I was on my way to work this morning, and after a good 10 mile stretch of smooth freeway driving I got off and about 300 feet after the off-ramp my car started really sputtering, shaking violently, and running like absolute crap. I could see big puffs of white smoke in my rear-view mirror coming out of my tailpipes. I knew I didnt have much time so I immediatly pulled over and as soon as I popped it up into nuetral it stalled. It absolutely refused to start back up. It would crank but would not even think about catching. I walked to the nearest pay phone to have my mom bring me some tools, I carry nothing in my car because I usually leave the tops off and doors unlocked, and I cant get a good look at ANYTHING because I have a bolt on my aircleaner where a wing nut should be.

So she finally arrives with my girlfriend and I get my cleaner assembly off and have my girlfriend crank it while I take a look at things. I thought maybe water got in the distributor because it rained this morning and I have no hood seal, but this was not the case. Upon cranking the engine, both injectors just start DUMPING fuel down the bores which almost immediatly are filled up with fuel like little cups. Okay...great...its flooding itself while cranking. WTF do I do? Having recently gone through my TBI unit with new gaskets and the like, I noticed that a previous owner had made the fuel pressure regulator adjustable. So, using my basic caveman-like logic, what do you do when you have too much fuel? Why, lower pressure of course! I took the thing apart right there on the side of the road, and couldnt remember which way would lower the pressure, up or down. I took a chance and moved the little notch thing downward, once again, basic logic right? Down = low pressure? Anyways, I put it back together and had her crank. Progress had been made, they were firing like normal but it still wouldnt start. I got in the driver seat and tried starting the car with a little finesse of the pedal and got it running. It would not hold an idle and ran like ****, but at least it ran. It was acting like it wasnt getting enough fuel.

I figured maybe I knocked something into shape when I took it apart and lowered pressure, so I took it back apart again and moved the pressure regulator notch back to where it was before, about half way. I cranked and they fired like normal and the engine started. This time, it ran just as good as always. I drove on to work, and then drove it the whole way home tonight without a hitch.

So thats my story, here are my questions.

First, what could have cause this problem of the injectors just dumping uncontrollably, and why would the problem fix itself when I took the top end of the TBI off? I doubt me adjusting the fuel pressure had anything to do with it, that seems like more of an ECM thing that anything else. I did disconnect the battery terminal before I worked on it, could re-setting the system have fixed the problem?

And second, where should my fuel pressure regulator be set at? I have mismatched injectors, I believe to be a 61# and a 65#. I'll be fixing those as soon as I can, but its all I got right now. I've always just kinda guessed on where it should be set. And even though I'm running the 305 PROM on a 350, my car has always run ritch. Could lowering the pressure fix this?

Thanks
Andy

 

Sorry its so long, I try to include every detail because I know from experience that its often the little overlooked details that solve problems. Come on, help me out guys

 

Cliffsnotes:

What could cause my injectors to shoot so much fuel during cranking that the throttle bores fill up?

Why would this problem fix itself after I did the above mentioned things?

Where should the fuel regulator screw thing be set?

 

It may be an issue with the coolant temperature sensor (CTS). If the wiring or sensor goes open the ECM thinks that the engine is at -40 C and fuels it accordingly. It is common for the wiring to the CTS too become intermittent. This sensor is on the front of the intake manifold, 2 wires, yellow and a black.

To set the fuel pressure will need to use a gauge.

RBob.