Setting distributor timing without $$$$ scan tool? 1999 5.7 Suburban

[TylerZ281500]

base timing HAS to be set with a scanner or somethign that can read it. guessing might have "done the job" and sure the truck can accommodate to some extent some retard and advance to get timing where it needs to be a tthe +/- 2* setting. you may have gotten very lucky, otherwise suggesting stabbing it, regradless if it worked for you is a poor suggestion. The app is a great tool as suggested.

 

[kennythewelder]

I watched a YouTube video with a guy that cut inspection holes in a cap to use to set the distributor. When the spark was vertical it was within spec and didn't throw the code. When the distributor was a few degrees off, the code was set and check engine light would come on (the spark could be seen to be at an angle).

I'm thinking you may be wrong kenny.

I'd think you could line it up spot on 10+ times doing it the way you did.

I'd like to know what's right, I've read that the ecm would learn and I've read it has to be set. I've figured it had to be set and the learning may be some other vehicle that someone has introduced into gmt400 mythology.

I'm not saying that the timing can not be off if the distributor is not in the correct position ( rotor pointing to #1 plug wire on TDC compression stroke) But it is hard to believe that I got lucky enough to get mine stabed that many times in the exact correct spot by lining up my engine on TDC compression stroke and rotor pointing to #1 plug wire. I never pre marked anything. I just lined up my engine to TDC and stabbed the distributor with the rotor set to #1 plug wire each time.

 

[TylerZ281500]

mine started first fire 30* retarded, it ran, drove it around, knew it wasnt right, got it back to 0. without a timing light on the older stuff or a scanner for everything newer it may run, but it may not be within spec, as far as a CEL you could be within the computers tolerances to adjust it but it still doesnt mean its right. Hell i can line everything up and put the distributor in just about anything and itll fire, but its still requires further attention. id be skeptical that you are that good at it, because even the best of the best dont trust just plucking it in there.

 

[kennythewelder]

You guys can believe whatever you want, I know what I did, and what worked for me.

 

[Dr.Zoom]

I believe you.

I'm curious to understand exactly how it works. I'll spend some time learning about it eventually.

 

[Black_cirrus]

While I've never pulled a vortec distributor, I've seen several times and know 2 more who I'd trust that if you mark and drop it back in it will run in fact a few times I know its been checked and dead on. I have a knack of real close or 180 out but most of my distributors have been 4 cyl. or not the obd II type. I'd say the main reason for the scan tool off set on the vortec is cam sensor alignment for injector pulse and the main need for that is idle emissions.

 

[kennythewelder]

You must be registered for see images attach

I just walked outside into my shed, and took this pic. You can see the distributor that I ground the gears off of, so I can turn the oil pump shaft. The shaft gets out of alignment easy when pulling the distributor. With no teeth to mesh with the cam shaft, you can turn the oil pump shaft if it is out of alignment so the rotor can be pointed to #1 on the cap. One of these is the one that was in the truck when I bought it (the one with the broken off ears) the other distributor is one I got from the salvage yard to replace the one with the broken ears. The box is the billet that is in the truck now, but the truck would not run with the cam sensor it came with. The truck would start, but stalled on acceleration bad. The thought crossed my mind one day that I might be able to swap the cam sensors. No go, but after looking closely I could see that if I removed the roll pins I could just swap out everything. So I did that, and did the swap. The billet has been in my truck ever sense ( several years). Like I have said repeatedly, I never had to set the timing with a scan tool. Had the timing been off, I still have an old school timing light, and I would have just used that. I did not even need to time it with the light. I guess I got it close enough by pointing the rotor @ #1 that the ECM made the final adjustments.

 

[redfishsc]

Guys, I need to validate Kenny here. It is most definitely possible to manually reset the distributor, have a perfectly fine running truck, and throw no codes. I just did it, and if i can do it, it's doable lol.

Although he may have a slight misalignment on his timing that he's not aware of, and probably doesn't matter.

I followed the instructions on the link below. Worked PERFECTLY. I was a little nervous when I started it up, but it only sputtered momentarily (guessing because the fuel injection hadn't primed up evenly) and purred like a kitten.

It *might* idle a touch rougher than before, but it still idles more gentle than my 2003 Deville. I've had it up to 60mph so far and I'm not throwing any codes except the same old EVAP code that doesn't even trigger the CIL.

Now, regarding the cam CMP retard. I found an app that will read it on my Android. I already had a bluetooth OBDII reader (which I recommend you ALL get). The app is Car Gauge Pro. It will actually read the CMP retard, the app is $9, and is a massive pain in the ass to navigate and figure out where to find the CMP PID file. But it's in there.

Turns out, the way I set mine, it was at 4.5 degrees instead of the -2 to 2. I might go adjust it some time this week to see if it evens up the idle, but I won't be in any hurry.

I imagine if Kenny tried this on his truck, he'd find his CMP offset about the same, off by just a hair.

So yes it's entirely possible to reset the distributor.

Here's the instructions I followed. Basic stuff. The only snag I ran into was that the flat slot down near the oil pump was misaligned, and I couldn't get the distributor to seat fully..... but I used a long screwdriver to twist it into position.

http://www.gmtruckcentral.com/articles/distributor.html

 

[east302]

Which CMP retard did you use...cmp retard * or cmp retard **?

I get different values for both with CarGauge Pro. But, DashCommand also has two choices that don't use the asterisk and give the same value.

CarGauge Pro:

You must be registered for see images attach

DashCommand

You must be registered for see images attach

The two PIDs for DashCommand appear to be the same and match the two asterisk PID for CarGauge Pro. I'm not sure what the difference is, though.


Sent from my iPhone using Tapatalk

 

[kennythewelder]

Guys, I need to validate Kenny here. It is most definitely possible to manually reset the distributor, have a perfectly fine running truck, and throw no codes. I just did it, and if i can do it, it's doable lol.

Although he may have a slight misalignment on his timing that he's not aware of, and probably doesn't matter.

I followed the instructions on the link below. Worked PERFECTLY. I was a little nervous when I started it up, but it only sputtered momentarily (guessing because the fuel injection hadn't primed up evenly) and purred like a kitten.

It *might* idle a touch rougher than before, but it still idles more gentle than my 2003 Deville. I've had it up to 60mph so far and I'm not throwing any codes except the same old EVAP code that doesn't even trigger the CIL.

Now, regarding the cam CMP retard. I found an app that will read it on my Android. I already had a bluetooth OBDII reader (which I recommend you ALL get). The app is Car Gauge Pro. It will actually read the CMP retard, the app is $9, and is a massive pain in the ass to navigate and figure out where to find the CMP PID file. But it's in there.

Turns out, the way I set mine, it was at 4.5 degrees instead of the -2 to 2. I might go adjust it some time this week to see if it evens up the idle, but I won't be in any hurry.

I imagine if Kenny tried this on his truck, he'd find his CMP offset about the same, off by just a hair.

So yes it's entirely possible to reset the distributor.

Here's the instructions I followed. Basic stuff. The only snag I ran into was that the flat slot down near the oil pump was misaligned, and I couldn't get the distributor to seat fully..... but I used a long screwdriver to twist it into position.

http://www.gmtruckcentral.com/articles/distributor.html

TY.