Lt1 retarding timing, no power ,bad milage
Registered User
Joined: Jul 2004
Posts: 249
Re: Lt1 retarding timing, no power ,bad milage
When he said his mechanic said there was no knock showing on the scanner, perhaps the mechanic was looking at the current knock count.
Only way to have KR without increasing knock count is either low octane mode or burst knock retard, to my knowledge.
Only way to have KR without increasing knock count is either low octane mode or burst knock retard, to my knowledge.
Administrator
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
Re: Lt1 retarding timing, no power ,bad milage
I've seen numerous scans that show the knock count incrementing, with no knock retard, and also with significant knock retard and no movement on the knock count. Its confusing to me, but seems to happen regularly in the numerous data logs people ask me to look at.
Registered User
Joined: Jul 2004
Posts: 249
Re: Lt1 retarding timing, no power ,bad milage
Originally Posted by Injuneer
I've seen numerous scans that show the knock count incrementing, with no knock retard,
Originally Posted by Injuneer
and also with significant knock retard and no movement on the knock count. Its confusing to me, but seems to happen regularly in the numerous data logs people ask me to look at.
Thread Starter
Registered User
Joined: Apr 2006
Posts: 10
Re: Lt1 retarding timing, no power ,bad milage
I thank you guys for your help I dont know what else to do with the car, can u guys tell me how to check to see if the opti is alighned correctly and how posssible is it for the timing chain to jump time, bought a Haines manual but it is kind dim on the opti or timing and is there any lt1 nuts here in ohio that u know of I do not mind paying someone to fix it ,but I hate to pay someone to hang parts on it. I have over 1200.00 in diagnostic time in it now, and a few parts hung that I did not need.
Registered User
Joined: Jun 2003
Posts: 709
From: Oklahoma
Re: Lt1 retarding timing, no power ,bad milage
Originally Posted by Injuneer
Is it possible your mechanic is seeing timing values of "-25*" (for example), and assuming that means the timing is retarded 25*? Because that's not what the minus sign means when it shows up on a scanner. It just means the timing is ADVANCED 25* relative to TDC. Not all scanners show the "minus" signs, because is does confuse some people.
if it matters I have madz28 tune with knock desensitixing, but lt1 knock module.
Last edited by Blue96z28; Sep 17, 2006 at 05:14 AM.
Registered User
Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
Re: Lt1 retarding timing, no power ,bad milage
Originally Posted by Blue96z28
not trying to steal the thread here, but on the actron 9145, its like you say, showing the -negative 'Ignition Timing(degrees)' on my car it seems to go from -12 to -20 idle and -20 to -45 or more at cruise/WOT, and never gets out of the negative range, does this means its truely retarding more and more at WOT, or is this just a limitation of the scanner??? if thoose were actually positive numbers could it idle advanced like that?
if it matters I have madz28 tune with knock desensitixing, but lt1 knock module.
if it matters I have madz28 tune with knock desensitixing, but lt1 knock module.
Registered User
Joined: May 2020
Posts: 27
Re: Lt1 retarding timing, no power ,bad milage
What I have here is a problem that i can not find and 2 dealerships in southern ohio can not find. Computer is not storing any codes and only thing that has been diagnosed is the car is retarding the timing from off idle to 2000rpm all sensors are reading within specified values , fuel pressure is fine , new optispark,plugs,wires,map,knock sensor there are know signs of sensors pulling timing ,temp sensor is ok. last dealership I had thought the timing chain was off a tooth but would not guarntee this , I would think if this was the problem it would pull timing through out rpm range not only to 2000rpm
Symptoms are bad hesitation, running a littlewarm around 230 degrees , very bad gas milage and around 5000rpm timing is going ape crap, I f any won has a few suggestion I would greatly appreciate it ,getting tired of paying gm dealerships to not fix my car Thnaks so much
Symptoms are bad hesitation, running a littlewarm around 230 degrees , very bad gas milage and around 5000rpm timing is going ape crap, I f any won has a few suggestion I would greatly appreciate it ,getting tired of paying gm dealerships to not fix my car Thnaks so much
Thread
Thread Starter
Forum
Replies
Last Post
oldschool
Parts For Sale
16
Feb 9, 2016 09:21 PM