Can someone open this tune up and see if you see any problems with it for what im running. I have a old version of lt1 edit that I looked at the file with and do not know if it is showing me the correct info or not.

97lt1
Obd1 pcm
383 ci lt1
flat tops 11.9:1 comp
worked trick flow heads with 2.08/1.65 valves
single plane intake with mono blade tb
42lb delphi injectors with fuel pressure at 44psi
solid roller cam .700.700, 254/264 105.5 ls
Open 1 7/8 long tube header
250hp wet shot from a nx carb plate
trans , gear ratio is of no concern

Just wondering about the fuel side of it. I just got the engine running with this combo and the engine is running extremely rich to the point that it is fouling the plugs and getting fuel in the oil. Im running open headers and the tune is supposed to be in open loop so o2 sensor readings are kinda useless. My laptop died on me at the track the other night and i was not able to get any data on it. Working on a new one soon.
Thank you for any help.

 

Injector constant is set to 31.65 not 42lb. Do I get a cookie .

Gimme your email and i'll send you an updated file with a bunch of the little nitpicky crap fixed. It'll be a bin from tuner cats so you'll have to convert it back to .lt1 to use it in edit.

I wont do this because i'm not there to see the effects, but you need to really lower the individual cylinder fuel trims with the single plane intake because the flow is going to be ALOT more balanced at low speed. Set em all to zero and then add or remove fuel until header primary temps run the same it'll take some experimentation.

Imo it also has too much timing in it under moderate throttle but i'll leave that alone for you to figure out later.

 

troy@slammed98gmc.com

that is what i seen also. I just got this tune from bryan at pcmforless. Not sure why he has them set at 31, ive had 42lb injectors for awhile. I would appriciate it you could change that for me and email it to me. I dont have the license for this vin with edit so I cant change anything. I can put the program back in with cats program as a bin file.

 

Email sent, i was able to keep it in lt1 format.

 

Did that get you fixed up? Need anything else?

 

Thank you for doing that by the way. The engine will idle now, but is still running really rich. I can see 1.0-1.1 mv on both 02 sensors at times. Im picking up quiet abit of knock retard which I think is comming from the solid roller. Ive got bryan going back over the tune to see what he can do for it at this point. I may need more help before its all over with....

 

Have him try killing the invidual cylinder fuel trims by setting them all to 1. You dont need any much variation with a single plane your front holes are probably pig rich compared to the rest since a stock table adds up to 7 or 8% more fuel at idle for the front cylinders and runs closer to 1 as you get farther to the rear of the motor. Also if you're running an afpr make sure it is set dead nuts on where your injctors will flow 42lbs or the whole works will be off.

A knock sensor has never worked out for me with a solid roller lt1, and sometimes not even a hydraulic roller.

According to the tune you're running in maf mode is that correct? If i were you I would attempt to run in speed density if you're any good at programming, that big cam is going to **** off the maf sensor a little bit at low speeds and idle due to reversion.

I hope actually that you are good at tuning because you have got a long road ahead of you. If on the other hand you're not, you picked a hell of a setup to cut your tuning teeth on.

EDIT: Get yourself a wideband asap if you dont have one while you still have some hair left. I have a daytona sensors wego 4 unit and it is dead perfect for this type of tuning and setup. Has good internal logging with map and rpm inputs and will give you a graph or a/f ratios vs map and rpms. With that information you can get a good idea of what needs tweaked.

 

What is your fuel pressure? Some of these symptoms you mention sound like a ruptured diaphram in the Fuel Pressure Regulator, what with running rich and getting fuel into your oil.

 

Fuel pressure regulator is good. Ive checked that several times. I got another file from Bryan from pcmforless and he fixed a few things that where mentioned above and he set the injector constant at 44lbs due to the injector type. It ran much better friday night but still needs some work on the tune. still seeing over 1 volt on the O2 sensors. I made a few runs which felt like a rev limiter hit around 6900 rpms which caused my shift light (set at 6900 rpms) to flash on and off really fast and the engine would not go past that rpm. rev limiter in pcm and msd both at 7200 rpms. I changed the rev limiter in the pcm to 7500 and the msd to 7400 to see what would happen and I had the same results.I was just looking at some of the data logs and found a code 42 set around 7100 rpms according to datamaster in first gear. What is the difference between the rpm reading and the rpm 16 values in datamaster, when the code set, the rpm was at 3600 and the rpm 16 shows 7100. The next frame shows rpm at 6375 and the rpm 16 at 7158? 2 other runs had the same results with not revving up but no codes set.

Here is a link to the datamaster file where it set a code 42.

 

The stock PCM can't go past 7K RPM. Something to do with the resolution of the optisparks optical sensor I believe.

 

Bryan told me that 7200 was the limit and had the pcm rev limiter at 7200. He told me there where no timing tables after 7000 rpms would go another 200 rpms without problems.

 

Apparently your pcm did not hear what he said. j/k.

My experience here has been that some pcm's will do better than others. I have no earthly idea why. But i have seen some pcms fall off at 6900 as you described and i have seen some run to 7400 without much trouble.

Rpm 16 is i believe an average of the last 16 revs, think of it as a damped reading rather than instant rpm.

Get you a wideband and tinker with the tune until your a/f matches what it should be in the speed density table. It will take alot of he guesswork out of it.

I'll look at your datamaster log tommorrow maybe and see if i can see anything that stinks in it.

 

Thats not funny, thats going to cost me too much to be funny.

 

http://web.camaross.com/forums/showthread.php?t=493481

read what injuneer has to say in that thread about dtc42. Seems to be ICM related.

Also you have to figure out a way to stop your timing at idle from jumping around so much thats why your idle speed is so erratic. You are pig rich under wot according to your narrowband o2 sensors. Most of the time when I get it right on the wideband the narrowbands show between 890-910mv. Also something is up with your tps. its not showing zero% when you're idling at the beggining.

Also your maximum engine speed seems to be nearly 7200rpm in the logs. Also notice though that one reading freezes at abou 6400rpm and hangs there before going to 3600. That is probably part of your dtc 42 problem, its probably either the wire to the pcm or the ground circuit or the connection to the coil, but could also be the pcm.

Another thing is, the only lt1's that I have messed with that turn max rpm. I have equipped with crank trigger distributors. Usually I make a cover for the opti and remove the rotor etc and seal up the unit for good. Then use the coil wire to fire the crank trigger style dist. Its a pretty simple job to get it all in there, plus its alot safer than the stock lt1 oil pump drive imo. Just a pain in the **** to get in an f-car. All that remains is to get the thing in sync, I usually like to get it just before the post on the "boat anchor" phasing is not all that critical you just have to have enough rotor tip under the terminal at max advance. The lt1 rotor likes to explode and frag everything inside the unit when you start reving it like that is why I have done this before.

Have you put new plugs in it since it was running very rich before? If you havent a soot covered half fowled plug has different heat transfer properties than a good new plug. It also has diminished spark capacity which you need at high rpm.

 

Yeah I seen that it is still pig rich. It was a new set of plugs. The others where really fouled and soaked with fuel.

I have the idle screw open a bit more to try and stablize the idle speed some. I assumed that the timing was changing due to map signal being unstable??? Im no tuner by any means, Im not stupid either,Ive just left most of my tuning up to Byran and have great success in the past.

Here is the updated program that i was running last friday if you want to look at that.

Ive already had the stock rotor explode on me several years back, on a nitrous run no less. I have a msd cap and rotor and Ive inspected it a few times when I had the opti off and all seems well there.

You have a part number for the crank trigger distributor? I thought about doing something like that before and just ran out of cash so I just went back to what I had. You say you use the coil wire to fire the distributor, as in the spark plug wire? This setup just takes the high voltage out of the opti right, It wont allow the engine to rev any higher correct.