Alright. I'm back again. So my twin turbo car has been made functional. Other day I made 3 pounds of boost. So I guess you can say its getting pretty serious. But when that happened the timing was way off. Every cable was set back one. Now the timing is correct. 0 initial and I've set it to 8° at 700rpm. The engine is a 1985 LB9 305 TPI. Engine casting says it's a Monte Carlo SS motor. Its no longer a LB9, I've got!

TPIS Mini Ram
Holley 58mm
42Lb injectors
Twin GT28s
With Flowtech turbo headers

But I'm getting super lean readings at 30-45kpa its in the 20s. After a couple of VE learns its moved to 17s. The difference from the first VE to the last one was 30 points to each of the cells. But it seems all over the map is running lean. I haven't gotten a fuel pressure gauge. I want a nice one and that's 200 bucks. But have I ran out of fuel pump? Or is that low fuel pressure at the rail? I might buy a cheap ac gauge to check the pressure. But before the thing ran fine. But during that time the turbos werent spooling like they are now. Around 1400-2000 sounds like I'm hitting 2step. Thing isn't making any boost at that rpm. But when I let off they are surging.

 

Went ahead and got myself a pressure tester today and tested fuel pressure. Was at 38psi at the rail. With cranking the regulator down... WAY down it moved to 40 psi. I ordered a new pump. Hopefully I'll come back in a few days with some good news. Gotta pay to play!

 

Might plug the return line and see what the pump deadheads at? And check the injector pulse rate, might be wide open and still lean? Bigger injectors needed?

 

I'll try to dead head it tomorrow. I'm thinking the regulator might be suspect too. For injectors I moved from Lt1 24lbs to 43lbs injectors. At idle the pump has no problems supplying enough fuel. And the ECU is able to change the tune on those RPMxMAP cells. But 10% throttle at 2000 its lean. Did about 3 or 4 VE learns and its barely making a difference. Its making changes to the idle in same VE learns but changes in the problem spots do nothing. Still waiting on my Walbro maybe tomorrow I'll get it. Does anyone know if EBL flash any safety measures to stop the engine from killing itself?

 

Fuel pump got here today and I installed it today. I'll post of photos of what was going on with the pump but I found ribbon on some type of entry hole on the pump. Everything on the pump fell off. The rings that held the pump in place fell of when I tried to removed the pump.I went a head and used hose clamps the hold the pump to the rod that goes down. I also removed the old connector and drilled it out to use a cable gland and pulled the new fuel pumps wires through and I also pulled the sender wire too. My next question is, does the stock wiring have a good enough power source to power my walbro? My battery is relocated to the back and its got a kill switch and all. So running the stock power source to a relay to than turn on the pump with a good connection to the battery. That a good plan? I'd just need a relay.

 

Went ahead and changed the pump out and the PSI on the pressure tester is jumping like crazy while the pump is on. Did I mix the wire for power to the pump and the sender? I tested it beforehand held a test light to the damn thing. Turned on the key on then turned off.
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Anyone know what to do about the regulator? Im pretty sure I need a boost reference one so it picks up the PSI but the TPIS one doesn't do any of that. Yet cost like 160 bucks. So what do I do for a reg?

 

The FPR should already be manifold pressure/vacuum referenced. That is required even when not boosting the engine. Otherwise the injector flow rate changes as the manifold pressure/vacuum changes.

Just be sure to firmly retain the ends of the reference line. Least it blow off when in boost.

RBob.

 

I went ahead and got a AEM reg from summit that's boost referenced. Im going to attach it in back of the mini rams reg. I don't know if I got a problem with the reg but when the pump is on and the car is running the pressure gauge is all over place but stays past 50 psi.

I'll also tie everything down. I already had a cap come off my throttle body.

 

Update on the fuel pressure problems while the car is running. I ended up mixing the two middle connections. One was to a valve and the other was the actual return. Moved them back to where they are supposed to be. I sealed off the other line which probably went to my charcoal canister. Which is gone now. I still haven't started the car. The AEM regulator from summit didn't come with fittings and it didn't say on its description that it needed a -6 plug. Ordered it Friday.

 

Got all my parts and everything is connected. Fuel pressure gauge might be junk. I don't know. It's still jumping like crazy when the car is running. I can get the car down the street fine. I can also rev past 2k in neutral no problem. But when driving the problems are still there. Any ideas of what I should keep a eye out for? I'm sure I'm getting positive pressure around that RPM. Boost gauge gets near zero on vacuum. I took a couple pictures of the tables.

This is after a VE learn. Mostly cruise speeds in 4th gear and some on 3rd. Thiers no light throttle when driving. Its idle or 1500 rpm. Everything felt great under 2000

Here is my spark table. I think I see the problems. I'm a dummy but I think it's dropping timing when it gets to the higher KPA at that RPM. I used the stock LB9 table or the one suggested because of my iron heads.

Here is my VE table with highlighted RPMs.

 

While the car is running WUD is saying my pump is getting 12.8 volts while the car is ignition is getting high 13s

 

Not a god idea to second guess GM. At a minimum it shows a proper curve.

RBob.

 

So it looks good? I find it odd that as the car is actually moving up in the RPM under load that its going from the normal SA to dropping most of its timing. And the car isn't really under boost or anything. I'll have to do a data log and watch my MAP sensor while the car is moving. See where its at and what those spots look like.

But problems I still have are fuel pressure at the rail jumping like crazy. And not revving past 2000rpm.

 

I went ahead and removed more timing from the SA maps and its now moving past 2000 rpm. Wow. I got some learning to do. Ill look for a boosted SBC SA table so I can get a idea of what that looks like vs mine.

 

Have you checked the timing at the crankshaft with it under ECM control to see that it matches the ECM commanded SA? Having to remove SA to get the engine to rev sounds like a damper/timing-tab mismatch.

RBob.

 

The timing is spot on. I don't know if I need to tear everything down but when timing is put to zero it reads zero on the balancer. Same with it moving to 8 or even 20s. I do have a problem with the timing jumping 3-4 degrees all the time. It doesn't stay steady at 8. If it moves on the WUD, its moving on the balancer.


​​​​​​I've also been messing with tunes and changing out my SA tables for OE ones for LB9s and the LO3. I did end up changing out my sparkplugs. Old ones were fouled. Lots of carbon. They've been hit with a lot of fuel. I changed them and changed the gap like my friend suggested. Dude told me to get around .20 I got them to around .25. Thing is now missing pretty hard and I can feel something smacking something. Jolts the whole car. Ill be redoing my sparkplugs and leaving the gap whatever it is.
Interesting side note. I went a head and used a 305 TPI idle SA and SA table for the most recent experiment tune and my o2 sensor would read lean all the time. Pretty sure I added fuel in some spots to. I then switched back to my boosted1.0 tune before most of this happened and the O2 was reading like normal.
I'm about ready to sell this thing.

Here's the tables compared to each other. Exptune vs the first one made with the turbos making boost.

 

I've done some more tuning. I have been having WUD up and tunerpro up at the same time. Cutting out timing seems have helped my car. Seems like around 20 degrees is a good spot and around 26 is when I get the car to miss. I've moved past 2500rpm. Any suggestions one key items to mess with when tuning the fueling? And what spots to look at when the car is being tuned under boost?

 

Back again with more problems. I've removed the reg I installed and redid my fuel line. I also got the fuel pump on a relay with direct power to the battery. It's triggered by the old fuel pumps 12v. But with the TPIS mini rams stock reg, I can only manage 45 psi. I dont think I understand how to use the AEM regulator in place of the one on the rail. My first try was to place it on the return line, hoping it would hold pressure until it would increase to where I set it at, but it didn't work. I'm pretty sure I plumbed it wrong and if the stock reg was a one way type deal it would just hold pressure in the line and not in the rail. Now that I know the stock reg is toast I can think about how the AEM reg can be fitted in.

 

Back AGAIN! Better news this time. I've went ahead and added that relay for my pump and got it some decent power. When I did that I still had problems with the fuel pressure not being enough. I then took off the regulator and took it apart. The screw to increase pressure is barely a half inch long, the plate that's used to press on the diaphragm was like.. I've seen washers thicker then that. So I added three nickels to it, now I got a range from 40 psi to 100 psi of fuel pressure. The jumping of the needle is negligible. Fuel pressure is fixed. Seems like the injectors liked 60 psi, but now my fuel tank is rusted and peeling into the fuel. I'm gonna go ahead and do a 4th gen fuel tank swap and I'm going to redo my fuel lines as well.

 

reading thru and man, you've had a rough time.


any luck since the last post?

 

As I learned from you, even non stock ICMs can cause actual timing to differ from commanded... by 5 deg or more from my recent experience. In cases like that the spark latency table needs to be changed to match the particular ICM.

https://www.thirdgen.org/forums/diy-prom/465232-ebl-sa-latency-table.html

 

Sorry Gentlemen for the long hiatus but I'm back. I had issues with mg Civic had to rebuild the transmission and add a clutch and flywheel. I did the oil pan gasket three times to stop the leaking ended up getting a aluminum pan, but the thing still leaks. I ended up doing a RMS which was a pain, it was all a cluster lol I was supporting the engine by the old pan but for the RMS to come off the oil pan had to come off and I might as well use another pan. Then it turned out the trans was never the problem the CV axles c clip was to bent. But the trans still needed a oil seal and input shaft bearing. Anyway

To the camaro. I don't remember if I was asked about the injectors here, but they are EBay injectors it says they are 12ohms and high impedance. I should test them to check if that's correct.

As for how the camaro is, I reverted to a older tune and the car is running much "better". I seem to have a problem with car once it heats up and gets over 140 degrees. It starts to stumble and turn off, just not want to idle. I've also seen more boost after I welded the wastegates shut on the turbos, also seeing more boost and a better response from the turbos. I think my fuel issues have been fixed, I've got a good steady fuel pressure. The next issue I think is the timing and the tuning. I know while on the freeway if I get to a certain throttle percentage the damn goes into rolling two step, which is a cool party trick but not when I just wanna speed up.

I've had to replace my ICM a while ago, with a autozone unit because my OEM one got fried. I know it was a Chinese unit and I've been wanting to upgrade to a MSD unit.
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