what is the correct timing specs for 1991 7.3 idi non turbo. my ferret is coming in today and i am going to time it but i've read that 8.5 btdc isn't as good as closer to 9 with the new fuel?? i read that 9.7 btdc is the best. can someone confirm or give me more information please and thank you!

 

I made several marks on my pump for different numbers. Try different timing settings and drive it. See what feels best to your behind and see what yields best MPG.

 

Like he said, best to play around with it and see where yours likes it best. But pretty sure spec is 8* +/- 1.5* NA usually likes to run about 9*, whearas turbos like it about 6.5*

 

remember engine must be fully warm and carfully held at 2000 RPM to see the timing. it cant be checked at idle...

 

Pretty much. All the numbers you'll fine are for 2K, unless otherwise specified.

You can use any given speed for reference, as long as you go to the same speed every time. And higher revs are better due to slightly more fueling, so 2K is a good number.

 

I timed it at 9.7. Gonna see how this is. I may end up going closer to 9*

Thank you all for the info I timed it At 2000 rpm

 

The 7.3L turbo should be 6.5 BTDC? I am still waiting for my Ferret tool to get here to see where my old injection pump is at before i swap it.

Does everyone with a turbo run 6.5? I was reading some at 8 and 9?

 

I have mine set at 6 even. I like it.

 

Like i said, stock spec is +/- 8*. That said, following turbo threads and other timing threads, the turbo'd engines seem to enjoy a little less timing.

 

I know that when I was troubleshooting my (turbo) engine, I pulled the intake cover off(so no turbo boost), while cold. It did /not/ want to rev very well, and smoked quite a bit, missing and sputtering. With the turbo hat on and air supply connected, it revved right up and was stable, no missing.

The extra heat from the turbo compressed air allows for a lot more retarded timing when cold, and seems to have the same effect when hot. Everything is hotter, so the fuel should vaporize better/faster, so the 'effective' timing is probably close to more advanced timing NA

 

that makes perfect sense! Mine doesnt smoke at all under any throttle or load so i am curious to see where my timing is and to see if i can get it to get better than 14mpg before i order a new injeciton pump and injectors

 

You may want to turn up the fuel screw then; that's your limiting factor at this point.

Messing with timing will definitely give you some different results power and efficiency wise, though.

 

its my understanding that the ip when stock, and not governor omit... the fuel pulls off and timing stabilizes when held at most any RPM.. however 2000 RPM, is where the engine does most of its work in light load driving where one would want max efficiency so setting timing at this rpm is recommended. when at max throttle, pulling a heavy load, I assume the timing falls back some, to compensate for high EGT, and cylinder temps, that can cause thermal advance in combustion. this may account for the turbo guys preferring a later timing.. that seems to allow for better boost #s as was mentioned, some fellas can hear the difference in timing.

 

I realize im super late to the party. I just replaced my IP and Injectors. I undsrstand what "BTDC" and "ATDC" stand for. But does that mean to the left and right of the 12:00 mark on the IP housing? Also, are the 8* and 9* that you are speaking of mean degrees? I was instructed to start at 1/16" to the retarded side of the 12:00 timing mark and that gets me to where there is no smoke and fires off evenly. My IP obviously leans to the passenger side. If i set it at 8* or 9*, assuming those are degrees, it would really lean to the passenger side and look really off. Is that ok? Do others have to lean their IP pretty hard? Im a little confused as to why they put the noon timing mark on new IP's and not the 10:00. Unless the 10:00 was done after the timing was done in the factory. It runs smooth but still feels like there is a misfire or a dead cylinder even after everything ive done. I also just purchased a Fox Valley ET 886 machine for 35.00. Works great. Just need to know how to set it and what i am looking for. I.E: do i set it for advance or offset? If so how much do i set it at? I think i may have an unresolved exhaust leak that is causing it to not have enough backpressure. I did split the 2 to 1 taillipe and refabricate it into dual straights. It also has a ram air intake instead of a turbo. I couldnt justify spending 1300.00+ for something that could cause a run away motor and only adds single digits to torque and speed. Didnt seem worth it to me especially after my factory heads pressure tested good after 3 decades and over 1 million miles. Any help would be great. Im still searching for a users manual for the fox valley but no dice yet. Thank you for any help someone may provide on this issue.

 

Ive asked people so far and no one can tell me what it stands for. What does the * stand for? Is that degrees? I bought a timing machine but not sure where to set it at because i dont know what the symbols y'all are using stand for. If that is degrees, then that would put my ip at a serious angle on the mounting housing.