ultradriver10000
Forum Member
Friends and facebook market place
LT1 coil conversion
- Thread starter mustangmike6996
- Start date
ultradriver10000
Forum Member
This one isn’t horrible. Complete newer 5.3l drop out $800
https://www.facebook.com/marketplace/item/833819204355001/?mibextid=6ojiHh
https://www.facebook.com/marketplace/item/833819204355001/?mibextid=6ojiHh
ultradriver10000
Forum Member
chunkybs
Club Member
gen 4 5.3 aluminum block
$700
https://www.facebook.com/marketplace/item/725925165735550/
If you plan to rebuild here's a iron 5.3 for $200. Set of $100 gen 4 rods and fresh bearings and she's a ready to rock.
https://www.facebook.com/marketplace/item/915426726566069/
$700
https://www.facebook.com/marketplace/item/725925165735550/
If you plan to rebuild here's a iron 5.3 for $200. Set of $100 gen 4 rods and fresh bearings and she's a ready to rock.
https://www.facebook.com/marketplace/item/915426726566069/
WhiteHawk
Club Member
Crap, I need to go pick that up!
Punch those 5.3 iron blocks out a bit and you can use 5.7 LS1 parts.
-Geoff
ultradriver10000
Forum Member
exactly, iron block 5.7 is nice
mustangmike6996
Club Member
A small update on the LT1 Opti....
I got the second AIP Opti sensor, installed it and bench tested it on the O-scope. I could see the high res and low res signal. I put the distributor back in the car, cranks but wont start. No spark from the coil.
I am going to go back through the factor service manual diag process a 5th time and make sure I did not miss anything. The trouble tree keeps pointing to a failed distributor or distributor connection (the connection(s) to the distributor are good).
I will be reassessing the car at some point this weekend/early next week. I'll post the findings. The LS conversion is starting to look way more appealing.
I got the second AIP Opti sensor, installed it and bench tested it on the O-scope. I could see the high res and low res signal. I put the distributor back in the car, cranks but wont start. No spark from the coil.
I am going to go back through the factor service manual diag process a 5th time and make sure I did not miss anything. The trouble tree keeps pointing to a failed distributor or distributor connection (the connection(s) to the distributor are good).
I will be reassessing the car at some point this weekend/early next week. I'll post the findings. The LS conversion is starting to look way more appealing.
mustangmike6996
Club Member
I don't know too much about the LSs as far as choosing this vs that. Other than displacement, how is the 5.7 different from the rest of the LSs?
If you were going to swap an LS into a C4 Vette, what engine would you go with and why?
ultradriver10000
Forum Member
Just depends what your goals are. 4.8/5.3/5.7L are all "small bore", meaning that you'll have to use the older cathedral port heads. 243/799 heads would probably be your best bet there. These combos could make 300-450hp pretty easily and reliably.
6.0/6.2L are "big bore" and will allow you to use LS3, LSA, LS9 big square port heads that flow really well.
Iron block is about 80lbs heavier, but can handle big power. Think 1000+ hp easy. Aluminum blocks are lighter and proven to 1000hp.
Best budget set up? Iron block 6.0L with a mild cam, ls3 heads and intake. 500hp pretty easy.
6.0/6.2L are "big bore" and will allow you to use LS3, LSA, LS9 big square port heads that flow really well.
Iron block is about 80lbs heavier, but can handle big power. Think 1000+ hp easy. Aluminum blocks are lighter and proven to 1000hp.
Best budget set up? Iron block 6.0L with a mild cam, ls3 heads and intake. 500hp pretty easy.
mustangmike6996
Club Member
A little update on my optispark issue...
So the timeline goes something like this:
2011- replace Opti and ICM (no spark)
2011-2014, mostly stored, some short trips every few months
2015- drive the car to work as a daily for the season
2016-2021 car is mostly being stored again with occasional trips
2022-present... No spark diag
For the diag, I followed the troubleshooting chart in the Factory Service Manual. Initially I had diminishing spark but could run the car on starter fluid (I'm assuming because it's more combustible than fuel). Eventually the spark completely quit. I replaced the ICM and coil with OE Delphi and AC Delco parts. No spark. Started the diag process all over from step 1. It calls out the distributor. Can't find a good/cheaper replacement so I go with AIPs sensor for $65 and replaced the opti extension harness with a new aftermarket parts (goes from the intake down to the distributor). Put it all back together and no spark... At this point I start the diag process again. Instead of pulling the opti connector I was pulling the intake side of it (it's easier to access and read voltage/gnd). I keep diagnosing the car, which now needs a battery but I use my jump box to aid the weak battery. I finally get completely fed up with the car and start back at step 1. Check for power at pin C, has power, check for ground at pin D, missing. Thinking I flipped the connection in the process, I reached and gave GND on pin A. I stop and ask WTF, is that harness pinned wrong....YUP, the new harness was pinned backwards.
So long story long, I transposed the pins and got spark. At this point the car is completely flooded (brand new plugs too). I come back today with a new battery and retest, got the car to stumble and start/stall etc. Eventually I got it fired up and cleared the overly rich condition.
Tomorrow I'll be reinstalling the water pump and letting it start/run and heat cycle a few times.
It's been a hell of a time with this.
So the timeline goes something like this:
2011- replace Opti and ICM (no spark)
2011-2014, mostly stored, some short trips every few months
2015- drive the car to work as a daily for the season
2016-2021 car is mostly being stored again with occasional trips
2022-present... No spark diag
For the diag, I followed the troubleshooting chart in the Factory Service Manual. Initially I had diminishing spark but could run the car on starter fluid (I'm assuming because it's more combustible than fuel). Eventually the spark completely quit. I replaced the ICM and coil with OE Delphi and AC Delco parts. No spark. Started the diag process all over from step 1. It calls out the distributor. Can't find a good/cheaper replacement so I go with AIPs sensor for $65 and replaced the opti extension harness with a new aftermarket parts (goes from the intake down to the distributor). Put it all back together and no spark... At this point I start the diag process again. Instead of pulling the opti connector I was pulling the intake side of it (it's easier to access and read voltage/gnd). I keep diagnosing the car, which now needs a battery but I use my jump box to aid the weak battery. I finally get completely fed up with the car and start back at step 1. Check for power at pin C, has power, check for ground at pin D, missing. Thinking I flipped the connection in the process, I reached and gave GND on pin A. I stop and ask WTF, is that harness pinned wrong....YUP, the new harness was pinned backwards.
So long story long, I transposed the pins and got spark. At this point the car is completely flooded (brand new plugs too). I come back today with a new battery and retest, got the car to stumble and start/stall etc. Eventually I got it fired up and cleared the overly rich condition.
Tomorrow I'll be reinstalling the water pump and letting it start/run and heat cycle a few times.
It's been a hell of a time with this.
dave89iroc
Club Member
I do recall those jumpers being pinned wrong at times
mustangmike6996
Club Member
I contacted the company, they confirmed that they did have a bad batch and think they have them isolated.
I just reinstalled the water pump this weekend. The car fought me when trying to restart but eventually ran (poorly). I think I am fighting old gas and fouled plugs. I plan to swap the plugs some point this week if possible and retest.
When I did get the car running and up to operating temp the service engine MIL tripped. I jumped the ALDA and got code 26, quad driver fault. From what I dug up really quick, this is possibly a wiring issue to the purge valve, EGR or air pump... or ECM. I need to verify all of those circuits are ok. I am wondering if the harness that was incorrectly pinned caused any ECM damage.
dave89iroc
Club Member
I hated those quad driver faults, just so unspecific , good luck, sounds like you're getting close
mustangmike6996
Club Member
A little update...
I pulled the newish plugs and put in a cheap seat of copper Autolite plugs (I can clean those if the get carbines up during diag). The car would start but not run great and stall at idle.
As for the quad driver DTC, that was my fault... I didn't have the air pump connection fully seated. Oops
I was brainstorming with a buddy and he mentioned the cats being plugged. Well, I thought I had a weak starter +it was cranking slow and surging). I dropped the passenger side pipe at the manifold and the car cranked faster/better then fired up quicker. I did the same to the driver side, dropped the cat and the car cranked good then fired up but it needed throttle to run. I could get it to run great at 1200-1500 RPM but it still doesn't want to idle. I think it's got an air/fuel issue. At 1200 RPM I was at 17 in/hg vac with slight fluctuations when it would stumble a bit.
So... Now I need to pull the cats the rest of the way out and make a legit catless test pipe (I'm not paying $900 in cats until I get this drivability issue sorted out). Unfortunately it seems like I'm going to have to drop the whole exhaust to pull the cats. Then punch the media out, reinstall and retest. I'll probably have to get new upstream O2s (I'm betting they are fouled to hell now)
Once that's all reinstalled I can focus on the poor idle quality. Then hopefully get the car reassembled and running this summer.
I would also like to mention that whoever worked on the C4 engineering packaging team can go kick rocks. On top of the usual 80s-90s GM usually mixed metric and SAE bolts, some fasteners are puzzling for placement. I am lucky enough to have a good set of professional tools and I'm working on a car that's not seen snow/salt. I can't imagine doing this job on a usual 30 year old MI car.
I pulled the newish plugs and put in a cheap seat of copper Autolite plugs (I can clean those if the get carbines up during diag). The car would start but not run great and stall at idle.
As for the quad driver DTC, that was my fault... I didn't have the air pump connection fully seated. Oops
I was brainstorming with a buddy and he mentioned the cats being plugged. Well, I thought I had a weak starter +it was cranking slow and surging). I dropped the passenger side pipe at the manifold and the car cranked faster/better then fired up quicker. I did the same to the driver side, dropped the cat and the car cranked good then fired up but it needed throttle to run. I could get it to run great at 1200-1500 RPM but it still doesn't want to idle. I think it's got an air/fuel issue. At 1200 RPM I was at 17 in/hg vac with slight fluctuations when it would stumble a bit.
So... Now I need to pull the cats the rest of the way out and make a legit catless test pipe (I'm not paying $900 in cats until I get this drivability issue sorted out). Unfortunately it seems like I'm going to have to drop the whole exhaust to pull the cats. Then punch the media out, reinstall and retest. I'll probably have to get new upstream O2s (I'm betting they are fouled to hell now)
Once that's all reinstalled I can focus on the poor idle quality. Then hopefully get the car reassembled and running this summer.
I would also like to mention that whoever worked on the C4 engineering packaging team can go kick rocks. On top of the usual 80s-90s GM usually mixed metric and SAE bolts, some fasteners are puzzling for placement. I am lucky enough to have a good set of professional tools and I'm working on a car that's not seen snow/salt. I can't imagine doing this job on a usual 30 year old MI car.
ultradriver10000
Forum Member
Cut the cats out and weld in straight pipe. The cats are worth decent money, maybe 80-100 each.