dawb

I dont exactly have an f body, but i have 2 trucks (2500 chev and a Jeep YJ) with 305 tbi's. This site seems to be the most familiar with the motors.

Last week, I did a tuneup in the truck. cap/rotor/plugs/air/pcv/fuel filter. On the weekend, we went on about a 700km roundtrip, with no problems. Even went to work for 2 days without a problem. Then today, on my way in, the truck stalled 4 times in the Tim Hortons parking lot. I was able to get it started everytime (sometimes right away, sometimes not) and was also able to get it to work. I didnt work on it, or start it until after (9.5 hours later) which it then died 5 times consecutively. Each intermittent run time being shorter and shorter.

Now, we were able to rule out a fuel pump relay, but thats it ( i changed in a new one). I couldnt hear if the pump was turning on, as there was a loud shop behind the truck, however, with a testlight, there was power AT the pump for priming. When cranked, there was no power.

I read at this thread, https://www.thirdgen.org/forums/tech...again-new.html that the ecu will only power to the FP if it is receiving proper ignition information. For this guy, it ended up being his Dizzy that was the problem. Maybe I am just hoping that its not the fuel pump. I have a new pump, but I also have a spare Dizzy from the jeep original (now has MSD) and another extra Ig Module.

Would it be wise to chuck the extra Dizzy in to see if that sends signal to the pump? or even just the ig module? or do u think its the fuel pump?

I did not take the air cleaner off to check for fuel, but i couldnt smell any, and we cranked the motor quite a bit.

I left the truck at work as i didnt have any tools to test it really. I really dont want to change the pump in all this Vancouver rain

evilminds

sounds to me like maybe the hose inside the tank that fuels the pump may have come loose from the pump..or has a hole in it..basically not feeding a constant flow of fuel to the TBI..if you can here the pump prime when it does startup..and you can hear the pump prime when you have to restart it after it dies on you..then i would say time to check inside the tank.....might also be a good idea to also check to see if your actually getting fuel from the injectors when it dies,,if you can hear the pump prime.

just a thought..

juanillox8

iTrader: (7)

i have a chevy 3500 454 tbi it had the same symptoms (and i also had just replaced cap and rotor) it was the distributor two of my coworkers had the same problem with their truck and it was the dist i strongly recommend changing it

RFmaster

You can rule out fuel pump / in tank hose by a simple functional test. - Take a look at your fuel pump relay. On most C/K TBI harness there is a small (about 4") red wire with test connector attached to fuel pump relay. Apply +12 volts with 10 to 15 Amp inline fuse - this will turn on fuel pump and allow you at least to test if your distributor is generating DRP for ECM. If ECM sees DRP pulses it will fire injectors during cranking (fuel / spark / injector pulses). If you do not have this test wire you can simply remove relay and with 1/4" spade terminal attached to a suitable test wire apply +12 to gray wire - FP side of relay switched circuit.

//RF

UnderCover89TBI

iTrader: (25)

its the ignition control module, change the distributor or just the module. especially if no fuel from tbi and no spark. i did a tuneup on mine and then the next day the module went out. why i dunno.

dawb

Thanks for all the quick replies! it absolutely was the distributor (or the module/dist combo). I dont know why i didnt notice when i swapped cap and rotor, but the plate the module sits on was all powdery and green and corroded. swapped in the spare distributor, and fired right up... havent fully set timing yet, but was enough to get me home for now! so weird that I actually shouldnt have tuned it up! haha jk

hopefully for some better fuel mileage now, and glad i could return the pump and not have to change it to find out its not the prob!

thanks again all!

UnderCover89TBI

iTrader: (25)

you welcome. thats what we are here for! now just help the next guy/girl when you can...

juanillox8

iTrader: (7)

thats the best way to show gratitude