99 GXE hesitates from stop to start

[carChick]

I'm posting this for my wife because she is having hesitation problems with her car. She had the engine flushed and the fuel injector replaced. Since then when she starts to move forward from a stop, the car lags, like it isn't getting fuel. I need to get this taken care of because we have a new baby coming and I don't want her pulling out in traffic and getting hit.

Our local Nissan dealer of course couldn't find anything. I changed the plugs, wires, cap, rotor, fuel filter, put that STP stuff in.

Nothing worked.

Now I read about

Bad Mass Air Flow SensorBad connections (previous writer mentioned)Faulty ECU (ECM)Faulty Cam Position SensorFaulty Coil PacksOxygen SensorTBS ( throlle position sensor)

and then I heard someone say that his iginition switch got water in it when he washed his engine.

could all be culprits.

I don't want to spend 1000's of dollars on this damn car and I am not Mr. Goodwrench by any means. Can anyone suggest the next logical step as to what to get replaced or checked?

thanks for any help

[Darius]

I don't know if it was a typo or not, but did you mean she got all of her injectors replaced? If so, I would look at the O2 sensor or MAF sensor. Those seem to be problem areas since they are sensitive sensors. I would recommend starting with the cheapest (O2) first and working your way to the most expensive (injectors).

Correct me if I'm wrong, but if you have a distributor, you don't have coil packs.

[carChick]

Honestly I don't know. That list I copied and pasted from a google search as things to try.

The invoice only says "fuel injector service"

I guess I'll ask them to start with the 02 sensor and the MAF sensor

[Darius]

How much was the invoice for the fuel injector service? If it's hundreds of dollars, then she probably had one replaced. If it's a small amount, it could just be an in-tank fuel additive. Does one look shinier than the others?

[carChick]

The invoice says

Fuel Inj kit $29.75

engine flushenvirolution engine flush (power flushing of engine)engine life-guard systempreventive maintainence $90.45

fuel inj serviceinjection flushmenu serviceperform injection flush with injection cleanerclean fuel injectors $70.20

Brought it back Sat. and now they say it is the fuel pump and the fuel regulator. Now the car is worse than ever. Hesistates almost 95% of the time driving.

I'm not gonna be paying out the arse and spending $200+ here and there as they keep reaching for solutions to the problem. The damn car worked fine until they did the engine flush and the injector service. But I can't prove that.

Seems every time we go back they find something else to fix. I'm at wits end here

[Darius]

It doesn't look like they replaced any of the injectors. I would doubt it is the fuel pump, but it is possible. Now the fuel pressure regulator is just a joke. They're trying to rape you with that.

Try this, run the engine, pull each spark plug one by one and make sure the idle drops and the motor stumbles as it should. Plug the wire back in and go to the next one. If you find a cylinder that does not affect the idle no matter if the plug is connected or not, then that's the problem cylinder.

If all cylinders make the engine stumble, it is something more general like the O2 sensor or fuel pump. It's odd to hear about a fuel pump failing, but it's possible. Get back to me when you try this.

I wouldn't let them change out the fuel pump and regulator until you check this because they're trying to F you in the A with the regulator and possibly the fuel pump. Regulators are so simple that they go bad very rarely. I am wondering if the fuel injector flush washed something into an injector and plugged it.

[carChick]

I finally have some good news with all this doo doo. I had my cousins friend who owns a shop give it a once over again. He ran what diagnostics he could a week ago being that Nissan apparently locks people out from doing complete diagnostics. My wife supplied him with all of the invoices from Nissan so he could double check what they did. He didn't think it could be the pump or regulator either. Also mentioned that the O2 and MAF sensors are possibly culprits generally only if the engine light comes on. (No light came on, don't know if this is true or not)

I already checked the plug test you mentioned so ruled that out.

He noticed the fuel pressure was running low. (Again I'm no car guru so that means nothing to me ) and replaced the regulator with an aftermarket one (for less than half the price of the dealer). Brought the pressure right up and all seems to be fine. No hesitation to speak of. He said the fuel pump was fine. Now I don't know if maybe the flush goop got in the regulator or what. Don't know but at least this is resolved.

He too thought that something might have happened when they did the flush but as he said there is no way to really prove if they f'ed up when doing it or not.

I trust this guy as he's a good friend of my cousin for years and never bent me over a barrel for any prior work to my wifes, his or my mom's cars. I'm pissed at the fact that Nissan f'ed up and was digging for solutions (over $1600 if I would've let them do anything) without fessing up. Never again will I take it to the dealer.

Anyway, thanks for your help and sticking with me on this

[Darius]

Cool! Glad to hear you got a second opinion. I never bring my cars anywhere especially not a dealer because their labor rates are double that of anyone else's and their part prices are about 8 times that of other shops for OEM greatness .

The pressure regulator probably wasn't keeping enough pressure and, therefore, enough fuel to your injectors. The low fuel pressure probably made the dealer mechanics think it was the fuel pump.