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6.5 fishbite

Messages
16
Likes
1
Location
Sweden
Thread starter #1
Hi!
I have a 95 6.5td with 7500miles and have a fishbite problem.
Moster happen at highway speeds, but i have 3 Times hard a exhaust poof while ideling.
Things changed/deleted
New Relocated pmd w. Extension. Also new harness from pump.
Op filter removed
New batteriets
New ignition switch
No air in fuel Checked at return line
New lp and relay mod
Cleaned tank and removed sock.
Cleaned all grounds i could find and added a copper ground eng-frame.
~1-2psi at WOT fuel pressure.
No codes, accept a recently 58, High temp transmission. I have Checked with gmtdscan and The temp jumps up to around 150c for a mili second and tend to stay at 150 when shift lever is in reverse.
I think i have almost change everything i have been told. Only Things i could think its left is either the Pcm or IP...
 

Will L.

Well-Known Member
Messages
7,826
Likes
6,859
Location
Boulder City Nv
#2
Fuel quality/ contamination?

Drain 1/2 liter into glass container. Smell and ensure diesel only- no petro. Let it sit for an hour then see if anything has settled in the bottom or a thin amount at top. Water on bottom will look like Little bubbles.

Test cps and optic sensor by unplugging the cps then start truck. It will be harder to start but should start. If it starts plug it back in and unplug the optic sensor. Try starting same results should occur. If it starts both ways they are both working.

The 1-2psi at wot- is this traveling up a hill? If just sitting still it is toast. Fuel consumption is vastly higher under a load than sitting in nuetral or park.
It should be no lower than 9psi btw. A momentary flutter down to 1-2 psi when you first stomp the pedal is ok, but not sustained. If it is driving up a hill, full throttle, and sustained 1-2 psi that is most likely your problem.
9-14 psi desired.
 
Messages
16
Likes
1
Location
Sweden
Thread starter #3
Fuel quality/ contamination?

Drain 1/2 liter into glass container. Smell and ensure diesel only- no petro. Let it sit for an hour then see if anything has settled in the bottom or a thin amount at top. Water on bottom will look like Little bubbles.

Test cps and optic sensor by unplugging the cps then start truck. It will be harder to start but should start. If it starts plug it back in and unplug the optic sensor. Try starting same results should occur. If it starts both ways they are both working.

The 1-2psi at wot- is this traveling up a hill? If just sitting still it is toast. Fuel consumption is vastly higher under a load than sitting in nuetral or park.
It should be no lower than 9psi btw.
momentary flutter down to 1-2 psi when you first stomp the pedal is ok, but not sustained. If it is driving up a hill, full throttle, and sustained 1-2 psi that is most likely your problem.
9-14 psi desired.
Only clean dieselfuel. And this has been going on for aboute a year and have tried diesel from other stations too.
The sensors are working.
The pressure is at uphill, highway its around 8-9psi
 

SnowDrift

Radical Right Wing Extremist
Messages
1,842
Likes
448
Location
Central Ohio map dot
#5
There's some sort of little electronic filter up by the injection pump that has been known to cause this symptom, too, but I can't recall what it is. Someone on here will know, for sure. I had this on my '95 and it didn't return after I replaced the part.
 
Messages
16
Likes
1
Location
Sweden
Thread starter #8
Sounds to me like you need a scanner to monitor it while driving. Might have an intermittent connection giving you grief.
The scanner doesn't show anything strange, closuretime stays at 1,82 ms. And fuel mm2 too.
There's some sort of little electronic filter up by the injection pump that has been known to cause this symptom, too, but I can't recall what it is. Someone on here will know, for sure. I had this on my '95 and it didn't return after I replaced the part.
Thanks for that but as I wrote in The first post the OS filter is removed
 
Messages
12,959
Likes
3,036
Location
alaska
#12
I ended up replacing the CPS on a truck that showed no missed counts on a scanner. Fixed it right up. It did run smooth when I unplugged it and had it running on the OS. It had more than a fish bite tho
 
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