my 99 3.4 wont start

[procrstinator]

you may have read my previous threads ,about my stupidity.i dumped 4 gallons of very bad fuel in ,put about 20 miles on it and parked it over night .i had no trouble the day i parked it ,ran as good as it ever did .ok so next morning i turn the key and the motor just turn .no start .i was bewilderd .then i thought oh no BAD GAS....well now im really not sure .i have drained the tank,changed fuel filter,blew the line from front to back with air,changed the plugs.Still no start .hooked a code readerup got a #3 cyl.misfire and a mass air flow sensor error.checked plug wires change plugs again and cleaned MAF sensor with carb cleaner.still no start.My question is >is it possible that the MAF sensor would keep car from starting? HELP!!!!!!!

[GTP Dad]

The MAF shouldn't keep it from starting. I am assuming that you have good spark so I won't discuss that. I am also assuming that you have good fuel pressure. There are two possibilities here if the spark is good. If the fuel pressure is low or non-existant you may have to replace the fuel pump.Or your injectors may be so contaminated that they won't work. If the fuel was as bad as you say then the injectors may be so dirty, or gummed up that they will not work properly. Same thing with the fuel pump. You may have to replace the fuel pump and then the injectors in order to get the car to run.

Try this, remove the hose from the air cleaner and while turning the car over spray starting fluid into the throttle body. If the car starts then the problem is in the fuel system. If not the ignition system will need some attention.

Hope this helps!

[procrstinator]

well it starts and barely will run like only a couple cylinders fireing.i was going to get just the pump and couldnt figure out how to separate pump from podso i put it back in kragens wants 289$.....directauto.com only 44 +shipping..but i guess you get the whole pod and pump

[BNaylor]

Originally Posted by procrstinator

well it starts and barely will run like only a couple cylinders fireing.i was going to get just the pump and couldnt figure out how to separate pump from podso i put it back in kragens wants 289$.....directauto.com only 44 +shipping..but i guess you get the whole pod and pump

As I mentioned in the other posts on the subject thats correct. Normally you replace the whole pod.



Try EBay. There are a bunch of GM OEM and Airtex fuel pump assemblies available for a lot less. Also you can try a salvage yard. Even if you could disassemble the fuel pump from the pod and put in an aftermarket such as a Walbro you may have problems with fuel intake afterwards especially when you get to low fuel in the tank.

BTW - Don't recall if it was suggested earlier but you can check fuel pressure at the rear fuel injector rail. There is a Schrader valve on the passenger side of engine injector rail. Alero pump puts out pretty good pressure. Typically it will read around 56 psi in the ignition run fuel pump prime position and 59 psi engine running and vacuum disconnected off the fuel pressure regulator. The test will either conclude the fuel pump is good or bad without guessing. Gauges only cost around $25 or so at Autozone.



Photo courtesy of Club Bob