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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Tazman on November 20, 2010, 10:30:33 am
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Just recently my truck has started dieing after starting.It only occurs when it is warm,such as a 15 mile drive shut off start again in twenty minutes.It will only stay running if I step on the gas.Usually I do not even touch the gas when starting.Any ideas?Thanks
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What engine? Fuel injected or carb? Have you tried tune up,fuel filter,plugs wires ect.?
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Sounds electrical. Coil gets hot shuts down till it cools then it will start the cycle all over doesn't have to be the coil just saying its a possibility like the control module or pickup coil most time its the ignition coil or ignition control module in my time working on my trucks
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If it's TBI could be the Fuel Pump
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It is the stock 350 with TBI.Thanks
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To test the pump, you need to have 10-15 lbs of pressure at the tbi unit.
Also, could be Ignition module and/or pick-up coil.
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The problem with testing these things is they most the time have to be hot cause that's when they will have the problem
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I will start with the coil ,hopefully that will be it.I do not feel like dropping the tank.Thanks
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I would not just throw parts at it.
Come up with a plan...
Make it die, then check for spark. If there is then it isn't th coil...
If no spark, it could be one of several things, and the coil is prolly good.
Could be Pick/up coil or Ignition Module...or both....
Could be pressure regulator in the TBI unit.
Could be clogged fuel filter....
Throwing parts at it is a waste of money, with an occasional "its fixed" in between a few hundred dollars....
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I've had that problem a few times and every time it was the igniton control modual.
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the coil and icm can be tested at a parts store i know autozone does it . but again it has to be hot sometimes the icm will pass but if its tested a couple times in a row it will fail
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I replaced the Ignition Control Mod,and it still dies at starting after hot.I plan to check the fuel pressure next.I appreciate all the help.Thanks
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Don't throw parts at it.
It will restart if you depress the accelerator?
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Yes it does.
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So unless you depress the accelerator it's a crank no start.
Two most likely causes,
1) TPS Voltage is higher than 2.5 Volts putting it in clear flood mode.
2) Fuel pump relay or hot start module faulty, oil pressure switch is completing the circuit
Got a paper clip and a digital volt meter?
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Can the fuel pump relay and pressure regulator be tested on the truck?
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You can test the coolant temp sensor it could be bad causing the ecm to give the engine more fuel than it needs. The sensor screws into the intake manifold, on the front passenger side, by the thermostat housing. Coolant sensor approximate resistance specifications: 177 ohms @ 212 deg. F. or 100 deg. C.
241 ohms @ 194 deg. F. or 90 deg. C.
332 ohms @ 176 deg. F. or 80 deg. C.
467 ohms @ 158 deg. F. or 70 deg. C.
667 ohms @ 140 deg. F. or 60 deg. C.
973 ohms @ 122 deg. F. or 50 deg. C.
1188 ohms @ 113 deg. F. or 45 deg. C.
1459 ohms @ 104 deg. F. or 40 deg. C.
1802 ohms @ 95 deg. F. or 35 deg. C.
2238 ohms @ 86 deg. F. or 30 deg. C.
2796 ohms @ 77 deg. F. or 25 deg. C.
3520 ohms @ 68 deg. F. or 20 deg. C.
4450 ohms @ 59 deg. F. or 15 deg. C.
5670 ohms @ 50 deg. F. or 10 deg. C.
7280 ohms @ 41 deg. F. or 5 deg. C.
9420 ohms @ 32 deg. F. or 0 deg. C.
12300 ohms @ 23 deg. F. or -5 deg. C.
16180 ohms @ 14 deg. F. or -10 deg. C.
21450 ohms @ 5 deg. F. or -15 deg. C.
28680 ohms @ -4 deg. F. or -20 deg. C.
52700 ohms @ -22 deg. F. or -30 deg. C.
100700 ohms @ -40 deg. F. or -40 deg. C
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According to the factory manual I have my truck does not have a hot fuel module.
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Never heard of one of those
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According to the factory manual I have my truck does not have a hot fuel module.
Coolant temp sensor is NOT a hot fuel module...
It tells the computer what temp the coolant is so the computer knows how much fuel it needs to spray...
If the computer thinks it's -40* it will flood your engine....
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(http://contentinfo.autozone.com/znetcs/product-info/en/US/wl2/SU109/image/2/)
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Just an update to my issue.Replaced the the plugs,wires,cap,rotor,ignition mod,coolant sensor and fuel pump.The latter two after testing had determined failures,the rest because it was needed.Truck is running like a top and is once again a pleasure to drive.I do have one more question.With out the use of a tach what is the best way to check and monitor the idle.Thanks
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With out the use of a tach what is the best way to check and monitor the idle.Thanks
The answer is in your question, you can get a tach for $30 and it is easy to hook up.