Hi, first off are you getting any engine trouble codes ??...Is the check engine light comming on??
No trouble codes and no check engine light coming on.....that's what's hard to figure outHi, first off are you getting any engine trouble codes ??...Is the check engine light comming on??
Engine is stock, it's a 1982 Corvette engine w/ cast iron heads. The computer chip is custom for a stock 90-92 f-body 5.7 TPI.Any other mods to your engine? Are you running a larger cam?What's your fuel pressure. Timing set right? Bad EGR valve can cause surging.
Sure sounds like you went down all the right paths. The only thing in your list of parts that I found odd was the 22# injectors because factory is 24# in my vette, but your chip programmer could have tuned them to spray longer. So that probably is not the problem. You need to check fuel pressure at the rail. Hook up a fuel pressure guage at the fuel rail. When you turn the key on,(but don't start it), The pump should come on for about 2 sec. and the pressure should go up to 35-38lbs with a stock regulator and hold there.(might drop a pound or two but should hold there) If it drops off, you have a problem in the fuel system. I just had one that was leaking off pressure in the tank. The coupling between the fuel pump and metal fuel line was bad. The car ran, but had a crappy idle and poor drivability.Engine is stock, it's a 1982 Corvette engine w/ cast iron heads. The computer chip is custom for a stock 90-92 f-body 5.7 TPI.
No EGR, written out of chip and using a block off plate..
Not sure on fuel pressure, still need to check that. I'm using a new stock TPI fiuel pump, pressure regulators, and rebuilt 22 lb injectors.
Timing is set 6 degrees btdc, I disconnected the timing plug in the harness first. My cap, coil, distributor, rotor, and plugs are brand new. Wires are installed in the right firing order...they are new custom cut to fit wires. They worked fine w/ my carb set up but I'm going to change them out with ac delcos as soon as they come in.
Harness is a custom job done by TPIparts.net , computer is rebuilt, and chip is a custom job w/ smog, egr and vats delete.
All the sensors are brand new, and gaskets are new. Throttle body is nice and tight....
The engine seems to "shake" more than it did with the carb set-up so something still isn't right.....
So stock injectors for corvette is 24lb?? I may have made a boo boo when I had my chip programmed. I told the guy 22lb injectors because I was under the impression that's what all 5.7 TPI injectors were.Sure sounds like you went down all the right paths. The only thing in your list of parts that I found odd was the 22# injectors because factory is 24# in my vette, but your chip programmer could have tuned them to spray longer. So that probably is not the problem. You need to check fuel pressure at the rail. Hook up a fuel pressure guage at the fuel rail. When you turn the key on,(but don't start it), The pump should come on for about 2 sec. and the pressure should go up to 35-38lbs with a stock regulator and hold there.(might drop a pound or two but should hold there) If it drops off, you have a problem in the fuel system. I just had one that was leaking off pressure in the tank. The coupling between the fuel pump and metal fuel line was bad. The car ran, but had a crappy idle and poor drivability.
Possibly. I run 30lb. injectors with mine, and have a custom chip from Motorvation. I know that when I changed from stock to 30lb, they had to burn me a new chip. I tried the car with the new injectors, but left my first chip in just to see what it would do, and it idled like ****. Put the new chip in they burned, and it runs great. So there is something to it. But factory is 24lb.So stock injectors for corvette is 24lb?? I may have made a boo boo when I had my chip programmed. I told the guy 22lb injectors because I was under the impression that's what all 5.7 TPI injectors were.
Would 24lb injectors with a 22lb chip setting make that much difference?
I went out and checked ran it with the lights off...no visible arcing I can see. I also checked the fuel pressure and it's healthy.the ignition wires can be brand new but if they are arking off anything you can't tell or even see it till its completely dark at night and ur around no lights...I know it sounds wierd but check for it. You can also have wire to wire arking and like i said you won't be able to see it unless its pitch black and u pop ur hood. Also you can try elimanating senors by removing each one one at a time to see the changes. Sometimes scanners don't pick up everything. Another quick easy check is to try removing a spark plug wire one at a time to see if there is a change or no change to see if it could be something between the spark plug and the dizzy. Just things to look for. It doesn't seem like a vacuum leak, but more electrical. Hope this helps. I have had many and still do tpi cars
I've bought bad alternators and starters right off the shelf. Especially at places like Advance or Autozone. If you want quality electrical components, go to NAPA. I've never got a bad electrical part from them. Always great quality. And yes, low battery voltage can cause an array of problemsI went out and checked ran it with the lights off...no visible arcing I can see. I also checked the fuel pressure and it's healthy.
But I did notice something weird, my battery showed 12.6 volts, but upon starting the car the alternator fluctuated between 6 - 10 volts and it never got higher than 11 volts.....it's a new alternator less than three months old. I've got a feeling that may be the source of my miss and other problems..
any ideas?
Yeah, that's what I heard. Autozone's site says this alternator is remanufactured with SOME new components.I've bought bad alternators and starters right off the shelf. Especially at places like Advance or Autozone. If you want quality electrical components, go to NAPA. I've never got a bad electrical part from them. Always great quality. And yes, low battery voltage can cause an array of problems