Ignition timing

Tiny
PARKER HEER
  • MEMBER
  • 1990 NISSAN 240SX
  • 2.4L
  • 4 CYL
  • 2WD
  • MANUAL
  • 205,000 MILES
I keep having problems with my ignition timing. I have installed the oil pump and distributor probably six times now and every time I have installed them at TDC on the compression stroke but it just does not work good. The car starts up but it will only start if the distributor is all the way advanced and the engine makes the “spark knock” sound and idles very bad wanting to shut off.
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Wednesday, March 7th, 2018 AT 7:50 PM

4 Replies

Tiny
HEYMAN1104
  • EXPERT
Hmm, I am assuming that you changed the whole timing set, right? If the car jumped time while it was running, you could have bent a valve or two. If my memory is correct, this is an interference/impulse engine. I do not remember the specifics of it off hand, but when they jump time while running, the top half of the engine can actually run backwards for a stroke or two while the bottom half is going the other way, causing you to bend valves. A bent valve could be causing your car to run badly.

Also, if you used aftermarket parts, it is possible that there is just too much slack in the aftermarket parts.

Finally, if I am not mistaken, Nissan did do an update to something in the timing chain guides some years ago. But the last I checked, the updated parts are only available at the dealership. Aftermarket companies have not got into that as far as I know.
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Wednesday, March 7th, 2018 AT 8:31 PM
Tiny
PARKER HEER
  • MEMBER
Hi thank you for your reply. I do not believe it would be the valves though because the timing would have to be off several teeth. I did my chain and guides and tension-er and there was no slack at all in the chain so I do not see how it could have possibly jumped a couple teeth. I think it has to do with the oil pump and distributor, I keep messing with them but no luck.
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Wednesday, March 7th, 2018 AT 9:18 PM
Tiny
HEYMAN1104
  • EXPERT
There may not be much slack when the engine is cold, but when that chain warms up, it does expand some. Run compression tests on the cylinders. You can borrow a compression test gauge from AutoZone. If compression is low, then we can bet on bent valves. Compression should be between 142 and 192psi with not more than 14psi variance between the cylinders. Good compression rules out the bent valves for sure.
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Thursday, March 8th, 2018 AT 4:46 AM
Tiny
RENEE
  • ADMIN
Hello PARKER HEER,

Here is a link to an article from our site with written step by step instructions, pictures and video to guide you:

https://www.2carpros.com/articles/how-to-test-engine-compression

If you have any questions or need further advice please reply to your post and one of experts will be happy to help you.

Thank you for visting 2CarPros and have great rest of your day!

Renee
Admin
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Thursday, March 8th, 2018 AT 10:49 AM

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