Hey all,

I purchased a 02 4.7L SLT 2 months back off of the original owner. 97k miles, dings and dents but overall good shape. He was getting rid of it because it hard starts and there is a strong odor of fuel accompanying the hard start. He told me 3 mechanics couldn't figure it out, so I did him a favor and took it off his hands.

I replaced the o2 sensors, and then did the spark plugs. While we were changing them, my wife noticed the #8 plug was damp and smelled like fuel, so we replaced the #8 injector (tested later, it was leaking) and the hard start issue was no more.

My current issues are thus: I have noticed that it idles low... like 500 low. It also idles a little rough. The idle was surging quite a bit as well, so I replaced the TPS which ended that problem, but it still idles low/rough. I am nervous it will stall, but it never has so I don't know if this is a normal idle speed? My old 92 dakota was around 700, so this is unusual for me.

The second issue is starting the vehicle up from cold, the accelerator is sluggish to respond and it kind of stutters. I have to press on the gas further than normal to get it to go... sometimes it hasn't responded until the pedal is half way down... Once it's warmed up it's fine, cruise control works fine etc. Any ideas? Thanks guys and gals

 

1) 500 RPM is the perfect idle for the 4.7l engine (in fact many v8s idle in the 500-600rpm range) when its warmed up, its where mine had always idled, although mine is nice and smooth so much so that some passengers think i shut it off when its still idling.

2) slow pedal response is one of two things weak trans engagement or a bad TPS.

if i were you i would start by checking the trans fluid since you already have a new TPS
keep in mind to do this when its at operating temp on a level ground, with the engine running and trans in nuetral

 

How long does it take the truck to warm up and have the pedal response return to normal?

 

It takes about 5 minutes for it to "warm up," so pretty quick I'd say.

I'll check the tranny fluid - previous owner never flushed it so that might be a place to start.

 

Thought about fuel pump?

That fixed my studdering in the AM/PM when the Durango had sat for more than 8 hours.

 

do NOT EVER FLUSH THE TRANSMISSION!!!!!!!!!!!! it will cause more problems than it solves (not immediately, but within a year or so you will be replacing the transmission)\

the correct procedure is to just drop the pan and change the fluid and filter

 

Really? Huh, I've never heard this... I always thought it was a good thing to do? If all I need to do is drop the pan, I'd be pretty excited as I hate paying to have a flush done.

Fuel pump could be possible. The pressure dropped after it warmed up... to I think around 40-45 IIRC. I figured most cars drop in pressure after they warm up so I didn't think it to be a big deal.

 

fuel pressure should be 48+/- 2 psi (basically 45-50, any less is not enough)

transmission flushes damage seals and push crap through the filter leaving it in the trans lines to wreak havoc before they have another chance to go through the filter. also make sure that you use ONLY ATF+4, this is all standard procedure on mopar transmissions, not sure about other brands but iw ould expect them to be the same.

 

My 4.7 in the Dakota idles at 500 but if yours is loping or not a smooth idle try cleaning the throttle body.
sharps is correct don't do a trans flush.

 

I hate to bump an old thread but I was browsing around (considering a CAI setup and some of those cheap RAM intake jobs look nice) and thought I should follow up as a courtesy.

I dropped the tranny pan and changed the 2 filters. No more stuttering. The old filter was clogged up pretty good so I am assuming since the problem went away and that's all I did (after the TPS), it was the filter. So THANKS. This forum has been an amazing resource and I've learned so much (and saved so much money) from my lurking.