Im about to get started installing my FAST today. I have a few questions for anyone who has done this. I will be using the factory ignition. How exactly do i need to wire this to the ignition? Also can anyone tell me what color the wires are for the fan relay (-) and fuel pump relay (-) ? I'm assuming they are inside the car since they are on the ecm side of the fast harness. Also, where did you guys drill the hole for the new harness?

heres the wiring pinout for the sefi box ( silver old style non xfi)

FAST EFI Instruction Manual

is your box set up for GM HEI ?

Doug

I have those instructions but they don't help me at all for ignition hookup. Just has 4 pin connector that says a,b,c,d and so on. I dont know what i am supposed to connect to that.

that goes to the distributor. is the gm factory plug labeled with abcd ? the wiring is NOT a to a, b to b ect ect and is different depending on if you have a coil on cap dist or seperate coil hei setup.

your ecu is made for an HEI ign , right? If your conector isnt labled tell me what type dist you have and Ill get you the hook up info.

Doug

I have hte iginition with the external coil with 2 connectors and the distributor with the module. One of the connectors from the module goes to one side of the coil and one connector comes off the bulkhead harness and goes to the other side of the coil. There is also a plug going to the other side of the module coming off the passenger side harness. I removed just about everything from the passenger side harness. My fast harness just has the big 4 pin weatherpack male connector. It says in the instructions that a connector is included to wire up whichever ignition i have but it didnt come in the box. My ecu is the 30-11100 part number that is for TPI cars. Oh and yes one of the plugs going to the ignition module has 4 pins and is labeled a,b,c,d but its is a completely different style smaller connector.

Ok you can do one of two things here. you can whack the conector off t5he fast harness and put the correct plug that fits the distributor (which is what I recomend) or you can get a female plug to mate with the fast harness and make an adaptor with the right dist plug on the other end.

either way heres the hook up
the fast terminal labled "A" goes to D on the dist
fast B goes to c
fast c goes to b
fast d goes to a

maybe you can pick up a dist connector at the auto parts store.

Doug

Ok thanks. What about the wire on the interior side of the harness labeled ESC? Also should i just remove the factory ecm harness entirely and just run new fan and fuel pump wires? These wires come from the drivers bulkhead and relays and go into fans and some go back into the passenger side factory ecm harness. I got just about everything out but that and a couple of other wires that i'm not sure if i'll need or not. Speedometer is next. I removed those wires from the ecm and left them there but i guess i'll have to reconnect them to something else at some point to make the speedo work.

the esc wire is for the knock sensor which I would NOT recomend hooking up. it will work without hooking it up.

My other questions? :-( I'm so close to having this thing figured out. I really appreciate your help.

Im not sure of your wiring/troubleshooting skills . for now I would bypass the factory harness and wire the fan and fuel pump to their own relays. remember the fast ecu triggers the relays by supplying ground to the relay. dont feed anything directly off the fast output.

I cant find much on the factory fan and fuel pump relays but i'm assuming that they are 2 of the 3 above the bulkhead with the big orange, little green, and little black wires coming off both of them. In fact i'm sure one of those is the fan relay as some of the wires go down to the fans. I just cant figure out which of those wires green or black are the ones coming off the (-) side of each relay. Do you have any idea what the orange wires do that go back into the car through the ecm harness?

sorry I dont know much about the factory wiring. the terminals should be labled on the relay. trace out the ones you can follow and extrapolate the rest :-) with the fast ecu totally disconnected, take a volt meter and see what terminals are hot and what ones are ground.
check this relay wiring info out.
http://www.motorsportsdigest.com/tech/perform3.htm

What you need is F.A.S.T. P/N 30-1302.

It's the ignition adapter harness for the GM remote coil HEI. It plugs into the distributor and then plugs into the FAST harness.

Here's the pinout as taken directly from the harness adapter itself

GM FAST connector (Delphi PA66 packard female plug)
PIN Wire Color PIN
A BLK/WHT D
B GRN/LT GRN G
C BRN/WHT F
D TAN/BRN E

Hope this helps,
--Dan

p.s. There should be a wiring diagram for your harness on the CDROM that came with the ECM. That's how I wired mine up and it went pretty well. Contrary to Doug's suggestion, I am using the factory ESC with my system and it appears to be working great. I purchased a new ESC sensor and used a 1987 ESC module that now gets its power from the XFI's fuel pump circuit.

This year I'll be bringing in a fuel pressure transducer, an oil pressure transducer, and perhaps even a nitrous pressure transducer into the analog inputs of the XFI for monitoring fuel and engine during race conditions. I might bring in oil temperature as well.

I cut the ignition plug off the fact. harness and cut the one off the fast harness and replaced it with the factory plug. a - d b-c c-b d-a like the manual shows. This should work fine.

Dan, my dual synch just died so I'm gonna put my stock small cap dizzy in until replacement parts show up. Can you help me with dist ref angle? Right now I have my dizzy @ 50* and all is good, my timing in the spark tables matches with the timing light, so my question is where did you set up your dizzy, from my XFI cd I'm thinking to set it at 50* also then put dizzy in bypass mode & I should see 6* on balancer-right??

yes the crank reference needs to be at 50 degrees , and the timing light should match what the ecu is commanding for timing. set the rotor phase if you can probably not worth it if this is temporary. select hei mode in c-com.
not sure what you mean by bypass mode.

By byapass mode, I'm just thinking in terms of stock GM timing set proceedures, disconnecting the est bypass wire to verify base timing. I gather this is not necc with the XFI. Thanks for the reply.

I'm having problems setting up my timing with the fact dist. I had it running with the crank reference at 50* but since changed it to 6* and tried to sync it with the bypass wire unplugged and now i cant get it to run.

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the 50 degree crank reference is for an ipu trigger and not hei , Im used to my ipu setup . the hei reference angle is 6 degrees with the bypass disconected. verify you have 6 degrees with a timing light. this is for the old style fast ecu, I think the xfi is the same but Ill double check that.

It is at 6*. Still wont run without lots of timing. Set the engine at 6* and put distributor back in a #1. Did nothign for me.

how much timing does it want to idle?

Remeber when you set the balancer at 6* BTDC and drop the dist in, you need to make sure you look at the pick-up coil, you need to have one of the triangular points on the dist shaft lined up with the outer triangular points on p-up coil, then look at where the rotor is pointing = #1 post.

1. set balancer to 6* btdc
2. install dist
3. rotate dist housing until pick-up coil "points" align
4. tighten dist
5. check rotor position, closest post should be your #1 (preferrable really close) or reinstall dist again to get best rotor phasing
6. set crank ref angle in c-com to 6*, set ignition type to GM HEI
7. put dist in bypass mode
8. unplug coil power wires
9. crank engine and observe timing with light, should equal 6*
10. plug in coil & fire engine
11. observe main dash in c-com. look at timing, should be ~30* or whatever you have it set to, then verify same number on balancer.

This should work. I think the pick-up coil placement may be giving you the headache.

I dont think you can move the pickup in the factory dist. Also, how can use a timing light with the coil unhooked? The inductive timing light pickup will have no signal.

Yeah I was just thinking about that, unplug the injectors. Its just so you can crank the engine & not have it fire up. No, you can't move the p-up coil , but you can move the whole dist, so wherever the inner part lines up, turn the housing so the outer part lines up. Meaning if you drop the dist in and the inner part of the p-up coil is 20* away from the outer point, your timing is already that far off, so turn the dist housing so the "points" line up. Then find the post that is your #1.

Ok, finally found some more time to play with this money pit. I still cant get timing right no matter what. I did notice while playing with the software that my vacuum almost doesnt exist. I plugged everything off on the intake and put a gauge on the power brake port. I'm getting about 6" there @ about 750-850rpm. In the software (spark advance vs. RPM & MAP) my little green dot is floating around in the 90-94kpa range at idle. Now this tells me that the ecm is just dumping fuel in to the engine which is why i need loads of timing to get it to idle. I'm running the 12-368-4 (comp cams 292xfi) cam. How much vacuum do i need to make this thing idle. I know that the green dot should be somewhere towards the bottom and not at the top when idling. Something tells me that this is the cause of my problems.

Just got off the phone with comp cams and fast. CC tells me that this cam will work fine with SD and should make 10" vacuum at idle. They also said i needed to call fast. I called fast and fast said that this cam should make a minimum of 8" of vacuum at idle. I explained to the guy that car ran fine (meaning 100% drivability) with the factory 730 ecm and custom tune with this same 6.5" vacuum. He basically called me a liar and gave me another number to someone who doesnt answer the phone. Alot of help CC is. I doubt i'll buy anything from them again. I've got $3k tied up here in their products and cant get them to help. Anyway, has anyone ever had an issue like this? This is a big cam and i cant seem to find any posts on TGO with anyone using this cam or one similar to it with a SD car.

My first impression is timing. Retarded timing=low vacuum; low vacuum=too much fuel.

Just try setting the timing by ear (for now) then look at your VE table and check what range the vacuum is in. If you have a mechanical vacuum gauge, start the engine and turn the dist back & forth(slowly) to find the highest intake vaccum possible. This should be close to your engine's desired timing.

I know this sounds crude but it is a method to diagosing your problem.

You can theoretically then read your timing on the balancer, then read your timing in the CCOM main dash, then adjust your dist refernece up or down to get the two to match, meaning if the balancer reads 30* and CCOM shows
34*, you go into operation params and adjust dist reference down by 4* and your balancer timing and your CCOm timing should match.

Remember once you set the dist position, you don't move it.

That is no vacuum, not low vacuum its no vacuum. I just went & compared to my car and key on engine off, I get like 95 kpa. Check to see that you have the proper vacuum going to the MAP, make sure it is manifold vacuum & not ported. Also, check your MAP reading with the engine off, then check it with the engine running, you should see an immediate change to around the 50kpa range. If you are in the ball park somewhere, you should see a minimum of 50kpa even on a really crappy running engine. Did you select the correct MAP sensor in operational params? You may have a bad vacuum source, a bad map sensor, wrong map sensor selected in CCOM, or a bad MAP sensor. Or really bad timing set like my previous post, but the 95kpa says you have no vacuum an engine can't run with no vacuum at idle only WOT. I want to help you work through this if you want, pm me and I'll give you my cell phone # I get free nights and I think I can help.

BTW; you didn't select Alpha N mode did you? Just a thought. Alpha N mode doesn't look at MAP for fueling, its soley based on RPM VS TPS.

Hey, got your voicemail but for some reason didnt get the call. I was going to call back but i don't have your number!

Sent you a pm.