help engine wont start
Thread Starter
Launching!
Joined: Dec 2003
Posts: 288
Likes: 0
From: Tifton, Gerogia
help engine wont start iv just got done wiht my LS1 conversion, into my 01 blazer, i started it up today but it wont run, it sounds like it wants to start but just wont, i have all connections hooked up, does this sound like i may not have enough fuel pressure?
is your pcm even getting power. i had that problem with my camaro. actually still cant get power to it. the pcm sends the signal to the fuel pump so that might be the problem. give some specifics on ur conversion & problem and i might be able to help better.
Thread Starter
Launching!
Joined: Dec 2003
Posts: 288
Likes: 0
From: Tifton, Gerogia
well the engine is a 98 as well as the pcm, and i have a painless wiring harness installed on it, i try to hook up an OBD II scanner to it and it gives me P04205 witch is somthing to do wiht the EGR but i took all the EGR stuff off, iv checked the the vats, all that is hooked up right, when i trun the engine over it sounds like it wants to start, and you can hear 3 or 4 cylinders fire, now i am thanking that the timing is off cuase i reused my stock timing chain, and it was really loose, how would i go about checking the timing? am i going to have to pull the front cover off again? 
even if the timing was off some wouldent it at least still try to run like ****?, i am going to check for spark and fuel tommrow, oh and the fuel pump is getting power. and prusser seem to be good, but still running off the 4.3 vortec fule pump.
even if the timing was off some wouldent it at least still try to run like ****?, i am going to check for spark and fuel tommrow, oh and the fuel pump is getting power. and prusser seem to be good, but still running off the 4.3 vortec fule pump. Thread Starter
Launching!
Joined: Dec 2003
Posts: 288
Likes: 0
From: Tifton, Gerogia
okay i found the problem it was a loose spark plug wire, now it fires up, but it is skipping for sure, maybe its the fuel injecters? how would i go about checking them? what else could be causing it to skip? the engine will not idle at all you have to stay on the gas. than it hits about 4k and dies.
Trending Topics
Thread Starter
Launching!
Joined: Dec 2003
Posts: 288
Likes: 0
From: Tifton, Gerogia
okay tested pressure was 75-80 psi at idle at the fuel rail. the only thing left to check would be the fuel injecters but i had them cleaned before i installed them, is there somthing else i could check, why isent my computer throwing any missfire codes? the only codes i get are EGR related (sigh)
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
That round thing on the stock fuel rail is not the regulator. It's some kind of pressure pulse dampner. You need another type of regulator to get the pressure down to 58psi. 75-80psi is waaaaaay too much pressure. Many of us are using the '99+ Corvette filter/regulator combo. It looks like this:
On the left is the filter/regulator and on the right is my pump.
On the left is the filter/regulator and on the right is my pump.
Thread Starter
Launching!
Joined: Dec 2003
Posts: 288
Likes: 0
From: Tifton, Gerogia
if its not the regulator than why is there a return line coming off it? everyone else told me that the 97 vette rail had return line and regulator at the fuel rail and not inside the tank. so can i just get any kind of inline regulator at like Autozone or some place like that? that dont need a return line back to the tank?
The '97-98 Vette rails do have a regulator as you described, but the stock one isn't adjustable. For some reason, your pump may be delivering more volume than that regulator can manage and it's running up your fuel pressure @ the rail.
I believe somebody makes an adjustable replacement for the '97-98 piece that drops right into the same place, check TPIS.com or the usual vendors.
I went with an Aeromotive adjustable regulator and plumbed it into my car's feed and return lines, early pic is here:
http://www.warpten.com/carpics/ls1_0214/DSC00038.JPG
You always want a return hose or you'll deadhead your fuel pump and shorten its life.
I believe somebody makes an adjustable replacement for the '97-98 piece that drops right into the same place, check TPIS.com or the usual vendors.
I went with an Aeromotive adjustable regulator and plumbed it into my car's feed and return lines, early pic is here:
http://www.warpten.com/carpics/ls1_0214/DSC00038.JPG
You always want a return hose or you'll deadhead your fuel pump and shorten its life.
Originally Posted by sr_ryan1
even if i do get that adjustable reglator and drop the pressure a few psi's. i dont thank its going to fix the rough idle and skiping
Don't forget the PCM is running open loop for quite a while after initial cold startup...it can't adjust fueling to accomodate the overdelivery your extra pressure is causing.
Get the pressure down to spec 58psi and retest, I'll be you'll be a lot happier.
