Problems after Isolator bolt fix

I did not have the CEL on ( 2000 Windstar, 3.8 ) but since it was pinging and I had poor gas milage I decided to do the Isolator bolt fix.

It went smooth. The lower intake manifold was filled with oil to the point I could not see the isolator bolts. Any way, I completed all the steps, and put the beast back together.

As soon as I started the engine, I noticed it was idling poorly; jumping from 400 rpm to 1300 rpm. A few days latter, the CEL came on. I get the infamous 171/174 codes.

What you suggest. Could it be a vacuum leak.

Thanks for your help

I also did the isolator bolt fix on my 2000 3.8. Like you, I didn't have a CEL - but lots of pinging.

Yes, it could be a vacuum leak. Are you sure the fittings on the back side of the manifold are firmly in place?

If you spend some hood-up time listening to the engine, can you hear any new, unfamiliar sounds? Hissing or whistling sounds are what we're hoping to find.

Normally the 171/174 together indicate an intake leak on both banks. As suggested by Phil-1 look for a loose or disconnected vacuum hose etc.

Are you confident that the rubber port seals were installed correctly upon reassembly? Perhaps you accidently knocked off a hose somewhere else.

There is the infamous 90 degree 1/4" nipple that blows off the intake every time you start the engine and it coughs just once.

It is in the middle of intake, in the front, there is a 180 deg bend of 1/8" black Tygon tubing connected to it.

When this pops off, your engine idle will oscillate noticeably when the engine is cold. This is a massive vacuum leak.

There is the infamous 90 degree 1/4" nipple that blows off the intake every time you start the engine and it coughs just once.

It is in the middle of intake, in the front, there is a 180 deg bend of 1/8" black Tygon tubing connected to it.

When this pops off, your engine idle will oscillate noticeably when the engine is cold. This is a massive vacuum leak.

Yep, thats the fuel pressure regulator vacuum stub. Found that one out the other day.:icon16: I did a DIY de-carbing service just before my oil change. Idled the van and sprayed carb cleaner thru the PCV and throttle body and sprayed thru the FPB stub. Took her for a spin and had the horrible RPM oscillation at idle. Got home. popped the hood and found I forgot to reconnect the FPR line to the intake!

Joel

Found the problem,

It was a vacuum hose that I didn't connect.

Man, what a difference. No ping, more power, more responsive.

It been years since the van worked this well.

Thanks