Trouble with ignition

[ChucklePuck]

Hey guys, so I recently began having issues with starting my 2002 4.0 5speed. Starter died first, then shortly after replacing it, my spark plugs failed. While swapping those, a couple coils in the ignition rail snapped, so I replaced the whole rail. Then, a few days later, I got a code for the crankshaft sensor, so I replaced that too.

Once the engine starts running, I have no issue, it runs smooth and doesn't shoot smoke, etc ... but to get it going, it sometimes takes a few minutes and I just dont know why.

Should I check the injectors next? Or the fuel pump/filter? Scratching my head here haha

 

[Chris]

Hey guys, so I recently began having issues with starting my 2002 4.0 5speed. Starter died first, then shortly after replacing it, my spark plugs failed. While swapping those, a couple coils in the ignition rail snapped, so I replaced the whole rail. Then, a few days later, I got a code for the crankshaft sensor, so I replaced that too.

Once the engine starts running, I have no issue, it runs smooth and doesn't shoot smoke, etc ... but to get it going, it sometimes takes a few minutes and I just dont know why.

Should I check the injectors next? Or the fuel pump/filter? Scratching my head here haha

I'd check the fuel pressure for sure. The slow starts can also be a symptom of injector heat soak which is fairly common on 4.0 engines and usually solved by shielding the injectors with heat shield material.

 

[WestCoastDan]

With a good battery, good battery terminals, good battery cables, and good connections on them the next step is fuel pressure.
These old pumps are a definite failure mode, so don't ignore this as a potential cause, but...

I thought my battery was good and my fuel pump was failing due to weak/slow starting symptoms, but when I checked my battery age (2018) and replaced it (Ultima Marine), the slow start issue went away.

I like the marine version as it comes with the additional posts for connecting accessories.