Check the crank sensor harness - the older models have a silver cover (heat
shield conduit) that sometimes touches the starter connection and causes
starting issues (crank sensor voltage). Bumps in the road can cause the
problem to come and go at random.
On the fuel pressure, put a pressure gauge on the line and see if it falls
right away after the engine is turned off.
If you happen to have access to a scanner, watch the cam/crank sync when the
problem happens as well.
- Bernd
-----Original Message-----
From: Ned Buckmaster [mailto:Ned@Buckmaster.com]
Sent: Sunday, July 01, 2007 8:18 PM
To: dakota-truck@dakota-truck.net
Subject: DML: 2002 Dakota 4.7 hard start
I have a friend with a 2002 quad cab 4.7L 4x4 Dakota. For about 6 months
now, he has had intermittent starting problems with it. Sometimes, it will
start right up (like my 2K 4.7L 2x4 does all the time. Other times he has to
crank it for 10 to 20 seconds before it will slowly start to fire and then
start. It mostly happens after it sits for 5 or more minutes, but sometimes
it can sit for days and start right up. Once started, it runs fine, gets
good gas mileage, all is well. It has never shown any code on my code
reader. We tried Chevron Techtron injector cleaner first, and it seemed to
help for a few days. In fact, everything we do _seems_ to help for a few
days, then it goes back to not starting.
He took it to an independent mechanic, who measured the fuel pressure and
said the fuel pump was bad - and wanted hundreds of dollars to replace it.
We ordered one from RockAuto, and put it in about a month ago. It started
right up for a few days, then started doing the same thing.
we then installed new plugs and removed and cleaned the throttle body.
Installed a new PVC valve. Worked good for a day or two. At this point we
started swapping parts between his and my truck. IAT first - same thing.
Then the IAC valve - same thing. My truck still starts fine.
He plans to get a fuel pressure gauge, and see what it is reading when the
truck won't start. But since we have already replaced the pump, and there is
no filter or anything in the line, I can't see low fuel pressure being the
problem.
Anyone have a thought on what else could be going on with this truck? We are
running out of ideas.
Thanks,
Ned
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