Extended Crank

Needaram · Aug 12, 2012

Ive had this problem for months. When my truck sits for awhile like overnight especially after a cooler night It cranks more than it should. Its a normal crank not slow or anything.

Ive changed
Fuel Pump
Cap/Rotor
Plugs
Ign. Coil

Any ideas guys/gals

Thanks

MADDOG · Aug 12, 2012

Check that injector up in the TBI at the top of the intake manifold. It may be clogged up or wore out. You might just need a new injector.

ktm1217 · Aug 13, 2012

I have the same problem with my truck ! lol ive done the fuel pump, plugs, wires, cap, rotor, fuel pressure regulator, rear 02 sensor, tps, iac motor, crank positioning sensor, and i think thats it lol either way, i still have the problem. it does it when it sits for more than like 20-30 mins maybe..? but if you ever figure it out, id be glad to know what the trick is lol

SmokedRam · Aug 13, 2012

MADDOG said:
Check that injector up in the TBI at the top of the intake manifold. It may be clogged up or wore out. You might just need a new injector.

What injector are you referring to? The Magnum 5.2 is an MPI fuel delivery system, there isnt an injector in or on the throttle body.

the codes · Aug 13, 2012

mine does this when it's sat about a full 24 hours. it sat all day pretty much so I'll try to get a vid tomorrow if it does it

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Needaram · Aug 13, 2012

Idk what injector hes talking about.

the codes · Aug 13, 2012

iv been thinking a msd ignition box would help fix this problem

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Okiespaniel · Aug 13, 2012

I'll check the factory manual tonight and see what it says...somebody remind me if i forget

suzukiquadrider · Aug 13, 2012

check fuel regulator.

Bigtman07 · Aug 13, 2012

The Injectors are actually in the intake. We don't have TBI we have EFI. Just for info. I personally have never seen this happen. My truck does it sometimes int he winter but that's cause my battery is junk.

Needaram · Aug 13, 2012

suzukiquadrider said:
check fuel regulator.

Thats with the fuel pump assembly which has less than 1000 miles on it.

Needaram · Aug 13, 2012

Okiespaniel said:
I'll check the factory manual tonight and see what it says...somebody remind me if i forget

Thanks cuz I dont have one lol. I have a haynes but thats it

Okiespaniel · Aug 13, 2012

Well I checked my factory service manual...

It suggests the you would need to run a diagnostic test on your fuel system for leakdown issues.
When cold, your engine should be a 0 psi pressure, however the fuel pump should bring it to pressure (49.2 psi).
The tests use a fuel pressure guage and special t hose fitting to check for leaking injectors or the fuel pump pressiure regulator/filter assembly.

Let me ask you...before you to turn the key to start, how long does the pump run? It should take about 2 seconds maybe 3 to pressurize the system. If it runs longer than that I would suspect a leakdown issue.

Even on new pumps, specially aftermarkets...poor quality can give you a bad assembly.

Needaram · Aug 14, 2012

Okiespaniel said:
Well I checked my factory service manual...

It suggests the you would need to run a diagnostic test on your fuel system for leakdown issues.
When cold, your engine should be a 0 psi pressure, however the fuel pump should bring it to pressure (49.2 psi).
The tests use a fuel pressure guage and special t hose fitting to check for leaking injectors or the fuel pump pressiure regulator/filter assembly.

Let me ask you...before you to turn the key to start, how long does the pump run? It should take about 2 seconds maybe 3 to pressurize the system. If it runs longer than that I would suspect a leakdown issue.

Even on new pumps, specially aftermarkets...poor quality can give you a bad assembly.

Pump runs about 2 seconds. And I have a OEM replacement in it.

Okiespaniel · Aug 14, 2012

I would still recommend a leakdown test...you may have a leaking injector.

It will certainly beat throwing more parts at the problem.

Needaram · Aug 14, 2012

Okiespaniel said:
I would still recommend a leakdown test...you may have a leaking injector.

It will certainly beat throwing more parts at the problem.

I agree

ktm1217 · Sep 19, 2012

Did ya ever figure out what the problem was on your truck needaram??

jlb · Sep 19, 2012

The pump pressurizing the fuel lines wouldn't necessarily be able to force all the air out of the lines, just bring the pressure up, so it would still take a couple cranks for the fuel to get to the injector. I think a leakdown test is indeed the thing to do.

Needaram · Sep 20, 2012

I havnt had time to do a leakdown test sorry guys been busy lol

Luddy13 · Nov 24, 2012

i have the exact same issue except with mine itll run for a second then die and if you dont keep your foot on the throttle for a good minute itll stall out. i already did distributor cap and rotor, plugs and wires, iac, tps, fuel pump (done last year after it died). if anybody has figured this out i would really like to know cause its driving me nuts

Extended Crank

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