1st gen NIGHTMARE!!
Administrator
Joined: Apr 2010
Posts: 87,479
Likes: 4,223
From: Clayton MI
I would say 'sorry', but, I'm not. 
Another member also posts from his phone, and some of his posts are truly cryptic. I have him a ration of grief as well. All in good fun.
Another member also posts from his phone, and some of his posts are truly cryptic. I have him a ration of grief as well. All in good fun.
Professional
Joined: Mar 2008
Posts: 162
Likes: 2
From: Fort Lewis
Your problem could be
Hello ladies and gents!
Got a good one for ya. 1993 Dak with the 3.9. Bought the truck a few months ago for my boy who just got out of the Marines. He loves this body style. Drove 100 miles to buy it and had no issues. Drove like a dream! Fast forward a few weeks. I tried to start it once a month till he.got back stateside. First time after purchase it started but ran real bad. Popping and backfiring through the throttle body and exhaust. Missing bad and will barely run. What the heck!?? It ran and drove amazing on the 100 miles trip home??
Prior owner replaced the fuel pump (it has 40+ PSI @ the rail). Water pump, timing set, NTK O2 sensor, gutted cat, belts, hoses etc etc. Checked dizzy and it is all good. Pulled intake and replaced all the gaskets. Replaced both coolant temp sensors. Replaced air intake sensor. Replaced MAP sensor, throttle position sensor, idle control valve and the ECM. Pulled #1 plug and brought it to TDC and checked dizzy timing again, all good!??? Replaced the fuel filter too just because. Replaced all vacuum hoses. Every once in a while it will start up and backfire a couple times then smooth out and run normal!?? Even had him pull the wiring harness down and check all solder joints and repaired.all of them including under the fuse box and both fuel injector solder joints.
We have pulled just about every hair from our heads. Totally lost at this point. The iac makes a loud hissing sound when it runs bad. Its quiet when it is running right?? Any ideas folks???
We have scoured the web endlessly without a hint to a solution.
Got a good one for ya. 1993 Dak with the 3.9. Bought the truck a few months ago for my boy who just got out of the Marines. He loves this body style. Drove 100 miles to buy it and had no issues. Drove like a dream! Fast forward a few weeks. I tried to start it once a month till he.got back stateside. First time after purchase it started but ran real bad. Popping and backfiring through the throttle body and exhaust. Missing bad and will barely run. What the heck!?? It ran and drove amazing on the 100 miles trip home??
Prior owner replaced the fuel pump (it has 40+ PSI @ the rail). Water pump, timing set, NTK O2 sensor, gutted cat, belts, hoses etc etc. Checked dizzy and it is all good. Pulled intake and replaced all the gaskets. Replaced both coolant temp sensors. Replaced air intake sensor. Replaced MAP sensor, throttle position sensor, idle control valve and the ECM. Pulled #1 plug and brought it to TDC and checked dizzy timing again, all good!??? Replaced the fuel filter too just because. Replaced all vacuum hoses. Every once in a while it will start up and backfire a couple times then smooth out and run normal!?? Even had him pull the wiring harness down and check all solder joints and repaired.all of them including under the fuse box and both fuel injector solder joints.
We have pulled just about every hair from our heads. Totally lost at this point. The iac makes a loud hissing sound when it runs bad. Its quiet when it is running right?? Any ideas folks???
We have scoured the web endlessly without a hint to a solution.
This is the only thing left other then the PCM that deals with timing of the engine.
Dudster
Champion
Joined: Sep 2013
Posts: 2,724
Likes: 153
This guy Larry on a different forum seems to have the manual method dialed in here is a 3 comment exchange in which he explains how to do it. I think Larry is retired now.Message:
They are all set the same
crank at TDC 0
rotor tab center over cyl line on pickup plat
is 0
with a degree wheel 3 degree's befor TDC center
rotor tab over cyl line +3
The way I do it I use no degree wheel TDC crank
looking from front of truck back edge of tab
with cyl line +3
you can do it either way
at 0 the injectors fire at TDC
at +3 they fire 3 degree's before TDC
With the hotter cam I am running and a 112 center
line over the 114 stock cam I am fireing mine at
+6
using this method and than checking with the snap
on MT2500 I always get within 1 degree of what I
am shooting for
If you go behond +8 it will trip a code
Larry
J&J Auto
Message:
Okay, so after I turn the crank over and line up 3 deg BTDC, the center of the distributor rotor should be in line with the distributor housing's "line" for cylinder #1?
That's +3 for fuel sync?
So then fuel sync +3 = 3 deg. BTDC?
Relf
Message:
you got it
the stock cam the intake valve opens 8 degree's
before top dead center and when this opens the
exhaust valve is also still open the scavaging
effect actualy when the exhaust is pulsing helps
pull the fuel charge into the cyl
The V6 all being a little diff run the best
between +3 and +6 the factory dealers are not
alowed to set the sync behond 0 for some reason
and your missing a lot of the scaviging effect
along with throttle response performance and gas
mileage at 0
What a bunch of knuckle heads hey
Larry
J&J Auto
They are all set the same
crank at TDC 0
rotor tab center over cyl line on pickup plat
is 0
with a degree wheel 3 degree's befor TDC center
rotor tab over cyl line +3
The way I do it I use no degree wheel TDC crank
looking from front of truck back edge of tab
with cyl line +3
you can do it either way
at 0 the injectors fire at TDC
at +3 they fire 3 degree's before TDC
With the hotter cam I am running and a 112 center
line over the 114 stock cam I am fireing mine at
+6
using this method and than checking with the snap
on MT2500 I always get within 1 degree of what I
am shooting for
If you go behond +8 it will trip a code
Larry
J&J Auto
Message:
Okay, so after I turn the crank over and line up 3 deg BTDC, the center of the distributor rotor should be in line with the distributor housing's "line" for cylinder #1?
That's +3 for fuel sync?
So then fuel sync +3 = 3 deg. BTDC?
Relf
Message:
you got it
the stock cam the intake valve opens 8 degree's
before top dead center and when this opens the
exhaust valve is also still open the scavaging
effect actualy when the exhaust is pulsing helps
pull the fuel charge into the cyl
The V6 all being a little diff run the best
between +3 and +6 the factory dealers are not
alowed to set the sync behond 0 for some reason
and your missing a lot of the scaviging effect
along with throttle response performance and gas
mileage at 0
What a bunch of knuckle heads hey
Larry
J&J Auto
Thread Starter
|
Registered User
Joined: Mar 2020
Posts: 15
Likes: 3
Well folks! Think we found the problem.
Was syncing the dizzy and could not get 5 volts! Got 1 volt max through my Fluke. Scratching head.... Happen to bump the harness where the cam sensor leads into the main harness, low and behold there is that 5 volts!
Pulled back the shielding and found a factory solder joint with three orange wires. The boy missed one! Kinda scary cause he was a helicopter mechanic!! 😂
Anyhow, he knew what to do and got that issue corrected. Truck runs great again! I made the boy do this on his own so he would get to know his truck. He learned alot and found that he hates wiring diagnostics lmao....
Thank you to all who pitched in and pointed us in the right direction. 👍👍
Was syncing the dizzy and could not get 5 volts! Got 1 volt max through my Fluke. Scratching head.... Happen to bump the harness where the cam sensor leads into the main harness, low and behold there is that 5 volts!
Pulled back the shielding and found a factory solder joint with three orange wires. The boy missed one! Kinda scary cause he was a helicopter mechanic!! 😂
Anyhow, he knew what to do and got that issue corrected. Truck runs great again! I made the boy do this on his own so he would get to know his truck. He learned alot and found that he hates wiring diagnostics lmao....
Thank you to all who pitched in and pointed us in the right direction. 👍👍
Grand Champion
Joined: May 2019
Posts: 5,158
Likes: 724
From: S.W. Indiana
Yep. I can herd cats too! I program the birds by feeding them all year. This keeps a healthy population. During the summer, when the skeeters get bad, I let the feeders run dry. After the birds scarf the mosquitoes down, I refill the feeders. I have barn swallows in the garage that chirp away while I'm in there but if someone comes in with me, they shut up. I even had a female Cardinal that would perch by me when I was filling the feeder. She even perched on my shoulder a few times when I was wearing a black jacket or shirt. The male would just sit about 20 feet away and give me dirty looks for messing with his woman.
Want to call your cat? Take your electric can opener outside and turn it on. Your kitty, and many others, will show up in no time.
Last edited by ol' grouch; Apr 3, 2020 at 07:07 PM. Reason: i kant spel wurth a durn.
Grand Champion
Joined: May 2019
Posts: 5,158
Likes: 724
From: S.W. Indiana
Well folks! Think we found the problem.
Was syncing the dizzy and could not get 5 volts! Got 1 volt max through my Fluke. Scratching head.... Happen to bump the harness where the cam sensor leads into the main harness, low and behold there is that 5 volts!
Pulled back the shielding and found a factory solder joint with three orange wires. The boy missed one! Kinda scary cause he was a helicopter mechanic!! 😂
Anyhow, he knew what to do and got that issue corrected. Truck runs great again! I made the boy do this on his own so he would get to know his truck. He learned alot and found that he hates wiring diagnostics lmao....
Thank you to all who pitched in and pointed us in the right direction. 👍👍
Was syncing the dizzy and could not get 5 volts! Got 1 volt max through my Fluke. Scratching head.... Happen to bump the harness where the cam sensor leads into the main harness, low and behold there is that 5 volts!
Pulled back the shielding and found a factory solder joint with three orange wires. The boy missed one! Kinda scary cause he was a helicopter mechanic!! 😂
Anyhow, he knew what to do and got that issue corrected. Truck runs great again! I made the boy do this on his own so he would get to know his truck. He learned alot and found that he hates wiring diagnostics lmao....
Thank you to all who pitched in and pointed us in the right direction. 👍👍
Helicopters are built to be maintained and repaired. Cars and trucks are designed to be fast, cheap and easy to build. Field service is an afterthought. I'm pretty sure the folks who design windshield wiper blades hate people.
I've got an old GMC I dragged out of a barn. It would warm up then start to run rich and die. I finally tracked it down to a $10 coolant sensor. It would tell the computer it was -40 degrees regardless of how warm the engine got. $10, 5 minutes and the problem is cured.
Champion
Joined: Jan 2013
Posts: 4,737
Likes: 374
From: Northwest Louisiana
I've got an old GMC I dragged out of a barn. It would warm up then start to run rich and die. I finally tracked it down to a $10 coolant sensor. It would tell the computer it was -40 degrees regardless of how warm the engine got. $10, 5 minutes and the problem is cured.
RwP
Administrator
Joined: Apr 2010
Posts: 87,479
Likes: 4,223
From: Clayton MI
Yep. I can herd cats too! I program the birds by feeding them all year. This keeps a healthy population. During the summer, when the skeeters get bad, I let the feeders run dry. After the birds scarf the mosquitoes down, I refill the feeders. I have barn swallows in the garage that chirp away while I'm in there but if someone comes in with me, they shut up. I even had a female Cardinal that would perch by me when I was filling the feeder. She even perched on my shoulder a few times when I was wearing a black jacket or shirt. The male would just sit about 20 feet away and give me dirty looks for messing with his woman.
Want to call your cat? Take your electric can opener outside and turn it on. Your kitty, and many others, will show up in no time.
Want to call your cat? Take your electric can opener outside and turn it on. Your kitty, and many others, will show up in no time.
Helicopters are built to be maintained and repaired. Cars and trucks are designed to be fast, cheap and easy to build. Field service is an afterthought. I'm pretty sure the folks who design windshield wiper blades hate people.
I've got an old GMC I dragged out of a barn. It would warm up then start to run rich and die. I finally tracked it down to a $10 coolant sensor. It would tell the computer it was -40 degrees regardless of how warm the engine got. $10, 5 minutes and the problem is cured.
I've got an old GMC I dragged out of a barn. It would warm up then start to run rich and die. I finally tracked it down to a $10 coolant sensor. It would tell the computer it was -40 degrees regardless of how warm the engine got. $10, 5 minutes and the problem is cured.
We never had a skeeter problem there. 