timing questions?

[adam g]

Ok my pulse adapter will be here tomoroe. After driving my 91 that I bought from Greg Pettit I realize how much of a dog mine is. I have some questions. First since I only have the pusle adapter and a timing light does any one else time this way?. My thinking is that i will compare the two trucks timing at idle and move my 89's pump accordingly. I see on many of the past posts that you guys are checking at many different rpm ranges. What is the reasoning? The 91's tach is screwy it will be difficult to check at other rpms. The 91 has an ats turbo on it, it will hit 10 psi in a hurry stays under 800 degrees and smokes pretty good. It also has a 5spd. The 89 has a hypermax turbo and will struggle to see 8 psi gets up to 1100 degrees in a hurry and has very little smoke. It is an automatic. Both turbos are non wastegated but I would expect the 89 to run just as good. I see the 0 mark on the timing plate were should I set my advance on the timing light to aim to hit this?

 

[punkmechanic]

I just used a pulse adapter to check mine (that is all we have at the dealership). All the "oldtimer" techs agreed that mine should be at 9 degrees advanced. I still think it needs to go a bit more but I need to get a new pyro and replace the pump and injectors first, then Im gonna start messing with timing.

I would be careful with your timing too. you need to make sure the engine is up to it before going crazy with the timing, It will likely take awhile to do real damage, but if you have a ton of miles and an injector with a bad pattern it could turn bad quick.

just my thoughts

 

[Brimmstone]

I have a pulse unit and a lumy probe but to be honest the pulse unit doesn't get used much. I time mine with the lumy probe at 2 degrees after and it runs perfect.

 

[tradergem]

If I remember correctly the timing should be 8.5* BTDC at 2000 rpm when using a pulse adapter and timing light. You line up the timing mark on the dampner with the 0* mark on the timing plate with the timing light and then look at the degrees on the meter to see how advanced or retarded the timing is.
Jim

 

[RLDSL]

The official spec is 8.5 deg btdc @ 2000 rpms. It may run better a bit more advanced than that , up to about 1.5 deg more. Start at spec and if you have time, play with it a bit.

 

[Diesel JD]

Brimmstone is that 2* ATDC at 1400 or 2000 rpm?

 

[Agnem]

1400 for an ATDC lumy reading. Using the pulse adapter, you always set at 2000.

I see on many of the past posts that you guys are checking at many different rpm ranges. What is the reasoning?

Can't say I've noticed those posts. If you do a lot of timing, you can start to recognize patterns. For instance, I can often tell at idle if a truck is going to be advanced or retarded, but I still have to run it up to 2K to be sure using the pulse method.

 

[adam g]

Thanks guys for the timing advice. I was at 4 deg btc. bumped it up to 8.5. Didn't make a huge difference. I did notice a little more smoke. Started a new cold air intake. But it looks like the old stock hypermax down pipe has to go. 2.5 inches is just not enough.

 

[Agnem]

It should have. I've had guys get excited over a 2 degree advancement. Sounds likely your injectors are worn out.

 

[Brimmstone]

Brimmstone is that 2* ATDC at 1400 or 2000 rpm?

I'm probably set wrong but I have it set at 2* ATDC at 750 RPM. It runs like a bat out of hell and pulls like a freight train. My old pump finally took a dump after a friend borrowed it and ran it out of fuel completely gaulding the pump. I put one on from a 91 7.3 N/A truck that was a stick also and got the old beast up and running for now. I'll get a new pump for it soon but for now it runs. To be honest I'm sure my timing isn't right anyways as all my injectors are about done also. The truck has well over 200k on the original injectors.

 

[jtate]

brimmstone what type of luminosity probe timing meter do you have? the reason im asking is i have a snap-on mt1480 lumi/mag meter that im not to famillar with. i tried setting my timing to 2* also but dont know if its supposed to read -2.0 or just 2.0 to be atdc. if someone can clear this up for me that would be great. right now i have it set at 2* and the pump is rotated all the way to the passenger side as far as it will go.

 

[Brimmstone]

I have the MT480. If I remember right it should be just 2.0 on the display. One of the reasons I love the MT480 so much is it is simple. I personally feel that your gear is off a tooth some how. I went through a bunch of grief with mine because my helper took the entire chunk off my engine. We are talking pump, cover, and gear. I told him to go home and I would think about not killing him the next day. As to your engine I would take and remove the advance wire from the pump and use a jump lead to trigger the advance with it running. If the timing is incorrect you'll hear the powerstroke rattle. Trust me if you have never heard this you will understand what it means immediately if you're at 2* ATDC. Again I feel that your gear is a tooth out of position. I only needed to move my pump a little past the mark to get it in spec.