I have an 89 Dakota, 3.9 fuel injected and it has a weird problem. I twill start just fine in the morning when it is cold, it will start just fine when it's warmed up, but for some reason if it sits there for 10 hours when I'm at work, it doesn't want to start. It acts like it's flooded. How can a fuel injected vehicle get flooded? The other day my battery was almost drained from cranking. It finally started when I held it to the floor. I haven't had this truck long and I have other stuff to drive, I'm just looking for brainstorming right now and to learn about the fuel system on it. I'm not that good at working on fuel injection. The PO said the fuel tends to siphon back into the tank when it sits. Things are not adding up to me with this issue.

 

Holding the pedal on the floor will put the PCM into 'clear flood' mode, and it dramatically dials back on how much fuel it feeds. I would be tempted to plug in with a scanner that can read live data, and see what the PCM thinks engine temp is when it doesn't want to start, and compare that to actual temp.

 

I keep thinking it's a temp related problem too. It's almost like it doesn't want to fire up when the truck is luke warm. During these days the weather was warming up to around 40 degrees, when I crank it in the morning it was near freezing. I did read in wiki these Dakotas do siphon fuel back into the tank when the truck sits and they updated the pump around 1992 or something. I'd be interested in a fuel pump swap just because. But yeah, your info adds up becuase the other day it didn't want to start after work, so I held it to the floor and it finally fired, as soon as it smoothed out I took off just for it to die in traffic before it warmed up, then it was very stubborn. So if it is the PCM getting the wrong temp reading, what can I do? I'm not against throwing money at it to replace sensors until it's mostly new, I'd rather know what I have than to break down. The PO gave me some receipts because he was already throwing parts at it, let me check and see what is new.

 

Alright, so we have....New Plugs 7/17/2014, Computer Balancing at Ford Country 9/25/2013 (What is that? A reset?), Oh, a new fuel pump at Napa Part# P74082 4/18/2013, Fuel Vapor Hose on Supply line replaced 2/21/2013 138K miles, Fast idle solenoid replaced 10/27/2011, New passenger side Fuel Injector 10/17/2011, and that's pretty much it. When I replaced the exhaust on the truck the O2 sensor looked new. These dates are old, but it only has another 17K miles since the time of the work so I will rule out these things, not that any of it helps me with this issue. So if I were to start throwing money at it, mainly sensors, what would I be replacing? Like I say, I think sometimes it better to have a 'Fresh Start'. I don't have a code reader, I still need to get a repair manual, I might do that today. Is there a way I can pull up codes withut a code reader? Like the 3 times ignition switch trick or anything like that?

 

Computer Balancing would probably be the wheels and tires.

Fuel Pump may still be failing with age; if these vehicles aren't run enough, they'll have problems due to rotting from sitting still.

The repair manual you should have is the Factory Service Manual; it was printed by Bishko for Chrysler Corp, and you can sometimes find them on Ebay. (You may notice you don't drive a Chilton Dakota or a Haynes Dakota, but a Dodge Dakota ... )

And yes, the ignition switch key dance will kick out the codes.

As to your original problem - I'll lay even odds it's due to leakage of an injector flooding the intake when it's just warm enough, and overnight the gas evaporates.

(The other thing I'd definately check would be all vacuum lines in case something's opening when warm.)

RwP

 

Yep, I'm thinking I'll have to spend more time on this think than I wanted. I'm gonna start by cleaning connections and replacing a few cheap sensors, tune up, vacuum hoses, the leaky fuel injector was a theory I beat around too. This is why I stick to carburetors. Clean em every 3-5 years and they work just fine. I think for the time being I'll just carry around a can of ether, that should keep me from getting stranded anyway.

 

Yep, I'm thinking I'll have to spend more time on this think than I wanted. I'm gonna start by cleaning connections and replacing a few cheap sensors, tune up, vacuum hoses, the leaky fuel injector was a theory I beat around too. This is why I stick to carburetors. Clean em every 3-5 years and they work just fine. I think for the time being I'll just carry around a can of ether, that should keep me from getting stranded anyway. I only bought this thing for when it snows, I wouldn't mind doing a solid axle swap later if things aren't to beat up on it.

 

Alright, so went and did some checking and cleaning. I found one small vacuum hose that didn't effect much for the heater coolant unit. Then I used the ignition method to pull up the codes and got 12, 22, 55. So I'm off to buy a Temp Coolant Sensor. Hopefully that solves it for now.

 

It's fixed. The Temp Sensor was in sorry shape and it was low on water. I replaced it, filled it back up and it fires up great. Maybe it won't go to the wrecking yard for a while longer.....

 

Gotta love the easy ones. (well, 'easy' in a very relative way......)