Your chance to be my new best friend

[hotrodneb]

Thank you for looking. I am a NEW HPT owner (48h now) I have done my first tune and have managed to solve several issues that 2 before me haven't. Yes--this is the third time this VIN has been liscensed in this car. If you have suggestions on my tune file I am more than willing to accept them. This is a 1998 LS1 in a 1968 Firebird, 4l60 on fresh rebuild with am increased stall convertor (don't know exact spec), 411 PCM swap, mid length headers, 2.5" exhaust, Stock TB and intake. I am an old grandpa who cruises with grandma, but occasionally like to remember what it was like being 18. I am looking for a modern production car ride, that will perform when I want it to. This tune comes close to what I am looking for, but most certainly is needs improvement.

The reason for this post------
I have an intermittent idle issue. It seems to drop a cylinder at random intervals, in gear, at idle. As far as I can tell this is the only time I notice any issue. I have checked wiring, replaced O2s, swapped coils, swapped injectors, pretty much eliminated everything but programming (I think)

I have posted my latest tune, a driving log, and an idling in-gear log.
Your help is GREATLY appreciated. Thank you

68 Firebird-Final.hpt
post-tune.hpl
Idle Issue.hpl

[hotrodneb]

Bump...Happy Halloween

[blownbluez06]

1:50 into your driving log, you've got a lean spot that's bringing in knock. Richened it up and a few other little things. attached

[hotrodneb]

THANK YOU. I appreciate the help.
I will load this in the morning and post the results with a log

[hotrodneb]

First "blownblue" (or others)....be sure to message your address so I can send birthday an Christmas cards

Uploaded the tune and drove. I would say that the changes masked the issue, but it is still there. Beginning, driving, and warm logs attached. Curious was the fact that after returning home it seems to feel like it was missing in neutral at idle. I have also attached a scan of it idling in neutral. This might be something I just have to live with, the car isn't supposed to spend a lot of time sitting there idling in neutral.

The tune file attached is a fresh load of what is in the car currently.

ALSO----The trans really slams into drive and reverse when cold. This completely goes away once the trans is warmed up. I find LOTS of stuff on 1-2 shifts/etc, but nothing on 0-1 shifting. Any help here might get a suprise inside one of those cards <smile>



68 Firebird-Final-changed.hpt

scan cold.hpl
Scan driving.hpl
scan warm.hpl
scan neutral.hpl

[blownbluez06]

Here ya go. This is all I can do without having more to go on.

This should stop it from slamming into gear when cold, hopefully. That's your tight, converter relative to your idle speed.

As for your missing cylinder, I see something happening on the driver side. If you don't have a good, multimeter, I would recommend getting one. Make sure your plug wires are on fully. If you have MSD wires, take them off, meter each one and roll your wrists while metering. Replace any out of range wires. Make sure you pay attention to the actual resistance. Some meters will have a "K" in the display. That's "kilo" or thousands, so if you have some that are 29 ohms (about the right resistance for MSD) and some that are 2.9K, the 2.9K is junk. Send it in for a replacement. Also, make sure you're running the right plugs. NGK TR55iX (part# 7164) is good for relatively stock motors. Don't try to gap these. If you need further help figuring out what cylinder is causing issues, go buy a infrared temperature gun. The generics are 29.00 and the good Raytek are more. Scan each exhaust primary and look for the cold one. Trade injectors, coils and wires with another cylinder to help isolate the trouble.

Best regards

Bret

[hotrodneb]

THANK YOU.....thank you Thank YOU!!!!!

MSDs and NGKs bought and installed.....Idle issue seems to be solved. You are my NEW best friend, and I won't even ask to borrow money.

Previous was new and I just got what came off the shelf. ACs and a set of OEM fit that ohm'd out abound 3K

As far as the transmission goes.......I don't think I will be letting it cool down enough to check now that it is running right

Thank you sir, you are the "Most interesting tuner (man)" I know