First time swap. LQ9 into 95 OBS

[Jeebalow]

I had read that you can completely get rid of the DRAC. I know it's a little late now but maybe it will help others.
You have the VSS connected to the PCM right? What year is your 6.0? The PCM has vss in and has a 4K (what our 95's speedo needs) vehicle speed output circuit as well. So you can just splice the speedo input whire wire to the PCM speed output and the gauge should work. Then the speedo calibration can be done with the tune. I got all this from lt1swap.com which is what I used to rework my harness. Sorry I saw so late, been crazy busy with my last term as an undergrad.

[kewljay223]

i thought for sure the pcm could only control the 96 and up speedos. otherwise i would have just gone that route. lol oh well. i got it calibrated so im good with it but if it goes out, i know what to do to fix it. thanks

[Carazy]

Awesome write up, I am doing a twin turbo lq4 swap into my 95 gmc Suburban 2500. I got a low mileage lq4 out of a 05 Denali Yukon XL, got to take a vid of it idling in the donor vehicle and robbed a lot of parts all the way to the efans. I am prepping the engine now so when I pull the engine out of the truck I can make quick work of the swap. I am looking forward to upgrading from my Whippled 454 TBI. Your thread has cleared up a bit for me but some things are a little bit foggy but I will handle each concern as they come up so it doesn't start getting overwhelming.

[kewljay223]

for sure man. good luck on the swap. dont think it will be a quick swap tho. it will always take longer than you think. and yeah, the foggy things will make sense when you actually come across it durring the change over. any questions just ask. there are a lot of little things learned along the way that i didnt post about that may help you. have fun. and most definately start a thread of your own. i want to see how you do the turrbo setup as thats coming up in the near future for me and i have no idea about FI. lol so ill probably be coming to you with some questions!!

[gagliano7]

Fyi my 1999 5.3 pcm controls my 1992 speedometer.

[kewljay223]

for sure man. good luck on the swap. dont think it will be a quick swap tho. it will always take longer than you think. and yeah, the foggy things will make sense when you actually come across it durring the change over. any questions just ask. there are a lot of little things learned along the way that i didnt post about that may help you. have fun. and most definately start a thread of your own. i want to see how you do the turrbo setup as thats coming up in the near future for me and i have no idea about FI. lol so ill probably be coming to you with some questions!!

ok now i just feel like an idiot now that i have two of you telling me i could have done it the other way!!! i dont know where i got my info from but OBVIOUSLY i was wrong.... lol should i leave it now that i got it correct or is there any beneficial reason i need to change it?

[Mickeymotormount]

I would leave it. If it works, don't mess with it. For what it's worth, my '99 PCM does control my '94 speedo.

[gagliano7]

Just make sure you have the vss going to the computer so the pcm knows your speed. You can leave your speedo the way you have it.

[kewljay223]

yes pcm is getting the signal. thanks.

[kewljay223]

been a while since ive updated. havnt really done anything too it due to work and funds. but im getting a shipment of parts today and will be starting the 80e swap next week. so more updates then

but i have a slight concern that i just noticed today. the other day when i was getting on the on-ramp to the fwy, i punched it pretty hard, reved up to about 6k or so im sure (tach only goes to 5k) and it just cut out. so i let off the gas and punched it again and she woke upand went. havnt had that happen since. but the other day i notced when i turned to motor on, it kinda stumbled and its done that once or twice since. so today, just for the hell of it i checked my fuel pressure gauge, which is at the rail, right when i turned the key. shot up to 60 like it should and shut off after 2 sec like normal AND THEN IT INSTANTLY DROPPED TO 20 PSI!!! and it continues to fall but very slowly.

i remember when i first got her running, the pressure would hold for quite a while. and this is im sure why she hesitates when starting if i wait to crank more than a couple sec. im correct in assuming this is not normal right??? so i tried it a few more times and same thing happend. i listend/smelled for leaks throughout the engine compartment and nothing. i think i may have smelled a SUPER SLIGHT smell of fuel but it could be just from the TB. idk.

i still need to jack the truck up when i get a chance to finish looking at the rest of the lines. but until then, any idea why its not holding pressure? if i cant find anything, do you think its possible its in the tank?? and BTW, while the motor is just idling, the pressure is at about 50psi. i thought it was supposed to be at 60 no matter what.... please help!