Engine/Transmission (1994 - 1998) Timing for towing???

[USMCBay]

What timing advance is best for heavy towing.



With my 4k GSK it is a bit touchy already... just a touch of the throttle advances it through each gear to full RPM without "gassing" it. You have to get used to it. I wouldn't want a stranger driving it...



I want to advance the timing... I'm considering 15*° or 15. 5°



What is the physical effect of advancing the timing other than "more power"?

Will it make the throttle more touchy?



I'm not trying to snap a weak link - I just like the power when towing empty or if I need to GO. :-laf

 

[GAmes]

I don't think it gives you more power, but I'm sure you'll get better mileage. I have mine set at 15. 7 with a 3k gsk and I'm happy with it. The downside of advancing the timing is it raises the tq curve a bit so the engine lugs at a higher rpm than before. I need to keep at least 1900 rpm while towing or the engine just bogs down.



Your touchy throttle may be from a broken (or weak) throttle return spring. If you want to go cheap, NAPA has a good variety of replacement springs. If you want Cummins (and have a strong heart) get a throttle spring from the Jacobs exhaust brake.

 

[Vaughn MacKenzie]

Unless you're using the truck for competition switch out to the 3K GSK. . . that will really cut the touchy throttle issue. A 3GSK works great and gives plenty of RPM.

As for timing it won't make your truck any more touchy but I always say shoot for 15. 75 degrees +/- a couple tenths.

 

[EKlem]

The higher the rpm you run, the more advanced your timing needs to be in a very generalized sense. For this reason, advancing your timing hurts your bottom end but helps your top end. The other thing about timing is that greatly advanced timing will increase your cylinder pressure too much so that you blow your headgasket. A pretty happy compromise seems to be 15. 5 degrees or so, the truck will still start well and you won't loose too much bottom end but you will get better fuel economy and more top end.

Also, I agree with Vaughn's comment that if you aren't going to the pulls or drags, a 3k gsk would be more streetable.

 

[USMCBay]

Yea... I think I am going to yank out the 4GSK springs. To be honest I would never get RPM's that high anyway so not sure why I put them in anyway.



I've had some say 17° is okay at stock bolts and gasket... but I wouldn't want to loose my bottom end anyway for towing.

 

[FordCummins]

Before you go pulling them out, try loosening each set of springs 1 or 2 "clicks". This should improve the driveability in terms of "touchyness".

 

[USMCBay]

Before you go pulling them out, try loosening each set of springs 1 or 2 "clicks". This should improve the driveability in terms of "touchyness".

Well now that makes sense because when I installed the 3K's I went . 06 back to where they were when I pulled them... Then... when I ordered the 4k's I read some post that said they need to be at . 075 or so.



It would make sense that I go back to . 06 to regain my original throttle response. It makes sense...



I will post the results but it may be next week.

 

[hsmith]

On mine with the 3k springs and a bit of timing I had a terrible surge at low rpms when towing. Noticed the return spring was broken. Problem solved. Now empty, I unhook it cause it is more fun to drive, more responsive. Snap it back on when I hook up the TT.

 

[USMCBay]

On mine with the 3k springs and a bit of timing I had a terrible surge at low rpms when towing. Noticed the return spring was broken. Problem solved. Now empty, I unhook it cause it is more fun to drive, more responsive. Snap it back on when I hook up the TT.

Call me crazy but... Snap what back on?

 

[hsmith]

The return spring that was broken and replaced.

 

[12V Ford]

I'm running the 4k's and they used to be touchy. I have them set on 1 hard click and it is better. Also when I put the 370's in, I had the springs tighter, and the rpm's would catch themselves when the idle returned, and loosening the springs to 1 click fixed that.



To me and my brother, it felt like I had more power with the 4ks because it reved so much better. I don't think I'd run more than 16* timing for towing and daily driving.

 

[USMCBay]

Yea... Micheal from Hot Rod Diesel suggested 15° for my application. He will set it for $150 which is worth my time and the tools for sure would pass that!



There is something to be said for convenience...



I will turn my GSK back 1 click - try it... I may go another click - try it. Then I should know to go back a click or leave it. I really need to fine tune the D%^& thing. I haven't done that. I really wonder what turning my diaphram screw (fuel screw?) in the back did. I turned it in til it touched and backed off about half a turn.



I may need to tinker with it more and slide my AFC and Plate around... well I don't really have any problems... will probably leave it full forward. I may Grind my AFC foot this weekend - is that right?