V6Discussion and questions about the base carbureted or MPFI V6's and the rare SFI Turbo V6.
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I have a question. Did you get that beast running? If so, how bad is it idling?
That nipple on the top pass side of the 2.8 TB is how the engine breathes at idle. There was a tube running from the PCV inlet nipple on the back of the intake manifold (not the plenum) to that nipple for idle air. You need to swap to the 3x00 TB... Or find a way to hook that nip to the intake... The harness connectors aren't THAT hard to swap in if you want to swap to the newer TB.
I haven't worked on it in a while. I know how to hook up the IAC valve. Look at the pipe plug I have in the UIM keeping dirt out till I can put an elbow in there. The electrical isn't a problem either; its the mechanical throttle lever of the 3100 that doesn't work in the firebird. If I was going to make a TB adapter anyway, might as well make one that uses easy (stock) components like vacuum lines, IAC, throttle cable, TV, TPS, and mounting hardware. I know all of that can be replaced by some other means, but stock is easier.
Any way you could get a TB from a 3.1? That would be the easiest way to solve some of your probs. Everything is the same except for the top plate and the air hole for the IAC. You can keep your vac block (where the lines connect to at the top) from the old TB and just pop it in there.
Well, I didn't mean for the pics to take so long, but I haven't had a chance to work on the car for a while.
The 3.1 TB is on the right. Notice that I have removed the coolant block from the bottom, the differences in the top cover, IAC and TPS, and that the 3.1 has a large corner plate on the upper plenum that the 2.8 did not, for the IAC inlet.
If I knew before, i would have used the 3.1 TB. The TB spacer would leak with the 3.1 TB, so I have to stick with what I have, this time. thanks though, saved me a trip to the jy on a Saturday.
Finnaly made time to work on the project. Driver side header is almst done. Its made of 1 1/2" sch10 (1.9"OD; 1.68"ID) 304L stainless pipe and weld els into a 2 1/2" flange. The 2 1/2" tube will go under the oil pan (stock location) and up to join the passenger header. Then they will both go forward (toward radiator) and in front of the motor to the turbo.
mild steel flanges... I always weld the flange from the inside and tack it on the outside. I also use 312 filler rod with the TIG for dissimilar metals. On these headers I'll probably weld the sides from the outside and the top and bottom from the inside due to the shape of the pipes and to clear the bolts. I'll also cut the cylinder head flange to reduce thermal expansion, and more importantly, clear the plug wires.
go all the way around the outside if possible. leaving a gap for the bolt head leaves a good place for a crack to start forming.
i went all around on mine and with the iron heads the bolts are closer together,and i was still able to get a reg head bolt without touching except on one tube. i had to take the cutoff wheel and grand a small flat on one lil part of the weld.
be carefull if u decide to cut apart the flanges after the headers are welded that thing is gonna spring all over the place lol. my ds header i cut the flanges and had to use a couple bar clamps to pull everything back in a straight line
I thought about it springing out. I was thinking I could minimize that if I weld the entire header up before welding the cylinder head flange. Right now its tacked in two places per runner. I was planning to cut the tacks to relieve all the preload and then weld the flange on. I'll probably not cut all the way through the flanges, but leave an inch at the bottom.
Don't cut the flanges. Every set of headers I have done that to, or had to deal with that had been cut would not fit or seal correctly after the the first removal. The flanges didn't stay flat relative to the head surface and this caused the sealing problems.
I now make sure that the flanges from one end to the other are bridged in some form or another. My current technique is to use metal rod (dowel), place it between two flanges where it won't interfere with the plugs, or bolts. Some bridging links will require bends to clear the dip stick tube and such.
Don't cut the flanges. Every set of headers I have done that to, or had to deal with that had been cut would not fit or seal correctly after the the first removal. The flanges didn't stay flat relative to the head surface and this caused the sealing problems.
I now make sure that the flanges from one end to the other are bridged in some form or another. My current technique is to use metal rod (dowel), place it between two flanges where it won't interfere with the plugs, or bolts. Some bridging links will require bends to clear the dip stick tube and such.
hes dead on, i had to weld pieces inbetween my flanges before i could remove them. if they were mild steel it wouldnt be that big of an issue but once u heat cycle those stainless headers a few times and remove them if the flanges are seperate they will go every wich way
Good advise... i'll see what I can do about it next time I work on it... might not be untill next weekend since I'll be in Chile for work this week... Summer time there... sweet.
Forgot to mention, when you do weld up the headers, make sure they are bolted to a spare/scrap head, or a strong flat piece of steel. This will keep the flange(s) in line and straight, while welding. Also let the headers cool after welding before removing them from the head/jig.
Which terminal on the coils do I put each spark plug wire? Any diagram or picture would be helpful. You can guess which stage of the process I am right now.
Glad to see you got the DIS wheel worked out. I've gone in a different direction than the drawing you sent me and am trying to get a reasonably priced production version available.
As far as the wire orientation, the numbers on the coils are correct, obviously ignore the numbers cast in the lower manifold since it's turned 180 degrees.
I finnally finished all the fabrication etc. I can't get it to start. I hooked up the timing light to the #1 cylinder and it is firing right on top dead center with the by-pass unplugged. I hooked up the laptop and I'm not getting a DRP from the coil pack and the base pulse width is 0.0mS, so the injectors are not firing. I added a wire for the tach and the needle is not moving either when I crank the engine. I double checked the wiring of the coil pack.. i need to triple check it i guess, then I'm not sure what to check.
I went through all the wiring many times and found a missing ground pin on the ecm. I added another pin to the ecm harness connector for a system ground that is used on the 165ecm, but not the 302ecm. I spliced it in with another system ground wire that was existing on the other connector. I can get the pin numbers if needed. Then I fired the injectors a couple times manually by grounding them straight to the frame with a length of wire.
The car fired up after a couple rotations of the crank. It ran like crap since it needs calibartion work, but it ran none the less for a couple of minutes, untill it conked out for some unknown reason. I worked a little on the tune then tried to fire it again, but the starter is fried from all the abuse this weekend. I think the MAF sensor might not be reading properly among other problems since it threw codes 33, 42, and 43.
How did you go about wiring in the ICM with the '302? I have been working with the '727 (ie '730) a lot lately, and am just curious how you went about it with the earlier ECM.
I never used the DIS with the 302, just the 165. I looked at both wiring diagrams (3100 and 2.8). All it comes down to is just matching the colors of the insulation and grounding the black wire to the block (or intake). There is a pin for "tach signal", but it doesn't seem to be working yet.
I can't seem to get it to start again. For some reason it is really hard to turn over. the starter cranked all day Saturday, but now that its getting fuel (as of this afternoon) it is very hard to crank. My best guess is its flooded really bad with fuel. My brother bought a new stater and we burned it up in under 90 seconds. I ordered a 170ftlb starter from summit 10 minutes ago. I'll try cranking with the injector fuses out to clear the flood when I get the starter (not ready to trust the WOT-clear flood method as hairy as the electronics are).
plenty of spark... lots of fuel (maybe too much?)... still no start... just some smoke from the downpipe (and my ears). We added 10 gallons of new gasoline and primed the fuel pump about 8 times, but maybe old gas is still in the rails. It seems like the ignition timing is unstable at slow (cranking) speeds.
Did you change the spark offset to accommodate the DIS vs distributor? The spark for the DIS base timing is ~57 degrees BTDC (one cylinder away minus the distance between the reference notch).
I have run DIS on a '7727 ECM without a problem by using the 57* offset, and used a FWD DIS mask ($a1) on an iron head car by using the same method only reverse.
I changed the "Spark Reference Angle - Base Timing" to zero (0.00 degrees) because it fires right on TDC with the bypass wire connector unplugged. Is that wrong? or is there something else I must change?
AFter doing some research on the "trigger wheel". Why do so many people say the 7th notch on the wheel should be 10* after the first notch? If you measure the actual crank it is alot closer to 8.7* than 10*.
AFter doing some research on the "trigger wheel". Why do so many people say the 7th notch on the wheel should be 10* after the first notch? If you measure the actual crank it is alot closer to 8.7* than 10*.
Not sure. Did you measure from the trailing edge of the reference notch to the trailing edge of the first timing notch? The sensor sees falling rate.
I am not familiar with the MAF code you are using, but with the $a1 mask I have the option to change the spark reference angle (this same principal applies to MegaSquirt with GM v6 DIS), and need to offset it when using DIS, also can use this same code mask on the distributor by setting the offset to "0"...
As far as I know, you can't just replace the distributor with the ICM without PROM changes.
Last edited by firstfirebird; 08-06-2009 at 10:02 PM.
Yeah, I measured the trailing edges and got 11mm IIRC and drew lines straight out on CAD to get 8.67*. I put in a 10 degree angle and the distance from trailing edges comes out to 13mm IIRC. My measurement couldn't have been off by more than .5mm (as opposed to 2mm/.079"). I trust what I measured more than the popular 10*, but I doubt that is going to really make any difference.
I tried a few angles in the chip (20*, 45*, 50*, 57*, 60*). 60* had the most effect, but it was a bad one with backfiring. Does the "7th slot" indicate cylinders 1/4, 2/5, or 3/6 to the ICM? I think I need to keep looking into the calibration like you're suggesting. I'm also working on a more accurate wheel to eliminate one more place for error. thanks for the reply!
I set up the wheel so the first of the double slots is approaching the sensor when #1 is at TDC. is this correct?
Yes, that is correct.
The way the module works is once it gets the EST signal, it retards the tarming by about 60*, and therefore the commanded timing signal in the ECM needs an addition 60* to put the timing relative to TDC back where it should be. This is why you will be able to start and run the car with the EST signal disconnected, but not attached using dizzy settings in the bin.
It really requires changing some offsets and biases (or adding a patch to the bin), to add the additional 60* of base timing. Also some changes to min and max timing need to be made.
I'm running DIS with $59 in my Datsun currently, and had to make some changes to biases to make it work. I've modified an S_AUJP bin, that should do the same but haven't tested it yet, and my test bench is down so I can't verify the changes on that yet, either.
I can't find an offset in tuner pro ($6E) that can be used. There is the "Spark Reference Angle - Base Timing" constant, but that would need to be set to -60, which cannot be done. The maximum value that can be entered into the spark table is 90 so that limits me to 30* of timing. I could advance the wheel 10 degrees to give me 40* max and that will be plenty, just the numbers will be weird.
I can't find an offset in tuner pro ($6E) that can be used. There is the "Spark Reference Angle - Base Timing" constant, but that would need to be set to -60, which cannot be done. The maximum value that can be entered into the spark table is 90 so that limits me to 30* of timing. I could advance the wheel 10 degrees to give me 40* max and that will be plenty, just the numbers will be weird.
Advancing the pick-up will work against you, especially at start.
You may need to add the biases to the xdf, whihc means you'll need to find a hack/dissasembly for $6E and add what is needed.
Changing the base timing angle is not what you need to do, well setting that to 0 will help advance the timing a bit if it had any other value you in there. This value is subtracted from the overall timing equasion. You need to add a total of 60* (when using a 60 degree v6 DIS ignition system), to get the timing in the right spot.
You should find a "max spark advance" value (may be worded a bit differently) that will limit the maximum spark advance to way less than you will need. Typical settings I see are in the 45* neighbourhood, you will need to set this over 100*, IIRC mine is set to 105*, though I run very little timing at RPM, usually around 18* or so, so my commanded is usually les than 80* advance. At idle I'm higher and usually around 87* or so on average, which is 60* less at the crank for timing, due to the way the DIS ignition module works.
Thanks for the good info. I'll play with it and report back the solution. Mind linking me to some code hacking threads? I have a BSME and have taken intro courses in C++ and Java, but I don't know where to begin for the GM ecm stuff.
I downloaded the $6E ARAP_hac and found a spark adder vs LV8 vs coolant that I should be able to add plenty of spark accross the table. I'll also need to increase the disable temperature for this table. I'll try it out in a couple days when I can get back to it.
The timing is firing at the right time (most of the time) with the coolant spark adder increased by 56*. The notches in the trigger wheel are more accurate than I can measure (they were cut on a CNC machining center). I think the times it misses is due to the engine cranking too slow. At first I thought it might be because it had been sitting for a year, but its not getting any easier after plenty of cranking with oil pressure. I've sprayed WD40 into the spark plug holes and cranked it without the plugs and its still hard to turn. The next test will be to loosen all the rocker arms to see if that makes a considerable difference.
I want to confirm few things that I'm pretty sure are right just to continue to eliminate problems.
Firing order: 1,2,3,4,5,6
Passenger side cylinders, front to back: 1,3,5
Driver side cylinders, front to back: 2,4,6
The waste spark ignition system means 1&4, 2&5, and 3&6 fire at the same time.
According to the cam card (COMP CAMS 260H) the intake valve is at .006" lift at 24*BTDC. That means, for example, the #4 intake valve is already open when the 1&4spark occurs for #1 power stroke. This may not be too much of a problem at higher (idle) rpm, but at super slow cranking rpm, its like the distributor being 180* out and correct at the same time.
Don't concern yourself with the waste spark system, I have sold several Comp 260h cams and are all in and running fine. The largest cam one of my customers is currently running is 280 without any issues.
Don't concern yourself with the waste spark system, I have sold several Comp 260h cams and are all in and running fine. The largest cam one of my customers is currently running is 280 without any issues.
Yep, I had a GMPP equivilant of the 260-2 in my "Franken60". Cam works fine with DIS, and boost.
I just looked back through some of the thread, and I would STRONGLY suggest swapping to a '7730 ECM and running $8F. That is what I did with the "Franken60", a long time ago, and it worked decent, definatly needed to be tuned, since I was running a manual and all $8F bins are for automatic tranny, but worked. You could also load $A1 to the ECM and see how that fairs as far as start up goes, this would eliminate spark timing, from the bin as an issue.
I would also check the reluctor wheel. Bring it back to TDC #1, and make sure the CPS is pointed at the notch before the "home" notch. Do you have any better pictures of the reluctor wheel, something looks a bit odd, with the width of the notches and the relation of the home notch from the angles I can see.
__________________ If you're not living on the edge, you're taking up too much space.
I'm not sure why you are having problems other than maybe you're having issues with the offset.
Do you have a '7730 ECM you can try? I have a starter .bin I could give you that I used to run a 3.4 4th gen Camaro and '7727 ECM ('7730's water proof brother). All I did was transfer all the data from the stock 3.1 $88 mask into the $a1 mask and twaeked it a little for idle.
If you don't, I probably have an extra ECM and MAP sensor here somewhere if you want to try it. I can just trade you the MAF and '165 even for it to get you going.
Pulled the motor yesterday. took me and my bro about 5 hours. Popped the oil pan off today and found #1 rob bearing spun. Motor turns no problem with only the #1 rod unbolted. Next step is to figure out exactly why it happened. Maybe because it was sitting so long (more than a year) outside in a plastic bag before I got around to putting it in the car and try to start it.
I think that insulation's seen better days. Rod bearing's a bummer.
__________________ Increasingly I find the difference between a 'fact' and opinion is the number of people that believe it.
3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, early '769' heads with 3500 valves, LS6 springs & mild porting, worked over heddman headers, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle. 210hp at 5800ft (that's 270hp at sealevel )
its 1-1/2" sch.10 into 2" sch.10. The 1-1/2 pipe size is actually 1.9"OD 1.68"ID. I wanted to leave room for "improvement". 2" pipe is 2.38"OD 2.16"ID. The 35mm wastegate is 1-1/4 pipe I had left over from my camaro (I ran out of 1-1/2 by that point). The 1-1/4 pipe is 1.66"OD 1.442"ID (36.6mmID).
