Timing ...help!! 94 k1500, 5.7, $OD, 7427

**axisT6** · 08-02-2016

I don't think it would hurt to replace the dizzy. Get a D.U.I. unit if you do. Also, what shape is your AC compressor in? I had false knock all over my spark map years ago and couldn't figure it out. Ended up being a bearing going out in my AC compressor. Took care of it, false knock went away.

**BigBanks78** · 08-03-2016

My vortec distributor (1998 4.3l v6)can't be turned either way but are u sure distributor is installed correctly? like its not advanced a tooth or something similar?

**dispoejoe95** · 08-03-2016

Big...I've checked my timing at least a handful of times just to be sure, so I think it's good but I am going to pull my dizzy out tomorrow to check shaft end play. Read a few great threads on a different forums tonight about this topic...mine has to have about 1/4" vertical play in it. Opinions vary but the majority from what I read tonight feel the correct spec is 0.012" - 0.015". Even if it isn't my knock issue it can't be helping my timing.

AxisT6 - Never thought about the ac compressor...worth a look. Also can't say i had heard of a DUI distributor. If i end up going that way, I'll definitely look into these.

Thanks.

**dispoejoe95** · 08-06-2016

I checked my distributor, I guess I over exaggerated a little. 0.055" vertical play and 0.005" side to side. I don't believe either is really bad enough to contribute to spark scatter. I'll shim out the vertical play and reinstall it for now. Maybe down the road I'll replace it.

**dispoejoe95** · 08-06-2016

Another thing I keep going back to in my head...Was eliminating the EGR a mistake? Has anyone ever had this knocking issue because they eliminated the EGR or cured knocks because they reinstalled it? I eliminated it just because it was easier than buying the tube and messing around with plumbing it in. Not to mention I'm not certain the EGR will fit under the bracket coming off of the AC compressor to the intake. Any thoughts?

**ony** · 08-06-2016

did you acutaly disable the egr,or just the part to keep the check engine light off?

**Fast355** · 08-06-2016

Originally Posted by dispoejoe95

Another thing I keep going back to in my head...Was eliminating the EGR a mistake? Has anyone ever had this knocking issue because they eliminated the EGR or cured knocks because they reinstalled it? I eliminated it just because it was easier than buying the tube and messing around with plumbing it in. Not to mention I'm not certain the EGR will fit under the bracket coming off of the AC compressor to the intake. Any thoughts?

I deleted my EGR with the 0411 intake and then removed the valve and pipe when the Marine intake went on. EGR has its on spark adder tables it uses when it turns on.

**dispoejoe95** · 08-07-2016

Originally Posted by ony

did you acutaly disable the egr,or just the part to keep the check engine light off?

No, I've definitely done more that just disable the error code 32. Over time, in desperation i guess, I started adjusted things just to see what it would do, if anything. Here is the list of EGR related changes I've made.

1) SCALERS - MINIMUM EGR TEMP ADJUSTED TO 151° C
2) FLAGS - SINGLE PASS EGR TEST - UNCHECKED
3) EGR CODE 32 - UNCHECKED
4) Desired EGR vs RPM vs Vacuum - Table set to zeros
5) SCALERS - Minimum Speed for EGR maxed out
6) Scalers - Max TPS for EGR enable from 64.8% to 0%
7) EGR Spark Correction vs. RPM vs Vacuum to 0
8) Desired EGR Gain Factor vs Temp to 0
9) egr fuel reduction vs RPM vs Vacuum set to 0's
10) Backpressure EGR - not set
11) Altitude spark bias adjusted to zero
12) EGR start up temp from 14.8° C to 151° C

**dispoejoe95** · 08-07-2016

Originally Posted by Fast355

I deleted my EGR with the 0411 intake and then removed the valve and pipe when the Marine intake went on. EGR has its on spark adder tables it uses when it turns on.

Would this be the "EGR Spark Correction vs. RPM vs Vacuum" in the $0D mask?

**Fast355** · 08-08-2016

Originally Posted by dispoejoe95

Would this be the "EGR Spark Correction vs. RPM vs Vacuum" in the $0D mask?

That would be the one, should not be in use with the EGR temp constants changed to disable it however. I always Zero it out anyway.

**ony** · 08-09-2016

on older ecms the egr leans the mixture out as it adds timming that is proble what adds to more mpg.

**dispoejoe95** · 08-13-2016

Originally Posted by ony

on older ecms the egr leans the mixture out as it adds timming that is proble what adds to more mpg.

Interesting, I hadn't thought about that. To offset the "used" up exhaust gases being introduced into the combustion chamber. Controlled by "EGR fuel reduction vs RPM vs Vacuum"... right? I have set to Ø so I think I have this taken care of and my mixture shouldn't be leaning out. Looking at my WB02, it doesn't appear to be lean at all. Hard on the throttle average AFR is 11.5 to 12.5. If anything, maybe it's a little too rich.

**ony** · 08-13-2016

on the ecm files I have messed with example the bpw is 181, when the computer calls for the egr it changes the bpw to 164 and adds timming but if the egr opens then you have a vacuum leak and the map rises putting in more fuel. playing with egr %,or correction or bpw when the egr is called for is how I tunned my egr but I don't have a wide band o2sensor just the blms and the set of my pants.this sounds funny but I smoothed them 3 tables when I tought it was correct and it seamed to smooth it out.