when the motor is cold, it starts like a typical old carburated engine, then once its runnin and warmed up its fine. you go out on the road, its got power, 4 barrel is strong, and then after the motor is good and heated up, if you shut it off, sometimes it will drag real bad, and not start, then sometimes cranks normal and still not start. but always when the motor has lost all the heat, It starts fine. Its had a new battery and alternator(and plenty of other engine work) Im thinkin its either the starter or timing. cuz theres a knock in the starter after it fires up, then smooths out.
2007-02-26 10:14:36 · 11 answers · asked by wheels47012 3 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
75 chevy truck,350 HEI
2007-02-26 10:15:39 · update #1
You have to differentiate between not starting. The two choices are cranks but will not start and no crank. I am not sure what dragging means??? If the problem is it cranks and will not start when hot, it is probably a problem with either the ignition coil, ignition module, or the pick-up coil which will mean it has no spark. To diagnose this, plug a test light to known good ground and the other lead to the tach output on the side of the HEI distributor. The test light should light when the ignition is turned on and blink very quickly when cranking. If the light does blink, it will be either the high tension coil located in the top of the coil or with some connection to it. If the light does not blink and either stays on solid or goes off, the fault is with the primary ignition. You can really only check the pick-up coil for resistance and AC output when cranking. If this tests good, replace ignition module. If you are having problems with the motor not cranking when it is hot, check the starter draw when attempting to crank. Anything above 180A is too high and will need another starter or an overhaul. I am assuming all the batttery and ground connections have been checked for cleanlisness and torque to eliminate this. Good luck.
2007-02-26 10:26:54 · answer #1 · answered by Deano 7 · 0⤊ 1⤋
It sounds like the carburator flap is staying open too much. There is usually a vacuum part on the carburator which causes it to open and close somewhat when the engine is off or running. You will need to check all those parts and make sure they are operating properly first.
Of course it could also be your battery or starter motor, doesn't work well enough to start the engine without the carburator being choked.
2007-02-26 10:25:35 · answer #2 · answered by rscanner 6 · 0⤊ 0⤋
Check to make sure the mechanical advance mechanism-(just under the rotor) in the distributor is working very ,very freely. While you're there check the pickup coil wires for cracking right where they enter the pickup coil. If the distributor is original and mostly untouched it should be replaced with a quality rebuilt unit. This was the first year for HEI and the factory parts were inferior compared to the aftermarket"Standard" brand. If you still have the original Quadrajet carb chances are the jet well plugs are leaking down causing a mild flood condition that 350s hate when hot. These 2 conditions can cause a double whammy to consistant starting. Old pistons can swell when hot making hot starts impossible.
2007-02-26 10:58:59 · answer #3 · answered by racer123 5 · 0⤊ 0⤋
I'M not saying that the starter is not getting weak and the time is off a Little but it sound like to could have a vapor lock problem to put a heat shield on the starter and if it have got the mechanical fuel pump on it put some insulation on the fuel line coming up by the alternator most of the time this is right wear they like to vapor lock and it the feul pump is getting a lettel weak that do's not help thing. the only reason that i'm saying this is you said it well not start aftor it get hot do you have to pump the gas to get it started ween it hot if you do that is a good sing that the gas is evaporating from the heat. i hope this helps
2007-02-26 11:07:33 · answer #4 · answered by master of none 3 · 0⤊ 0⤋
Country Boy, Most Chevy pickups had a starter shield above it to protect it from the exhaust manifold heat. The primary and secondary windings in the starter heat up just as if you had been cranking on it for a long period of time. Go to your local Chevy dealer and get one. They are a snap to install. Don't bother with a scrap yard used one, new ones are too cheap to mess with a scrapper.
2007-02-26 10:58:23 · answer #5 · answered by Country Boy 7 · 1⤊ 0⤋
If by "engine dragging" you mean it is cranking slowly before firing up, I would say starter. This is VERY typical of Chevy V8 starters. Yours is weak, and if not replaced, will eventually fail. They are susceptible to heat stress being as close to the exhaust as they are. I would get the starter replaced, or DIY, and get a lifetime warrantied one out of AutoZone or Napa.
2007-02-26 10:30:50 · answer #6 · answered by Doug K 5 · 0⤊ 0⤋
Used to have the same problem with a Suburban. The starter would get hot. Cured it with a aftermarket super duper hi-torque performance starter. They are not cheap, but saves a lot of headaches.
http://www.hitorque.com/
2007-02-26 13:23:44 · answer #7 · answered by Trump 2020 7 · 0⤊ 0⤋
Sounds like the starter needs overhauled or replaced. Could need a timing chain and gears replaced. You didn't mention how many miles are on the engine.
2007-02-26 11:26:19 · answer #8 · answered by Anonymous · 0⤊ 0⤋
check your ground connection on the block and make sure its clean and you are getting good contact if that doesn't solve the problem then have your starter checked do you have headers? be a good idea to get a heat shield for your starter
2007-02-26 11:53:59 · answer #9 · answered by James F 1 · 0⤊ 0⤋
80 bucks for yours?......I found a nice pole to run it into.....There sure is allot of Country Boys out there.
2007-02-27 08:32:33 · answer #10 · answered by 1st Responder FF/EMT 3 · 0⤊ 0⤋