I give up on my 2000 frontier

[dan14sweeney]

About 2 months ago i believe i got bad gas in my 2000 frontier v6. I have done everything in my knowledge to fix it i have essentially done a complete tune up i have replaced the timing belt, cap, rotor, plugs, wires, drained the tank changed the fuel filter, gutted the cats and the darn thing still wont run for much more than about 30- seconds to a minute and runs horrible when it does start. I am out of ideas and turning to fellow nico users for help. I need to fix her so i can get back out on the trails.

[Rev_D21]

Could the injectors have been damaged by the bad fuel?

[dan14sweeney]

Im not sure

[Rev_D21]

That could be a another place to check. It could be timing related too, like timing belt related. It might have jumped a tooth.

[LEMHEAD16]

Vacuum leak? That could cause the engine to run like poo and then die after about 30 seconds.

Did you do anything to it before the problem started? What makes you think you got bad gas? It's very rare these days to get "bad" gas that would cause this sort of problem, Unless you pored some stuff in the tank that had been sitting in a gas can for 10 years.

Are you sure you got all the plug wires on right after the tune up? Having wires crossed could cause the engine to run like poo too.

Fill us in a little more on what has been done to the engine.

[LEMHEAD16]

double post

[waynegarcia13]

A vacuum leak is possible but not the injectors they rarely go bad.$10 says it's the MAF sensor.Do you have a scanner? That sounds a whole lot like you have a bad Mass air flow sensor to me. If you don't have a scanner go hire a mechanic that does to do a diagnostic on it but make sure he has a REAL scanner not a cheap code reader there is a BIG difference. A diagnostic should only cost around $50+/- I don't know where your from but here in San Antonio there are a lot of mobile mechanics "i am one of them". I am sure there are some in your area, look on Craigslist in the automotive services section and you will see ads from mobile auto repair mechanics. Have you tested fuel pressure, spark from the distributor while the truck is running and stalling, is there an engine light on? You will find the problem if you go down the list: spark, fuel, compression, timing. Like i said if i was you i would definitely check the MAF sensor, with a scanner you can check it in 10 seconds. Give us a little more info. on what you have actually checked and tested don't just change parts out until you get it right that could take forever. For all of that money you spent on parts you didn't need you could of hired a mechanic to do a diagnostic, just find a guy with a matco, snap-on scanner, auto xray or mac scanner.

[dan14sweeney]

well the reason i guessed on bad gas was the problem arose maybe 30 miles into a tank of gas after filling up. I went ahead and replaced all of those parts because it was close enough to time to do them i just wanted to rule them out. I have been thinking the MAF could be the problem but have no way to test it. I have not checked fuel pressure yet but its on the list too. I guess like you said get some one to scan it would be the best start however there is no CEL. and i figured with how sudden then problem occurred it would at least trigger the check light but who knows.

[RT22]

Get codes from ecu, could have a bad sensor that once heated up a bit falls out of tolerance. Have seen it before. if a sensor sends wrong signal can make it run like crap.

[Desert Rat]

Check the air tube between the airbox and the intake. those often crack between the crinkles and allow air in after the MAF, which confuses the hell out of the MAF and could cause the symptoms you describe.

Often those go when a motor mount lets loose....not sure if you offroad the truck much, but that's something I'd check.

[dan14sweeney]

I do offroad it quite a bit however it has a custom aluminum short ram intake because the stock rubber hose was cracked

[waynegarcia13]

The MAF sensor and a lot of other sensors DO NOT always throw a code. As a matter of fact most of the time they don't throw a code and on the frontier and hardbody the never throw a code for the MAF. Don't give up man i guarantee it is something simple and dumb. I seriously doubt you got some bad gas but if you still think that then go buy a few bottles of octane booster and pour them in or drain the tank and add some high octane. A shop will or mobile mechanic will not charge you much to run a scanner on your truck. $10 says it's your MAF.

[Desert Rat]

I do offroad it quite a bit however it has a custom aluminum short ram intake because the stock rubber hose was cracked

At some point it has a flexible connector to the intake manifold...make sure you don't have any big air leaks. That would confuse the MAF.

[dan14sweeney]

I checked it and it was sealed up good but thanks for the idea i didnt think of that. It looks like today I will tow it up to the nearest Nissan dealership and have them run Consult on it and see whats up then ill fix whats wrong.

[dan14sweeney]

Nissan found no electrical problems however after a compression test cylinders 2 and 6 where right around 100 PSI way to low. now i gota decide whether to rebuild the motor or do a swap. any body have any suggestions

[longtooth]

Did they bother to do a leak down test after finding the low cyclinders so they could tell you why you have a runability problem?

[dan14sweeney]

no but i figured it didnt matter either way it has to come apart

[LEMHEAD16]

Not Really, what if you have a stuck lifter that isn't allowing the valve to close fully. I'm pretty sure the VG has hyd. lifters. Replacing a couple lifters would be easier and cheaper than R&R an engine!

It would be wise to find out where the compression is escaping, before you pull the engine for a rebuild. At this point you are just throwing parts at it and hoping to find a fix. that's an expensive way of diagnosing a problem.

If you don't have the capability of doing a leakdown test, pay someone to do it. Even if it cost you a few bucks, you would know for sure where the problem was. It could be a bent valve, stuck lifter, blown ring/ring land, or melted piston. Some of those would be less expensive to fix than others.

[waynegarcia13]

^^ agreed you gota do a leak down test even if its a bent valve or 2 thats a lot cheaper and less work than a motor rebuild. You can remove the heads and have them repaired in 1 day

[PEZi]

this is really old... but possibly the knock sensor?