Car doesnt like 5th-3rd downshift - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

240Driver39 · 09-11-2003, 10:42 PM

Hey hows it comin, ive had my car for bout a year or 2, engine is basically stock with 123k, runs fine, no real issues. Now here is my problem, kinda stumped and asked a few people and they were stumped too, and ive never read nething bout it, and no info in the fsm. I was cruisin in 5th at a lower speed, so i went to downshift to 3rd, clutch in, rev, shifter into third, clutch out, and i have no throttle action, and the car slowly dies, the tach slowly drops rpms, and stalls, first time i did it, i pulled off to the side of the road, tried startin it, started and idled VERY badly, no throttle action, and shut off, i pop the hood, nothing seems out of the ordinary, and after a bit i try it again, starts right up, runs like nothin ever happened. Okay so a week or 2 later i wanted to see if i could replicate it. Do the same thing 5th-3rd downshift, bam, does the same thing, the tach slowwwly drops and i have no throttle action and i slowly roll to the side of the road and it shuts off. I sit for like 5 sec, and try startin it, starts right up, and i drive off like nothin evre happened. Car runs great, no issues, cept this and it has me stumped, sorry for the novel but just was tryin to get all the details out. Can shift 5th-4th no prob, 4th-3rd no problem. Ne ideas?

Muzzy · 09-11-2003, 10:58 PM

wow thas really weird..i do that all the time..some times 5th to 2nd.
never experienced anything quite like that..it doesnt feel like its gonna stall as if u were in first duz it??

240Driver39 · 09-11-2003, 11:28 PM

no, when i say the rpms slowly drop after goin into 3rd i mean i rolled from like 50mph to a stop and the rpms slowly were droppin durin that time, till i stoped the car and it shut off, basically starin at the tach, slowly goin down, and having no throttle action

Halz · 09-11-2003, 11:51 PM

Does 4th to 2nd work just fine?

BeatJunky · 09-12-2003, 02:45 AM

I have a similar problem.

My gears just plain ol' like to cut off at certain rpms. For example lets say I lauch the car from complete stop to redline each gear and try to do max speed, 1st gear will redline fine, 2nd will redline fine third will only go to like 4,500rpm then I have no throttle play and car just rolls till the rpms drop back to 3,000rpms... at that point I get throttle control again. If I can shift from 3rd to 4th before 3rd cuts off, then 4th will do the same thing at 4,000 rpm and 5th does it at 3,500 rpms.

Anyone know whats wrong?

s0ldats · 09-12-2003, 08:59 AM

timing?

Armysweitzer · 09-12-2003, 01:13 PM

just in case your not doing it (hopefully are)...

Learn to Rev-Match

240Driver39 · 09-12-2003, 01:29 PM

read the original post

"I was cruisin in 5th at a lower speed, so i went to downshift to 3rd, clutch in, rev, shifter into third, clutch out"

i do revmatch....

*sykikchimp* · 09-12-2003, 01:57 PM

I know EXACTLY what your talking about. I found this out the hard way on the track. Entering turn 1 at LMS.. running about 120.. brake hard, clutch in, rev, shifter in, clutch out, bam.. NO POWER, like fuel had been cut.. pull off.. turn key completely off, then back on.. car starts, and runs fine. Scared the **** out of me.

What I believe I SHOULD be doing..

clutch in, BRAKE HARD, wait for speed to come down, right before turn it, blip throttle, shifter in third, release clutch smoothly, and transition smoothly from the brake to the throttle while comming out of the clutch.. definately tricky.

I believe I was hitting an emergency fuel cut on 3rd gear to prevent over-revving the engine. I was trying to get into third while the car was traveling to fast. If I waited just a second longer to get into third while slowing, I didn't have the problem.

The 3rd gear synchros don't like the 5th-3rd downshift either. **GRIND** a couple times before I got the timing down.

I think in order to really complete the 3-5 downshift smoothly when you are at track speed, you have to double clutch heel/toe downshift, and MAKE SURE your not trying to engage 3rd at too high of a speed. I did this successfully 2 or 3 times, and it made a WORLD of difference. double clutching allows you to move the transmission faster than the synchros would normally allow. The double clutch is an extra step from the previous scenario above, but it allows me to get into the gear earlier, and concentrate more on the brake/throttle-clutch out transistion.

short answer:
Your going to fast for 3rd, and hitting a fuel cut.

09-11-2003, 10:42 PM	#1
240Driver39 Zilvia FREAK! Join Date: May 2002 Location: Charleston, SC Age: 40 Posts: 1,090 Trader Rating: (1) Rides Gallery: 240Driver39 Feedback Score: 1 reviews	Car doesnt like 5th-3rd downshift Hey hows it comin, ive had my car for bout a year or 2, engine is basically stock with 123k, runs fine, no real issues. Now here is my problem, kinda stumped and asked a few people and they were stumped too, and ive never read nething bout it, and no info in the fsm. I was cruisin in 5th at a lower speed, so i went to downshift to 3rd, clutch in, rev, shifter into third, clutch out, and i have no throttle action, and the car slowly dies, the tach slowly drops rpms, and stalls, first time i did it, i pulled off to the side of the road, tried startin it, started and idled VERY badly, no throttle action, and shut off, i pop the hood, nothing seems out of the ordinary, and after a bit i try it again, starts right up, runs like nothin ever happened. Okay so a week or 2 later i wanted to see if i could replicate it. Do the same thing 5th-3rd downshift, bam, does the same thing, the tach slowwwly drops and i have no throttle action and i slowly roll to the side of the road and it shuts off. I sit for like 5 sec, and try startin it, starts right up, and i drive off like nothin evre happened. Car runs great, no issues, cept this and it has me stumped, sorry for the novel but just was tryin to get all the details out. Can shift 5th-4th no prob, 4th-3rd no problem. Ne ideas? __________________ 1990 240sx 5spd fastback

09-11-2003, 10:58 PM	#2
Muzzy Zilvia FREAK! Join Date: Jan 2003 Location: TX Posts: 1,555 Trader Rating: (0) Feedback Score: 0 reviews	wow thas really weird..i do that all the time..some times 5th to 2nd. never experienced anything quite like that..it doesnt feel like its gonna stall as if u were in first duz it?? __________________ lemme have a dollar

09-11-2003, 11:28 PM	#3
240Driver39 Zilvia FREAK! Join Date: May 2002 Location: Charleston, SC Age: 40 Posts: 1,090 Trader Rating: (1) Rides Gallery: 240Driver39 Feedback Score: 1 reviews	no, when i say the rpms slowly drop after goin into 3rd i mean i rolled from like 50mph to a stop and the rpms slowly were droppin durin that time, till i stoped the car and it shut off, basically starin at the tach, slowly goin down, and having no throttle action __________________ 1990 240sx 5spd fastback

09-12-2003, 01:29 PM	#8
240Driver39 Zilvia FREAK! Join Date: May 2002 Location: Charleston, SC Age: 40 Posts: 1,090 Trader Rating: (1) Rides Gallery: 240Driver39 Feedback Score: 1 reviews	read the original post "I was cruisin in 5th at a lower speed, so i went to downshift to 3rd, clutch in, rev, shifter into third, clutch out" i do revmatch.... __________________ 1990 240sx 5spd fastback

09-12-2003, 01:57 PM	#9
sykikchimp WOW addicted Join Date: Dec 2001 Location: the moon Age: 44 Posts: 6,525 Trader Rating: (0) Feedback Score: 0 reviews	I know EXACTLY what your talking about. I found this out the hard way on the track. Entering turn 1 at LMS.. running about 120.. brake hard, clutch in, rev, shifter in, clutch out, bam.. NO POWER, like fuel had been cut.. pull off.. turn key completely off, then back on.. car starts, and runs fine. Scared the ** out of me. What I believe I SHOULD be doing.. clutch in, BRAKE HARD, wait for speed to come down, right before turn it, blip throttle, shifter in third, release clutch smoothly, and transition smoothly from the brake to the throttle while comming out of the clutch.. definately tricky. I believe I was hitting an emergency fuel cut on 3rd gear to prevent over-revving the engine. I was trying to get into third while the car was traveling to fast. If I waited just a second longer to get into third while slowing, I didn't have the problem. The 3rd gear synchros don't like the 5th-3rd downshift either. GRIND** a couple times before I got the timing down. I think in order to really complete the 3-5 downshift smoothly when you are at track speed, you have to double clutch heel/toe downshift, and MAKE SURE your not trying to engage 3rd at too high of a speed. I did this successfully 2 or 3 times, and it made a WORLD of difference. double clutching allows you to move the transmission faster than the synchros would normally allow. The double clutch is an extra step from the previous scenario above, but it allows me to get into the gear earlier, and concentrate more on the brake/throttle-clutch out transistion. short answer: Your going to fast for 3rd, and hitting a fuel cut. __________________ Last edited by sykikchimp; 09-12-2003 at 02:01 PM..

09-11-2003, 11:51 PM	#4
Halz BANNED Join Date: Apr 2002 Location: bay area Age: 41 Posts: 214 Trader Rating: (0) Feedback Score: 0 reviews	Does 4th to 2nd work just fine?

09-12-2003, 02:45 AM	#5
BeatJunky Zilvia Junkie Join Date: May 2003 Location: Chicag-Ho Posts: 529 Trader Rating: (0) Feedback Score: 0 reviews	I have a similar problem. My gears just plain ol' like to cut off at certain rpms. For example lets say I lauch the car from complete stop to redline each gear and try to do max speed, 1st gear will redline fine, 2nd will redline fine third will only go to like 4,500rpm then I have no throttle play and car just rolls till the rpms drop back to 3,000rpms... at that point I get throttle control again. If I can shift from 3rd to 4th before 3rd cuts off, then 4th will do the same thing at 4,000 rpm and 5th does it at 3,500 rpms. Anyone know whats wrong?

09-12-2003, 08:59 AM	#6
s0ldats Zilvia Addict Join Date: May 2003 Location: so. cal Posts: 657 Trader Rating: (0) Feedback Score: 0 reviews	timing?

09-12-2003, 01:13 PM	#7
Armysweitzer Leaky Injector Join Date: Jun 2003 Location: Wakefield RI Posts: 72 Trader Rating: (0) Feedback Score: 0 reviews	just in case your not doing it (hopefully are)... Learn to Rev-Match