RKeats

This may be a rookie question but bear with me as I'm just figuring this stuff out as I go. The other day I started my car and it was fine, drove it 5 minutes to the store with no issue but when I came back out and re-started it, it ran like garbage and would just stall if I gave it any gas. After stalling a few times it eventually gave up on even starting and would just crank without even a sputter. Left it in the parking lot, came back the next day and it blazed up and drove home trouble free. Now I can once again start it first try every time and it runs as it should, but of course I'm now nervous to drive it anywhere. Fuel pump/filter are new. Any ideas?

PaulyC

Oh I just love intermittent FI issues, did the MIL come on during the episode? If so you could get a scanner and check the codes (or do it the old fashioned way at the ALDL if you don't have a scanner). Ill say this from experience though, TPS's can be intermittent and cause all kinds of starting and drivability problems when they get flaky. The other big culprit for this type of thing is coolant temp sensors.

Last, how new is the pump? If this is the first ride on it then I would inspect that as well. Make sure the connector is plugged in and clipped etc.

Lets hope a code was set though, that will point in the right direction.

RKeats

No lights at all but I haven't had a chance to run a scan. The pump was mid last year and if I recall it was a Delco so I can't imagine that would be the issue. I blew a rad hose last week and after fixing it in a parking lot I filled the car up with basically just a garden hose to get it home. It was running around the mid 100 degree range. Would that maybe point toward the coolant temp sensors?

PaulyC

Well not necessarily, that shouldn't have affected the sensor. You may want to make sure you distributor is all clean and dry if it got splashed when the hose farted out. Check the connectors as well. Also, in case you didn't know, the sensor for the gauge and the sensor for the cpu are separate so your dash temp is not what the cpu is seeing.

armos

Get the car into a failure condition and then check if you still have spark.
You can also try introducing starting fluid at the throttle body and see if it fires when you crank it afterward.
If that checks out, then check fuel pressure if you can. But it needs to be in a failure state when you do that.


I don't know how audible the fuel pump is on your car, but if it's audible, then you might also try this experiment (when it's in a failure state):
When you turn on the key, but without cranking the starter, can you hear the fuel pump prime for 2 seconds?
Then try blipping the starter for a moment, just long enough to turn the distributor a bit but *not* long enough to build any oil pressure. Can you hear the pump prime again for 2 more seconds?
The latter test is to see whether the ECM is receiving pulses from the pickup coil in the distributor. It will power the pump when it sees them. The first test is to check your fuel pump relay.

I'm not sure about your model, but on many cars it is possible to drive on a faulty fuel pump relay, due to a redundant circuit that powers the pump through the oil pressure sender. This might not be a reliable operating condition.