Haggerty

Well as expected the ECU wasn't getting proper manifold pressure reading. Once I switched to a 3rd vacuum line directly off the back of the manifold the car runs amazing. Still slightly lean on full throttle but only like 15 AFR, probably fixable with some tuning.

@GTSBoy This method was able to get readings of -10 to -2, so it looks like its monitoring. Now I need to figure out why the vacuum on the line provided isn't alternating with manifold pressure. I went with 2 lines that an RB25 tuner recommended but I'll get a longer hose and try directly off the back of the manifold. He may have been used to OEM intake setups while I have a DBW setup that removed the MAF and IACV.

@Murray_Calavera If I were an expert I wouldn't be in here looking for assistance. I am extremely computer literate, have above average understanding on how things should be working and how they should tie together. If I need to go to a professional tuner so be it, but I'd much rather learn and do things myself even if it means looking for some guidance along the way and blowing up a few engines. @GTSBoy I was hoping it would be as simple as a large vacuum leak somewhere but I'm unable to find anything, all lines seem to be well capped or going where they need to be, and when removed there is vacuum felt on the tube. It would be odd for the Haltech built in MAP to be faulty, the GTT tune I imported had it enabled from the start, I incorrectly assumed it was reading a signal from the stock MAP, but that doesn't exist. After running a vacuum hose to the ECU the signal doesn't change more than 0.2 in either direction. I'll probably upload a video of my settings tomorrow, as it stands I'm able to daily drive, but getting stuttering when giving it gas from idle, so pulling away from lights is a slow process of revving it up and feathering the clutch until its moving, then it will accelerate fine. It sounds like I need to get to the bottom of the manifold pressure issue, but the ignition timing section is most intimidating to me and will probably let a pro do that part. Tomorrow I'll try a different vacuum line to T off of, with any luck I selected one that was already bypassed during the DBW swap. (edit: I went out and did it right now, the line I had chosen did appear to have no vacuum on it, it used to go to the front of the intake, I've now completely blocked that one off at the bracket that holds several vacuum lines by the firewall. I T'd into the vacuum line that goes from that bracket to the vacuum pump at the front of the car, but no change in the MAP readings). Using the new vacuum line that has obvious vacuum on the hose, im still only getting readings between -6.0 and -5.2. I'm wondering why the ECU was detecting -5.3 when nothing was connected to the MAP nipple and ECU MAP selected as the source. @feartherb26 I do have +T in the works but wanted to wait until Spring to start with that swap since this is my good winter AWD vehicle. When removing the butterfly, did it leave a bunch of holes in the manifold that you needed to plug? I thought about removing it but assumed it would be a mess. I notice no difference when capping the vacuum line to it or letting it do its thing. This whole thing has convinced me to just get a forward facing manifold when the time comes though.

I guess one thing that might be wrong is the manifold pressure. It is a constant -5.9 and never moves even under 100% throttle and load. I would expect it to atleast go to 0 correct? It's doing this with the OEM MAP as well as the ECU vacuum sensor. When trying to tune the base map under load the crosshairs only climb vertically with RPM, but always in the -5.9 column.

As far as I can tell I have everything properly set in the Haltech software for engine size, injector data, all sensors seem to be reporting proper numbers. If I change any injector details it doesnt run right. Changing the base map is having the biggest change in response, im not sure how people are saying it doesnt really matter. I'm guessing under normal conditions the ECU is able to self adjust and keep everything smooth. Right now my best performance is happening by lowering the base map just enough to where the ECU us doing short term cut of about 45% to reach the target Lambda of 14.7. That way when I start putting load on it still has high enough fuel map to not be so lean. After 2500 rpm I raised the base map to what would be really rich at no load, but still helps with the lean spots on load. I figure I don't have much reason to be above 2500rpm with no load. When watching other videos it seems their target is reached much faster than mine. Mine takes forever to adjust and reach the target. My next few days will be spent making sure timing is good, it was running fine before doing the ECU and DBW swap, but want to verify. I'll also probably swap in the new injectors I bought as well as a walbro 255 pump.

Yep, the closest base tune available was for the GTT, I went with that and made all the logical changes I could find to convert it to Naturally Aspirated. It will rev fine in Neutral to redline but it will be cutting nearly 50% fuel the whole way. If I let it tune the fuel map to start with that much less fuel it wont run right and has a hard time applying corrections. These 50% cuts are with a fuel map already about half of what the GTT tune had. I was having a whole lot of bogging when applying any throttle but seem to have fixed that for no load situations with very aggressive transient throttle settings. I made the corrections to my injectors with data I found for them online, FBCJC100 flowing 306cc. I'll have to look to see if I can find the Cam section. I have the Bosch 4.9 from Haltech. My manifold pressure when watching it live is always in -5.9 psi/inHg

I seem to the be only person that is using a Haltech 2500 on an NA motor, I've installed a Bosch DBW throttle body to the OEM intake manifold and am having problems maintaining AFR even with the wideband o2. It will run extremely rich at idle and up to redline, but under load it will go extremely lean in the 20s and i'm essentially having to rev it over 4k and feather the clutch to get it up to speed. I've read a few other threads of about the butterfly, it seems removing the vacuum to it is supposed to have it remain open, i've noticed no difference under 4k with the vacuum line to it plugged. I'm hoping someone here has had luck using the NA manifold with Haltech, and if they happen to have a tune for it.