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ever see the truck run perfect before, or not in 10 years?
C2500 right not k2500 ,pickup.
NO ENGINE told ,4 engines 3 gas 1diesel.
but is gas so 4 engine not told (no fun there, blind)
4.7 to 5.7L and 5.4L gas.
crankshaft and cam
forgot to say sensor?
CAB means distrib CAP .
rotor sure.
why not new SPARK PLUGS first and for sure those ratty old HV spark wire, useless, I run NGK mag wires.
battery good, cranks fast and engine spins fast and does not start.
and engine compression is good
and we test that spark is good on all 8 cylinders not just one,all 8 are test
and also tested for spark timing. for sure if distributor was removed, or set loose at base and timing lost.
if all that is good the engine now runs on spray test fuel in a can. for 3 seconds, even with fuel pump fuse pulled.
if you get this far,
we check fuel pressure next and even for bad fuel.
no history of car told
bad fuel ,old rusty tanks wreck injectors.
26 year old truck,.
things bad that old are, all fluids and belts fuel filter packed in gunk and rust.
thermostat bad.
spark parts bad, cap/rotor wire sets x8 and spark plugs. (or timed wrong or put back wrong firing order)
injectors clogged, bad fuel or rust in the tank
bad FPR, bad map sensor.(or only clogged)
or bad fuel pump if pressure is low and FPR not bad.
most of my tests all take tools and meters
a tech can not fix cars lacking his tools.
and skills to use them./
even a timing light is needed on all distrb cars
and all EFI cars a fuel pressure gauge.
and compression gauge
and vacuum gauge.
Need to have the basics: air, fuel, fire. Does carb shoot gas down carb barrel when you pump the throttle? Do you have a good spark when turning over? Air you should have. Pull a spark plug or two and see if they're wet. Leave one out, connected to plug wire, and have base well grounded, crank it and see if you've a good spark (no gas fumes around when you do this!). Make sure plug wires are going to the right plugs.
A D-50 with a carb - that is a few years old and probably lots of miles on it.
If you know you has gas and spark to the plugs then either there is not enough compression (engine worn out) or the timing of spark to compression stroke of the engine is wrong.
Make sure the timing belt is ok
Then check compression - the lowest cylinder should not be less than half of the PSI of the highest cylinder and they should be about 125 PSI or more. If it is down as far as 100 PSI it may still run but is very weak. Be aware also that Compression guages can vary significantly in their readings.
While you are checking cylinder #1 - check to see if the distributor lines up to #1 tower on the cap while the compression stroke pushes air out.
Let me know if this helps you at all
Probably loses either gas or spark. So check fuel pressure when it won't start, and check for spark on a plug wire. If fuel pressure is low, probably a bad pump. If no spark, diagnose the ignition system: coils, ignition coil control module (ICM), crank position sensor, etc.
An easy way to see if you lost gas, is to spray carb cleaner or starting fluid into the air intake while cranking engine. If it rumbles and tries to start, you know it is a fueling problem.
Try putting a little gas in the top of the carb. Then try to start, if it starts then it's a fuel problem, clogged filter, lines, carb or fuel pump. If it doen't start with the gas then check for spark, disconnect a spark plug wire put on a spare spark plug, ground plug threads to motor and have someone turn over motor. You should see a spark between plug and electrode. Also you could check compression of engine, rings could be siezed and no compression will mean no start. If low or no compression, pour wd-40 or other lubricant into spark plug holes and let sit for a couple of days. Hopefully that would unsieze rings.
This could be a number of things...
Crank sensor, cam sensor, coil, PCM, spark control module, ect.
Start with the sparkplugs, make sure they are firing if not work your way back from there spark pligs, wires, coil, control module, cank and cam sensors, PCM this is what i would do if this rolled into my shop.
check secondary ignition ( spark getting to spark plugs ) your statement is telling me it isnt fuel, if the mechanics of the engine is good it can be secondary ignition also high mileage eng. might be a bad timing chain.. In the future eng. size is helpfull......
I had a similar problem and believe it or not it was the CAT. An easy way to test for this is to remove the O2 sensor right in front of the CAT. Once you removed it, plug it back in while unscrewed from the exhaust pipe and start up the truck. If it runs fine, the CAT is your problem. This is just a guess and it would be an easy and very cheap($0) test. You did not say if the truck was diesel or gas. Mine is gas that was exhibiting the same problem as yours...good luck!
you need to see if you are getting fuel sounds like the pump is bad
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