1984 Sentra stalling...

[Torch]

Hi,

I'm working on an '84 Sentra with the 1.6 liter E16(s) engine, this car is really worn out and has not been taken very good care of, the new owner would like to get it running. This cars problems are mainly caused by the previous owners being absolute [insert creative words here].

Anyway...

Problem # 1, the car stalls when you press on the gas pedal, I cannot find any loose vacuum hoses. If you slowly press the gas pedal the engine stumbles but keeps running, if you double tap the gas pedal then stomp it when the engine is in high RPMs it will take off and keep going, I was able to hold it at 4000 RPMs for a couple of minutes it seemed to do ok.

I'm assuming that the problem is being caused by a worn out accelerator pump seal or the pump is just not working at all, any other suggestions?

Problem # 2, a few mintues later after holding it at 4000 RPMs the engine's RPMs starting going up and down while sitting at idle then stalled but started right back up again with the ignition key. I'm assuming that this is either a fuel pressure problem or something to do with the timing or something that is overly retarding the timing to the point that the engine stalls.

Problem # 3, the SENSOR light above the steering wheel is on, this is an automatic FAIL at the emissions testing stations where I live, how do I pull the codes out of the engine computer? Considering the year of this car I'm assuming that I can short two pins together and make the SENSOR light blink or do I need to use one of those scanner boxes? I left the battery unhooked for over 10 mintues, the light came right back on.


Help!

[ProZach626]

Hmmmmmm... easy fix. Sell your can and run by the store and pick up one of these:
http://www.subaru.com/shop/overview....A&trim=WRX_STI

[Torch]

Thanks, but that is not an option.

[slideways...]

well to be sure, you need to do a compression check, fuel pressure check, and hook up a vacuum guage. also, get a timing gun and check timing.

[Torch]

Hi,

From what I have read online there is supposed to be an ECM buried somewhere in the car, there is a little adjustment screw that can be turned all the way to the right that will cause its light to flash the trouble codes.

Does anyone know if this is true? And if so where the ECM is buried at?

[Torch]

Well,

I found the ECC module, it is directly under the driver's seat mounted in a bracket, it has a recessed on/off switch and two LED's, one red one green, they both turn on when the iginition is on, if you flip the switch to ON the red light goes off but blinks once when the engine stalls.

Anyone have any idea what the red light and the on/off switches functions actually are?

[nismo_pilot]

hook up a 400 shot of nitrous and clean out those cylinder heads with a spray at 3500 rpm, what it come alive dawg!

[Torch]

Hi,

Thanks for replying, this engine is not set up for NOS, if I were to use NOS on it it would explode which I guess would sort of fix the problem as I would be getting a new engine for it.

Anyway, please don't reply to my original questions or further comments unless you have something feasible and relivant to contribute to actually fixing the problem. Aside from annoying me the moderators may come down on you for wasting server space and everyone's time.

Back to the subject...

Thanks for you suggestion Slideways, I thought the timing might have been off as the distributor did not look like it was set in the right place, the timing had been advanced 15 degrees, it is much happier at 8 I might drop it down to 5. A funny thing happens when your power stroke runs out of power before the piston reaches TDC (it stalls).

I thought there may have been a problem with the O2 sensor but it started out low then steadily climbed until it went into the 1000+ mV range which I'm not sure is ok or not. From what I have read this O2 sensor should fluctuate between 100 and 900mV, it just seems to keep climbing higher and stays there which may be from the engine running lean or low fuel pressure (see next paragraph).

I also think there IS a fuel pressure problem, after running for about 15 minutes the engine finally warms up, the engine's idle will start to swing back and forth then a minute later it dies but starts right back up again stumbles around for a bit then levels out. I could not find any fuel pressure before or after the fuel filter.

Anyone know if the fuel pump comes AFTER the fuel filter? if it does what I am seeing would make sense.

The temp sensor had me worried but after getting the engine nice and hot the fan finally came on.

I am not going to have a chance to pick up a manual until Tuesday, does anyone have a PDF of where the fuel pump is located that they could send me?


Thanks.

[nismo_pilot]

ok ive been on these forums for over two years now helping what i consider to be my friends and also some new comers to fix and or learn about their cars, i guess its too much to ask for everyone to have a sense of humor who comes on this site, also there is no such thing as running NOS in your car, you can run a nitrous oxide system that you bought from a company called "NOS", but there is no such thing as a power adder called NOS, and even an sr20 equipped sentra will only run about a 100 shot without requiring colder plugs, lower comp, and retarded timing, hence the 400 shot joke, now that weve got that out of the way your fuel pump should be in your tank, on newer models the filter and pump are right there in one place but your car was made 2 years before i was born so i really couldnt tell you, jgycustoms may have a manual or some information on their site, if not you can always call a nissan tech and see if hes got enough free time to answer a few simple questions, on a car that old double check to see if your dist cap may be warped. As far as your fuel pressure, click your ignition to "on" with your door open and listen for the fuel pump, if it takes more than 1-2 seconds to quit humming you need a new one, also at fault could be your injectors and or fuel rail. Concerning your issue with O2 sensors, they control fuel mix in low rpm conditions I.E closed loop mode in your ecu, the heater coil may be going out in your sensor causing false readings at low temps and just a general crappiness in performance, pull it out of the exhaust and turn your car all the way on without cranking and see if you get voltage and heat coming from the sensor, i would also check your incoming air sensor for its performance as well, check those and get back with us. And hey, lighten up dude, were here to help but were also here to have a bit of fun, loosen up and youll fit right in

[nismo_pilot]

pwned by teh double post

[Torch]

Hi,

Sorry for my lack of sense of humor, I have one (really I do), will try to lighten up.

Just for clarifications sake, I was born in 1970, when Nitrous Oxide systems became commonly available sometime in the 1980's NOS was the major company that produced them, and at least in my day NOS was a nickname for Nitrous Oxide which I why I used "NOS" in my earlier posting.

I know what needs to happen if you plan on using a blower or Nitrous, if you don't build the engine correctly either your heads end up in low earth orbit or what is left of your crankshaft ends up in someone's back yard in China sticking up out of the ground.

This engine has the carb. it does not have fuel injection.

The O2 sensor is the one wire version, there is no heater circuit, although I have a 99 Suzuki Esteem that has the four wire version so I know what you are talking about.

I left the fuel line unhooked from both ends of the fuel filter and started the engine, there is no fuel pressure at all, zero, none, yet the fuel filter had fuel in it when I disconnected it. From the filter the hose goes down to something under the intake manifold that looks like a very odd regulator or fuel pump, then there are possibly two other hoses that come off of that but I cannot see where they go there is too much stuff under there. As far as the fuel filter goes I was able to blow out the remaining gas in it with my mouth so I know that it is not clogged.

I believe that this has an air sensor in it that is built into the air filter housing, I'm not sure though.

Buying a manual for this car either tomorrow or the day after.

Thanks for the help : )

[Torch]

I have found out one other thing regarding the fuel pressure, the voltage at the connector to the fuel pump (which is under the trunk (THANK YOU Nissan for putting in a fairly easy to remove cover plate inside the trunk!)) keeps switching between 0 and 12 volts...

0 12 0 12 0 12 0 12 0 12 0 12........

I cannot find this switching voltage at any of the fuses in the fuse panel, I get the same thing if I disconnect the connector from the fuel pump.

Any suggestions on what is doing this?

[nismo_pilot]

if this helps you should be able to find a whole other complete and running motor for what its going to cost in time ad money to diagnose this, id look into how expensive it is to swap to a ga16, same displacement but i dont know if it mounts the same, plus you get EFI and its easier to work on, i think fugiot said you could snag a whole motor and all for around 300 bucks

[Torch]

Thanks, as much as I would rather have a fuel injected engine than the carb. version it currently has that is not an option at this time.

[Torch]

While reading the manual I bought I found out that the unit under the trunk is nothing more than the sending unit for the fuel gauge on the dash, the 0 12 0 12 0 12 0 12... is probably some kind of square wave that works with the variable resistor in the sending unit.

The actual fuel pump is mechanical and is bolted to the engine underneath the intake manifold (where I thought it was), so I need to hook my fuel gauge up to the carb and check the fuel pressure there.

More tomorrow...