I need help!My friends's 89 pulsar with the GA16i will not start properly.It has new NGK plugs,new plug wires,new cap and rotor,new fuel filter,and had the injector cleaned.But the car still won't start properly.It will crank but won't start. Everytime if we give it some gas,it will start right up.And then the idle will kind of drop to 500rpm or below and sometimes dies.Yes we thought it might be the AAC issue so we put a brand new AAC unit in but still no change.It feels like it's not getting enough gas to start.Once it gets started,it runs smoothly,but sometimes the idle will drop below 500rpm and die randomly.
We need help because it's my friend's only car to go to work!We are suspecting it's the fuel pump but it's getting regular fuel pressure so we are all confused.
make sure all sensors are plugged in and all vacuum lines are hooked up and there are no leaks.
Then check the computer for error codes. If you don't know how,
-This is how to get into the Mode to read the codes.
-And this is what the codes mean
Check all those problems, and then clear the codes and see if you can get it to run again.
If what you do doesn't fix the problem, I suggest cleaning all the sensors.
Here is a walkthrough by bob89sentra on how to do just that.
still doesn't fix it check compression and timing. If they are within specs I'd replace the distributor.
You have a nice weekend (or several late nights) ahead of you guys. But it should all move fast.
(btw, a 6mm allen head wrench is needed to remove the throttle body, its easy to clean sensors when its off the car)
Enjoy
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Have you ever seen a stock '87 sentra go over 100 mph?
Sadly i have. shortly there after it locked up.
But all is soon better. Put in a '89 ga16i because i could. Took me less than two weeks to do the wiring and put the motor in. :D
Runs, but small problems are keeping me from driving it :/
Is it having the problem starting when cold, hot, or both?
It it is a hot start problem it might be the CTS is bad.
If it is a cold start problem it might just be the fast idle set too low, or passably the wax pellet fast idle controller is getting stuck or gone bad.
If it is both hot and cold start then I would re-check the FICD, AAC, and Idle up solenoids, then check, clean/adjust the TPS and throttle switch.
Bob
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89 Sentra owner 9 years 205,000 miles and counting!
It happens when either cold or hot.
Weird,the whole IAC unit is supposed to be a new one,so I wasn't suspecting that way,but all the symptoms really shows it is the IAC unit not functioning correctly.
Also when we changed the fuel filter,we had a mechanic to do the timing for us as there were spark knocks(running lean).The timing fixed that problem.
He also checked out that the faulty brake booster killed the engine,a vacuum leak.The car originally only had this stalling problem,but now it kind of shifted into not idling and not starting.
A little update.We checked out that the anti-backfire valve was disconnected.And there is a sensor with a yellow connector disconnected too.Now the car idles fine,but sometimes it couldn't start after like a 3 minutes drive.If we turned the car off,then if we wanna start the car again,it would just keep cranking.
It seems like it just couldn't start randomly.Everytime if it couldn't start,it needs a little bit gas to start it up.The first two or three seconds the idle will kind of stumble,drops to around 500,and then goes back up to normal 800.
It really feels like a fuel-related problem,but can it be something related to ignition?Like the coil or pcv valve?
I also notice that whenever I hit the brakes,every lights in the car will flash.So I suspect the battery or the alternator is weak too.
Really need some help to pin-point this starting problem.
then check, clean/adjust the TPS and throttle switch.
Bob
Have you done this?
The throttle switch and TPS are suspect some times when it won't start without pushing a little on the gas pedal.
If the lights in the car flicker when the brakes are applied then it is likely the altenator is going out. Check the voltage at the battery at idle, and 3500 RPM it should never fall below 12.5 V at idle with headlights on, and all other ACC, and shouldn't get above 13.9 V at 3500 RPM.
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89 Sentra owner 9 years 205,000 miles and counting!
next question...
when the engine is cold (perferably in the morning) start the engine. what RPM does it idle at when cold? Then watch the temperature gauge and when the temp starts to come up off the cold mark does the idle go down?
Next when the engine is fully warm check the EGR valve for proper operation. (when idling there should be no movement on the diaphram) Then revv the engine up past 3,000 RPM and allow it to return to idle and feel if the EGR diaphram moves up.
Also check the ABV (anti-backfire valve) for leakage if it were worn out / leaking it could cause random idling problems.
Bob
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89 Sentra owner 9 years 205,000 miles and counting!
The engine wont idle at all when starting in cold temperature.It will just drop right back down to 0.
If I hold the gas for a while,it does start.The idle is about 1500rpm.
The idle goes down when the engine warms up,it normally goes down to 800rpm.
If starting the car when the engine is warm,the idle will drop to 300rpm.The engine will run rough a bit,but won't die.Then it will go back up to 800rpm.Everytime I need to give it some gas so it will crank over.
Last time we checked out the ABV was disconnected.After reconnecting the ABV,The starting seemed better,but didnt cure the problem.
OK next take a can of starter fluid and spray it around the intake manifold and vacuum lines, if there is a leak the starter fluid should effect the idle speed.
Besides replacing the spark plug wires and cap/rotor again I can't think of what else would fix this problem.
Just another thought...
I know you had the timing fixed by a mechanic, but if you can borrow a timing light from a auto parts store, I would re-check the base timing (engine idling with the TPS unplugged) and make sure it is set to 7 degrees BTDC
Bob
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89 Sentra owner 9 years 205,000 miles and counting!
And there is a sensor with a yellow connector disconnected too.
Woah I can't believe I missed this, that sensor is probably the CTS, and if it is not connected It would do exactly what you describe.
The CTS should have a yellow connector with 2 contacts, and is located above the water pump on threaded into the left side of the intake manifold (looking from the front of the car).
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89 Sentra owner 9 years 205,000 miles and counting!
Alright after a long stop in the shop, the car now is running again.Connecting the CTS back seems to fix the problem,but now the car will chok on gas.It's like suddenly let go of gas,even if I hit the gas pedal constantly.It happens if I wanna cruise,or any slow acceleration that doesnt require a lot of gas.If this happens,even if you hit the gas,it wont speed up,and then suddenly there would be a big bog.It feels like suddenly a bunch of gas got dumped into the engine.
This problem wont show if I need more gas to speed up,like on the freeway.
This choking issue makes me kind of nervous to drive this car in town.Would that be the CTS itself go bad and causing all these?I notice the fan comes on frequently,as if the car is very hot.And the temperature will kind of drop a bit when I drive on the freeway.
Alright after a long stop in the shop, the car now is running again.Connecting the CTS back seems to fix the problem,but now the car will chok on gas.It's like suddenly let go of gas,even if I hit the gas pedal constantly.It happens if I wanna cruise,or any slow acceleration that doesnt require a lot of gas.If this happens,even if you hit the gas,it wont speed up,and then suddenly there would be a big bog.It feels like suddenly a bunch of gas got dumped into the engine.
This problem wont show if I need more gas to speed up,like on the freeway.
This choking issue makes me kind of nervous to drive this car in town.Would that be the CTS itself go bad and causing all these?I notice the fan comes on frequently,as if the car is very hot.And the temperature will kind of drop a bit when I drive on the freeway.
.:Check this first:.
There is a throttle damper located on the driver side of the TBI under the air cleaner. It sounds like either it was adjusted too far, or is wearing out. When properly adjusted it will dampen the last 5% of the throttle closing, and allow the engine to smoothly return to idle. If it is jerking when you are cruising (light gas pedal) it could be adjusted too far open, and the last part of the damper is worn out causing it to lurch the car. On a vehicle with a manual transmission I would personally remove it, or adjust it so it doesn't ever effect the throttle.
A faulty CTS also might cause too much gas at lower throttle positions (especially when the engine is warm). If your mileage is less than 29-32 MPG for city driving then CTS, O2 sensor, air filter, and spark plugs/wires can be suspect.
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89 Sentra owner 9 years 205,000 miles and counting!
.:Check this first:.
There is a throttle damper located on the driver side of the TBI under the air cleaner. It sounds like either it was adjusted too far, or is wearing out. When properly adjusted it will dampen the last 5% of the throttle closing, and allow the engine to smoothly return to idle. If it is jerking when you are cruising (light gas pedal) it could be adjusted too far open, and the last part of the damper is worn out causing it to lurch the car. On a vehicle with a manual transmission I would personally remove it, or adjust it so it doesn't ever effect the throttle.
A faulty CTS also might cause too much gas at lower throttle positions (especially when the engine is warm). If your mileage is less than 29-32 MPG for city driving then CTS, O2 sensor, air filter, and spark plugs/wires can be suspect.
We installed with a new CTS yesterday,but the choking still exists.Will absolutely check out the throttle damper.
The mileage is actually pretty good on this car.It can can around 35-38MPG.
Yea we also suspect the air filter,or the O2 sensor too.Plugs and wires are almost brand new.NGK plugs with wires from Schucks.
Is this the throttle damper you are talking about?It seems like it wasn't connected to anything so we just removed it. If it's not the right one,please show me a picture how it looks like.
We changed the air filter too,but still no luck...
We will install a new O2 sensor and see what will happen.Anything else to be suspected?I run out of ideas what the problem can be.
Linear Mode
