No power on start up

[Mikel]

Hello,
I have a '96 XJ. 4.0/AW4. When I stop the engine and restart it shortly after (always happens when warm), it will feel as if it's running on half the cylinders for about 30 seconds, with a rough idle and very little power. Goes away on its own. No check engine light.

Any ideas what it could be? Has 205K miles. Thanks.

 

[Agreen]

Sounds like leaky injectors. Pull the injectors off and leave them on the rails, turn the key on and see if any of them drip with fuel pressure applied.

 

[Mikel]

Thanks. The injectors are Bosch 0280155703 remans with about 40k miles.

 

[Agreen]

It also could be a bad O2 sensor. I had one drive me wild because on a hot restart, I'd take off and it just felt like the transmission was stuck in 3rd gear. After a couple of seconds it would clear right up as if nothing ever happened. I replaced the upstream sensor (use only NTK brand, by the way) and the problem never happened again. Maybe give that a go?

I'd still take a look at the injectors for post-shutoff drips. I have heard of some websites selling Bosch injectors that are just Bosch knockoffs that look really convincing.