7.3 hard start

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Jun 18, 2023 | 09:02 AM

Layton7.3

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7th Gear

Joined: Apr 2023

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7.3 hard start

I just rebuilt my 2002 7.3 Powerstroke because it was running on 7 cylinders. Now I am getting hard start issues it takes my truck 10 seconds of cranking before it builds oil pressure and takes about 15 seconds to start. I replaced the low pressure oil pump and my hpop reservoir dose not leak down. Before the rebuild it had hard start issues but I assumed that was because it was running on 7 cylinders. Any ideas?

Jun 18, 2023 | 09:11 AM

Sous

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From: Lake Hartwell, GA

Have you taken any measurements with FORScan like ICP, IPR DC, cranking volts, etc?

Jun 18, 2023 | 11:26 AM

Kwikkordead

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From: Rio Rico, AZ.

Without any hard data to consider, this sounds to me like HPOP pressure is taking too long to build. Common causes of that are weak HPOP and/or internals on the injectors are leaking HPOP oil. When it finally starts, does it "taper up" or have that characteristic "bark" then idles?

Jun 18, 2023 | 01:54 PM

FordTruckNoob

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From: Henderson, NV

How far has the truck been driven after the rebuild? It can take awhile to work the air out of the fuel and HP oil galleries.

Jun 18, 2023 | 01:55 PM

Layton7.3

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7th Gear

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It will be cranking for about 15 seconds getting nothing and then it just fires right up

Jun 18, 2023 | 01:58 PM

FordTruckNoob

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From: Henderson, NV

That would be all the air in the galleries getting compressed before it reaches required pressure.

Jun 18, 2023 | 06:57 PM

MoBill122

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Joined: Nov 2009

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From: Woodstock, GA

You didn't give any info on the 7 cylinders...... if you were getting a code on # 8, that is common on these trucks. Especially if you have a chip.

Like the others, go drive it 50 miles down the interstate to get the air out.