I need some help with my 2002 Dakota 4.7 Magnum. I purchased the truck with a dropped valve in the number 2 cylinder. I have replaced the head and had a valve job done on both heads. I replaced the timing chain set and did a rebuild on the entire engine. New bearings, rings, pistons, gaskets, oil pump, water pump, crank sensor, cam sensor, coolant temp sensor, injectors, spark plugs, and coils. I triple checked the timing chain set when installing. After installing the engine, it will crank and act like it is firing on a few cylinders but will not run. I have fuel pressure at the rail and when removing the plugs they are wet with fuel. It makes a sound when cranking like it is compressing with a sound that is hard to explain, kind of like a boil in hot tar. The exhaust is not hooked up as someone tried to steal the cat and cut the exhaust. They also cut the fuel filler hose because it had a locking gas cap. I have the filler hose clamped off to mimic a fuel cap installed. I also have the O2 sensors plugged in, but they are not in the exhaust stream as the exhaust is not installed. I am not getting a CEL on the dash. If anyone has any ideas I would be very grateful. I just picked up a spark tester but have not had an opportunity to test but will be this afternoon.

 

When you first turn the ignition on, does the check engine light come on? If not, need to start with that.....

Does the fuel pump prime? Getting power to the coils while cranking??

 

HeyYou. Thank you for replying. You helped a ton on my last issue. The CEL does illuminate when the key is turned on and the fuel pump does prime. I am going to be checking coils in a few hours once I get home. Will report back as soon as testing is complete. I do know that at least some of the coils fire due to the fire coming from the manifolds.

 

I checked power at the coil plugs when cranking and I am getting 5.5 to 7 volts at each plug. It tries to start after cycling the key multiple times. Fuel pressure issue? What is a good fuel pressure reading?

 

I have 49 psi with fuel pump relay jumped. Has dropped to around 10 psi in 3 minutes after deactivating fuel pump.

 

I just checked injector signal with noid light and I have signal to injectors.

 

I think pressure is ok.... but, not 100% sure on that. You have spark, you have fuel, I would like to think that air isn't a problem..... (might wanna check for mouse nests in the duct work...) Now, the questions becomes: Are you getting the right amount of gas? Too much, or too little, and it won't run. Try holding the gas pedal on the floor, see if it will start. Also, if those are champion plugs, my experience with 'em is, flood 'em out once, and they are done.....

 

The plugs are autolite copper 5224. I even tried starting with fuel pump relay jumped and it did not start. Tries, but doesn't run. I am draining the fuel tank now and refreshing. Fuel is slightly yellow, but since the fill hole was cut I want to eliminate water/contaminants.

 

Do you have a compression gauge? Check all 8 holes and verify that the cam timing is where it should be. You should have 125-130 psi per cylinder or so (~9.5:1 compression, 1 atmosphere is ~14.5 psi).

Assuming that you have good compression on all 8, and the coils are firing in the proper order, and the injectors are firing in proper order, then as HeyYou said, your issue could be air related. If you hold the throttle wide open, it will go into "Flooded" mode and will turn the injectors off for about 8 revolutions to pump the fuel out then turn them back on and will pretty much start under any and all conditions, whether it should or not. I learned that the hard way on my 408 when I had a few things wrong and it REALLY shouldn't have started and did anyways...and again when I was having cam sensor issues on Rocky Mountain Race Week and it was acting like the distributor was 180 out.

 

I will grab a compression tester today, but the engine and heads are freshly rebuilt. I know it could still be an issue so I will check. I attempted the WOT for 8 revs and no change. When I installed the timing chains I set the #1 cylinder at TDC before installing the head and checked it after head was installed. I then installed the chains with colored links in appropriate gear windows and made sure the colored links lined up with the dots on the cam gears and that the gears had the V8 mark at 12 O'clock. The harmonic balancer TDC mark lined up perfectly with the timing cover TDC mark. The crank keyway was pointing toward the #1 cylinder. Is there a way to verify timing without removing the valve covers? I know there are inspection plugs, but they don't line up with the cam gears. I feel like I am chasing something simple. I have access to a Snap-On Solus Pro diagnostic computer. Would this be able to help me in any way?