Retarded Timing....

[98mark8lsc]

This is on my black 98.

I've noticed for a while that I'm losing power in the top end. It's still pretty quick, but I can tell it's not putting out what it should be.

I hooked up the Xcal2 with the SCT live link datalogging software, and from what I can tell, it's retarding timing when I get on it.

Rather than tell you guys what I've tried, and taint your replies, I'm gonna ask for your recommendations, and I'll say whether or not I've tried it (or even thought about it). lol.

What could be causing it? Feel free to ask for any clarifying information.

Thanks!

BTW, I only use 93 octane gas.

 

[DLF]

As load increases, timing is pulled by the tune. What total timing are you logging @ 5-6K @ full throttle?

 

[steve]

put colder plugs in, i run 2 steps colder

 

[driller]

With this heat wave we've been experiencing, wouldn't the Air Charge Temperature and Engine Coolant Temperature retard WOT timing?

 

[98mark8lsc]

As load increases, timing is pulled by the tune. What total timing are you logging @ 5-6K @ full throttle?

I'm not sure. What specific value would I be logging to find that out? Sorry, I haven't spent much time with this stuff.

I have to admit, when it comes to tuning, I don't know a whole lot. I certainly want to learn though.

I don't know much about the SCT software either. I bought the X2 back in 2006, and tried hooking up to my Windows Vista laptop back in 2007 when I first bought the laptop, but there was some issues with the SCT software and Vista at the time, so I left it alone. I recently decided to try getting back into it, and it seems to work now with the newer updated software.

I plan on getting the PRP sometime in the near future as well.


Anyway, I think I've heard of timing being pulled as load increases, but it just seems like it's pulling way tooooo much.

At one point, I thought maybe the IMRC's were stuck closed or something. I pulled the intake and replaced the gaskets to fix a vacuum leak, and cleaned up the IMRC's really well. I put it all back together and verified that they operate when and as they should, so it's not that. However, I imagine that IMRC's stuck closed would feel very similar to what I'm experiencing right now.

 

[98mark8lsc]

put colder plugs in, i run 2 steps colder

I currently have some Iridium spark plugs in there that I've had since 2007-2008, only about 15-20k miles. It wouldn't hurt to take them out and check though. Maybe I'll just replace them anyway. Do you know what part # yours are?

 

[98mark8lsc]

With this heat wave we've been experiencing, wouldn't the Air Charge Temperature and Engine Coolant Temperature retard WOT timing?

If it were only in the heat, I would agree with you. I've had this issue for quite a while though, and the weather doesn't seem to have a noticeable role in it.

 

[steve]

I currently have some Iridium spark plugs in there that I've had since 2007-2008, only about 15-20k miles. It wouldn't hurt to take them out and check though. Maybe I'll just replace them anyway. Do you know what part # yours are?

i run the 2 step colder coper plugs, don't have the part number off the top of my head, been posted on here a few time, try a search.

 

[DLF]

I'm not sure. What specific value would I be logging to find that out? Sorry, I haven't spent much time with this stuff.

SPARK_ADVANCE, LOAD, and RPM

put colder plugs in, i run 2 steps colder

There's no reason to run cooler plugs in a stock motor, unless you want to foul them.

I run Autolite XP-104 plugs, which are the stock heat range, and my car is plenty quick.

 

[steve]

There's no reason to run cooler plugs in a stock motor, unless you want to foul them.

IDK, when JW dyno tuned my stock Mark he recommended them because the compute was pulling a few deg out on the top end. But what does he know, he was only an automative engineer for Ford and Roush and was part of the team that set the land speed record with the mark viii. I have been running them for over 100k miles and have yet to foul one.

 

[DLF]

IDK

You're right about that.

I could maybe see 1 step colder plugs, and I'd be suprised if JW had recommended more than that, but anything's possible.

Anyway, I've got the dyno sheet, timeslips, and datalogs to prove that it's not necessary.

And before we make any recommendations to Jay, he needs to provide some datalogs.

 

[98mark8lsc]

he needs to provide some datalogs.

I'm gonna get them as soon as I can. I don't drive the 98 very often, and don't have a lot of extra time lately, but I'm hoping to get a chance tomorrow.

I just ordered some AP104's from Advance online. With the online coupon codes, and the mail-in rebates going on right now. They'll end up being about $5 for whole set of them. I also got a new fuel filter and a crank position sensor...

 

[DLF]

Do you have a tune or a chip? Or are we dealing with the stock tune? What PCM code do you have?

 

[98mark8lsc]

It's a flash tune from Torrie at fastpartsnetwork through an Xcal2. I have a BTC0 computer code.

 

[DLF]

It's a flash tune from Torrie at fastpartsnetwork through an Xcal2. I have a BTC0 computer code.

Has the car always felt the same way since you loaded the tune, or is this something new?

Anyway, proper datalogs will tell us what's going on.

 

[98mark8lsc]

I recently tried flashing it back to stock, and it felt the same. I don't really know how long it's felt this way.

Ever since I started using the 97 as the daily driver, the 98 doesn't get driven that much, so It's hard to tell...

 

[KStromberg]

I'm only going to throw this out there for the halibut. TPS


And steve, 2 steps colder plugs on a stock car?!! LOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOL If JW told you that, he has apparently gone SENILE. I don't care what he has done in life.

DLF, go 2 steps colder and run 12.50s!! LMAO

 

[94PearlWhite]

Have you considered possible excess play in timing chains or your timing chain tensioners?

 

[svtlincoln]

Have you considered possible excess play in timing chains or your timing chain tensioners?

If the timing chains have that much play that it's pulling timing then wouldn't that mean they were jumping teeth? which would then cause incorrect timing all over the power band? I would think that'd be a very obvious racket. lol.

 

[KStromberg]

If the timing chains have that much play that it's pulling timing then wouldn't that mean they were jumping teeth? which would then cause incorrect timing all over the power band? I would think that'd be a very obvious racket. lol.

I had a timing chain tensioner failure which caused massive chain slop on the passenger side and caused a hell of a noise, so yeah you're right. It's not timing chain/tensioner issues unless it sounds like this:

http://www.youtube.com/watch?v=43g6_ul9pAg&list=UUzAG3n7bbZ39T3azT66TiEA&index=5&feature=plcp

Furthermore, I don't think the TPS like I had mentioned is the issue either since he already stated that the datalogs showed timing being pulled up top. (I guess I need to learn to read LOL)