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Old 08-03-2017, 12:02 AM   #1
BR3W CITY
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Tackling a botched build, need SBC advice.

No shock to most of you, I'm an LS guy. Distributors make me dizzy. This post may be long, because this thing is driving me nuts.
------------------------------------

I had a friend/customer bring by his recent purchase, a 65 fleet he had sent up from TX. He asked I go through it, and some of the stuff I discovered is mind boggling in terms of its crap-factor.

RELEVANT INFO: '65 fleet, with a goodwrench crate 350, MSD vac advance HEI, and an FITech Go EFI 400 and command center. Its got some generic block huggers, and a Summit Holley-knockoff manifold.

PROBLEM:
The thing starts ok, but pops and backfires randomly (no rhythm). It can't take much load without making the backfires worse. It will go into gear and can go ultra-light throttle to 35-45. Trying to go much more makes backfiring worse.

WHAT I'VE DONE:
Started at Suck Bang Blow. Its got clean air, and all the throttle stuff works mechanically.
  • The FITech command centers had some known issues with their internal pump, as well as venting and pressure concerns. I read through all their "documentation" (what a joke, I would NEVER give FiTech my money after experiencing this thing). Went through all of it and wasn't getting any of the known big issues. Venting was good, lines all setup correctly and pump appears to be functioning well.
  • I had to replace the spark plug wires because the "builder" used regular MSD's with the block huggers and 3 were burnt to a crisp. Put a fresh set of plugs in it at the same time. Saw small improvement in idle condition but thats really it.
  • Noticed that the dizzy felt a little loose as I was replacing plug wires. I've seen, and had it happen, that the last person working on the car didn't have a dizzy wrench and so they didn't lock it down all the way. Naturally, I wanted to check out the timing.
Soooo..I pull the vac line off the HEI, fire it up and go to read the timing. No sign of the witness line for timing, so I play around with the light to make sure it wasn't set goofy. In doing so, I noticed that if I set the light to nearly 60* ahead, I could just get the line to come around enough to be seen. This is weird.

So I give the dizzy a wiggle to see what kind of movement I have, and no amount of swing brings the line around...so its WAAAY off. But, its still running. The whole 60* thing starts bugging me, so indicate 60* off the timing mark and make a new reference mark and start seeing where it ends up. I went all the way around the balancer doing it, and find out that with the distributor on #1, I can get a timing mark to line up....at almost exactly 120* OFF where it should be.

SO, I look at the firing order and realize that #6 would be up at the same time. I swap the timing light over to #6...and SURE ENOUGH my original timing mark now lines up when using the light.
MY THEORY / WHERE I NEED HELP: So, at this point I'm being led to believe that when the junk was put together, they put the dizzy in place when #1 was TDC on the exhaust instead of on the compresssion. Even getting to this point had my head spinning. What is the correct way to sort this out? Is it as simple as pulling the dizzy, realigning the original timing mark at #1 TDC on compression, then stabbing the dizzy back in and retiming?

This has been an odd ass troubleshooting, as I've never had a car run that far off, but I guess in terms of firing order and timing, it does seem possible. Help me out guys.
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Old 08-03-2017, 01:27 AM   #2
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Re: Tackling a botched build, need SBC advice.

If the timing were truly that far off, it would not start. You more than likely have a bad harmonic balancer that the outer ring has spun or a balancer that has the timing marks carved in at 12 o'clock requiring a different timing cover to get a correct reading. First make sure it is wired correctly and you have a solid 12v to the HEI cap while running, and not the original resistor wire. Double check the wiring on the FITech unit to make sure it has all the correct power and grounds. Also check the fuel pressure to the unit. Dirty fuel filter?
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Old 08-03-2017, 01:31 AM   #3
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Re: Tackling a botched build, need SBC advice.

Pull the #1 plug and reset the distributor accordingly. While you have that plug out and affirming TDC, make sure the timing tab is lining up with the mark on the HB. Double check the firing order following each wire as well...I'm not even going to comment on the fuel injection because I'm a die hard Quadrajet guy..."jus sayin"
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Old 08-03-2017, 06:30 AM   #4
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Re: Tackling a botched build, need SBC advice.

You might have an incorrect timing pointer. I would double check that firing order too.
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Old 08-03-2017, 11:26 AM   #5
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Re: Tackling a botched build, need SBC advice.

My panel had the same problem with the timing marks not even being close using the #1 cylinder. If I put my timing light on #3, it was close. Figured out my balancer outer ring spun. Had a buddy with the same problem too.

Here is what the backside of mine looked like when I removed it.

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Old 08-03-2017, 07:35 PM   #6
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Re: Tackling a botched build, need SBC advice.

I agree with some of the previous suggestions. Pull the plugs find TDC for #1. Verify the timing mark on the balancer. Once that is know good, Reinstall the Dist with the rotor pointing to #1 plug. Put all the plugs back in and double, triple check firing order and spark plug wires. I bet that fixes it. If not at least you will know the ignition is good. You may also want to make sure you have full 12V to the Dist/Coil set up as points system used reduced voltage as to not fry the points.

Once the ignition system is working correctly, the Fi-Tech system will probably need to relearn.

Good Luck. Remember Keep it simple and methodical in trouble shooting.
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Old 08-03-2017, 08:30 PM   #7
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Re: Tackling a botched build, need SBC advice.

Update: Decided to not trust the timing mark at all, and pull the drivers valve cover and watch the valves. I got the valves both closed to where I could spin the pushrods easily, and checked the markings.

The balancer was no where near close, like still 40-60* off, so I'm going with the fact that the balancer either spun, or was never put in right. I put a small dayglo hash on the balancer at the 0 point with everything still lined up.

I checked the rotor, and it was correctly pointing at #1. Its hard to tell if its "perfectly" at #1, but I had placed a reference mark on the cap and the dizzy base, and the center of the rotor lines up pretty straight with those.

When I did the plug wires, I simply replaced the old wires 1 by 1, instead of starting from scratch. It seems like they PO swapped #2 and 7, but may have also started #1 on the #2 plug position? To be sure, the #1 position on a GM HEI is the FIRST pole clockwise of the wiring/module, right?

I redid the firing order the way I know18436572 (unless it changed lol), and made sure I had a solid connection on all my wires adding some dielectric for good measure.

I reset all of the relearns on the FITech, and flashed the ECM.

SO: Its now extremely hard to start, and doesn't like idling right away. I did get it started with the vac advance disconnected, and had to give it throttle to around 1500-2k as it warmed up. Allowing it to settle into idle causes it do die pretty fast, and pretty abruptly.

I was able to use my new mark on the balancer to try and set base timing, and had about 17*.

The good part, is that if I kept the idle up, the engine now rev'd way more freely, and could rev up and down (back to my hand idle speed around 1500) without misses or bogging. At that point it had sounded better than it had at any point, and wasn't shooting flames or massive gunshot backfires. It still refused to idle correctly however. I tried with the vac advance both on and off, and it prefers having it disconnected.
I bumped the commanded idle speed in FiTech up a bit (from 800 to 1000), but it still had some issues maintaining idle, almost like it was encountering resistance.

So at this point, I was able to turn up the manual idle screw on the throttle body and the truck would hold a 12-1500rpm idle. It would rev fairly freely, and still sounded the most even it had since I've seen it. It did still immediately die when I put it into gear. I tried to restart a few times, but the battery was low from all the starting for a few days..so she's on the charger for the night.

What do ya think? It seems like straightening out the spark was crucial, but these other/new/different problems still have me a bit behind the ball.
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Old 08-04-2017, 01:30 AM   #8
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Re: Tackling a botched build, need SBC advice.

Checked for vacuum leaks?
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Old 08-04-2017, 06:01 AM   #9
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Re: Tackling a botched build, need SBC advice.

Quote:
Originally Posted by kwmech View Post
Checked for vacuum leaks?
That's what it sounds like to me too.
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Old 08-04-2017, 11:00 AM   #10
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Re: Tackling a botched build, need SBC advice.

Umm... the throttle body doesn't have a "manual" idle screws. Those are to help set the IAC count, which needs to be in a specific range. You cannot adjust the FiTech like a carb. You'll never get it right.

I HIGHLY recommend you check out this thread on Chevelles.com as it's the best FiTech tread on the web at this point. Actually the whole EFI area has the most info on this unit and the Sniper.

http://www.chevelles.com/forums/89-e...tings-etc.html
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Old 08-04-2017, 11:30 AM   #11
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Re: Tackling a botched build, need SBC advice.

Ok, the thing where an idle screw WOULD be, is the thing I had to use. It refused to stay running without it. FiTech says that the IAC is on the drivers side...this was on the passenger.

Going back to the fact that this FiTech is just.....just...bad. Had to read 30 threads on all of the vent and return line problems, figure out why the internal pump was all over the place (the PWM control apparently). I'm seriously considering just going and slapping a parts store 650 on this thing so it runs.
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Old 08-04-2017, 12:33 PM   #12
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Re: Tackling a botched build, need SBC advice.

Where is the timing tab? There were more than one location from factory over the years. One was almost straight up, you see it down behind water pump. The other's are about 2 o'clock looking at front of motor. If crate motor they may have used the old timing chain cover. Try setting timing with a vacume gauge. Move the distributor untill you get max vacume, maybe about 18 inches of vacume, then go back just a little to about 1 inch less then max. At max you might get a ping.
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Old 08-04-2017, 12:36 PM   #13
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Re: Tackling a botched build, need SBC advice.

A basic HEI distributor doesn't know and doesn't care which post you connect to #1. What does matter is that the post selected as #1 matches the arrival of #1 piston to the top of the compression stroke when the timing is set for 0 btc and that the rest of the wires match the firing order. It also doesn't know or care about the timing mark on the balancer. Sounds like the engine builder stabbed the distributor off a post or two and just adjusted the wires to match. Nothing wrong with using #8 or #2 for your timing adjustments, depending on which way things are off, as long as YOU know which cylinder is TDC compression stroke when the balancer mark is at the 0 mark.

Don't know much about FI systems but does yours get any information from the distributor or a sensor on a flywheel or balancer? Wondering if it has gone into some kind of "limp home mode" due to conflicting or missing inputs.
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Old 08-04-2017, 12:37 PM   #14
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Re: Tackling a botched build, need SBC advice.

Digging your troubleshooting here. I agree with Chevy_Mike on the IAC. After reading a bunch of post on the chevelle forum I have a thoughts. On the hand held controller can you should be able to see the relevant AFR ratio, IAC count etc.. The IAC stepper count is anywhere from 4-10 on allot of the setup guys are posting. What is the IAC count when your problem child attempts to idle and abruptly shuts off? If the AFR is lean will holding the throttle open partially clearly indicates a vacuum leak or exhaust leak (but you should hear that at different times). From what I have read guys are having problems with coming from part throttle back to idle and the ECM does not compensate properly. I would try get the idle screw back to its factory position and leave it. Something is screwing up the ECM and the IAC count and AFR may be a symptoms. Good luck and keep us posted.

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Old 08-04-2017, 06:44 PM   #15
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Re: Tackling a botched build, need SBC advice.

I have been following the FiTech product for over 1.5 years now. I actually have the very first Go Street EFI from them (I was first on the wait list and took 5 months to come out). I haven't installed it but I watch a lot on the forums and Facebook about issues.

8 times out of 10, major problems are related to installation error. Most problems were related to the FCC fuel unit but once fuel delivery issues were solved, most found the EFI units work well. They do have their quirks about them and do require some "tuning" but most of that is from the control unit, not the mechanical part. Once those are set, you tend to not play with them.

The biggest thing is most think this is a plug and play unit. It is not. It does require being correctly setup both mechanically and computer. I can say, if you're playing with the screw on the pass side of the unit, you already do not know what needs to be done. None of these are idle screws. They are throttle stops and need to be adjusted correctly. The linkage is not progressive and if you don't have the butterflies sync'ed, it will cause problems. ANY leaks in the exhaust system will cause problems. Not having the fuel system correctly setup will cause problems. RFI noise from the ignition or running a MDS box not wired correctly will cause problems.

The ones who had it best first started with a WELL running engine (i.e. carb setup). With it running great, they made the switch. At that point is was all setup of the EFI part and not trying to troubleshoot timing issues, vacuum leaks, exhaust leaks, etc.

Not trying to bash on you but pointing out you need to solve all of the issues that do not relate to the EFI before you even start to tune the EFI.
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Old 08-07-2017, 01:24 AM   #16
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Re: Tackling a botched build, need SBC advice.

Update, but first rant:
I'm not solely blaming the FiTech system for the trucks issues, but I am most totally saying that from the exposure that I've had to it...the available documentation, the "help" from the mfg, and its inconsistency to function as all the resources tell me it should...it would never be something I would spend money on, nor install on my own vehicle. Not when I've had success with other comparable EFI systems, and not when used to the function of "real" fuel injection. I'm glad its worked for those of you that it has, maybe this one is just crap. I have more related to why in my update below.
/rant


Update: So after verifying all the stuff in the last post (firing order, condition of all ign component, timing mark location in reference to actual TDC and cap/rotor)...we had a mostly running car. There were no vacuum leaks I could detect, and according to the screen, the engine is pulling like -16hg at idle as a reference. Found the factory adjustments for the throttle screws and reset them (passenger side is NOT iac screw, according to the guide). Fully re flashed the "ECM" to its factory V8 config, and re did the setup AGAIN.

Didn't want to catch after the flash. Got it to catch and idle again with some pedal input. Consulted guide for cranking and start enrichment, made two small tweaks in line with suggestions. Felt better when cranking and caught quicker, still idled like dogsh!t.

Did the IAC calibration/adjustment process, but again ran into the limitations of their guides. At no point does it allow the IAC screw to be dialed back far enough to get the IAC count within spec, but also keep the motor running. With the TPS% setup and checked the way they wanted, the truck started with a 200 IAC count. I can only manage to get it as low as 82 and keep an 850-ish idle. It still feels like its hunting, and any less IAC adjustment and it will instantly die. I had some luck on forum threads with things to try, haven't gotten through it all yet. Some of the info conflicts itself.

Its also during this time that the FITech just decided to stop commanding the fans. Awesome. Checked and tested all the wires, fuses, relay. I can manually energize the relay and get fan control. Checked all the Fan settings in FiTech, and made sure all the commands and on/off points were correct. Still nothing. Put a meter on the signal wire coming off the FITech unit and forced it to fan state ON, but it didn't appear to have any sign of a signal. Had to put the fans on a switch for testing so she wouldn't melt herself down. Also had the FITech screen whitescreen out on me once as well. Yay.

Mike, install yours and tell me whats wrong with mine. Or give me some hope and tell me that its perfect and I just have a bad one.

With the thing timed, mostly new ignition stuff which all outwardly seems to be working, no leaks of any sort, and no other signs of clear mechanical defect...I do not know what to blame besides the only component that I don't really have control over...fuel. Otherwise I need oddball suggestions, because "normal" stuff isn't fitting the bill. I may not be builder-of-the-year, but for f*cks sake I've built enough power on dumb setups that didn't require this level of head scratching. Its just a damn goodwrench crate motor, and I've seen 8-10 threads with people being able to at least idle/drive/log this exact setup (HEI, Goodwrench 350, base tune with only the quick start settings done).

TL;DR Don't agree to fix undocumented half-built projects, unless the customer is willing to let you start ALL the way over. Otherwise you'll chase your tail like I have for the last few days.
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Old 08-08-2017, 05:22 AM   #17
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Re: Tackling a botched build, need SBC advice.

Put a carb back on there, get it running correctly and then start over with the fitech. You'll never get the efi doing its thing on an engine that might have other issues.
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Old 08-08-2017, 11:22 AM   #18
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Re: Tackling a botched build, need SBC advice.

Yea, basically told the owner I'm chasing my tail until we know that the thing ACTUALLY has a baseline to work from. Reaffirms; exactly why you don't take over incomplete projects lol.
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