Seems random. Sometimes just a pop, then a pop,pop. Some are louder than others. With higher rpms they get more frequent, but still random
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Seems random. Sometimes just a pop, then a pop,pop. Some are louder than others. With higher rpms they get more frequent, but still random
Had the day off, decided to work on the Monte. Figured I would pull out all the stops and start completely over like this never happened. Took several peoples recommendations and put fresh fuel, spark plugs, even a new coil just for the hell of it and started it up.........
This may be premature but I just called and added insurance back on it.
Letting it cool now and I will go back and add the dfi back in as I have no fan control wired into the stock ecm at this time.
Giggity......
https://www.youtube.com/watch?v=3Ban6DiBup0
(Sorry for the poor quality, next one will be better)
Installing the blowah next
Blower install........GO!!!
Quote:
Originally Posted by firebird_1995
I will be there the 14th and are shooting for TNT night Wednesday the 17th if you want to come out, in whatever vehicle. Gonna try to get the Nova down in the 12.70's.
That sounds good man, can't remember if you did the spring in the elbow yet or not??
Vids not good on my phone... How is it???
Co-Owner/Admin @ LTXtech.com
Try this one :D
https://www.youtube.com/watch?v=ssZ3-sd7zr0
Edit: damn it sucks too. I'll try again.....
Ok im satisfied for the next 3 minutes... now do a burnout with it lmao
Ahhh haaaa! Sounds gooder!
Lol thanks. I took another idle video in the highest quality I could on my phone and it still looks like crap. Not sure why its doing that, the others I've taken looked better.....
https://www.youtube.com/watch?v=4HxXWTwz9tQ
Is the dfi back on the car?
So here's the rundown going back to the very first startup.....
My original intentions were to start the engine up with stock injectors and without the supercharger to break the engine in before pouring the coal to it. That didn't happen. So when I got it ready I fired it up with 60# injectors and the supercharger attached and found it would start and immediately die. It took a lot of troubleshooting to finally find out the msd opti was the culprit. What was happening was as soon as the key was released, the system voltage would spike due to the starter being dropped from the load. Evidently msd optis don't bode well with voltage spikes and it caused the accel dfi to lose a crank signal and stop firing. I've since learned that the accel dfi uses a 12v signal on the low resolution side of the optical sensor where the factory pcm uses 5v. I was told this is normal and "nobody else has had a problem like that". I think that's why most guys running accel dfi have problems with msd optis but I can't prove it. Anyways I changed the opti out with a known good gm unit and it fired up and ran, but it now would backfire through the exhaust. So the troubleshooting began again. I thought maybe my known good opti was bad so i replaced it, no luck. Then i removed the supercharger and 60# injectors in lieu of stock equipment, then swapped icm/coil, spark plugs, wires, various sensors, readjusted valves, checked fuel pressure, tried numerous tunes and eventually removed the dfi and installed a stock pcm. At this point the engine had about 10 minutes of run time and about 500 startups on it and the oil had been changed 3 times due to fuel contamination. Plugs had to be cleaned every 20 starts or so because they were fuel fouled. This lead to the compression test. The only compression tester I had was an old Napa balkamp tester. It had a flexible hose but you have to hold it in the spark plug hole. Hard to do while cranking. So I went to O'Reillys and borrowed theirs. When I ran the compression test I found ~75# on all cylinders. Added oil to the cylinder and the pressure would rise to around 125. While troubleshooting the issue where it would start then stall, every time the key was turned those big injectors were dumping fuel in and washed out the rings. So I rering it. Still backfires. I grab the O'Reillys tester and its back to 75# pounds. At this point I can't believe that ALL cylinders were at 75# both times. I have my wife come out and help me as I put the Napa tester in and it reads 125-135. I mix and match gauges and hoses and come to the conclusion that the O'Reillys tester has a leak in the hose. Now, I can't deny that fuel was finding its way past the rings the first time, so it probably needed new rings anyways, but I almost junked the whole project because I thought the new rings didn't take. So now that I knew the compression wasn't an issue, and the backfire persisted, I tried a few more last ditch effort things, readjusted valves, changed tunes, nothing. So this morning I decide to try a few suggestions. Popo suggested trying a hotter heat range plug and featherburner suggested a fuel drier and fresh gas. I had been swapping betweeen autolite 103's and a previously used set of ac delco tr44s. I bought a set of autolite 106's, a new coil, a bottle of heet, and 5 gallons of 87. I changed the plugs and coil, added the heet and fuel. Guess what, no backfire. I swapped the new coil out with my old one just to see if that was the culprit but there was still no backfire. So my thought are, while the autolite 103's were definitely too cold, the ac delco tr44s should not have been and I tried both. The entire fuel system was new from the tank to the injectors. During troubleshooting with the 60# injectors, I had put 5 gallons of 93 octane fuel in on three separate occasions. It is very humid here and the temperature spikes from hot to cold all the time so i guess it could have happened like that or maybe i got a bad batch the first time. So I don't know when or how I got water in the fuel, but I'm leaning towards that being the culprit of all this heartache.
The end!
Yes. I'm using a tune George Landis wrote for a few boosted lt1 cars hes done in the past.Quote:
Originally Posted by JPack
I have a section i cut out of an aluminum 90 that keeps it from collapsing.Quote:
Originally Posted by JCZNova
I'm hoping I'll be working closer to home by then. I've been saying I'm going to meet you guys out there but it just hasn't happened yet.
Quote:
Originally Posted by firebird_1995
It's awesome that something is finally going right for you on this swap. Hope you can make it out, as this is the last time I will be in town, and the last testing I will have prior to the Shootout.
Thanks! I needed to catch a break.
Well I'm always looking for reasons to get out of work, I hate driving 4.5-5 hours a day and we need to tnt my dads car anyway. Sounds like a plan!
So happy things are coming round for u... Def do t wanna jinx u...so pleaseeeee keep us posted!
Co-Owner/Admin @ LTXtech.com
I just can't believe it would be something so simple like plugs or fuel. Maybe it was a combination of both. Either way, that problem is solved. But........ I think I may have a potentially fatal design flaw with this setup.
With the throttle body moved from the front of the intake to the inlet of the blower, I've extended the distance under vacuum from a little to a lot. While this by itself isn't an issue, should a coupling blow off under boost the engine would be free to suck in all the air it wishes to consume. My concern is, if this were to happen the map sensor SHOULD sense the drop in pressure and adjust the AFR accordingly and keep the engine from going lean but with no throttle blades to shut the air off, the engine would runaway. I guess that's what rev limiters are for but depending on when and where it happens that could be bad. Next design, the throttle body is going back to stock location.
Glad to hear the dfi was not Tue issue. and car working out for you!
Thanks. I wouldn't have told you if the dfi was at fault anyways :pQuote:
Originally Posted by MeanTA
^ this guy offered to help pay for any repair needed to the dfi, even though he never ran it. :thumbup:
LOL.... Fair enough:)Quote:
Originally Posted by firebird_1995
I was just doing the right thing.
Im confused on ur question about air... If u blew off any coupling...wouldnt u go FAT rather than lean? I mean it would be between the blower and the TB where ever it would be...and that would kill boost...and no matter how much air the tb pulls from fresh air... It would not be as much as boosted air.... or am i misunderstanding
Co-Owner/Admin @ LTXtech.com
No you're right. I was just thinking that after you lift off the throttle the ecm might command an idle cell in the fuel map and go lean, based off its thinking that little to no air is coming in. But in the end, the map sensor should save you there.
I agree...and im assuming ur gonna run an AF guage which will be immediate tell tale once u feel power loss...and u WILL feel it...Quote:
Originally Posted by firebird_1995
Co-Owner/Admin @ LTXtech.com
Yea. Maybe its not as bad as I think after all.
I do understand ur concern!!!Quote:
Originally Posted by firebird_1995
Btw... What are u gonna do with the hole in the hood?
Co-Owner/Admin @ LTXtech.com
This guy right here...
http://www.summitracing.com/parts/sum-470450
Unless I can find a good used cowl hood on craigslist.
Will that cover it amd remain centered or no?Quote:
Originally Posted by firebird_1995
Co-Owner/Admin @ LTXtech.com
Yep. I looked at going with a small, off centered hump (think 80's turbo trans am) just big enough to cover it but I though it wouldn't look right.
Sounds like your close enough to start thinking about getting in some track time :finger:
If you are worried bout a runaway, toss a 58mm TB on there (not sure what you have on there now) and rig up like an old choke cable to use to force the blades shut if that ever were to happen. Obviously you would want the blades to be reversed from stock and spring loaded open.
Facebook is looking for more pics... So when u can... Pics and a disortation that u would like me to use... no rush.
Co-Owner/Admin @ LTXtech.com
Ditto….Quote:
Originally Posted by bsgreenz
Trying to find a B-body that isn't completely roached is a full time job tho'… .
Man there are so many tables in this dfi program and everything is done in realtime. To say I'm overwhelmed is an understatement. The biggest issue I see now is my injector pulse width. Accel recommends not going lower than 1.7 ms and the lowest idle I can obtain without inducing a roll is 1000. While I don't mind this the pulse width sits at 1.3-1.5 here and once put in gear it dies. I also noticed pressing the brake makes it go wonky ( I'm assuming because of the vacuum booster). It holds vacuum with the engine shut off so I don't think its bad. Currently I have a stock fuel pressure regulator on so I might try this adjustable one I got from Larry and turn the pressure down a bit and see if that helps the pulse width and idle.
Well that ain't gonna work. I wasn't clear on what those fmu's do. They only raise the pressure under boost, nothing under vacuum. I've done a lot of reading on it and guys are able to get these 60# injectors to idle fine at lower pulse width so I'm just going to have to keep messing with it. @JPack do you have any idle tuning tips for me??
Map sensor on its own good source of vac? No kinks cracks etc? Fpr vac source in good location? Played with target afr @ idle points? What map do you have on now? 02 feedback good and is it in ideal location? How much vac is the car pulling at idle? When on the gas a little bit does the brake peddle get hard or soft? How about at idle? Fuel pressure with no vac applied is what? With applied and blip of throttle what does it do?
Thats where I would start. Make sure all your ducks are in a row and lets go from there.
Found the page I was looking for in the manual.
http://i3.photobucket.com/albums/y77...psdfccac5b.png
Map sensor is in stock location on intake, I've read that putting it on its own 10" long vacuum line will help dampen the pulsations that make it go into a hunting pattern, I may need to do that.Quote:
Originally Posted by JPack
Fpr vac source is stock location, hose in good shape.
I have not messed with target AFR points. It calls for around 14.5:1 and the wideband is reporting around 11:1. While closed loop fueling the correction is maxed on rich.
2 bar map
Wideband o2 is new and about 4" after the collector. All joints are welded.
Vacuum at idle, dfi is reporting -5 to -6 psi from map sensor. My boost/vacuum gauge reads a steady 17"
Brake pedal seems firm, I'll have to pay a little more attention to it tomorrow.
Fuel pressure WAS around 45psi at idle with vacuum plugged in. Hard to read the gauge because it fluctuated a lot. I haven't checked it with no vacuum applied. I might go do that now.
I'm running this 400lph pump and it is hotwired. I have 1/2" supply and 3/8 return. BUT the stock gn pickup has a tank return size of 5/16"-1/4" iirc.
Damn that thing seems louder at night for some reason.
Ok, key on engine off it pressurizes to 55 psi. After the pump stops running it drops to 40psi
Startup with vacuum applied it fluctuates from 55-45 rapidly. With vacuum removed it fluctuates from 55-50psi. Blipping the throttle doesn't seem to change pressure any.
I'm running a stock fpr. With those numbers, it must be restricted at the tank pickup.
Off topic...arnt u gonna need a boost ref fpr so it goes to 1:1 under boost.
Co-Owner/Admin @ LTXtech.com