Stalls after starting and when stopping and rough idle

Tiny
RUBYANDTHEPEACH
  • MEMBER
  • 1988 NISSAN SENTRA
  • 188,000 MILES
When testing the TPS, AIC valve and MAF, if they have to be taken off, are there gaskets/seals that have to be replaced? Was hoping maybe they're just dirty and can be cleaned.
Thanks.
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Thursday, October 17th, 2019 AT 8:20 PM

10 Replies

Tiny
KEN
  • ADMIN
Hello

It sounds like you have a vacuum leak. To be sure here are two guides to go over to help us fix the problem:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

and

https://www.2carpros.com/articles/stall-at-idle

Please run down these guides and report back.
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Saturday, October 19th, 2019 AT 12:52 PM
Tiny
RUBYANDTHEPEACH
  • MEMBER
The idle gradually has gotten worse, it's rough and has a rich emission smell. If you hold your foot steady on the gas after starting it, the idle will go up and down. Sometimes surges and cuts out when driving. About 9 mos, ago I changed most of the vacuum hoses, except the brake booster hose. Did the PCV hose, but used fuel line(thats what the parts store sold, and evidently they don't carry booster hose either).
So unless it's a throttle valve or intake leak, not sure. Bad EGR maybe, Or coolant temperature sensor?
Any help is appreciated.
Thanks
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Saturday, October 19th, 2019 AT 6:43 PM
Tiny
KEN
  • ADMIN
Lets run the codes to see what comes up. Here is a guide.

https://www.2carpros.com/articles/nissan-obd1-diagnostic-trouble-codes-and-retrieval-procedure-1984-to-1994

Let me know what you find please.
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Sunday, October 20th, 2019 AT 11:43 AM
Tiny
RUBYANDTHEPEACH
  • MEMBER
Ken,

I tried this. After 4 blinks (which coincides with the Check motor light), I turned the screw all the way back counter clockwise. The description doesn't say which way to turn it (according to sources on the internet, it's clockwise first, get flashing lights, then back). Then it does nothing. No lights flash at all.
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Wednesday, November 6th, 2019 AT 2:29 PM
Tiny
RUBYANDTHEPEACH
  • MEMBER
I had a guy send me a flow chart that says start car, let it warm up, go to mode 3, turn back counterclockwise get code 55 (which it does). After that, no other codes pop up. There's obviously something wrong with the car since 55 is no malfunction.
Thanks,
Chris
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Wednesday, November 6th, 2019 AT 2:34 PM
Tiny
KEN
  • ADMIN
Code 55 means the computer considers the car to be okay. It sounds like the exhaust could be clogged here is a guide to help confirm the issue:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please run down this guide and report back.
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Friday, November 8th, 2019 AT 3:35 PM
Tiny
RUBYANDTHEPEACH
  • MEMBER
Just curious. Should the cars ECU be in mode 3 or 4, and should it be started or just have ignition on?
I was thinking maybe I did it wrong. The car doesn't really have a lack of power. When driving it smooths out, but will slightly cut out then kick in again, and when coming to a stop, then you feel the bad idle and it sometimes stalls. Starts right up though every time. But its mainly a rough idle (up and down if holding the gas steady), some surging, stalling, and a very rich high emission smell when it is cold or hot.
Have to try the vacuum gauge thing, or pull the 02.
Something else. Before changing the ECU, a lot of soot was covering plugs and 02. After the change plugs returned to normal, and 02 looked okay (same one in though). Is it possible the reed valves(in the air intake valve on snorkel) or something else is plastered with soot?
Thanks again.
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Saturday, November 9th, 2019 AT 10:24 PM
Tiny
KEN
  • ADMIN
It should be in 3, 4 is for programming I believe. It sounds like the exhaust is leaking into the intake. Can you check the A.I.R. System to see if it is in good shape? Can you please shoot a quick video with your phone so we can see what's going on, that would be great. You can upload it here with your response.
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Monday, November 11th, 2019 AT 11:29 AM
Tiny
RUBYANDTHEPEACH
  • MEMBER
Ken,

I did a vacuum test on the EGR valve and it holds vacuum. Don't know if it's closing or opening all the way though. If you push up on from the bottom while the car is running, it runs rougher or stalls. Also connected a vacuum gauge to a throttle body outlet(fuel vapor canister), and the needle bounces rapidly between 8-15 in. Someone said could be a broken/weak valve spring and do a compression test. I did. Let car idle for 5-10 mins. Pulled plugs. 1st set, 180-180-176-169. 1 hour later(12 cranks each cylinder), was 175-175-170-172. Did a few more tries. Never more than about 6-7% difference on lowest cylinder. Is it better on a warm motor and how many cranks are needed to get a good result? From videos on the internet it differs from 4-5 cranks to 10 seconds each cylinder.
I was also planning to take off EGR and clean it/soak it overnight to see if it helps.
Have also changed PCV valve 2 weeks ago.
I'll try to do a video.
Chris
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Thursday, November 14th, 2019 AT 11:06 PM
Tiny
KEN
  • ADMIN
The compression is good, try to get that video. Also will it run on starting fluid?
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Saturday, November 16th, 2019 AT 10:40 AM

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