khulsebus

iTrader: (2)

I stand corrected, thanks Dave.

alex722607

iTrader: (3)

I too thank you. Now I know exactly what to do because I know how the fitment will be.

Oh and yea I kinda figured it wouldn't run (or well for that matter) without the rockers being fully seated. I just wanted confirmation. On the subject of engine internals I know my dad is very familiar with the gen 1 SBC (because he built one) and gen 3 is different in several ways, so its a learning experience for both of us.

dprest68

iTrader: (1)

You're welcome guys. Glad I could help.

alex722607

iTrader: (3)

Got everything buttoned up, rockers done, dipsticks in place and got it ready to fire.

Before I turned the key, I plugged into OBD2, but got a no communication. Checked it with a multimeter and it shows that with the key on the serial data wire gets shorted to ground. I have a feeling it is the unnecessary STAR connector coming back around to bite me in the ***. Now that I have the proper terminals, I can go ahead and remove it. Turned the key, but it did not start. I suspect 3 things. The ground on the body, wires removing themselves from the pcm connector, or a missing fuse. I will diagnose tomorrow when I have light.

alex722607

iTrader: (3)

Ladies, Gentlemen, and whoever else follows this thread, I need help.

I have confirmed that everything is connected properly, finally after using a different adapter for the scanning tool, I was able to read the code. It is P1626. It decodes as a VATS issue. But it is not.

It cranks, and I have tried both the VATS box which uses the key, and the bypassed BCM (not at the same time). Both send out the same signal. The PCM sends out a 5 volt and the VATS modules each send out a 2.5-2.6 voltage signal. I checked the fuses for everything, and pouit a noid light on the injectors. The light does not come on, but I have 12v+. Also I have no spark. \


Is this the PCM f***ing with me. I was all set to move the car to shelter it from the impending storm, and this happened.

I spent the entire day combing through all the wiring and pinouts, checked that I have the right wire connected for fuel enable everywhere and so on.


HELP please

alex722607

iTrader: (3)

oh and I have no security light telling me VATS is bad, it comes on after turning the key to run, and shuts off as it should

scooter

iTrader: (11)

The VATS signal is not a constant voltage, it is a square wave with a specific frequency, you can't check it with a volt meter.

alex722607

iTrader: (3)

Hmm.

When I looked at ALLDATA it wouldn't tell me that its possible the ECM went bad. When I looked in the 1988 f-body book for VATS I came up with a symptom table which says that if I measure the fuel enable wire and have the other end of the volt meter connected to ground I should come up with a volt range of 2-3 volts.



since the VATS is the same between both vehicles the trouble tree should be the same from the f-body manual. If anyone could take a picture of it that would be great. I will keep scouring for it aswell. But all paths are pointing me to a bad PCM. I contacted my tuner but have yet to hear back.




I have the 5 volts with the condition mentioned, and I have the 2-3 volts with thew condition mentioned

scooter

iTrader: (11)

The VATS from an LSx BCM is not compatible with the VATS from the 88, as I said, the VATS in the newer cars is 40-60Hz signal. You had me doubting myself, but in my 99 F Car service manual this is what it says. It's 3 pages long or I would post it for you

alex722607

iTrader: (3)

Okay, I see what you are saying.

So what I did was I found the link to the 2000 f-body service manual and found the 40-60 hertz frequency you are talking about.

So I went outside and got the fuel enable wire from the 4th gen BCM tested. I came up with 29.43 hertz. Its not the PCM, its the BCM. And thanks for clarifying about the 88 VATS box. I guess I am going to get a new BCM and permanently delete the VATS box. I will program the new BCM to the key for the car.

Thanks Scooter

alex722607

iTrader: (3)

I feel like a complete moron. I just realized that when I checked frequency on the VATS module and not the bcm- they are in the drivers side footwell and I was working in the pass side footwell. They are right next to each other and I was too lazy to walk around and double check. As it turns out I checked the BCM and got the value of 50 Hz- like its supposed to be. I realized this just after I sent an email to my tuner saying it wasn't the pcm. So I sent an email to him again, retracting the last email and telling him that the ECM is at fault and I need to see what he says about replacing it. And no I don't hate VATS yet -- but this better be damn well worth it, cause I am starting to go nuts.

dprest68

iTrader: (1)

Have you tried doing this...

I was having a similar issue with my car. I removed the relay and jumped the two end wires.

alex722607

iTrader: (3)

I didn't need to because the car cranks. Thanks though

scooter

iTrader: (11)

I THINK the key is coded to the BCM, so you may not be able to get your existing key to work the that BCM. I think I read that the BCM learns a key resistance and then you can't use a different resistance key after that. Unless a Tech II tool can reset a BCM, but I don't know. I got a complete interior harness for my other car from a 99 Firebird and I made sure the guy gave me one of the two keys, so I could at least measure the resistance and I could replace them without buying a bunch of them or resistors

alex722607

iTrader: (3)

yeah, however I bypassed the system with a resistor and if it was at fault then I would see the security light. also it is emitting a 50Hz signal. the pcm is not doing anything with it. I checked it all the way to the pcm connector and its in there nice and tight. It has to be the pcm. I am getting VATS tuned out of it for free and am getting a spare back up just in case. One better work.

Unbelievable, something that is supposed to protect the car is standing in my way of moving it to shelter to finish it.

cypris09

iTrader: (1)

Well hopefully that solves your problem. Junk yard came through and found me a ecm. Said if it works I can pay for it later if not just return it. So that works out. I really hope I get a quick breath of life out of this thing. That way I knew it was my ecm and I can have vats tuned out again.

On a side note I finally read through the thread. Good stuff! Reminds me of my build. I just never stopped and took pictures haha

alex722607

iTrader: (3)

I hope you get it to purr to life. My pcm that I am having VATS tuned out is still on its way to the tuner, but the second one I had tuned (just in case) might be here sooner (finger crossed with the blizzard and all). Really hoping to get it under shelter so I can finish touching up.


Thanks for the kind words and hopefully it was just the ecm (for both of us)

alex722607

iTrader: (3)

Out of Curiosity, if I had my pcm tuned for 3.23 gears and I have 3.27 (my mistake which I just noticed), what could I expect? I don't know much about gearing in the rear end.

scooter

iTrader: (11)

That isn't enough to make the speedo off at all. The tire wear will have more of an effect

alex722607

iTrader: (3)

Since the PCM's come tomorrow and I couldn't just not do anything today, I connected what was left over. I ran a vaccuum line from the throttle body to one of the lines coming of the gas tank, I could not find a clear answer about whether to or not on the gas tank swap thread. I also put the white plastic thing on another one of the lines. That same thing that was used on the 3rd gen tank. Oh by the way, do I need that and if so where can I get a new one? I think motobooks had that in his thread, but I forget.

I also installed the coolant fans, they fit perfect with a little bending of the PS cooler (prybar). I also tightened down all the steam line clamps. I also cleared the area around the gas pedal and brake and reinstalled one of my hush panels to ensure that nothing will intefere with the gas pedal or brake. It is too damn cold to hide everything properly and the sooner I move it into the garage, the quicker I will be able to put it together right. I also made sure my fule line had loom over it so it does not rub anything.

alex722607

iTrader: (3)

pictures

alex722607

iTrader: (3)

and more

cypris09

iTrader: (1)

Looking good! Other than mine finally starting I'm still way behind. Not to mention I think I'm going to buy the racing innovations swap headers and get rid of my manifolds. That ecm needs to hurry up and get here so you can hear this thing start. Best of luck to ya.

alex722607

iTrader: (3)

About that.... My old ecm came back today with vats tuned out and still no start. No spark and noid light is out. Fuses Are good. Other than the coolant temp sensor and O2 sensors everything is plugged in.it has to be the PCM. I am not getting codes other than the generator code which I tink is irrelevant. Thanks to USPS my new pcm is not here yet even though it was supposed to be. Any suggestions? Vats is irrelevant at this point and i checked the pinning on the tps sensor just in case.

cypris09

iTrader: (1)

I probably missed it as I'm on my phone but Jic here's what all I checked
1. Power to inj both on and crank?
2. Spark? (Mine started on starting fluid)
3. Are you getting a tach signal at all? (Mine was more or less a bouncing needle)
4. Fuel pressure checks out? ( mine was solid and yours probably is too but what the heck)
Obviously you saw mine was the tps. All I did was unplug it and it fired up.
p.s. Usps takes its good ol time on everything

alex722607

iTrader: (3)

yup, I checked power to INJ1, INJ2, PCM IGN, and PCM BAT and all grounds. I also checked Fuel pressure- its just right. I am getting a tach signal both on my scan tool and on the dash. My dad did the spark plug to block test and we put a noid light on the injectors at the same time. I cranked and nothing, no spark and no pulsing of the injectors. I also unplugged the tps just for the hell of it, and nothing. The only thing I can think of is that possibly the injector driver is bad on the computer. I mean besides the HO2S and the ECT, everything is plugged in. Of course I don't know if a bad injector driver would have anything to do with no spark. And also if the PCM is indeed fried, would the tuner see that something is wrong with it.

cypris09

iTrader: (1)

Check and see if you get power to the coils? I'd guess bad ecm for the rest though. Atm my Trans isn't plugged in or my o2 and tps sensors and it starts.

alex722607

iTrader: (3)

I did exactly that with my dad today. I also checked schematics and what not. It turns out that the ignition relay gave powert to the INJ1 and INJ2 intermittently ... go figure. So I dug deeper and relaized that the ground for the IGN relay had a loose connection to the point that it was hanging in the terminal by very little. So I guess it was [partly a bad ecm and partly a bad connection.

But I am not out of the woods yet. It will start up but wont stay running. I unplugged MAF, jumpered the 2 PCM coolant temp wires together and no dice, it dies just after starting.

The only thing I could think of is that the PNP wire to the PCM is not connected at the PCM. Would this do it??

alex722607

iTrader: (3)

Well It works! The cars runs and she purrs so nicley. It runs so smooth, smoother than the SBC ever did. I still got a lot of work a head of me, mainly cleaning up and what not not to mention the exhaust. This morning I jumpered the PNP feed to the PCM, replaced my old battery wire bolts which explained alot, and tightened down the oil pressure sensor. Then I ran it and tried to shift. At first it would not shift, then I realized that I only put 6 quarts of fluid in it total and it takes 11-12. So I have 8 quarts in it now, and will get more tomorrow. It is good enough to drive, well put put to my grandma's nice warm garage. More to follow, and of course a video of it running.

Street Lethal

iTrader: (16)

Nice build, came out great, and congrats on the successful swap. Your not too far from me, we should line them up one night this coming Spring, we'll see what that LSX is made of...

- Rob

alex722607

iTrader: (3)

Thanks! Yup I'm down

alex722607

iTrader: (3)

It is so different then the Gen 1. The day I turned off the old motor after taking it for a drive I saw that the car was shaking violently, she would not stay running at a traffic light and I had to do fancy footwork with the gas pedal and brake pedal. The only thing I miss is the sound the old one made. Today when I was finally able to fire it up, I still have a bunch of stuff disconnected, namely the exhaust, no air filter, no O2's and a hush panel that is holding on by one screw because I crammed so much up there just do be able to drive it 8 houses down the street. The first time I started it I forgot about the brake booster vacuum and it revved up so high I startled myself.

And with no exhaust I feel like an a$$ starting it past 8 at night

WTR388

When I realized I had enough done on my car to start it, it was 11pm. Garage door was open, it was open manifolds and the neighbours house is about 20' from the garage... I also happen to work in the same shop as him, he wasn't too impressed at work the next morning lol.

cypris09

iTrader: (1)

Glad to hear you got it started! We have so much snow in Ohio right now I can't even move my car out of the garage to start it so unfortunately I'm stuck with where I'm at until it warms up and the snow melts. My sounded a bit different from a gen 1 but mine didn't have o2 sensors and it's not full of coolant. Plus it was only about 10 degrees out haha

alex722607

iTrader: (3)

Drove it today. Wow.

Oh and for some reason it wouldn't automatically shift into 2nd? I had to manually up shift. I never made it to 3rd. Could be because tcc is unplugged. .... And I just remembered that the trans 12v+ key on feed could be disconnected because of the fuse not being there

alex722607

iTrader: (3)

Well over the past few days I have removed my old VATS module and have hooked up the bcm in that capacity. I have also installed my new brake switch, tidied the relays for the theft system and installed my hush panels for the drivers side. The pass side is still in a bit of chaos. I ranthe PNP feed wire from the PCM to the body hanlrness now it's just a matter of installing the pins in the wire. Additionally I marked up and had my dad weld the exhaust so that it is a direct fit on the pass side but the drivers side is still yet to be done. It. Looks like the right tire won't rub at all now as it did ever so slightly with the SBC in the car.

alex722607

iTrader: (3)

Today I managed to install the pins for my washer fluid pump and level sensor. Then I worked on the headlights. I also figured out the placement for the PCM. I still need to route a/c lines and modify the heater box not to mention the exhaust. The pass side looks really crowded already.

alex722607

iTrader: (3)

The past two and a half weeks have been busy but I still got time to work on the car every now and then. I completely finished the exhaust tubing save for having to replace the catalytic converter ball flange because its warped. I put the dash back together for the most part and was able to drive it for the first time. IT WAS FUN!!

The only thing that screwed me over was the stupid speed sensor. You see when I purchased the trans it came without a speed sensor. I got one that was supposed to be oem fit for my application. I then realized I needed a 98-02 f-body tailhousing and when it came it had a speed sensor already in it. I decided that I should replace the used one with the new one. So I did, and all went well until I drove it. No speed, no auto shift, and no shift past 2nd. So today I checked it with a scan tool and the pcm wasn't seeing speed, so I neew it had to be that. I rem,oved the new one and replaced it with the old and bingo- running driving car.

Now I am waiting on the 4l60e f-body dipstick because after installation of the heater box my 700r4 one wouldn't work and I got too damn pissed off with it so I cut it welded it shut and stuck it in the hole. I can't drive far though.

ohh and the hood alignment is out of whack big time.

The_Wraith

Great project! It amazes me how guys on here do cool swaps and lots of custom work only to have a handful of replies in their threads.

Yet people on here post wax jobs and other novice work and their is a million responses and thumbs up!

alex722607

iTrader: (3)

Yea I agree, but its winter, so I am not really that concerned that not many people have responded. I was very ambitious undertaking this task in the winter, and more ambitious in the amount I rebuilt.

I took it for a ride today and noticed a tapping/ticking noise on acceleration. Also there is a small exhaust leak at the right side manifold where it mates to the pipe probably because it is not seated all the way. Also my catalytic converter ball flange came in the mail today so I can cut off the old and replace it with the new one.

I also ordered parts to rebuild the rear suspension namely the sway bar links because they are so bad, they may as well not be there. I also have to change the fluid in the differential and replace the gasket because it failed and it leaks a lot.

Another thing I have to do is work on the engine noise in the cabin because this sucker is louder than the other.

khulsebus

iTrader: (2)

What are you going to use for the rear suspension? I told you that you'd enjoy the swap once you got it done.

alex722607

iTrader: (3)

Yea, I do enjoy it. You should have seen the smile on my face.

I got Prothane 7-1132 and we'll see what happens

khulsebus

iTrader: (2)

I guess those end links should do the job. I meant what are you doing for the rest of your suspension? Like rear control arms, relocation brackets, torque arm, panhard bar. I can't remember if you said you had changed those out already or not.

alex722607

iTrader: (3)

Actually, as far as everything else, it has not changed. My dad said that he did the lower control arms (front and rear) and when I replaced the front ones they were fine, so I figured I would leave the rear for now. As far as the panhard bar/track bar, I left those I just replaced the bolts. The torque arm is stock 3rd gen, no relocation bars needed.

The only thing I am really concerned with is the rattling noise I kept hearing while driving and there seemed to be play in the suspension. The rattling I am attributing to the gas tank filler neck not being properly secured.

Another thing I noticed is that I kept hearing a tapping when revving the engine which could be the rockers, the exhuast leak at the manifold, or the new lifters. The new lifters I suspected only because of the location of the oil hole on them. On the LS1 lifters it was in sync with the oil hole in the block, but on the LS7 lifters it is to the side. I don't know if this makes a difference or not. I will fix the exhaust leak first, then check for tapping. If it is tapping I will check the rocker adjustment.

scooter

iTrader: (11)

No rocker adjustment on the LSx engines, just torque the bolts down as far as I know

khulsebus

iTrader: (2)

I meant are those parts stock or aftermarket. All of these cars need the relocation brackets (especially if it's lowered), it puts the instant center in the middle of the car instead of way in front. It attaches to the rear axle and lowers the rear control arm mounting point downward. It was the best $35 I've ever spent.

alex722607

iTrader: (3)

yea that is what I thought, and that is what we did so I dont know, but well see what happens after I tighten the exhaust flange nut some more. It is already at 36 ft.lbs on the right side. Spec is 26 ft. lbs



I have to look in to that one.

RTGTA

I've spent the better part of the last hour reading this entire thread and all I can say is... Wow! What an awesome job you've done. I would love to do an LS swap in a 3rd gen, just not my IROC lol. Keep up the good work man! I'm not worthy *backs away, slowly, bowing to you*

alex722607

iTrader: (3)

Thanks for the compliment. Virtually anyone that knows anything about an internal combustion engine can do this. But it certainly helps when your dad is next to you giving you pointers.

alex722607

iTrader: (3)

Every time I think it would be a great time to get a video of the car in action it's either snowing or I'm not at home