4.0 OHV Devils.

[sn0border88]

I recently did some work to the 4.0, removed radiator to pressure wash and flushed system. Did minor cleaning of everything under the hood to try and get the mud and grime out. Anyways, I dont drive it much as of alte because I walk to work. When I do drive it, it goes all kinds of wierd. its fine in 1st and usually 2nd gear, but if I feather the throttle, or anywhere under half throttle it bogs down to about 1300-1500 RPM and if I give it a little more gas it will jump back to 2000-2300 only to drop down again very shortly. It never does this under WOT and once the engine warms up I dont really notice it either.

At first I thought it was the trans, but I have also noticed an unsteady idle. When sitting at a stop light it bounces around 500-700. Sounds like I have a really agressive cam. As soon as it goes into park it idles a little high, 1000 or so but will soon start bouncing like I said earlier. After about a min it kicks up real high to 1200 or so and stays there until I give it a little gas, in which the previous process resumes.

No other problems noticed cruising in OD or really anywhere over 45.

WTF is going on?

I do have an intermittent CEL but I havent seen it in a while. My code puller is broken and I suck at it anyways so if you guys dont ahve any better ideas I may take it to a shop and have them pull em.

 

[Rhett]

Vacuum leaks can cause that to happen. Was it doing it before you flushed the rad/block? Maybe you have a plug wire arcing?

 

[sn0border88]

no, nothing was wrong before the flush. In fact it wasnt until I did the cleaning a few days later that i noticed this, I must of left a vacume line off then. Any idea where to look.

 

[KPT]

You can get the codes off an OBD1 with a paperclip. Connect the single wire on the diag connector (next to the fuse box) to one of the connectors on the bigger plug. If I'm remembering right, its the furthest one on the right top of the smaller end of the plug.

 

[sn0border88]

My code puller is broken and I suck at it anyways so...

I say again... I tried it a few times and never got any better at it. Im morse code challenged.

So no one has an idea?

Can a mod please post this is the 911 or 1991-4 forums.

 

[Bigcheck1]

check the cam position sensor. It may have gotten wet when you removed the radiator. Sounds like something may not be connected, wet, or loose. I know that engine like the back of my hand. let me know if you need any help.

 

[sn0border88]

and the cam position sensor is...

 

[Bigcheck1]

front of engine, underneath, right by the crank pulley if I remember correctly.

 

[jimbo74]

sounds to me like a tps or a maf issue