Trouble Starting Cold

96 Cherokee Sport, 4WD, Auto, 112K

When starting from cold (say sitting overnight) it will start, but it is not smooth at all. I have to keep the key turned, and it cranks and rumbles for a second before it fires up. Once it is running, it's fine. If I start it up after running it, it fires up with no problem.

Have brand new plugs, wires, cap and rotor that are firing fine... any other thoughts?

Thanks!

My jeep is a throttle body injection, but in your case I would suspect the Throttle Position Switch, or the Idle Air Control Valve.

denisond3

I have heard TPS from a few people... What would be involved in checking this, and if that is the case, is it a difficult/expensive repair?

Thanks again!

The only way I know to check one would be to compare its resistance (across its range of positions) with a new one just out of the box. But if the old one tested good I would likely replace it anyway - and keep the old one as a spare. At www.rockauto.com they list them from $27 up to $43 dollars, plus shipping cost. I dont know that I would buy the cheapest one though.
They list the idle air control valve (in the fuel/air parts listings) at $34 & $51, plus shipping cost.
Good Luck....