• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

need help 3.0 to 4.0 conversion


redneck1959

Active Member
Joined
Aug 7, 2007
Messages
42
City
florida
Vehicle Year
2002
Transmission
Manual
im working on a 2000 ranger i converted from 3.0 flex fuel to 4.0 ohv, ive already had the dealer flash the pats and computer so it all works now but it still wont crank up, it turns over fine if the fuel pump is turned off with the inertia switch, but if u spray it with starting fluid or fuel from the pump it is like its hydro locking. im stumped hope someone can help me thanks
 
Check the firing order. You might have it wrong.
 
I am getting ready to do the same swap. I will have the donor right next to my truck when I do this so subscribed
 
Hydro-lock means crank stops turning and will not turn again in the same direction.
(because fluid is in the cylinder and piston can not compress it to get past TDC.)

Maybe you mean when you give it fuel it fires and crank stops, but you can still crank the engine after that?
This would be if spark and maybe valve timing are off.
If you have a timing light you could check that spark timing for #1 is at/near TDC while cranking.
Also a compression test, all spark plugs removed, throttle plate open, should get you 170psi per cylinder average.

Cylinders are
3 6
2 5
1 4
Front of engine

Firing order is 1-4-2-5-3-6
3 4
2 6
1 5
Front of coil
 
Last edited:
i sure wish i could figure this out it has me stumped the truck and donor 4.0 are both 2000 model
 
RonD by the way you word it there then it is not hydro locking for sure but its doing exactly what your saying about fuel doing it even a squirt of starting fluid will make it do it i just rechecked the firing order again and its for sure right i already tryed crank sensor and cam sensor also im gona go check the compression be back in a few
 
110 is pretty low on #3, was it hard to get tester in there so maybe not a good seal?
#5 as well?

110psi would probably just be a misfire not a no start

Did you happen to look at the tip of the tester after pulling it out of each cylinder?
Were any wet?

Drain the coolant and try to start the engine
 
I haven't filled with coolant yet cause it has not fired up yet, but all the plugs were wet and smelled of fuel and the whole time you turn it over it smells of gas, and I was thinking at 110 it would still run mabey just a misfire or something
 
The 2000 Ranger will have a 65psi returnless fuel system.
Is the 4.0l OHV from an '98 or new Ford?

Or did you change fuel rails and injectors?
 
2000 3.0 4x4 5 spd flex fuel truck and the donor was a 2000 4.0 4x4 5 speed
 
i just checked the camshaft syncro and it was off a little i used the tool to set it when i was at tdc on compression stroke and it mad it roll over a little easier but still no crank and it still slows down while turning over
 
what really confuses me is if you hit the inertia switch so the fuel pump is off, after the fuel in the rail goes away it rolls over smooth, then you can shoot it with starting fluid and it does just like if the pump was on
 
is there a difference between the harness's I kept the dash harness from the 3.0 and used the 4.0 under hood and engine harness and remember both are 2000 year
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top