Have to crank forever to start

Hey guys,

I have a 1992 Laredo 4.0L 5 speed and ever since I bought it this past may its taken an awful lot of cranking to fire it up. Probably anywhere from 20 to 30 seconds as long as I just hold it and let it crank. Fires every time though. Its a little more difficult to start when its cold. Its almost like its getting too much fuel because it smells like its running rich and kinda pops and sputters a bit until I can get it to rev up after which it is fine.

While at this point it is more of just an inconvenience, I'm just waiting for the day that it won't fire.

I know that these things have bad crankshaft position sensors, could this be attributed to it?

Any feedback would be much appreciated. Thanks in advance.

Tristan

BudgetXJ said:

Hey guys,

I have a 1992 Laredo 4.0L 5 speed and ever since I bought it this past may its taken an awful lot of cranking to fire it up. Probably anywhere from 20 to 30 seconds as long as I just hold it and let it crank. Fires every time though. Its a little more difficult to start when its cold. Its almost like its getting too much fuel because it smells like its running rich and kinda pops and sputters a bit until I can get it to rev up after which it is fine.

While at this point it is more of just an inconvenience, I'm just waiting for the day that it won't fire.

I know that these things have bad crankshaft position sensors, could this be attributed to it?

Any feedback would be much appreciated. Thanks in advance.

Tristan

Click to expand...

You have main grounds at:
The fender liner near the battery
The firewall, driver's side above the cylinder head
Passenger side of the engine, near the dipstick.

Check and/or clean all three. On the two attachment points to the chassis, take a small wire wheel and clean them down to bare metal and apply corrosion inhibitor (not "liquid electrical tape", and not - for the love of Gawd and all you hold holy - WD-40. Check your hardware store, electrical section...) when you reassemble them. It's a cheap fix, and will work probably seven times out of ten.

Faulty grounds can cause erroneous sensor readings, which sounds like your problem.

Also, be sure to clean both battery terminals well (bare, shiny metal) and apply corrosion inhibitor on reassembly. Since it's a different environment, you'll have to use something different - but you can make this one yourself:

~1/8 cup of petroleum jelly
2tbsp baking soda

Mix thoroughly. Apply to all surfaces (inside and out) of the battery connections. Store remainder in closed container, in a cool dry place.

The petroleum jelly helps to protect the connection, and the soda neutralises the acid vapours. Check and reapply every six months or so, or whenever you ford a deep water crossing, or you clean the engine bay.

In addition to 5-90's excellent suggestions, how old is the starter? I've replaced the starters in my '92 and my son's '95, with NEW units (about $100 at Advance), and WOW! They start a lot faster! When an electric motor gets old, it starts to draw more current, leaving less for everything else, hence the slow fire. If the grounding works, then all good. If not, don't be afraid to consider the starter.

Thanks guys. I'll clean the grounds and check the battery connections tomorrow morning. I hope its not my starter but it wouldn't surprise me if it is a little old and tired. But hey at least it matches the rest of the heep.

let us know if that works, mine takes awhile too