 '74 2.0 FI, hesitates at 4300 rpm |
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| moneysmarts |
 Apr 19 2005, 12:44 PM
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#1
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Member  Group: Members Posts: 164 Joined: 2-March 04 From: Central Massachusetts Member No.: 1,745 Region Association: None 
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Hot or cold, engine runs great and pulls strong right up to 4300 rpm.
Then, it hesitates and bucks a little until about 4500, then runs fine again to 6000. Valves were done last fall, new fuel filter and plugs this spring. Oh ya, also has MSD. Where should I begin looking? |
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Replies(1 - 19)
| JeffBowlsby |
Apr 19 2005, 12:49 PM
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#2
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914 Wiring Harnesses Group: Members Posts: 8,510 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None
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Throttle switch?
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| 3d914 |
Apr 19 2005, 12:55 PM
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#3
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Senior Member Group: Members Posts: 1,275 Joined: 24-September 03 From: Benson, AZ Member No.: 1,191 Region Association: Southwest Region |
ms,
It may be necessary to remove the TPS (throttle Switch) cover and clean the contacts. You may think its easier to buy a new one, but I've had to do this even on new ones. The contacts can have burrs on them and groove the circuitry. Enjoy! |
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| TheCabinetmaker |
Apr 19 2005, 01:33 PM
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#4
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
6000rpm? (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif) Last fall is a long time between adjustments unless it sat all winter. |
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| moneysmarts |
Apr 19 2005, 02:17 PM
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#5
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Member Group: Members Posts: 164 Joined: 2-March 04 From: Central Massachusetts Member No.: 1,745 Region Association: None
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Yup.
Sat in a warm garage all winter while we froze our tails off. It's been about 2000 miles since valve ajustment. And, OK, call it 5800 RPM (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) 's. What's wrong with that? |
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| moneysmarts |
 Apr 19 2005, 02:19 PM
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#6
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Member Group: Members Posts: 164 Joined: 2-March 04 From: Central Massachusetts Member No.: 1,745 Region Association: None
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Gerard:
Have you got any pictures I can see to use as a guide? |
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| bd1308 |
Apr 19 2005, 04:00 PM
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#7
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
dont spend a bunch of time foolin with the TPS....check your centrifugal advance...thats what MY problem was.....took apart the dizzy, cleaned her out and put it back in...put OIL DOWN THE SHAFT and good to go!!
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| Brad Roberts |
Apr 19 2005, 06:34 PM
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#8
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914 Freak! Group: Members Posts: 19,148 Joined: 23-December 02 Member No.: 8 Region Association: None |
Steve,
stock engines fall off around 4800. Really no need to spin them to 6k. I would certainly check the advance/retard setup. B |
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| moneysmarts |
Apr 19 2005, 06:40 PM
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#9
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Member Group: Members Posts: 164 Joined: 2-March 04 From: Central Massachusetts Member No.: 1,745 Region Association: None
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Thanks Brad.
It's not really falling off when I get the hesitation. It kind of bucks a little, almost like there's no spark, at about 4200 +/-, then I get another good push of power for around 1000rpms before shifting. Does that make sense? |
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| MattR |
Apr 19 2005, 06:46 PM
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#10
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Advanced Member Group: Members Posts: 3,279 Joined: 23-January 04 From: SF Bay Area Member No.: 1,589 Region Association: Northern California |
Shifting at 5200 rpm (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)
I dont baby my car, but if it aint running right thats a pretty high RPM to shift at. I saw a throttle on headrage's car and its not a carburator so I dont understand it, but there are little prongs that come in contact with the body that do something. I would pull off the throttle body and try to compare your tb with another one. Headrage's throttle body was all out of whack and his car wouldnt run right. Its worth a shot. |
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| nebreitling |
Apr 19 2005, 06:51 PM
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#11
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Member Emeritus Group: Members Posts: 3,314 Joined: 26-March 03 From: San Francisco Member No.: 478 |
moneysmarts:
this exact thing would happen to my Djet'd car. i never figured it out. tried different TPS's, MPS's, cleaned and nearly rebuilt distributor, ditched points, etc.,... and it was never resolved. it was a REAL PITA autocrossing, where i'd stumble as soon as i got into the powerband (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif) |
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| bd1308 |
Apr 19 2005, 06:55 PM
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#12
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
another thing....check timing and dwell AND double check your F.I trigger point connections...the trigger points usually don't go out, but my connections were corroded and almost disconnected...puts a new meaning to the phrase hanging on the last thread....
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| Brad Roberts |
Apr 19 2005, 07:09 PM
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#13
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914 Freak! Group: Members Posts: 19,148 Joined: 23-December 02 Member No.: 8 Region Association: None |
Trigger points.
And check the grounds for the injectors on the back of the block as it transitions UP. Trigger points..make the car buck when they are starting to fail. B |
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| moneysmarts |
Apr 19 2005, 08:07 PM
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#14
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Member Group: Members Posts: 164 Joined: 2-March 04 From: Central Massachusetts Member No.: 1,745 Region Association: None
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FI Trigger points? (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)
What the... |
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| Eric Taylor |
Apr 19 2005, 08:12 PM
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#15
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Senior Member Group: Members Posts: 909 Joined: 1-June 03 From: Newport, OR/Eugene Oregon- UO Member No.: 770 |
They are in the distro. They are the one's that fire the injectors at the right time. Can cause hesitation and stumbling in the car. Mine did.
Eric |
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| redshift |
Apr 19 2005, 08:33 PM
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#16
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Bless the Hell out of you! Group: Members Posts: 10,926 Joined: 29-June 03 Member No.: 869 |
yaya clean all that crap in the dirt-stro, and check the trigger gaps.
And about shifting, do it just short of where you do it, I get out of first around 4500, and the other gears at 5500. Stay on the tuning. M |
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| Demick |
Apr 19 2005, 08:34 PM
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#17
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Ernie made me do it! Group: Benefactors Posts: 2,312 Joined: 6-February 03 From: Pleasanton, CA Member No.: 257  |
I once had a 2800rpm stumble like that. Turned out to be a dirty ground (transmission ground strap), but could be any of the grounds.
Demick |
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| 9144guy |
Apr 19 2005, 08:44 PM
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#18
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Member Group: Members Posts: 253 Joined: 26-February 05 From: tulsa,ok Member No.: 3,672 |
check the points,rev limiter installed?...ive replaced alot of points that have fixed that problem. includng last week before club race, had magnetic ing. went bad, installed stock pionts, ran like a batt-outa-hell
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| Allan |
Apr 19 2005, 08:47 PM
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#19
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Teenerless Weenie Group: Members Posts: 8,373 Joined: 5-July 04 From: Western Mesopotamia Member No.: 2,304 Region Association: Southern California |
I keep seeing a bouncing bear?????
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| Mueller |
Apr 19 2005, 08:49 PM
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#20
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914 Freak! Group: Members Posts: 17,146 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None
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uh oh...another 914/4 owner that has not read this site: 914 D-Jet info...a MUST read for new 914 owners (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) shame on you... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) |
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