1. Home
  2. Jeep and Willys (new and old)
  3. Jeep Cherokee hard starts (CPS?)

Jeep Cherokee hard starts (CPS?)

Hi all -

I have a 1991 Jeep Cherokee Laredo with the in-line 6 and auto-transmission. I have been fighting a hard starting problem as follows. In the morning from a cold start it will take up to 10 seconds to start. And then it will run very rough until it warms a bit. Subsequent restarts then take less than 2 seconds, and I don't even need to step on the gas. When it starts hard, I have tried the trick of turning the key on and off a few times to let the fuel pressure come up. This seems to make it worse, if anything. I have replaced the plugs, wires, rotor, cap, air filter and CCV tubing (no PCV valve on this model). There is no leaking around the injectors, pressure regulator or fuel lines that I can see.

From everything I've read on this group and elsewhere, the next likely

candidate is the CPS. I've read that this gadget is not easy to get at. So, my question is, is this something that a DIY'er can tackle without screwing things up? Where exactly is it located? Do I need anything other than basic handtools to get it out and get a new one in? Any other words of advice?

Thanks for all your help, Bud

Reply to
Bud
Loading thread data ...

You are describing a dirty connection on the TPS or throttle position sensor. The best cleaner is electronic contact cleaner but WD40 will work in a pinch.

The sensor is on the throttle body. Both plugs and sockets there can benefit from a clean.

And if the 91 still has the renix computer system they all seem to take a while to start first time in the day, but they run smooth still....

The CPS plug and socket also fail from bad connections, but that usually causes a stall. While you have the contact cleaner out, that plug can use it too. The CPS is on the bell housing top drivers side. Follow the wires for it's plug, most are on the top of the intake manifold.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Reply to
L.W.( ßill ) Hughes III

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.