89 Dakota -- runs like crap overnight

Hi,

I inherited my mom's 89 Dodge Dakota V6 with TBI. It hasn't been
maintained too well for a while, but neither has it been driven much.
It drove fine for about a month after I got it, being driven
occasionally. It did have an issue with very occasionally dying
immediately after starting. On the second start, it was always fine. I
figured it would go away with the tuneup I would give it soon. Then one
day when I went to drive it after it had sat for two days, it would
barely start, once started would bog badly, and die unless revved. When
it was driven, it would hesitate badly and then lurch forward, or die
as soon as it was in gear. The engine smelled rich. The engine only
smoothed out, a bit, at high RPMs (3000).

No codes in the computer. I replaced the air filter, plugs (quite
worn), cap, rotor, wires, coil. It ran less bad. I then replaced the
MAP sensor, since it seems to be a common issue, and also cleaned the
sensor contacts and the contacts in the computer on the fender. That
made no difference. It will start, no longer dies immediately, and will
idle rough. Still hesitates badly, and occasionally die in gear. The
power kicks in suddenly at a 1500 - 2000 RPM, and the truck lurches.

I'm next replacing the fuel filter, which is likely ten years old or
more. I plan to do the rest of the basics for maintenance to get it to
a good baseline. However, this happened overnight, indicating to me
that something failed overnight. I'm also going to pull the O2 sensor
to see if possibly the catalyst collapsed/clogged. Any other
suggestions for possible culprits?

Thanks.

Larry

 

IAC valve. just went through something similar. AutoZone carries them.

 

Thanks. However, did you have issues at RPMs above idle, and
hesitation/lurching? Unless this Dodge is different from other cars
I've worked on, the IAC is just a bypass valve to control idle when the
throttle is closed. My cheapo Haynes manual doesn't have a air flow
diagram. I believe that at open throttle, it should make no difference.
This engine runs rough at idle, and open throttle. It runs better at
higher RPMs, but still quite rough.

Larry

 

Naw, it's a blown hub cap gasket.

beekeep

 

Either that or it needs muffler bearings!

DJ