7.3 non turbo stops pulling?????
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Freshman User
Joined: Apr 2005
Posts: 29
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From: cleveland ohio
7.3 non turbo stops pulling?????
I noticed that I tried to pull the truck past 2200 and the truck just stops pulling like someone shut off the key,I am going to do a Mechanical fuel pump so I know it is good tomorrow,what about the injection pump? The symptom to me seems like a fuel pump so I am starting there,any suggestions??
Post Fiend
Joined: Nov 2004
Posts: 5,638
Likes: 1
From: Manitoba
Fuel filter, why not do a fuel pump pressure and flow test before replaceament.
Do pressure and flow test on the fuel at the Schrader valve on the filter(FSS- fuel shutoff switch disconnected). Remove the tire valve core and hook a hose and pressure guage on it should see 4-6 psi when cranking. Then do a fuel quantity test same place, should see 1/3 pint in 10 seconds of engine cranking, route fuel to a suitable container with a hose.
If there is a problem with the lift pump and you are changing it, ensure the new pump comes with instructions as to correct installation proceedure if it is the newer model pump with the almost straight arm.
Do pressure and flow test on the fuel at the Schrader valve on the filter(FSS- fuel shutoff switch disconnected). Remove the tire valve core and hook a hose and pressure guage on it should see 4-6 psi when cranking. Then do a fuel quantity test same place, should see 1/3 pint in 10 seconds of engine cranking, route fuel to a suitable container with a hose.
If there is a problem with the lift pump and you are changing it, ensure the new pump comes with instructions as to correct installation proceedure if it is the newer model pump with the almost straight arm.
Thread Starter
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Freshman User
Joined: Apr 2005
Posts: 29
Likes: 0
From: cleveland ohio
Originally Posted by PLC7.3
Fuel filter, why not do a fuel pump pressure and flow test before replaceament.
Do pressure and flow test on the fuel at the Schrader valve on the filter(FSS- fuel shutoff switch disconnected). Remove the tire valve core and hook a hose and pressure guage on it should see 4-6 psi when cranking. Then do a fuel quantity test same place, should see 1/3 pint in 10 seconds of engine cranking, route fuel to a suitable container with a hose.
If there is a problem with the lift pump and you are changing it, ensure the new pump comes with instructions as to correct installation proceedure if it is the newer model pump with the almost straight arm.
Do pressure and flow test on the fuel at the Schrader valve on the filter(FSS- fuel shutoff switch disconnected). Remove the tire valve core and hook a hose and pressure guage on it should see 4-6 psi when cranking. Then do a fuel quantity test same place, should see 1/3 pint in 10 seconds of engine cranking, route fuel to a suitable container with a hose.
If there is a problem with the lift pump and you are changing it, ensure the new pump comes with instructions as to correct installation proceedure if it is the newer model pump with the almost straight arm.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
Max torque on a 7.3 is around 1900 RPM.
So once you are past peak torque the pull sort of levels off even though peak HP is around 3100 RPM.
Do you have a stock exhaust and air intake?
What tranny and gear set is in the rear end?
What size tires are you running?
Where are you? sea level or 10,000 feet in elevation.
So many things enter into how your truck runs that no one considers.
So once you are past peak torque the pull sort of levels off even though peak HP is around 3100 RPM.
Do you have a stock exhaust and air intake?
What tranny and gear set is in the rear end?
What size tires are you running?
Where are you? sea level or 10,000 feet in elevation.
So many things enter into how your truck runs that no one considers.
Thread Starter
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Freshman User
Joined: Apr 2005
Posts: 29
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From: cleveland ohio
Originally Posted by Dave Sponaugle
Max torque on a 7.3 is around 1900 RPM.
So once you are past peak torque the pull sort of levels off even though peak HP is around 3100 RPM.
Do you have a stock exhaust and air intake?
What tranny and gear set is in the rear end?
What size tires are you running?
Where are you? sea level or 10,000 feet in elevation.
So many things enter into how your truck runs that no one considers.
So once you are past peak torque the pull sort of levels off even though peak HP is around 3100 RPM.
Do you have a stock exhaust and air intake?
What tranny and gear set is in the rear end?
What size tires are you running?
Where are you? sea level or 10,000 feet in elevation.
So many things enter into how your truck runs that no one considers.
I know there are limits but this thing at 2200 seems like I shut off the key,it just stops.I have been building race cars for ever and I know when engines are done but this just totally stops like a rev limiter.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 15
From: Nutter Fort, WV
Bear with me for a bit, trying to diagnose an engine by typing is a little hard.
Cleveland is only a few hours away.
Does it do the same thing in 4th gear?
If you have 235/85-16 tires and 3.55's with a ZF 5 then 2200 should be around 75 MPH.
Does that sound about right?
Tachs and speedos can be wrong.
In second or third you should be able to wind it out to about 3300 RPM real easy.
Will it do that?
When you say you have a 2.5" Y pipe, does it come together and the three inch starts at the end of the Y?
The three inch should go up past the place the pipes come together. The right head drops in the end of the three inch and the left head drops in the side of the three inch pipe. The 2.5 inch is really 2.25" ID which is way to small for a 445 CU in motor.
This is a drawing of what I am saying for the exhaust.
This is a picture of an air intake for the engine.
That is 40 square inches instead of the stock 9 square inches of intake area.
A 7.3 needs to have 425 cu ft of air through it every minute at 3300 RPM.
That is why the intake and exhaust are so critical for it to run good.
As far as the altitude question I asked, you have to understand we regularly have people here from Iceland, France, Germany, Canada, Norway and all over the US.
What a truck runs like in Ohio at 900 feet will be a lot better than in Colorado at 9000 feet.
Now for the next question, do you ever see black smoke out the exhaust?
Cleveland is only a few hours away.
Does it do the same thing in 4th gear?
If you have 235/85-16 tires and 3.55's with a ZF 5 then 2200 should be around 75 MPH.
Does that sound about right?
Tachs and speedos can be wrong.
In second or third you should be able to wind it out to about 3300 RPM real easy.
Will it do that?
When you say you have a 2.5" Y pipe, does it come together and the three inch starts at the end of the Y?
The three inch should go up past the place the pipes come together. The right head drops in the end of the three inch and the left head drops in the side of the three inch pipe. The 2.5 inch is really 2.25" ID which is way to small for a 445 CU in motor.
This is a drawing of what I am saying for the exhaust.
This is a picture of an air intake for the engine.
That is 40 square inches instead of the stock 9 square inches of intake area.
A 7.3 needs to have 425 cu ft of air through it every minute at 3300 RPM.
That is why the intake and exhaust are so critical for it to run good.
As far as the altitude question I asked, you have to understand we regularly have people here from Iceland, France, Germany, Canada, Norway and all over the US.
What a truck runs like in Ohio at 900 feet will be a lot better than in Colorado at 9000 feet.
Now for the next question, do you ever see black smoke out the exhaust?
