Pulling time on WOT but wideband shows neither too rich or lean

[toonwarrior]

Well I shouldn't say WOT, but essentially anytime I'm above 30% throttle my car starts pulling timing.

It's a 1994 Impala SS with LT1 and t56 but with the torqhead 24x and gen 3 ls pcm conversion using HP tuners, the file has the base timing, injector settings and what not from torqhead which are all fairly conservative from what I've been told. My engine is stock except for the long tube headers it has. The knock sensors came with the torqhead kit which are KS7 standard brand sensors that are for the 2002 astro van.

I've worked on dialing my MAF and SD base tables to around 1 lambda which it seems to be for the most part based on my wideband gauge. At Idle it's still a bit rich but think it's just a matter of 1 or 2 more calibrations though.

Now the issue is I throw it back into the main tune and try to rev the car out it starts running into KR, but I'm staring at my wideband which is reading 14sh and when PE kicks in, the 12ish range, the trims before PE kicks in doesn't seem too alarming, it's not perfect but I don't think it'd be the reason for it to run into KR, but maybe I'm wrong.

Unfortunately my wideband isn't wired up to my hp tuners data logger but it will be soon once the pro-link arrives.

One frame before KR kicks in

tuneframe1.PNG

One frame after it kicks in, you can see it ramp up to 7 degrees fairly quick, but nothing on there is alarming in terms of trims or IAT.

tuneframe2.PNG

I tried desensitizing the Knock sensors by about 15% but didn't seem to do anything.

I've attached the log file and tune file if anyone wants to take a look and see if there's anything glaringly wrong.


This is my first time dwelling into this stuff so I tried my best to be informed as possible reading through the forums before asking.

So let me know your thoughts and how I should approach this issue

[5FDP]

Try turning off burst knock, currently it's set completely wrong. It's set to 0.00 meaning it's always on and the most responsive. Set it to 7.999 and that will turn it off. Burst knock can spike on quick throttle transitions or when it starts to enter PE.

[blindsquirrel]

Injector data is not right - flow rate table is flat like for a referenced regulator, offset vs volts vs vac is sloped like for returnless/nonreferenced.

Turn off the AIR pump in System Options - '1' means present, '0' means not. Even though AIR is disabled by the ECT setting it should still be turned off everywhere. Same for Spark > Catalyst Heating - zero that whole table out since everything else in the file looks like you no longer have cats.

[toonwarrior]

Yea I definitely boogerd the burst knock and didn't realize it! Was referencing goat ropes garage video and must've 0d out the table incorrectly.

As far as the injector data the gen 2 lt1s are a bit different from the gen 3 and newer motors, I can't explain it but this is a base tune setup for Lt1s which a lot of the b-body / f-body guys start out with if they did the torqhead conversion

Will definitely try out the other suggestions and report back tomorrow

[blindsquirrel]

Are you really going to explain injector data to me? Me? I know quite well how the tables change based on the regulator/fuel system type and yours is not correct. Gen 2 injectors doesn't have shit to do with it.

[blindsquirrel]

Look. This is your file compared to a stock 2002 Camaro. Only your flow rate has been changed, the rest of your file is still leftovers from the LS1 12482704's.

screenshot.17-03-2024 22.23.59.png

It's your job to identify which injectors you have and then track down the correct data for them, or tell us what they are and ask for help in getting the right data.

[toonwarrior]

Sorry not trying to pick a fight just here to learn and I appreciate the time you are taking out to respond

The stock 2002 file is an ls1 engine.

This is a 1994 lt1 (gen 2 SBC) engine which is using a 24x conversion setup to be able to use the gen 3 style pcm, from what I know is LT1 is vacuum referenced. So there isn't really a base file I can compare to unless it's another LT1 file which there won't be any factory configurations since lt1s were discontinued when the ls1 came out.

I've looked at a few 24x conversion files and it's similar. My car is on stock lt1 injectors which is what the torqhead base tunes are set to

Honestly not as much info on that as I thought I'd find on this topic.

https://forum.hptuners.com/showthrea...11-97-LT1-swap

And I apologize I'm advance

[blindsquirrel]

The file is not correct no matter how many other people are using them that way or if all the conversions are sold that way. Those old style injectors are heavy and slow, I guarantee they will not play nice using leftover data for a newer, lighter, faster injector. You can either find someone who has accurate data in the correct format (which may not even exist, since "everyone" uses the wrong data with these conversions), or buy different injectors.

injector dimensions2.jpg

[SiriusC1024]

Agreed.

[blindsquirrel]

I mean, a 24# injector at 43 PSI and a 1:1 regulator is only good for 350 HP at the crank. It'd need injectors even if you did have all the right data to use the the LT1's in the Gen 3 PCM.

[toonwarrior]

Interesting, I'd have to do some research on some options, I know one style is the 30 Lb Ford SVO Red Top Injectors which a lot of LT1 guys go, there's another 36lb option that's sold by one of the impala forum members that I could go with and fairly sure a few guy of the guys who bought them have 24x conversions so maybe I can get some data from that.

Actually I have a file from a buddy that I'm pretty sure is using the 30lb injectors (i cannot remember if they were the Ford ones) but based on the flow rate vs KPA it is set to 30. His car is fairly similar to mines in setup (lt1 with longtubes) and t56, but 30lb injectors and a 52mm TB while mines is the stock 48.

His car was tuned on the dyno by one of the better shops here so I'm curious to see if maybe I can just use the data he has setup and get those same injectors. Though just comparing files I can't find much difference in fuel setting changes other than the flow rate vs KPA

impala stock3.hpt

[blindsquirrel]

If you did the smart & economical thing and used $55/set L96 injectors, here's a file with full data at your rail pressure & regulator type...

toonwarrior - 12613412 L96 injectors, 43psi, refrenced.hpt
(your original file, just with a less unwieldy filename)

[blindsquirrel]

All the ancient injectors with that fat body are slow and old and dumb. They are also prone to leaking out the side of the body and setting your car on fire.

[toonwarrior]

I guess the challenge I'm having here is that I don't think LS based injectors work on the lt1 fuel rail, or atleast not without some modifications which I wouldn't trust myself dealing with the chance of causing a fire.

Unless someone tells me otherwise. There are some companies like racetronix that have plug and play solutions but I don't know enough about them that they solve the "old and dumb" problem with the stock injectors or similar to that.

Thank you for the file I'll dig into it and gain a bit of better understanding.

[blindsquirrel]

The LT1 rail and manifold openings are the same as LS stuff. Only a few of the LS engines use something different (see injector dimensions photo above, it gives o-ring sizes and everything). LT1 length is the same as LS1, so you'd just need whatever top spacers would be used to put the shorter truck injectors into a LS1.

[toonwarrior]

Awesome thanks for the info. Guess it doesn't really make sense to do a 24x conversion and then not utilize the benefits of being able to install a more modern injector

[blindsquirrel]

https://www.ebay.com/itm/274424906026
https://www.ebay.com/itm/132370243894
and whatever top adapter needed to get back to the correct length.

I know I'm like a broken record recommending these injectors but everything else is ~$400 for a set.

[Alvin]

The knock sensors spiking right to 7 degrees (max in your tune) is 100% a characteristic of a bad knock sensor/pending knock sensor code. If you check the service manual when a knock sensor code is present on these the PCM defaults to max retard anytime you are in PE or a good load. If you were to scan it after one of these drives I'll bet you'll see a code pending.

I've done maybe 20 LT1, SBC, and BBC 24x EFIconnection and Torqhead swaps at this point. I don't think any of them had properly working knock sensors. people say it works, people say to use the 5.7 express van blah blah blah.

In my experience they either do nothing at all and are always quiet or max out like this.

I didn't review the other parts of your tune but fueling/etc isn't the cause of this...

[blindsquirrel]

fueling/etc isn't the cause of this...

Of course not, but that doesn't mean other issues shouldn't be fixed. Sure is a shame injector PW/duty cycle isn't being logged (or O2s, even! what kind of log is this, anyway?!), it's always cool to see those over-100% numbers.

[Alvin]

Of course not, but that doesn't mean other issues shouldn't be fixed. Sure is a shame injector PW/duty cycle isn't being logged (or O2s, even! what kind of log is this, anyway?!), it's always cool to see those over-100% numbers.

I'm trying to answer his question about knock directly.

When he comes back to ask why the tune isn't shaping up or car runs bad we can get into the rest.