Hi guys, just some quick info about my truck, then issues I've been having.

1993 Dodge Dakota sport
3.9 V6
Manual transmission
2WD

I'm posting these together because I think they're related.

1st issue:
When the truck is under load (accelerating) it has a loss of power from around 1600-2400 RPM. Occasionally this will be accompanied by a *thunkathunk* sound coming from the engine. Engine idles fine, revs up normally when stopped. It just doesn't have the same oomph as before.

2nd issue:
My truck won't start when it's cold, it turns over fine, sometimes acts like it wants to start, but doesn't. It's only been doing this since winter came around.

Is this a fuel pump/sending unit/pressure issue?

I've replaced the fuel filter recently.
Codes it is throwing are 12 and 55, which, from what I've read, don't help much.

Sorry about the diatribe, any and all thoughtful input is appreciated!!!!

Let me know what other answers I can provide and I will be glad to answer to help solve this problem!

 

When was the last tune up?

 

Sure sounds like the notorious intake plenum gasket. It needs to be replaced. Check inside the throttle body for oil at the bottom of the intake. If so your gasket needs to be replaced.

 

A few weeks ago when I started having this starting issue. I put new plugs and wires on, along with the fuel filter. I threw some parts at the problem hoping to solve it. It needed it anyways.

 

I will be sure to check that tonight.

Just curious, why would it affect performance that way? Gumming up sensors? Air not flowing correctly?

 

Check here for details.
https://dodgeforum.com/forum/2nd-gen...um-thread.html

 

Wow, that's A LOT to go through, but from what I gathered through that thread and the plenum picture thread, I don't have a blown gasket.

I took a peek through the throttle body and I don't have any pooling of oil, only slight amounts of residual oil lining areas.

I was fiddling around with my PCV valve and the hose connecting it has a crack in it, once I find out where to get that hose I will replace it, along with the PCV valve.

 

Ok, update time.

I've checked my fusible links, and sure enough, they weren't connected in several areas, so I reconnected, and taped everything up again. No luck, still not starting.

Today was a little warmer, and sure enough, she started up.

So I got my fuel pressure tester on, with the engine running and with the vacuum line on the fuel pressure regulator off/on it ran at about 29 psi, give or take.

When I turned off the engine, the pressure slowly climbed up to about 40. Is this normal?

 

I would think a rise in pressure when you turn it off would be normal because the injector, either TB or direct, shut off and the pump is doing its job, but I havnt read F.P. so I dont know for sure.

When my CPU temperature sensor was defective on the 5.2 94, ( never had a cold start problem with the 89 3.9), it was a starting nightmare and it would code nothing some times. Once I changed it the problems went away. It actually starts better than it ever did. Since no codes came up constantly I put a small heater under the hood overnight. Next morning it started fine, that combined with help from Crazy got me to the diagnosis of a temp. sensor problem. If you do change the sensor be very careful unplugging the lead. Mine was trash and as soon as I touched it it went to pieces. I don't know where this sensor is on the 3.9, check facs for location.