i finally got the fuel injection going on my car, and for some reason tons of black smoke was comming out, i did the carb-tpi swap with an LT1 intake, and i think either the fuel pressure regulator is bad as in stopping all the gas from going in the return line, or the injectors are staying in closed loop.....it wont idle it wants to stall most likely because it has too much gas, im running the lt1 intake with stock FPR and 24lb lt1 injectors.... anyone have any ideas of what my problem could be, i know a sensor being unpluged wouldnt do it, and the vaccum hose on the FPR i have going to the intake.....someone clarify what my problem is please!

 

Who burned your PROM? I pulled the fuel rails, unplugged all but one, and had it shoot into a clear container while checking my fuel problem. (The injectors were firing, but not shooting fuel.) Then I did the same thing for all 8 injectors. That way, I could tell what shape my injectors were in.

 

im leaning more tward the fuel pressure regulator, because there was soo much black smoke, i ran the car for about 30 seconds and it filled my garage so i couldnt see the back of the car, thats how bad it was, and i think even if the injectors stayed in cylce it wouldnt be that bad....

 

IIRC, John Millican did your prom? I thought all he did was turn off the EGR (maybe I am mistaken). Is the PROM in your ECM from a 305 or 350?

 

john did the prom because i was putting the lt1 on my 400. i know it wouldnt be anything to do with that because there is no way that just the injectors staying in cycle wouldnt make my garage fill with black smoke in like 30 seconds

 

Hi,

If you don't have a fuel pressure gauge set, now would be a good time to pick one up. Advance has them for under forty bucks.

Also, have you verified all your wiring and vacuum lines, and checked for codes (an open cts circuit, for example, could cause symptoms similar to what you're describing)? Also, be sure there's no gas in the oil.

-B

 

The ECM is what fires your injectors and if you have black smoke, then THEY ARE FIRING. Also, have you double checked your wiring as the others have suggested?

 

i know i dont have all the vaccum lines on, there are 2 on the TB im not sure where to put them, i know i need one for my PCV valve, and im not sure but when i think about it, i hope the vaccum nipple i hooked the FPR up to actually has vaccum but im pretty sure i have all my wires hooked up right, there all labeled i double checked everything, i deffinately didnt want to mess anything up on the wiring. im going to unhook the return line and run it into a bottle and turn the key on and see if anything comes out, how much should come out of it?

 

Double check that you have full manifold vacuum to the MAP sensor, and that the MAP is the the correct TPI part and not the old carbureted part. No vacuum to the MAP can also cause a rich condition.

-B

 

Andrew,

A properly operating fuel pressure regulator doesn't even really need a vacuum line to regulate. With the vacuum line disconnected it will go max fuel pressure as it would at WOT. For a stock FPR this is about 42psi.

Do you have a handheld vacuum pump? If so applt vacuum to the regulator and see if it holds vacuum.

If you want to disconnect the return line and see if there is fuel coming out with key on expect to fill a pint container pretty quick. It's easier with two people, otherwise just turn the key on and listen for the fuel pump to run a second of two then check your container.

Some of your injectors might be stuck wide open or not operating at all. Are they new or used? What brand are they? If used when was the last time they were ran? Injectors don't like to sit for a long, long time.

I have some tested 24# LT1 injectors here that I can swap you out with for a small cost of cleaning and shipping, or you can send me yours to clean and test.

 

John, The LT1 injectors i bought from you that you already tested and cleaned before you shipped them to me(also had you do my prom), i didnt even take them out of the baggy you sent them in untill the other day, what i did notice, is that 6 out of 8 of the injectors, i can touch them and feel a strong pulse running in them, and the other 2 it is hardly strong at all.....i dont know what thats about...but anyways after i hooked on one of the vaccum lines to the pcv valve, it didnt smoke anymore.

 

As TMX asked above, have you verified the CTS is working properly? If not, it will run PIG rich, usually making it even hard or impossible to start after the plugs get fouled.

Can you scan it? Have any codes?

Doesn't sound like an injector or regulator problem to me to be that extreem.

BTW, I had a PROM I burned one night do that to me, once. Never did figure out what caused it. Reburned it, problem went away.

 

OK, I had forgot about the injector sale. I should have checked my invoices before replying. I am getting old.

I hope you hooked up the PCV to it's dedicated port. Here's a picture of the LT1 ports locations.

 

my pcv isnt hooked up like that, the guy i bought the intake from gave me the grommet for it but wasnt sure what it was for, well now i know, but those 2 nipples one vaccum andone for the pcv, are plugged off with alen plugs and on the other side there are 2 nipples one i ran to the fuel pressure regulator......here's the vaccum lines i have, one big one in the pic for the brake booster, and 2 small ones on the pass side on the intake and one on the TB, i have the one on the TB going to the pcv valve on the valve cover. one small nipple on the pass. side is pluged with a rubber plug, and one is going to the FPR. and im not sure if my CTS is fine or not, but its not smoking since i hooked the pcv valve up, but i got the grommet to run one on the drivers side.