My car has started doing an odd thing. Its a '96 Chevy Blazer… after I fill up the gass tank it will not start for a couple of minutes. It will turn over but not “catch”. after a few min of trying once in awhile it will catch very roughly then smooth out. From then on it will start the first time every time with no problems until the next time I fill it up.
Any thoughts?
Question: will it do this if you just turn the engine off for the same amount of time as you would if you filled it up, without actually doing so? That is, does this happen because you filled it up, or because it was turned off and re-started within a few minutes?
It starts fine any other time… short trip off and on or not. It only happes after I fill it up.
Weird. I can think of any number of things which will cause hard starting after being turned off and re-started after a minute or two. But this stumps me. I wonder if Rick or GaryT have any ideas?
I’d be suspicious of the charcoal canister and the related components of the evaporative control system. It sounds like the vehicle is being given an over-rich mixture at startup after refueling.
I would suspect first that there’s some serious gunk in the gas tank bottom that is getting stirred up during fueling. After it gets settled/filtered a bit, then things are back to normal.
This of course can cause problems with/be caused by the aforementioned fuel filter problem.
In olden days, water was a common contaminant that would cause such problems. Gas dryer, labelled “safe for fuel injectors” etc. can be tried. Small chance that it would work, but it’s also a lot cheaper than a new fuel filter and having your tank flushed.
I’d bet your fuel pump is inside the gas tank. Filling up (if by filling up, you mean all the way up) may be causing a problem with the fuel delivery system, but I have never experienced this before so I’m at a loss.
If you had a gun to my head I’d say it’s the fuel pump.
I agree with danceswithcats. It sounds like something is amiss with the evaporative control system, which manages fuel vapors from the tank. I would guess that excess vapor, or maybe even liquid fuel, is finding its way to the engine and over-richening the mixture.
When filling, you should let it automatically click off and stop right there. Adding fuel past that point has no real benefit and gets liquid into areas that are designed to deal with vapor. If you happen to be overfilling it (past the click-off), that might be exacerbating the problem, and it’s conceivable that ceasing to do so might alleviate the symptom.
You may find you can “work around” the symptom by holding the accelerator pedal to the floor when starting after a fill-up. On most vehicles, this enages “anti-flood mode” by shutting off the injector activation. The sure fix, though, would be to have it tested and repaired by a competent auto repair facility.
Well here is something… I did have my Fuel Pump (which yes is in the tank) replaced 3 months ago.
I didnt think it had been happening that long but MAYBE it has.
Im not sure about the topping off the tank thing… I will experiment with it.
today someone told me to make sure I made the gas cap click for a good 3/4 turn before stopping… and tonight I did that after filling it… but THEN I did go into the shop for another 10 min or so to buy snacks which I havnt done before… I usually just jump back in the truck… and it started right up./…
I am going to experiment with not topping it off and such… Hmmmm…
I actually had a car that did this exact thing. Dances and Gary nailed it. It is almost for certain a evaporate problem. For whatever reason vapors from the tank are going into the evaporate canister, but for some reason the vapors are getting into the engine past the evaporate valve.
If your evaporate canister is accessible try unbolting it and see how heavy it is. If it is very light this is normal. If it weighs several pounds it is full of liquid gas, and needs to be replaced.
Next look at the evaporate valve, I think it might be leaking