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From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
If you snag a plane ticket I'll feed you, give you a full tank of gas, and let you let mine eat until something breaks.
Now that's FUNNY! Thanks for the offer though.
you should be out looking for a foundry. I hear they have good ones in Mexico. Adiós gringo
Yeah, I know...BUT, I did go over to the NEW Speedway Motors store in west Phx and had a talk with them about the manifold. Waiting to now hear back from their main HQ.
Also, I got fed up with this tire non-sense and called Summit and ordered tires and they say Sept is the "NEW" due in date, but we shall see. Going to try and get to checking the valves this weekend and oil change along with "maybe" replacing the dizzy with my new DUI that I have had like forever now, but we shall see. My son is down here from CO setting up a new site at the Army base down south from here and is going to come up for the weekend to give me a hand. He should be here until mid Sept, so I have plenty of time to get this stuff done.
So I dumped about 2 quarts of fuel out of all 8 cylinders because the injectors decided to go full duty cycle while cranking. Guess it's time for an oil change. Seems fine otherwise.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by 84 4+3
So I dumped about 2 quarts of fuel out of all 8 cylinders because the injectors decided to go full duty cycle while cranking. Guess it's time for an oil change. Seems fine otherwise.
HOLY CRAP!! That is something I need to ask Bob about and will be talking with him tomorrow anyway and will mention it. GL
I think my offsets for voltage in the tune are off which may have caused it. It cranked just slower than if should of. I suppose it hit a different part of the ve table too but something wasn't happy for sure.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
According to Bob at Dynamic EFI, the EBL as itself can not cause that issue. Something is commanding the injectors to fire. It is receiving distributor reference pulses which is keeping the fuel pump activated along with pulsing the injectors while cranking. He suggested looking at your dizzy or harness wiring. I'm not sure the VE table would cause the issue, but I will take a look at that input. Hope you get it sorted out soon. Crazy issue for sure.
According to Bob at Dynamic EFI, the EBL as itself can not cause that issue. Something is commanding the injectors to fire. It is receiving distributor reference pulses which is keeping the fuel pump activated along with pulsing the injectors while cranking. He suggested looking at your dizzy or harness wiring. I'm not sure the VE table would cause the issue, but I will take a look at that input. Hope you get it sorted out soon. Crazy issue for sure.
yeah the harness was good when I swapped the intake a few weeks ago. I'm guessing a weak battery caused the issue. Even while cranking there is a bit of fuel spraying but it seems reasonable. I don't know. We'll see how it goes next start.
That’s a lot of fuel I can’t get my head around how you could hydro lock an engine like that. From memory you have 80lb/h injectors running at higher pressure. So I guess that could produce around a litre a minute x2 (to make the maths simple) but even then the engine would have done plenty of cycles in that time. Let’s say 100 cycles in a minute. It only opens the valves every second stroke so that’s 40cc over 8 cylinders. So is 5ml per cylinder enough to hydro lock an engine? I don’t think it is so there must be something wrong with my maths.
That’s a lot of fuel I can’t get my head around how you could hydro lock an engine like that. From memory you have 80lb/h injectors running at higher pressure. So I guess that could produce around a litre a minute x2 (to make the maths simple) but even then the engine would have done plenty of cycles in that time. Let’s say 100 cycles in a minute. It only opens the valves every second stroke so that’s 40cc over 8 cylinders. So is 5ml per cylinder enough to hydro lock an engine? I don’t think it is so there must be something wrong with my maths.
40 ml would for sure hydrolock it. You figure my total compressed volume is about 78cc at TDC.
My math shows me flowing a little over 1000cc/min at my current fuel pressure so that is about 33 ml second. Couple that with it probably only cranking at roughly 90 rpm... thats about 1.5 revolutions per second at best. Now you have ~10 ml entering 4 cylinders. That brings static compression up to ~11.8 to 1 on 4 cylinders slowing cranking down a little more. With the slower speed and volume of fluid in the bore you aren't spraying all that fuel out the exhaust, especially with the overlap. Then you do it again. And again. After cranking for 40 seconds with a weak battery... thats more than enough to stop cranking. Then after throwing a charger on it on high for an hour then trying to start normally it makes sense that it just stopped on the compression stroke. It's well within the realm of possibility.
40 ml would for sure hydrolock it. You figure my total compressed volume is about 78cc at TDC.
My math shows me flowing a little over 1000cc/min at my current fuel pressure so that is about 33 ml second. Couple that with it probably only cranking at roughly 90 rpm... thats about 1.5 revolutions per second at best. Now you have ~10 ml entering 4 cylinders. That brings static compression up to ~11.8 to 1 on 4 cylinders slowing cranking down a little more. With the slower speed and volume of fluid in the bore you aren't spraying all that fuel out the exhaust, especially with the overlap. Then you do it again. And again. After cranking for 40 seconds with a weak battery... thats more than enough to stop cranking. Then after throwing a charger on it on high for an hour then trying to start normally it makes sense that it just stopped on the compression stroke. It's well within the realm of possibility.
Yeah I don’t know. Your numbers are more precise but close enough to mine. I don’t understand why you say 40cc will hydro lock it if your compressed volume is 78cc (forgive me for swapping between metric units 1000ml=1000cc=1litre but I figure you know that anyway). I take your point about slow cranking but there is another problem and that is the injector duty cycle. Obviously there is higher flow during starting but surly it’s not 100%. I feel like there is either something I don’t understand (highly likely) or something else is going on.
Yeah I don’t know. Your numbers are more precise but close enough to mine. I don’t understand why you say 40cc will hydro lock it if your compressed volume is 78cc (forgive me for swapping between metric units 1000ml=1000cc=1litre but I figure you know that anyway). I take your point about slow cranking but there is another problem and that is the injector duty cycle. Obviously there is higher flow during starting but surly it’s not 100%. I feel like there is either something I don’t understand (highly likely) or something else is going on.
If it gets 40ml in the bore that gives an effective compression ratio of nearly 21:1... I don't think there are many starters capable of dealing with that so for that instance... yeah i think thats all it would take. The pussle under the car was huge after blowing out the bores.
after it was all fixed even while cranking, if I pull the throttle bodies shut they'll get a cm of fuel in them after about a second. I did adjust my minimum air gap to correct that after (one of the adjustments i made while sitting) but that's a damn lot of fuel cranking. The other odd thing is I don't have asynchronous fueling enabled. So both injectors pulse at the same time iirc.
If it gets 40ml in the bore that gives an effective compression ratio of nearly 21:1... I don't think there are many starters capable of dealing with that so for that instance... yeah i think thats all it would take. The pussle under the car was huge after blowing out the bores.
after it was all fixed even while cranking, if I pull the throttle bodies shut they'll get a cm of fuel in them after about a second. I did adjust my minimum air gap to correct that after (one of the adjustments i made while sitting) but that's a damn lot of fuel cranking. The other odd thing is I don't have asynchronous fueling enabled. So both injectors pulse at the same time iirc.
Ah yeah right I get it now. I wasn’t thinking compression I was just thinking volume and space in the cylinder makes perfect sense now thanks.
Man that’s a lot of fuel though isn’t it. I’ve always wondered about the actual flow rates of these type of injectors. When you do the calculations of how much power you can make it never adds up. I always think that those injectors must actually flow a lot more.
Ah yeah right I get it now. I wasn’t thinking compression I was just thinking volume and space in the cylinder makes perfect sense now thanks.
Man that’s a lot of fuel though isn’t it. I’ve always wondered about the actual flow rates of these type of injectors. When you do the calculations of how much power you can make it never adds up. I always think that those injectors must actually flow a lot more.
the math on mine at my pressure adds up at 80% DC actually pretty close. Its not exact but well within reason. Says 375 instead of 350 at the wheel. The 80 lb/hr ones are rated at 12 psi I believe
the math on mine at my pressure adds up at 80% DC actually pretty close. Its not exact but well within reason. Says 375 instead of 350 at the wheel. The 80 lb/hr ones are rated at 12 psi I believe
yeah I found something once that said those type of injectors were rated based on 12psi (except for one type of 454 injector). But a lot of that stuff seems to have disappeared off the internet now. The thing is if you do the calculations on power based on injector capacity it alway falls short on the actual dyno results and that’s using eddy current dynos like a DynoDynamic or Mustang which tend to give lower (more realistic) results. I was talking to the local efi guy I use to buy and test injectors. He said he could test flow on that type of injector so I might get him to do it at some point for interest sake.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by 84 4+3
the math on mine at my pressure adds up at 80% DC actually pretty close. Its not exact but well within reason. Says 375 instead of 350 at the wheel. The 80 lb/hr ones are rated at 12 psi I believe
Actually, the TJ11 injectors which they say are 90# injectors are not really 90# per say at 13psi. I have another new set of TJ11s just in case and had them flow checked at the shop that I take injector to. At 13psi the "90s" flow exactly 80pph. At 15psi, they flow 90.1pph. I set my FP at 30psi with these injectors, vacuum referenced.
Actually, the TJ11 injectors which they say are 90# injectors are not really 90# per say at 13psi. I have another new set of TJ11s just in case and had them flow checked at the shop that I take injector to. At 13psi the "90s" flow exactly 80pph. At 15psi, they flow 90.1pph. I set my FP at 30psi with these injectors, vacuum referenced.
There seems to be so much varying info on the TBI injectors that no one really knows what's what lol.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by 84 4+3
There seems to be so much varying info on the TBI injectors that no one really knows what's what lol.
Yep! I haven't found a pair of true 90s for a long time. They say these TJ11s are 90, but not at 13psi they aren't. I still use them though and they seem to work just fine for me. They also say that the max pressure on these is 32psi, not sure how correct that is, but at 30psi they work ok.
I think I've finished up... or at least done as much as I can. I've opened up the rest of the runners to the point a car fits through each evenly. Then I cranked up the pressure on my media cabinet and with a very wide tip ran blast media through each runner to knock down some of the roughness I can't reach... this is the result of all that work over the last month or two...
We'll see how she does...
Ironically enough I look at it now with all the modifications and it really does look like an L31 vortec base now...
Guess it's time for an oil change. Seems fine otherwise.
