03 5.3 vortec in 79 impala
01-02-2016, 10:02 PM
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03 5.3 vortec in 79 impala Hello there everyone!
A little background on my project.
I have a 79 impala that i got from my dad as my first car when i was 16. He got it from his grand dad who bought it new back in the day. When i got her she had the stock 305/2 barrel carb setup with 200,xxx miles on it. Regular maintenance had been done but nothing major. As you can imagine she was lacking in the power department which was good for a 16 year old, not so good now.
Jump a little forward. I have gotten a 00 wrangler and havent driven the chevy for a few years. I go to the mountains for school and take it with me with the intent to put a new motor in but never have the funds to do so. End up bringing it back home when i move back.
Jump forward again. I have gotten some funds together and a place to work and have now installed a 5.3vortec/4l60e combo with roughly 100k on it. I have followed instructions to cut down the wiring harness to what i need and have it temp wired up in the garage (should work but have some wire management and all to finish)
now ive run into an issue that i need help with. I have spark, air and fuel. When I turn the key the fuel pump primes to roughly 48psi on the schrader valve. crank it up and it starts up for about 1-2 seconds then shuts off. Doesn't really sound like its stalling, more like its losing fuel, spark or air. put a test light on the circuit to the fuel pump and watched the pressure gauge. once it primes the test light goes off but once i start to crank the engine it comes back on. The pressure goes up to roughly 55psi when it fires up but comes back down once it dies. I thought this was low but i can feel pressure in the return line to the tank so i assume the pressure regulator is sending extra back to the tank. I pinched the return line and got the pressure to roughly 90psi and it had no effect on the motor running. The motor starts up initially so i assume its getting spark. I have a spark tester but i have to find it. As far as air im not quite sure how to test if something is wrong there. I have the OBDII plug hooked up and i scanned it. only codes i have are for evap system but from what i looked up about them there should be no noticeable problems with those codes (I left off the evap system so thats why i have the codes).
So im pretty much stuck at this point. Why would it start up but then immediately cut off? Any ideas from the experts out there?
ps. The whole fuel system is new. I put in a 96 impala ss tank with the following pump and a new filter. The pump has pretty much the same stats as a pump for a 03 tahoe (within 2psi) so i figured it should work.
http://www.autozone.com/external-eng...?checkfit=true
A little background on my project.
I have a 79 impala that i got from my dad as my first car when i was 16. He got it from his grand dad who bought it new back in the day. When i got her she had the stock 305/2 barrel carb setup with 200,xxx miles on it. Regular maintenance had been done but nothing major. As you can imagine she was lacking in the power department which was good for a 16 year old, not so good now.
Jump a little forward. I have gotten a 00 wrangler and havent driven the chevy for a few years. I go to the mountains for school and take it with me with the intent to put a new motor in but never have the funds to do so. End up bringing it back home when i move back.
Jump forward again. I have gotten some funds together and a place to work and have now installed a 5.3vortec/4l60e combo with roughly 100k on it. I have followed instructions to cut down the wiring harness to what i need and have it temp wired up in the garage (should work but have some wire management and all to finish)
now ive run into an issue that i need help with. I have spark, air and fuel. When I turn the key the fuel pump primes to roughly 48psi on the schrader valve. crank it up and it starts up for about 1-2 seconds then shuts off. Doesn't really sound like its stalling, more like its losing fuel, spark or air. put a test light on the circuit to the fuel pump and watched the pressure gauge. once it primes the test light goes off but once i start to crank the engine it comes back on. The pressure goes up to roughly 55psi when it fires up but comes back down once it dies. I thought this was low but i can feel pressure in the return line to the tank so i assume the pressure regulator is sending extra back to the tank. I pinched the return line and got the pressure to roughly 90psi and it had no effect on the motor running. The motor starts up initially so i assume its getting spark. I have a spark tester but i have to find it. As far as air im not quite sure how to test if something is wrong there. I have the OBDII plug hooked up and i scanned it. only codes i have are for evap system but from what i looked up about them there should be no noticeable problems with those codes (I left off the evap system so thats why i have the codes).
So im pretty much stuck at this point. Why would it start up but then immediately cut off? Any ideas from the experts out there?
ps. The whole fuel system is new. I put in a 96 impala ss tank with the following pump and a new filter. The pump has pretty much the same stats as a pump for a 03 tahoe (within 2psi) so i figured it should work.
http://www.autozone.com/external-eng...?checkfit=true
01-03-2016, 05:24 PM
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I have not had any programming done to the computer. I was hoping that the vehicle i got the motor and trans from didnt have the VATS system, i never saw the tahoe and didnt know if they all had the system or not and my setup didnt come with the bcm. Also for a while i wasent getting a code for the VATS and i figured if it was a theft thing the car wouldnt start at all. As it turns out though the code finally popped up, i forget what code number it was right off, saying something about the security system was shutting it off. I have tried to find a way to bypass the VATS system without the bcm but so far ive come up with nothing other than reprogramming the ECM.
01-03-2016, 07:04 PM
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1st dont pinch the return line , 2nd , its the vats ,it must be turned off , classic vats issue it runs for a couple turns and stops , vats disables the injectors , you need a tuner to turn it off , and most disable the rear 02 sensors at the same time
01-03-2016, 07:21 PM
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i pinched it with my hand so i could let it go quick, didnt clamp it or anything like that. and yeah the more i look the more it sounds like the vats thing. I took the rear o2's out so ill have them disabled too. also took out the evap purge system so ill have to have that disabled too.
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03-13-2016, 10:38 PM
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hey guys. sorry to take so ling getting back on here. I travel for work and dont get to play with the car as much as id like.... anyway.
I ended up buying a hptuner and disabling the VATS. After that she fired right up. ive since gotten things together, a little rigged here and there ill admit, and got to drive her around a little which was AWESOME after not driving it for years basically.
Now on to the problem im having. im new to the whole tuning thing and all that so hopefully i dont sound too dumb here but my issue is that the front driver cylinder, #1, is not functioning. Im not quite sure whats going on with it but after letting the car run for a minute all the other exhaust tubes get HOT and that one is still cool enough to grab on to. I dont know if its connected or if ive got another issue going on but on the scanner when i open the gauges and start the car the o2B1 and o2B2 start off around the same level (roughly 445). They stay that way for about 40 seconds then they diverge. o2B1 drops down to 50ish and o2B2 goes up to 900ish, this happens in about 15 seconds. Not sure if cylinder problem is causing this or if this is causing cylinder problem or if they are completely different problems.
I started with trying to figure out whats up with cylinder 1. so far i have tried:
-check for spark: yes
-check power to injector: yes
-swap injector for injector 3: no change
-swap coil for coil 3: no change
-swap plug wire for plug wire 3: no change
-swap plug for plug 3: no change
noticed a MAJOR difference in plugs 1 and 3. 3 looked like it had been running rich, probably from lack of exhaust and open long tubes, but 1 looked like it had been running SUPER rich, like the plug was wet and major carbon buildup.
I also did a pressure test on 1 and it held pressure. i forget the exact number but it was around 140psi.
My thought was that the ecu was not providing the ground for the injector to open but then there should be no buildup on the plug......
any ideas on what might be going on? my next step right now is to swap the o2 sensors and see if anything changes.
I ended up buying a hptuner and disabling the VATS. After that she fired right up. ive since gotten things together, a little rigged here and there ill admit, and got to drive her around a little which was AWESOME after not driving it for years basically.
Now on to the problem im having. im new to the whole tuning thing and all that so hopefully i dont sound too dumb here but my issue is that the front driver cylinder, #1, is not functioning. Im not quite sure whats going on with it but after letting the car run for a minute all the other exhaust tubes get HOT and that one is still cool enough to grab on to. I dont know if its connected or if ive got another issue going on but on the scanner when i open the gauges and start the car the o2B1 and o2B2 start off around the same level (roughly 445). They stay that way for about 40 seconds then they diverge. o2B1 drops down to 50ish and o2B2 goes up to 900ish, this happens in about 15 seconds. Not sure if cylinder problem is causing this or if this is causing cylinder problem or if they are completely different problems.
I started with trying to figure out whats up with cylinder 1. so far i have tried:
-check for spark: yes
-check power to injector: yes
-swap injector for injector 3: no change
-swap coil for coil 3: no change
-swap plug wire for plug wire 3: no change
-swap plug for plug 3: no change
noticed a MAJOR difference in plugs 1 and 3. 3 looked like it had been running rich, probably from lack of exhaust and open long tubes, but 1 looked like it had been running SUPER rich, like the plug was wet and major carbon buildup.
I also did a pressure test on 1 and it held pressure. i forget the exact number but it was around 140psi.
My thought was that the ecu was not providing the ground for the injector to open but then there should be no buildup on the plug......
any ideas on what might be going on? my next step right now is to swap the o2 sensors and see if anything changes.
03-14-2016, 07:36 PM
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ok so i figured out the issue. the plug for injector 1 is bad and is not making contact. if i push on it it will contact and things run MUCH better. now i have another problem i think. So the 02 B1 and o2 B2 start off at the same level then they both drop down. After that the o2 sensors bounce back and forth between high and low. is this supposed to be happening? I would think that they should stay around the same level and only vary a little as the engine adjusts its self. if I accelerate they both go up, come back down and then go back to bouncing.
ill post a pic of the graph in a minute
ill post a pic of the graph in a minute
03-14-2016, 07:42 PM
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and heres a pic of the graph when i give it some gas. I was apparently not watching the graph very well while doing that because the o2's did not go up then back down, they went crazy. If you have any idea whats up please let me know or if this is normal please let me know that so i can stop worrying.