i have a 94 sonoma with a fuel problem.. okay i posted yesterday that it keeps cutting out and then finally wouldn't start. well had it towed to my house. went out this morning, flipped the key and by damn it started normal. went down the road and back and shut it off, went to start it and nothing. just rolled over. went underniether to fiddle with the fuel filter gave up on it after a bit. started the truck and it started up again. you wouldn't think its the pump right??
2007-06-03 01:42:03 · 4 answers · asked by dave51_1998 4 in Cars & Transportation ➔ Car Makes ➔ GMC
its a v-6 motor. I've been having trouble with my battery positive terminal. it keeps coming loose. could that be part of the problem also?
2007-06-03 02:51:14 · update #1
If the motor won't crank at times, then yes the battery post thing is an issue. Even if it isn't an issue now, it will become one so deal with it and do it properly. The thing with your intermittent is this, you have to eliminate one of the suspected culprits as both of these jobs will be expensive. At the back of the intake plenum and kind of buried a bit is a fuel pressure port where we used to screw on a fuel pressure guage so as to see what the fuel pump pressure is doing in the line. This will have to be checked to be sure which part is the problem. The normal fuel pressure at idle is around 55 psi and when revved it should quickly pop up to about 65. When the truck acts up is the time to perform this as it will obviously check good when running. You should be sure about the spark available to the plugs as well. Take the connectors off of all the spark plugs on both ends including the coil ends and inspect for corrosion and/or carbon tracking as this truck was huge for this problem too. If you are satisfied that you don't have any ignition problems that you can find, when it acts up check to see that the spark is being delivered to the plug end by checking it while cranking the motor over. If you have strong and consistent spark, then you have eliminated the ignition as the culprit. If you have none, weak, or inconsistent spark you have a problem that needs further diagnosis. When checking fuel pressure when the motor will not start or is limping along, if the pressure is approaching the proper number, 55, but the motor is chugging or not starting I would suspect the central port injection system. If the pressure is very low or none, I would suspect the pump. Try priming the pump by leaving the ignition in the off position and the fuel pressure guage installed. Then turn the ignition to on not start and observe the guage reading. If the pressure builds quickly and then falls away quickly, I would suspect the injection. If it does not build up, I would again suspect the pump. As a general rule as well, when the injection system goes the motor generally does not run as good as it used too and it uses more gas than it used too. That is not a hard and fast rule but just another to send you in the right direction. When in doubt, just yank the intake plenum off the truck, it only takes about a half an hour to see inside. If it is full of gas inside or one side is clean and the other is covered in carbon soot, the injection system has had it. I know there's a lot of stuff here, but this crap is so expensive that we always needed to be sure before doing anything. Good luck.
2007-06-03 04:55:38 · answer #1 · answered by Deano 7 · 0⤊ 0⤋
Yeah the terminal could be an issue but I'm pretty sure this is your answer ( IF IT'S A VORTEC V6 ) this does not apply to other V6 's . GM installed one central injector inside of a two piece intake that has 6 nylon tubes coming off off it , most drivability techs call this the "spider", each tube has a pintle on the end . What happens is this , the heat tears up either the nylon fuel parts ( the fuel supply lines are nylon too )
or the fuel pressure regulator ( also inside the intake ) Fuel leaks inside the intake and randomly floods the engine from time to time . Check this by removing the plastic cover that says Vortec on it , remove two Torx screws in the VLIR actuator ( round part in plain sight , right on top ) look inside with a flashlight ( don't use a cigarette lighter please ) You'll se that one side of the intake is very clean from all the extra fuel leaking . Get you a cheap manual and remove the top of the intake , determine the leaking part and fix it . Your plugs have been washed so at least dry them out real good . I've done this about 10 times it's very common .
2007-06-03 08:51:48 · answer #2 · answered by barryinhouston 1 · 0⤊ 0⤋
Sounds like a fuel filter or fuel sock is plugged to me.
2007-06-03 09:29:15 · answer #3 · answered by Anonymous · 0⤊ 0⤋
there used to be problem with coil wire arching through check it
2007-06-03 08:46:22 · answer #4 · answered by ray p 3 · 0⤊ 0⤋