Rough Idle/Dies on Hot Startup '96 D1

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
I've had five more hot restarts and it's been fine. Luckily the replacement regulator came in a box of parts when I bought the truck.
 

96discoI

Well-known member
Feb 16, 2008
216
1
NorCal
of course it was in the parts box...sounds like the last owner got fed up like i do...i feel like i need to congratulate you as well as apologize for others sarcasm. It seems that there are many here who like to prove they are the epitome of intelligencia. You stuck with it and solved the problem without diving into the fracas of genius quips. You can find what you need here as long as you can search for 3 days first and then ask questions. Look for those who have shops and knowledge. happy rovering...
 

96discoI

Well-known member
Feb 16, 2008
216
1
NorCal
just for reasearch purposes for those of us in the future who need a quick diagnosis---- P0441 is the fuel pressure regulator causing a stall sputter problem.
 

p m

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Apr 19, 2004
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just for reasearch purposes for those of us in the future who need a quick diagnosis---- P0441 is the fuel pressure regulator causing a stall sputter problem.
I'm about to go on a limb and say it is not.
Meaning a bad pressure regulator can cause stall/sputter, but P0441 is an EVAP diagnostic code.
You may have had several things going together, but please be careful with generalizations.
 

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
I had been getting an intermittent P0441 code. My research had indicated that it could be an ECU issue as opposed to a genuine code. I would reset the code and continue on my way. It could be a coincidence. I'll see if that code reoccurs.

I'm in the midst of writing up a Tech article for the Fuel Regulator swap. It won't be terribly original as I'm copying the steps from RAVE and interjecting my own observations. I'll have it posted in the next few days.
 

p m

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Apr 19, 2004
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I saw that in your first post. Don't know if a permanently opened purge valve could cause poor idle - it probably could.

There may be some bizarre codes popping up every once in a while. My green truck pitches a P0420 - but only when one particular driver has the truck for more than a couple of days.
 

stu454

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Dec 15, 2004
5,407
61
Atlanta, GA
Well, shit.

I had a couple of rough restarts while warm this past weekend. I guess I'll check the plenum as noted in previous responses. I should probably ohm-out my replacement fuel temperature sensor and confirm that it's good.

In other news, I did get 13 mpg out of a tank this weekend.
 

Flyfish

Well-known member
Oct 29, 2004
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St. Louis
My old 96 D1 would die and not want to restart when hot. Turned out to be a short in the wiring to the fuel pump. FYI
 

stu454

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Dec 15, 2004
5,407
61
Atlanta, GA
I checked the butterfly going into the plenum. It wasn't dirty at all but I gave it a good wipe. There were no breaks or tears in the air pipe from the air box to the plenum. One of the clamps is broken, though. I suppose a new air box is in order.
 

latarheel

Well-known member
Oct 10, 2011
183
4
AZ
Stu,


Thanks for the research. I have a '96 D1 that does this in warm weather but never in cold. I installed a new temp sensor last summer with no resolution so will try the regulator now. If I let it cool down, it will eventually start but still a pita.
 

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
I swapped out the fuel temp sensor. I have not checked the coolant temp sensor.

The damned truck is almost twenty years old; I suppose I ought to change out sensors anyway.
 

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
Did you ever check the fuel temp sensor? While you're at check the coolant temp sensor too.

I just got a replacement coolant temperature sensor. I'll throw that at the problem before I drive out west this July.

If that's the problem, I'll send you $20 for a bottle/sixpack of your choice.
 

riceybean

Well-known member
Jun 29, 2008
861
0
Vancouver, WA
My old 96 D1 would die and not want to restart when hot. Turned out to be a short in the wiring to the fuel pump. FYI


Friend had this same issue(99D1), pulled the plug at the pump and it was burnt. Traced the wires back and found a short by the frame, fixed that and it has been fine.
 

jymmiejamz

Well-known member
Dec 5, 2004
6,010
362
35
Los Angeles, Ca
Instead of throwing parts at it, why don't you just pay someone to diagnose it? It will probably be cheaper and you'll know what the actual problem is. My first guess would be the shielding on the two wires going to the crank sensor are cracked causing a poor signal from the crank sensor to the ECU.
 

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
You springing for the difference when they roll snake eyes?

They did have a go at it about a year ago. They didn't figure it out. In two hours.
 

stu454

Well-known member
Dec 15, 2004
5,407
61
Atlanta, GA
I finally located the CkPS and inspected the wires. The jacket of both wires was damaged, I'm guessing from the exhaust heat. I did some cutting and splicing and buttoned it back up. One warm restart was good.

I'll see how it does over the next few days. I really hope that was the problem.