Hey guys. I understand you are sucessfully runnning a FAST ECU and Delteq together. Interested in how you accomplished this and if you are having any problems with it. Also interested in anyone else who may have some insight on this subject. Looking at the schematics from FAST and Delteq it seems possible. Delteq says yes, FAST says not sure. Looking for someone who knows for sure. Thanks, Rob. I'll be running the XFI ECU.

 

I'm interested as well. I have the older FAST system and am also going to be running the coil packs.

Jerry

 

Well I know for a fact the delteq works w/ the classic FAST box as both Roadie and 97WS6pilot are running it. The BIG question is whether the XFI can do the same and I was hoping to have that answer today but I still can't get the damn car to fire. Only conclusion I can come up w/ is the wiring diagram I have is a bad diagram OR I really suck at following instructions. I'm known to do the latter. I'm almost tempted to ship this SOB back stateside and have a pro look at it and ship it back but I've only got 12 mos left over here so I'll just wait.

I changed the crank ref angle from 10 to 6* and that didn't help. Only thing I haven't done is changed to a different ign setting like northstar's or GN buick but I don't think that would matter either. I hate the opti but if I can't get this SOB to start I may have to go back to it.

Hopefully Rob you'll have better luck than me and keep me from ditching the Delteq.

 

Roadie had some weird "invisible" rev limiter on the dyno that him and the experienced FAST tuner couldnt figure out. He is working on figuring it now, so hopefuly he can shed some light on the Delteq + FAST topic.

 

I had a non-start issue, but it was 2-fold... I first went to Delteq with my problem and they made a bypass cable for me. Instead of letting the Delteq brainbox process the signal before sending it to the ECU, the new cable fed the opti signals directly to the ECU (sharing them with the Delteq brain box).

However, that didn't solve my non-start issue. I took RealQuick's FAST box, plugged it in, and the car fired right up. The problem wound up being that my FAST box had "GM HEI" internals instead of "GM Opti" internals. FAST fixed my box and sent it back to me and all was good...

I haven't tried to put the original delteq cable back on the car yet, but that is going to be part of troubleshooting my mysterious 4800 rpm rev limiter (once I replace a header gasket this weekend).

Just a side note, there's a lot of different information around for the opti. FAST states the opti reference angle is 1* BTDC and to use 40uS as the inductive delay. BS3 states 6* BTDC and 24uS as the inductive delay. These numbers are very important because the first one can put you off 5 degrees of timing right off the bat. The latter affects how timing changes as rpm changes -- too high of number and timing will advance with an RPM increase and too low of number will make timing retard as RPM increases.

I'm attempting to get the right numbers for both and will share them when I figure it out. The inductive delay number I will find out by setting my timing to 30* across the board and using a timing light, making changes until timing stays the same regardless of RPM. The reference angle is going to be tricky since I have no timing pointer to reference.

 

Roadie when you sent your box back for the revision do you know what revision you got? I wonder if it's the same for the XFI as I sent mine back w/ the update "Opti revision" but I still can't fire it. Never heard anything about bypass cable from Delteq. Guess I need to give them a call.

 

sounds like you got it figured out from the other thread... I have the classic box and don't know what version of firmware is on it (off the top of my head).

 

Hey Roadie. Could you possibly send me a pic, or schematic of the bypass harness Delteq sent you. Still waiting on mine to show up from J.C. I'm pretty sure I can modify the harness' I already have and come up with the same thing. Kinda in a different ball park than some of you since I'm running XFI ECU and FAST harness', with no stock PCM or harness. I definately think the delay has a major part in this whole thing. It would be nice to see if one of us could get this working so we could pass the info onto everyone else. Thanks, Rob.

 

I'm still using the stock pcm and delteq. Sorry I couldn't help.

 

Still running stock pcm huh? I had heard you were running a FAST. Oh well. Are you running a proportioning valve on your ABS delete? I didn't see one. Thanks, Rob.

 

Stock PCM seems to be working great on my blower setup. Its pretty easy to control fueling with the PE vs RPM table and I get good driveability with my MAF on the pressure side. I just wish I could control the timing a little better.

I didn't need a proportioning valve because my fronts lock up first with the C5 brakes. I love having the additional space where my abs modulator used to be.

 

Roadie did you ever find out anything? Mine acts like it wants to fire but it just doesn't. I had to mess w/ the cranking fuel table as I wasn't getting no fuel but plenty spark. Once I did that it burped a few times but would never start. I tried 10* and 6* for the reference angle and it reacts the same way in either setting. According to the help file us using the opti requires 1* for crank ref angle. Gonna try that next and see what happens.

 

Sorry I didn't respond sooner... My truck was bent into a pretzel by a pair of Dodge Neons last week and I've been dealing with everything but my car since.

Still haven't fixed the rev limiter, but it does run...

I'm not sure how accurate that help file is... FAST XFI manual says 6* for opti (so does BS3). In all honesty, 6* or 1* won't make too much of a difference for first time firing.

I've tweaked that and the inductive delay in trying to fix my problem, but to no avail. Right now it's set to 6* and 24uS (settings recommended by BS3) and it seems to be pretty good. Timing does go just a tad bit to the retard side as it climbs RPMs, meaning the inductive delay should be increased a bit. I just haven't had time to find the perfect number yet.

First look at RPMs... Is the FAST box seeing RPMs while cranking? That's where I found out my box was the problem. It wasn't reading any RPM. Turns out my FAST box was set up for HEI, not Opti. Once I had that changed, it fired right up...

What does your VE table look like? At idle, mine was already in the 55-65 range. I expected it to be much lower than that. Even at 55-65, injector pulse width was only 1.2-1.3ms.

If you can take a log file while cranking, send it to me in email - jhuegen @ gmail.com - and I'll take a look. Just an FYI, the Delteq box will make spark even if the FAST box isn't telling it to. It does that to learn where it's at in the firing order. If the FAST box isn't seeing RPM, it's not commanding spark or fuel.

 

Damn. Sorry to hear about your truck. I hope you are ok and wasn't in the truck when it happened. I had my box sent back for firmware revision XFI2_23 which is supposed to be the replacement board for the opti ignition. At least that's what the work order says.

Read somewhere too about the XFI reading the rpm during cranking and that's something I haven't checked yet. I'll take a look at that tomorrow as well as the VE table but I think my numbers are lower thinking mid to high 40's. I'll datalog as well and shoot it to you. My day is pretty much over being 6hrs ahead and having to go to work in 8 hrs.

Thanks.

 

If you could shoot it over to me as well I'd appreciate it.

Jon