Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Nissan > Sentra | 200SX (USDM FWD)
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 06-20-2007, 09:43 AM   #31
Sparky1349
AF Regular
 
Join Date: Apr 2007
Location: Highland Park, Illinois
Posts: 129
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Quote:
Originally Posted by Torch
Heh,

This car is still in my driveway, bought another pump, it only put out 0.5psi, luckly the parts place gave me the $25 back.

Appears the lack of fuel pressure is due to the engine no longer being able to drive the fuel pump. I found a block off plate for the fuel pump hole (Chevy Big Block cover plate fits over the hole (with no modifications)) and will be installing an electric pump as soon as I can find one cheap enough.

More later...
Hey Torch,

You are one persistant dude! I would have given up about 3 months ago. This forum seams to be a little thin on help. Have a lot of respect for someone that pushes on alone.

Any way, about your fuel pump issue. You said you found a manual for this beast, does it show a push rod from the cam (or what ever is driving the fuel pump). I had an abused Chevy small block that the push rod from the cam to the fuel pump would stick due to poor maintenance (I don't think the oil had ever been changed). A little carb cleaner and some oil freed it right up and she ran great.

Post back and let me know, I'll try to keep an eye on this forum.

Sparky
Sparky1349 is offline   Reply With Quote
Old 06-20-2007, 10:10 AM   #32
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Nope, no push rod, I know what you are talking about I used to have a Chevy that worked the same way.

I would have not even worked on this car if it did not belong to a relative who has another working car that they can drive, I made a rule for myself a long time ago that I will not work on 1980's 4 cylinder carb. engines, they are just too hard to work on with miles of vacuum line and sensors and switches all over the place.

The diagram for this engine shows a jack-shaft that is driven from the timing belt, it has a gear that runs the oil pump and a lobe that cycles the fuel pump, not the way I would have done it, but then again I didn't design this engine.

Also figured out that the original pump has a vapor return line that feeds off the pressure output going back to the fuel tank which is why my vacuum gun could not pull a vacuum on it. Am going to block this line off when the electric pump is installed.
Torch is offline   Reply With Quote
Old 06-20-2007, 05:04 PM   #33
Sparky1349
AF Regular
 
Join Date: Apr 2007
Location: Highland Park, Illinois
Posts: 129
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Hey Torch,

Interesting! Can you get a look at the lobe that drives the fuel pump? Is it worn? Kind of find that idea out there a little, would probably wipe out the arm on the pump first.

If the cam is ok why didn't the new pump work? Can you stroke the pump by hand, maybe if you clamp it in a vice? If you can hand operate it with a pressure gauge on the output, the input line going to a cup of gas or carb cleaner and return lines open you should be able to measure about 10 psi (I think, never worked on a Nissan before). If you get good pressure you should be able to do the same with the inlet side and get 15" Hg (don't need the fluid for this part). I don't have a clue about the return line.

The reason I'm asking this is to find out if the pump is working ok, then I would look at a clog up stream some place. At some point you said you had redish orange stuff in the float bowl so I am thinking rust in the tank. Maybe you plugged the fuel line someplace. The filter is another question, I don't recall if you put a new filter on it but even if you did if there is enough crap in the tank you could have plugged up the new filter. I don't know how much they cost but it may be worth taking the filter off and cutting it in half and looking at the paper element (the inside).

My concern is even if you put an electric in you'll still be in the same place if the line is plugged.

If you are bound and determined to switch to an electric pump make sure you add a safety cut out in case the engine stalls. Before electronics they use to add an oil pressure sensor that would shut the pump off if you lost oil pressure, in the event of a crash the pump would shut off the fuel flow when the engine stopped. When you went to start the car it would run on the fuel in the bowl until you got pressure, the only tricky part is if you ran out of gas you had to crank it long enough to get oil pressure in order for the pump to start.

Good luck,

Sparky
Sparky1349 is offline   Reply With Quote
Old 06-21-2007, 11:42 PM   #34
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Hi,

Old and new pump have/had too much internal pressure to operate by hand.

There are no clogs in the line, in an earlier posting (yes I know there are a lot of them) I said that I was able to hook my vacuum gun up to the line and get gas all the way to where it hooks up to the fuel pump.

I've considered the safety cutout, may or may not do it, I have had problems with them in the past.

I have been through this problem before regarding the drive lobe going bad, I had an old pickup that did the same thing, only it would start out with fluctuating pressure that would slowly drop to zero after a couple of minutes at that point the engine would stall. Went through three different mechanical pumps from three different places they all did the same thing, installed an electric, pressure shot up to where it was supposed to be and the truck ran fine after that.

No there is no way to look inside the hole at the lobe, the fuel pump is bolted to the back side of the engine facing the firewall, there is so much stuff in the way I can barely get my hands up in there.

So, that is where I am at for now, hopefully I can find a cheap electric pump soon.
Torch is offline   Reply With Quote
Old 06-25-2007, 01:10 PM   #35
blownb210
AF Newbie
 
blownb210's Avatar
 
Join Date: Jun 2007
Location: albany, New York
Posts: 51
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Have you tried replacing the little inlet needle and seat filter in the carburetor? I worked on the "hopeless chokeless" B11 Sentra carbs at a dealer in the eighties. Unless you've rebuilt these carburetors, you would never know this filter exists. It very small and looks like a sewing thimble. Remove the carb top, the float and needle. Then use a 10mm socket to remove the fuel inlet seat. The filter is right there, pressed onto the brass seat assembly.

If that filter is clogged, it will look like the fuel pump is bad, and it might not be.

Mike
blownb210 is offline   Reply With Quote
Old 06-26-2007, 03:05 PM   #36
roonie
AF Regular
 
Join Date: Nov 2004
Location: saskatoon
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

hey torch...i give you credit for being persistant also! hey if in fact you run out of answers from this site you can always head over to nissanforums.com.
No im not selling anything.It just that i too have had weak responses to nissan troubles on this,and other sites also.Not to say i have not had any help..but hey...the more help the better ....right.good luck
roonie is offline   Reply With Quote
Old 06-26-2007, 06:05 PM   #37
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

blownb210: While that may be a problem it is not the cause the the carb. not getting any gas, there is/was gas getting to the fuel pump, there was nothing coming out of the output hose.

Also, while rebuilding the carb. it was extensively sprayed out with carb. cleaner.

roonie: Thank you for the advice, I already had that site book marked, I think I already have a posting over there for this.

Everyone else: Please read -everything- before asking me "Have you done this?", I know it is a lot to read but it will help prevent repeat questions and questions for which there are already answers.

Persistence can get you to the top of a mountain or the bottom of a very deep hole, at this point I'm not sure which direction I am heading :-)


Thanks again.
Torch is offline   Reply With Quote
Old 06-26-2007, 08:23 PM   #38
roonie
AF Regular
 
Join Date: Nov 2004
Location: saskatoon
Posts: 143
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

hey torch...there is also www.sentra.com ya know.
torch my post is right next to yours ..any chance you could have a look at the pic i posted and tell me where i might find the idle switch on this baby.The car goes down the road just fine but at idle the car sounds like a tractor as it is crackling and popping back through the throttle body.Anyway just looking to find the idle switch as that code came up.any help would be great.later
roonie is offline   Reply With Quote
Old 07-03-2007, 12:38 AM   #39
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Finally found an electric pump with (nearly) the correct output PSI (4.5 instead of 3.8), I don't think 0.7 psi is going to make any difference, I'm going to try to hook it up tomorrow.
Torch is offline   Reply With Quote
Old 07-16-2007, 07:58 PM   #40
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Car has fuel pressure and starts now, but still stalls when you press on the gas, I'm not sure what to do at this point, catalytic converter might be plugged up, I just don't know.

Is also leaking oil somewhere and has a vacuum leak somewhere near or under the the air filter housing, something might have wiggled loose while I was putting it back on.

-sigh-

More later...
Torch is offline   Reply With Quote
Old 08-06-2007, 01:35 AM   #41
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

Well, things have not changed much.

I think the vacuum leak I am hearing it just air going down the carb's throat now that the engine is actually running. I pulled the air cleaner housing off and plugged all the loose vacuum hoses except the ones that were supposed to suck air, the only problem with this is that the exhaust return hose that connects a small exhaust pipe to the air cleaner when exposed to air got so hot that it actually caught fire, so now I need to find one of those.

I also unbolted the catalytic converter from the engine's exhaust pipe to see if the cat was plugged up and causing the problems, with it unhooked the engine has an obvious miss in it which you can hear and feel, even at 4-5k rpms you can still feel it.

My eyes do odd things right as the sun goes down, I noticed an odd fog cloud sitting right over the carb throat that I could not see in the day light, I shined a flashlight down the carb and could see gasoline pooling up on top of the primary butterfly valve and when I full throttled it you can actually see a heavy spray of gas coming out of the venturi.

Back at idle the engine runs a little rough, I found that if I carefully place a shop rag over the carb throat and slightly adjust it the engine rpms will go up a little and then the engine runs very smooth, I'm not sure what would need to be done to make the engine run like this on its own, maybe it just needs a new carb.
Torch is offline   Reply With Quote
Old 08-06-2007, 06:05 AM   #42
rockwood84
AF Enthusiast
 
Join Date: Jun 2007
Location: eupora, Mississippi
Posts: 1,002
Thanks: 0
Thanked 2 Times in 2 Posts
Re: 1984 Sentra stalling...

hey torch, did you get it purring yet? the manual has a part in it that tells how to get the codes or it should. its been a couple of years since i read my '86 codes. but as i remember you have to flip the switch on the ecc one way and turn the key on but don't start it.the light will blink io let you know it is in check mode the it will put out the code then it will pause then put out the next code.its tricky to keep up with. but the manual will have the code meanings in it. one other thing what kind of distributor is in it ? one type has a pick-up coil and then one has a disk in it with a circuit board. the one with the disk will make it stall like you cut the key off and after it cools off it will run again for about the same length of time then quit again. i have had to put two in mine around $200.00.
rockwood84 is offline   Reply With Quote
Old 08-07-2007, 09:24 PM   #43
JudoJohn
AF Newbie
 
Join Date: Aug 2007
Location: St. Louis, Missouri
Posts: 59
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

My first Sentra was an '83. it had a carb, but no O2 sensor. i had a problem once or twice, and i cleaned the carb and it ran great. the bowl would get some sediment in it and the passages in the carb would need to be cleaned. the carbs are not hard to rebuild/clean. try that, too.
JudoJohn is offline   Reply With Quote
Old 08-08-2007, 09:44 PM   #44
rockwood84
AF Enthusiast
 
Join Date: Jun 2007
Location: eupora, Mississippi
Posts: 1,002
Thanks: 0
Thanked 2 Times in 2 Posts
Re: 1984 Sentra stalling...

yeah the carbs aren't too much unless it's got tbi then a little more to rebild. don't know if the put the little black round thing behind tbi on '84 but '85 had and it had a lot to do with the idle you could plug the hole in it and the motor would run at 3 grand take the plug off and it would idle back down. torch you ever figure out how to read the codes? check and see which distributor you have......pickup coil or disk...
rockwood84 is offline   Reply With Quote
Old 08-17-2007, 03:02 AM   #45
Torch
AF Regular
Thread starter
 
Join Date: Oct 2003
Posts: 449
Thanks: 0
Thanked 0 Times in 0 Posts
Re: 1984 Sentra stalling...

No, not running yet but I am finally getting somewhere with it...

Talked to an independent import shop who (so far) has given me good advice in the past. He said that the rebuild kits don't always have accurately sized O-rings and gave me two brand new Nissan O-rings for the A/F solenoid. He also said to check the fuel level in the site glass and adjust the float if the level is too high.

Something else that I did not realize was a problem is that I accidentally left the pin out of the anti-diesel solenoid which I didn't think was going to be a problem because the electric fuel pump shuts off when the ignition is turned off and cannot have run-on, but he said that it causes an internal vacuum leak inside the carb. which may explain the hissing that I have been hearing.

I also disconnected the cat from the exhaust pipe so the engine is breathing into free air, but the engine is still running the same way.

The engine computer under the seat is NOT the one mentioned in all the manuals, I did figure out that it is the non-California computer, it has a little recessed ON/OFF switch and a red LED and a green LED, from what I remember the red light comes on and stays on and the green flashes once. This computer does not have the toggle switch that you can rotate back and forth, I also removed the circuit board from the engine computer, it looks fine nothing is burnt or even looks odd.

Distributor... not sure what it has internally, I think it has a pickup coil but I'm not sure.

I already cleaned out the carb, will be tearing it apart again if the gas level is too high.

Lots to do, more later...
Torch is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD

Go Back   Automotive Forums .com Car Chat > Nissan > Sentra | 200SX (USDM FWD)

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 05:17 AM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts