well from decades of experience that it always take a bit longer and costs significantly more,
to do things correctly, too select the best parts you can afford, to get the machine work done CORRECTLY,
and accurately measure, and then as usually required,
carefully clearance and assemble the parts,
than most of the younger guys, who are generally pushing to get the project done understand
on the plus side,
most projects force you to learn new skills and justifies the purchase of,
or forces you too acquire new tools ,
you'll generally make new contacts, gain experience, maybe make new friends,
and once complete your usually pleased with what you built,
and proud of what you've accomplished,
and the process will usually kick up the respect for your skills and experience among,
those guys you hang out with.
if your car has the ability to let you read trouble codes USE THEM
any time you find any issue,or operating condition,
with any engine,
that comes and goes consistently,but the engine returns to its original state,
when some other factor, like time from starting the engine,driving speed,
or distance traveled or outside temps,
or engine temps, youll want to think about and think , and find out what changed, that potentially caused the issue?
in your case it would seem like the engine heat increased , but thats not the only potential issue.
whats the battery voltage?
are you 100% sure you have good fresh fuel in the tank and good fuel pressure?
did you just fill the tank with fresh fuel before the problem started?
did you run through a large puddle?
have any work done recently?
changed the tires?
hear and strange noises? have you checked the gauges or pulled trouble codes?
fuel pressure, at the fuel rail for injectors, or carburetor fuel inlet pressure,fuel temp, entering the carb, or injectors, check your exhaust back-pressure,engine coolant heat, transmission fluid temp. oil viscosity, your exhaust system temp, exhaust back-pressure, ignition wire heat, exhaust temps, etc. change as your driving,
check obvious things like fuel filters, air filters oil pressure, fluid levels, what do the spark plugs look like? whats the carb float level set at<etc.
a bit of testing and isolating each potential source, procedure would help here!
there will be obvious clues and having a few tools won,t hurt!

clear vinyl 3/8" tube is worthless for anything but testing, but its great for testing because you can see the fluid travel thru it during testing

the fuel looks like old cloudy PISS, its dark orange and as it sits I notice water beading in the bottom of the milk jug, after Ive pumped about a quart of fuel through the line we have easily 1/2 cup of rusty water.
its obvious that either his fuel tank or the gas in the 5 gallon can had water and debris in it and now that craps in the cars tank, being pumped to the carburetor
I suggest he drain the tank and get clean fresh fuel, and in the future , buy and use a marine fuel filter funnel and installing a water separating fuel filter between the fuel tank and the fuel pump in a location that he can easily check and drain sure won,t hurt

http://www.sears.com/mr-funnel-fuel...92011x000001&gclid=CNTIvNGbt8kCFQmOaQodydMBNQ
http://www.marineenginedigest.com/specialreports/fuel_filter_funnel.htm
these marine style funnels separate water from gas and can be purchased for under $24

heres the bolt that on occasion comes loose

having a decent quality fuel filter mounted between the tank and fuel pump in an easy to access location that separated water and makes draining it easy is a great idea on any older muscle car, a second fuel filter near the carburetor after the fuel pump is also a good idea.
once we cleaned the fuel tank and added fresh fuel and a fuel filter the engine ran great
any larger marine/boat supply and some truck stops sell water seperation fuel filters

$23

http://www.dickssportinggoods.com/product/index.jsp?productId=30723376&camp=PPC:q1cDy2AI_dc:77576702845|b:_inurl:30723376

http://www.basspro.com/Moeller-Mari...System/product/98150/?cmCat=CROSSSELL_PRODUCT

related info
http://garage.grumpysperformance.co...lectric-fuel-pump-selection.10664/#post-46091

http://garage.grumpysperformance.co...asonable-pontiac-v8-build-up.3213/#post-17212

http://garage.grumpysperformance.com/index.php?threads/fuel-line-problem.9305/#post-33637

http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/#post-69239

notice the products don,t work well, the cure is drain and clean and refill, but preventing the issue with the correct filter is far smarter

http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/

http://garage.grumpysperformance.com/index.php?threads/transporting-limited-amounts-of-fuel.11606/

http://garage.grumpysperformance.co...rential-compression-testing.11089/#post-49406

http://garage.grumpysperformance.co...ittent-cylinder-miss-problem.9478/#post-34812

T-Test · Nov 30, 2015

He is not a mechanic by my standards. It takes 4 things to make an engine run. Bet he can't name them. Can anyone but Grumpy do it? A challenge if you will.

Indycars · Nov 30, 2015

I've always heard 3, but if I had to guess at 4 components ..... Fuel, Air, Spark and Compression

T-Test · Dec 1, 2015

Indycars said:
I've always heard 3, but if I had to guess at 4 components ..... Fuel, Air, Spark and Compression

Correct. Take any one of them away and the engine will not run. What three were you told, as I believe there is an assumption to one always being present?

Indycars · Dec 1, 2015

The three I've always heard is Air, Fuel and Spark. Compression can be assumed if it was just running and you are troubleshooting a no start condition.

Johnatthebox · Jul 8, 2019

Man, I tell ya......... your threads are SO thorough and usefull, I think you should design some reference posters, like the ones they make for high school science classrooms, and market them to gearheads. Id buy em.....

T-Test · Jul 8, 2019

Indycars said:
The three I've always heard is Air, Fuel and Spark. Compression can be assumed if it was just running and you are troubleshooting a no start condition.

In the OP it was stated as BLEW UP OR SOMETHING! which to me says anything can be wrong including no compression if it has jumped time or pistons come apart.
But Grumpy asked a few questions and came up with a fuel delivery problem. Out of gas. Simple mistake or just plain don't know nothing about his car.
Like Grumpy said, isolate and test before tearing into something that don't need fixing, but it's only money, and not mine for not knowing.

Since zero clearance engines were built, I never forget about compression and timing as something will break when it goes bang and quits running.

Indycars · Jul 8, 2019

Johnatthebox said:
Man, I tell ya......... your threads are SO thorough and usefull, I think you should design some reference posters, like the ones they make for high school science classrooms, and market them to gearheads. Id buy em.....

Well thanks Johnatthebox, I appreciate the complement!

why is it that "isolate and test" seems to be a FORGOTTEN ART FORM

Grumpy

The Grumpy Grease Monkey mechanical engineer.

T-Test

solid fixture here in the forum

Indycars

Administrator

T-Test

solid fixture here in the forum

Indycars

Administrator

Johnatthebox

Active Member

T-Test

solid fixture here in the forum

Indycars

Administrator