Hey there Guys,

1993 5.8 Van.

Has not been driven for a couple of months. After much winding, battery drained to no more cranking.

Recharged battery and after a lot more cranking she slowly started but runs like a hairy goat.

Checked plugs, seems OK.

Disconnect plug a lead from the middle 4 (2,3,6,7) cylinders and no change to idle, healthy spark jumps to the block.

Disconnect plug a lead from the two opposing cylinders at front and rear of engine (1,5,4,8) and idle falters, healthy spark jumps to the block.

Swapped plugs between 3 and 4, and 7 and 8 to check test the plugs, symptoms remain the same.

It seems the injectors feeding the middle four cylinders are not operating.

Any thoughts on possible causes?

It was throwing code 25 with air bag light before it sat.

Cheers,
Shaun

 

Something you can check,
Do you have power to all the injectors with just the key in the on position?
When cranking can you place a piece of hose or something long enough to reach from each of the affected injectors to your ear so you can hear if the injector is clicking or not. They could be working and be plugged.
Have you tried to add some carb/choke cleaner to the intake to see if the engine smooths out when idling.
Could there be blockages in those runners from unwanted visitors that maybe made a home in there? The throttle blade should have remained closed while not in use, but you never know?
Did anybody mess with the dist cap or wires other than checking for spark?

 

Cheers Hanky,

Here in Santa Fe NM, I'm dancing with 30/35kt gusts with dust/rain/snow and van is outside so timing is critical!

Do you have power to all the injectors with just the key in the on position?
When cranking can you place a piece of hose or something long enough to reach from each of the affected injectors to your ear so you can hear if the injector is clicking or not. They could be working and be plugged.
Not yet checked
Have you tried to add some carb/choke cleaner to the intake to see if the engine smooths out when idling.
No, should have thought of this one myself, taa.
Could there be blockages in those runners from unwanted visitors that maybe made a home in there? The throttle blade should have remained closed while not in use, but you never know?
Did anybody mess with the dist cap or wires other than checking for spark?
No on both counts, checked the runners with upper manifold off and I'm the only one in there.

The fact that only the middle four pots are affected pointed me towards something electronical (my word), I'm an old school trained mechanic and essentially been off tools for 15 years or so, other than the occasional private stuff, and was hoping it might be a brainfart from the computer or something along that line.

As soon as weather permits I will check your points and report back.

Thanks for your help Hanky.
Cheers,
Shaun