Carbon buildup/issues

[83kid]

Hi,
So i have an 83 k10, with what i believe is a '90 350, mated to a 700r4 to np208 with what i believe are probbly 3.55's or something similar for the axle gear ratio
The 350 has about 40k on the rebuild, mild comp cams cam, i can provide link if necessary, msd ignition, headers, and a 600cfm edelbrock 1406

Problem i wAs having where it would diesel when i shut it off, so i was told run the highest pump gas, 93, and that fixed it. A wicked smart guy at my work told me to, and his theory is that theres a lot of carbon in the combustion chamber.
When i floor it, the engine revs up to about 2000-2500 rpms, and thats it. I dont usually use overdrive, because when i keep it floored till im doing about 70 its only at 3000, maybe a little more. It keeps climbing ince in third gear, but just goes slowly as your speed climbs.
Ill put it in 1st on the clolumn, and floor it, and it went up to 2500, thats it.

Why might this be?
I know my kickdown cableprobably isnt adjusted right, but i put it in first and floord it, so the kickdown shouldnt matter for that..
I have a fuel treatment, ring free, that supposdly will work well, so im going to do a shock treatment next time i fill up to rid myself of the carbon... Just why is this occuring? And my engine revs up in neutral to whatever you want it too, just hardly anything while driving..
Ideas?

 

[firebane]

What do your plugs look like and gapped at?
What is your timing set at?

Both of those can cause what is happening.

 

[83kid]

Havent checked plugs but theyre within the last couple thousand miles new, timing is right i think..
Theres the toothed piece, where to the very left of the toothed piece is says 0 degrees, then there a red slider which it looks like someone screwed on thats over to the right of that, around the place 10 or 12 might be.. Not sure really, just know it was like 3 or 4 tooths to the right
So would to the right be atdc, and left be btdc, or the opposite?
My shop teacher at school thought that, so if we ignored where the toothed metal piece said 0 was, we went to the right where the redmetal piece was pointing and assumed that was 0, i had currently been at about 14 degrees to the left of that ( these directions Are all relative to standing infront of the truck). So, i adjusted the timing so it was at about 8 degrees to the left of the red pointer. Ran like ****, stepped on it and itd hardly do anything, so i brought it back to whatever it wS befoere and runs much better..

So should i follow 0 on the teeth, or assume the red pointer is 0? What is the red pointer?
And, i only believe the motors out of a 90 truck because it hs the front core support and grill off a 90, and the 700r4 wasnt produced in 83... So it couls be a crate motor, or a 90..


Also, motor hardly reva up above 3 grand... So imo carbon isnt doubted

 

[firebane]

Havent checked plugs but theyre within the last couple thousand miles new, timing is right i think..
Theres the toothed piece, where to the very left of the toothed piece is says 0 degrees, then there a red slider which it looks like someone screwed on thats over to the right of that, around the place 10 or 12 might be.. Not sure really, just know it was like 3 or 4 tooths to the right
So would to the right be atdc, and left be btdc, or the opposite?
My shop teacher at school thought that, so if we ignored where the toothed metal piece said 0 was, we went to the right where the redmetal piece was pointing and assumed that was 0, i had currently been at about 14 degrees to the left of that ( these directions Are all relative to standing infront of the truck). So, i adjusted the timing so it was at about 8 degrees to the left of the red pointer. Ran like ****, stepped on it and itd hardly do anything, so i brought it back to whatever it wS befoere and runs much better..

So should i follow 0 on the teeth, or assume the red pointer is 0? What is the red pointer?
And, i only believe the motors out of a 90 truck because it hs the front core support and grill off a 90, and the 700r4 wasnt produced in 83... So it couls be a crate motor, or a 90..


Also, motor hardly reva up above 3 grand... So imo carbon isnt doubted

It sounds like you really need to figure out your timing tab to harmonic balancer to make sure everything is 100% in sync.

Also carbon buildup would not prevent a engine from revving to a point then dying; I would wager on improperly gapped plugs, a bad distributor, or timing off somewhere.

To give you an idea my truck with plugs gapped at 0.030 would not rev above 2500 rpm but when I re-gapped to .045 it ran awesome.

 

[kleedus]

is the 90 350 still tbi if so you need to unplug a tan wire set timing to 0 and then plug the wire back together. the computer does the timing on a tbi engine.

if it is still tbi it would be a conversion on the 83 hard telling how it was done to say where the tan wire is located now.

 

[Georgeb]

Just a thought but if there is a problem with the ESC module or the knock sensor it could be retarding the timing because it thinks it's preigniting.... Pretty sure it can be bypassed to rule it out.

Can you te us how much of the tbi system is there i.e. O2 sensor, themp sensor on the intake, egr valve (positive or negative pressure) what distributer/coil. Is there an ESC module.
Also, dieseling can also be traced back to running rich. What is in it for a thermostat? You need a 195 deg and should be running around 190 or 200 degrees.