I've got a 1995 Silverado with the 350 5.7l engine, motor has 170,000 well taken care of miles. I need some help on why it takes so long to start. The engine cranks over but takes at least 5 to 10 seconds to start. Any help would be appreciated. Thanks.

My 97 Suburban with the 350 engine has long starts when the battery is weak or the cables aren't tight enough. Look at your battery and pull up on the cables, and try it. I know that sometimes the positive cables can melt together. I need to replace ours for that problem b/c sometimes it won't start

My 97 Suburban with the 350 engine has long starts when the battery is weak or the cables aren't tight enough. Look at your battery and pull up on the cables, and try it. I know that sometimes the positive cables can melt together. I need to replace ours for that problem b/c sometimes it won't start


Thanks, but the battery is less than a year old and the cables are tight. Any other suggestions?

the only other thing I can really think of off the top of my head are the battery has a bad cell or the water levels are low.

Forget the battery. :rolleyes:

When you turn the ignition on the fuel pump should run for 2 seconds, then shut off. The fuel pump won't come back on until the ecm sees oil pressure. So with your expended crank, it sounds like the fuel pump is not coming on when you turn on the ignition, but is coming on once the ecm sees oil pressure. To varify this, turn the key to the 'run' position and use a test light on the fuel pump connection at the tank to see if it lights up for 2 seconds. OR since those fuel pumps are usually noisy, just listen for the pump.

You can also varify it by going to the Fuel Pump Relay (located underhood) and see if it is turning on. If not you may have either an ignition problem, wiring problem, or worse yet an ECM problem (which is what mine was). :)

Forget the battery. :rolleyes:

When you turn the ignition on the fuel pump should run for 2 seconds, then shut off. The fuel pump won't come back on until the ecm sees oil pressure. So with your expended crank, it sounds like the fuel pump is not coming on when you turn on the ignition, but is coming on once the ecm sees oil pressure. To varify this, turn the key to the 'run' position and use a test light on the fuel pump connection at the tank to see if it lights up for 2 seconds. OR since those fuel pumps are usually noisy, just listen for the pump.

You can also varify it by going to the Fuel Pump Relay (located underhood) and see if it is turning on. If not you may have either an ignition problem, wiring problem, or worse yet an ECM problem (which is what mine was). :)

Thanks for the reply, I'll check all the above this weekend.

those fuel pumps have the prime feature on them. i believe fuel pressure on the tbi's is 12-13 psi. as stated make sure you hear the fuel pump. if it starts out weak then picks up then the prime feature has gone bad on the fuel pump. one way to check is hook up a pressure gauge and turn the key on and see if the pressure jumps up. if not, buy a new fuel pump and make sure you get a new harness that goes from fuel pump to top of the sending unit

Just read this thread, and yes I would focus on the fuel pump like others have already said. If you need a new one...better brace yourself when hearing the price.:(

X2 Fuel Pump. If you're going to change it yourself, it is quicker and definately easier to lift the box off the frame. 8 bolts from underneath, unplug taillight wiring, ground wire and fuel tank filler neck. Get three buddies to help lift the box off.

Forget the battery. :rolleyes:

When you turn the ignition on the fuel pump should run for 2 seconds, then shut off. The fuel pump won't come back on until the ecm sees oil pressure. So with your expended crank, it sounds like the fuel pump is not coming on when you turn on the ignition, but is coming on once the ecm sees oil pressure. To varify this, turn the key to the 'run' position and use a test light on the fuel pump connection at the tank to see if it lights up for 2 seconds. OR since those fuel pumps are usually noisy, just listen for the pump.

You can also varify it by going to the Fuel Pump Relay (located underhood) and see if it is turning on. If not you may have either an ignition problem, wiring problem, or worse yet an ECM problem (which is what mine was). :)


I turned the key to the "run" position and heard the pump come on, no change in sound when it came on.

Those pumps are alot cheaper than the pumps for a truck 1 year newer.

I turned the key to the "run" position and heard the pump come on, no change in sound when it came on.

I guess a few quick questions:
1. Have you had this truck a long time and it just stated doing this?
The reason I ask is because a TBI engine like this one takes longer to start than the newer engines. TBI bleed the fuel back to the fuel tank when shut off, so they always have to 'prime' before they start. This is different than the Mutiport 'Vortec' engines that actually hold fuel pressure when the engine is off. So a TBI will always take a little longer crank time than the newer ones.

Does it do it everytime, or just sometimes?
This one is because you said the pump came on for 2 sec when you 'tested' it. Did you try to start it that time, did it fire right off? If it does it 'sometimes' it could be something like an ECM goofing up every once in a while or it could be the fuel pump relay not operating properly every time.

Don't forget easy stuff like changing the fuel filter. A dirty fuel filter will extend the crank time a tad too. The pump will have to push through the dirt first before it reaches the injectors.

Just for referance to others comments: The '95 and older fuel pumps are a LOT cheaper than the '96 and newer ones. ;)

I guess a few quick questions:
1. Have you had this truck a long time and it just stated doing this?
The reason I ask is because a TBI engine like this one takes longer to start than the newer engines. TBI bleed the fuel back to the fuel tank when shut off, so they always have to 'prime' before they start. This is different than the Mutiport 'Vortec' engines that actually hold fuel pressure when the engine is off. So a TBI will always take a little longer crank time than the newer ones.

Does it do it everytime, or just sometimes?
This one is because you said the pump came on for 2 sec when you 'tested' it. Did you try to start it that time, did it fire right off? If it does it 'sometimes' it could be something like an ECM goofing up every once in a while or it could be the fuel pump relay not operating properly every time.

Don't forget easy stuff like changing the fuel filter. A dirty fuel filter will extend the crank time a tad too. The pump will have to push through the dirt first before it reaches the injectors.

Just for referance to others comments: The '95 and older fuel pumps are a LOT cheaper than the '96 and newer ones. ;)

My Father bought the truck new in 1995, I was with him, My father passed away in 2003 and my mother kept the truck, my younger brother drove the truck "occasionally" since then. I got the truck from my mother about 1 year ago and replaced the fuel filter, egr valve, spark plugs and spark plug wires shortly after I got it.

The extended cranking only happens when the truck has been parked overnight.

I'd clean up the Iac passage and motor plunger. Wouldn't hurt to wipe out the throttle blade area while you are at it. Then, I'd look closely at the rotor within the distributor. Some brands gave me more trouble than others.

I'd clean up the Iac passage and motor plunger. Wouldn't hurt to wipe out the throttle blade area while you are at it. Then, I'd look closely at the rotor within the distributor. Some brands gave me more trouble than others.


Iac? not sure what this is. I'll look at the rotor, thanks.

The extended cranking only happens when the truck has been parked overnight.

Fuel pressure will be 0 and all the fuel will be in the tank, so it's totally re-priming when you first key on. The fuel pump could be a little weak or the filter a little clogged, but it's kind of sounding like it may just be normal.

Tomorrow, when you go to start it, key on and wait the 2 seconds before you go and start it. It will probably decrease the crank time considerably.

IAC= Idle Air Control
Big round thing on the side of the throttle body. It's a plunger that goes in and out for the computer to adjust the idle.

try turn key on wait 2 seconds, turn key off, then turn key on, wait 2 seconds and try start. if that helps, system leaking down check pressure regulator, may have trash in it. could be injector jummed up, could try strong dose of cleaner, see if that helps. have you checked fuel rail pressure.

I don't think its the iac because it has a long crank not idle problems.

As we all learned a long time ago, a gas motor requires a rich fuel mixture to start. The engine computer closes all of the throttle bypass passages when starting. This means the IAC plunger gets seated along with the EGR plunger. When the IAC plunger seat is partially fouled, the passage cannot close completely. This results in a lean mix while starting. Does the truck hot start well???

If the truck runs great once started, I'd stop suspecting the fuel system and start looking at things like the end of the rotor for fouling, the terminals in the rotor for "blossoming", and the plugs for gap. That engine will go, on avg, a 110k miles, before the OEM plugs are worn enough to require replacement. However, many people do not use the same ACDelco plug at tuneup time, nor do they use the same quality cap and rotor.

Remember that the spark has to "jump" not only the plug gap, but also the gap from rotor to distributor cap. Cold starting requres the best spark available.
The easiest way for me to check the cap, rotor, wires and plugs, is to connect a scanner (with the misfire menu) to the truck and watch the recorded misfire events. Once there are so many misfires, the CEL will illuminate, but many times I get the long crank syndrome before a CEL is illuminated. If the misfire stays with one or two cylinders, I'd go with the plugs. If the misfire is everywhere (all 8 on screen), I'd go with cap and rotor.


Thinking aloud here as I type, perhaps the ECT (engine coolant temp) sensor has gone south. When it does start, is the idle elevated (around 1000), or is right at the 700 or so like a warm idle. The ECT only feeds the computer, not the temp gauge itself. When it fails, the fuel mix is calculated wrong for starting (typically too lean).

id say fuel pump had the same problem on my 1996 k2500

As we all learned a long time ago, a gas motor requires a rich fuel mixture to start. The engine computer closes all of the throttle bypass passages when starting. This means the IAC plunger gets seated along with the EGR plunger. When the IAC plunger seat is partially fouled, the passage cannot close completely. This results in a lean mix while starting. Does the truck hot start well???

If the truck runs great once started, I'd stop suspecting the fuel system and start looking at things like the end of the rotor for fouling, the terminals in the rotor for "blossoming", and the plugs for gap. That engine will go, on avg, a 110k miles, before the OEM plugs are worn enough to require replacement. However, many people do not use the same ACDelco plug at tuneup time, nor do they use the same quality cap and rotor.

Remember that the spark has to "jump" not only the plug gap, but also the gap from rotor to distributor cap. Cold starting requres the best spark available.
The easiest way for me to check the cap, rotor, wires and plugs, is to connect a scanner (with the misfire menu) to the truck and watch the recorded misfire events. Once there are so many misfires, the CEL will illuminate, but many times I get the long crank syndrome before a CEL is illuminated. If the misfire stays with one or two cylinders, I'd go with the plugs. If the misfire is everywhere (all 8 on screen), I'd go with cap and rotor.


Thinking aloud here as I type, perhaps the ECT (engine coolant temp) sensor has gone south. When it does start, is the idle elevated (around 1000), or is right at the 700 or so like a warm idle. The ECT only feeds the computer, not the temp gauge itself. When it fails, the fuel mix is calculated wrong for starting (typically too lean).

I'm thinking it's the ECT sensor too. The engine runs strong and idles smooth after start up and when warm, the ECT sensor (at the thermostat housing) is the one sensor I haven't replaced yet.

I finally got around to check the fuel pump pressure, it's at 14psi so that isn't the problem. Could it actually be the ECT sensor?