So I’m cruising down the 91 East Sunday morning around three at roughly 80mph when some inbreed in a late model Nissan Sentra “SER” decides we’re going to play. So I crack open the throttle body and the car starts to backfire. I take my foot off of the gas and slowly start to roll into the throttle and she starts picking up speed with not so much as a hint of backfire. I get off on my exit and its pretty much the same thing. Jump on the gas and the car backfires. Slowly roll into the throttle and she runs just fine. Alright boys…what’s the problem?

 

Sounds like the fuel pump is on the way out. Also might be a regulator problem.

 

TPS switch maybe?

Weird that it would load up and backfire when you kick it to WOT.

 

Whatever it is...it's pissed!

 

I agree with Don, the fuel pump is dying and still working well enough for cruising, but when you get on it and need a "pump shot" it doesn't have the capacity. Your engine leans out and backfires.

 

Someone please correct me if I'm wrong, but I have trouble with the idea that an electric fuel pump dies slowly. My experience has been that they either work or they don't.

The factory pump delivers 70psi to the fuel rail. The FPR then reduces the psi down by bleeding excess fuel back to the tank.

Mike, check the fuel PSI. You might even try blocking the return line and taking a reading. With the return blocked, you should see 70 psi on the gauge. If so, I'd think the pump is fine.

Plus, Mike said that if he suddenly stomps on it, it backfires — BUT if he eases into it the car takes off. I'd think that a faulty pump would react the same regardless of sudden or slow pedal application. If there's not enough fuel at WOT, there's not enough fuel.

 

I just went down to do a little troubleshooting and now the car wont light off. When I turn the key to accessory I can’t hear the pump prime like I normally do. So strictly based on the particulars I think Don is right. I’ll crack the lines open and see if I’m getting any liquid gold but having had a couple pumps go out in the four cars I’ve owned I think it’s time to schedule an appointment with Dr. Don.

 

Mike, I can't remember off hand. Is your car TPI or TBI?

 

So thats what you meant when you called me at 2 am last night asking for a golden shower??

 

TBI ....we haven't converted it yet.

 

I've seen the dying fuel pump issue on a couple brand F products. Sometimes they do sorta work then later die.

Mike, take a piece of wood or something else like that and smack the tank but not enough to dent it. It'll likely run but I wouldnt drive it... probably die soon thereafter.

 

Typical GM fix, when all else fails, get a bigger hammer.

 

Hammer or Hummer?

 

No baby girl…the message I left on you answering machine was that your performance was solid gold and then I reminded you to take a shower before you went to work. You remember what happened the last time we got together and you went straight to work without freshening up… catch my whiff woops I mean drift.

P.S. I’m really sorry about ruining your silk shirt with the huge tiger and jungle motif. A little toothpaste and water should get the stain out. If not don’t worry about it…it’s on the back anyway…

 

When the original pump for the BB went out in the 90's the car still ran but had no acceleration...the fuel pressure was in the 20s.

 

I believe your wife has the hammer and you have the hummer.

 

That's right. Mike's wife wouldn't give him a hummer so he went out and got one.

 

Me thinks he went to the wrong store.

Red taillights do not = ...............

 

Why do you guys always get perverted on this board? Use the other one.

 

Kevin I totally agree! I came here with a legitimate problem asking for help and was immediately accosted. It is through no fault of my own that I happen to be this voluptuous and desirable. It seems like now more than ever I have to remind people to look at my eyes when they are talking to me. Now if I can just figure out how to make them stop whistling…

 

try holding your breath.

Kevin, I guess its all in the readers mind what statements mean.

 

Ok she is all better now. Turned out to be a bad ignition coil and thanks to the immortal BB (R.I.P.) I have a new to me 12-second ignition coil!

 

Aren't you glad you didn't change the fuel pump! I'm not sure why everyone immediately goes "fuel pump" whenever somoeone posts "my car is running a little funny".

Maybe I should just be quiet and start a side business selling new fuel pumps. I could make a fortune.

 

300k miles and the coil went? Sheesh... what is this world coming to???

 

Naw...you just need to get a list of the first things to analyse when a problem develops. That will prevent changing things that aren't bad.

After Mikey checked and found no fuel problems (which seems to have appeared obvious) he then went to the ignition to check for spark..voila!

 

I have that list and I use it.

I was just commenting on the fact that most of the time when someone posts "my car ran wierd today" the typical repsonse from everyone is "the fuel pump is bad". Funny though, 9 times out of 10, it's ignition related.

Yes, it was obvious from Mike's description that there wasn't a fuel problem. Everyone still told him his fuel pump was lame and probably needed to be replaced.

That's why I joked that I should start selling fuel pumps. If everyone's knee jerk reaction is going to be "buy a new fuel pump" I could have a nice little side business.

Glad to hear it was something simple and Mike got it resolved.

 

Uh, no it WAS obvious it could be a fuel problem from his description.
But sometimes ignition problems do wierd things.
I believe it was "check the fuel delivery first" and go from there. (you know "sounds like")
He had that same problem with the red car on Ortega Hwy. and it was fuel related. Anyway, nobody should jump in and change a fuel pump until they are sure that is what is causing the problem.
Just my $.02

 

One problem with bulletin boards is that people will post one symptom and ask for a solution. If your method of trouble shooting is to start changing parts until it is fixed, you had better have deep pockets. I looked through this whole thread. Nobody said it is definately a fuel pump, just that it might be. No mention was ever made of a fuel pressure test having been performed until the post where Mike posted the solution to his problem. No body ever even mentioned the coil as a possible problem. We can throw out ideas on the board, but the only way to find any problem is to follow an organised trouble shooting procedure. He could have gone out and bought an ignition module instead of a fuel pump, but that still would not have solved the problem. On the board the best we can do without looking at the car is to throw out "wild a$$ guesses." We can tell people what might be causing their problem to give them a direction to look in, but the individual still needs to do a thorough investigation of what is going on.

 

Why should we be different than 99% of the commerical mechanics out there, inc the dealers.
They are not diagonstic techs, they are parts changers.

 

It’s all about process of elimination…wont light off check fuel. Got fuel, check spark etc…

I hadn’t so much as opened the hood when I originally started this thread. So strictly based on my past experience (having lost a couple of fuel pumps prior to this) the characteristics of this problem were extremely similar to what I had experienced before where the fuel pump ended up being the problem. There was no way in hell I was going to replace the fuel pump before knowing without a doubt that it was the problem.

 

Excellent reason not to take a car to the dealer.

Mike, my post was not directed at you, rather at all of the "I told you so's" going back and forth after people expressed possible sources of your problem. The fact that you found a bad coil shows that you did some sort of trouble shooting procedure before throwing parts at it, unless it just happened that the first part you threw at it was a coil.

 

Well, it's tough to make a blanket statement like that. I've had bad dealership experiences and good dealership experiences.

Lately, my experience in dealing with the delaership on my truck has been pretty good. Normally, I wouldn't take my car there and would do my own repairs, but with the truck under full warranty I'm pretty much required to go there.

I've had two minor problems and the dealership took care of them and didn't just throw parts at it. They ran a proper diagnostic and pinpointed the issue. All for free and on one occasion even set me up with a rental car for a day. I did not ask. They simply said we're waiting for a part to arrive, so we're going to get you a rental so you can head off to work.

It seems there has been a big crackdown on the dealerships and their service. I know my local GMC dealership now fines the service managers for poor customer service.

I'm sure that comment includes me. So, I'm going to nip this right now before any more posts get made. My intial comments were meant to be light-hearted. Go back and notice all the "winkies" and "smilies" in my posts. I was trying to be funny. However, it appears it wasn't taken that way and some people were offended (another problem with message boards). For that, I apologize.

It also seems as if we might have the ghost of Dean still lingering. Just to sum up, we are all friends here. Sometimes we agree, sometimes we disagree, but it's all in the name of sharing our passion for cars.

In the end, Mike's problem was very minor and his car is back on the road with a quick fix. That's all that matters.

So, lets move onward and upward. Looking forward to seeing everyone at the Christmas dinner.