What is retarding my timing?

[danalihd]

Allen and other, I'm trying to figure out why my timing is dropping to 0.3 from 40 on my whipple charged truck. It's really f'n annoying that I can't drive my $40,000 truck anywhere. It looks good in the driveway though. anyway, this is what I posted on Ls1tech.com. the thought is,"that's not good" but without seeing how it is tuned, noone can tell me what's wrong.


Ok, hope this helps.

Long term fuel trim -4
Long term fuel trim -6.25
IAT 89
Spark 0.3
Knock retard 0
Boost 5
Fuel pressure 60
rpm 2000

The spark was up around 40. I hit 55mph, felt the torque converter lockup, lightly pressed the gas, these were the results. I'm hoping a lightbulb will go off in someone's head. Fingers are crossed. I sent a link to this page to Allen also. Thanks guys.

[RedHeartbeat]

Have you checked the fuel pressure while driving through the point it retards? Sometimes the fuel pressure is great at idle but volume while driving will fall off. Sounds odd to retard at lockup unless maybe the torque converter is rattling hard enough to be thought of as an engine knock. Have you pulled the power on the battery for 30 minutes to reset the PCM and see if it still does the retard?

[danalihd]

The worst i've seen it I had 70lb fuel pressure, 8lb boost, 2000rpm, 0.3deg spark.
No knock retard. Something is severely messed up.

[RedHeartbeat]

Is something wrong with your fuel pressure regulator? On vortech engines your pressure is supposed to be consistent unless you are using a regulator with a vacuum port that will increase pressure at low vacuum. I can't recall off the top of my head but I think the fuel pressure is only supposed to be betwee 52 and 56 lbs. 70 is way off scale, that would really screw up your fueling.

[farmtruc]

Any update on this Dan? I've been trying to think what could be wrong. no KR and that low of timing? hmmm.
there is a table in edit that has to do with axle abuse, but i checked and disabled it on your truck, it's only active on awd vehicles, and i think 4wd trucks, i disable just in case.
After we talked you mentioned a bucking feeling, did you have a chance to check the plugs or wires? Sounded like a cracked plug or miss, not every time will you throw that misfire code either, so you really can't go off the ses light.

allen

[danalihd]

I'm changing the plugs tomorrow. The guys on ls1tech don't seem to thing that's the problem. All i know is, i need this thing fixed asap and don't know how to get it done. Is it true that some dyno shops can actually do true computer tuning? Someone claims there's one up here in New England.

I can easily reproduce the above mentioned numbers so I also don't think it's the plugs. It's not only when i'm in 4th gear, but, that's when it is most obvious/embarassing.

I think the last tune might have been ok if i had the alcohol injection hooked up. Parish8 on ls1tech seems to think he could figure out the problem if he could see the files, which probably isn't going to happen I assume. and yes, it is actually 2:15am right now and yes, i'm awake because i can't stop thinking about the money pit i call my truck.

[farmtruc]

Originally posted by danalihd@Aug 17 2004, 12:15 AM
I'm changing the plugs tomorrow. The guys on ls1tech don't seem to thing that's the problem. All i know is, i need this thing fixed asap and don't know how to get it done. Is it true that some dyno shops can actually do true computer tuning? Someone claims there's one up here in New England.

I can easily reproduce the above mentioned numbers so I also don't think it's the plugs. It's not only when i'm in 4th gear, but, that's when it is most obvious/embarassing.

I think the last tune might have been ok if i had the alcohol injection hooked up. Parish8 on ls1tech seems to think he could figure out the problem if he could see the files, which probably isn't going to happen I assume. and yes, it is actually 2:15am right now and yes, i'm awake because i can't stop thinking about the money pit i call my truck.

hey, thanks for the reply, and like you , i finally got my access back so i'm up and it's 2:23 LOL.

We'll get in touch tomorrow and get this worked out. I know up in KS meet some guy with a new set of headers had a bad stumble, it was only under a heavy load and only in fourth, it turned out to be a bad wire, not saying that's your problem, but it's easy to check and remove from the equation.

if you can, shoot me a good number to get a hold of you and we'll discuss this and get on it until it's fixed, last thing i want is to have someone not have a good running truck,

talk to you soon,


allen

btw, i sent you a pm from tech