 Intermittent miss, Car bucks at part throttle |
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| billd |
 Oct 20 2005, 07:41 PM
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#1
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Member  Group: Members Posts: 327 Joined: 25-May 05 From: Palo Alto, CA Member No.: 4,145  |
I recently finished restoring my stock D-jet EFI. The car mostly drives fine (once its warmed up - I have issues with the AAR. However from time to time the car bucks - losing power for a quarter second or so - and then continues normally. So far this never happens at WOT - only at part throttle. It happens at relatively low RPM - from about 2,400 to 3,500. I haven't experienced it above 3,500 RPM. Any ideas on what it could be?
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| john rogers |
Oct 20 2005, 07:54 PM
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#2
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Senior Member Group: Members Posts: 1,525 Joined: 4-March 03 From: Chula Vista CA Member No.: 391 |
Every couple of years I have to open the throttle position switch and clean it out well with spray electrical cleaner and the contact areas with an eraser and then throttle response smooths out.
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| Cap'n Krusty |
Oct 20 2005, 08:03 PM
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#3
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
That would be the first place I looked. BTW, if the cleaning doesn't work (and BE VERY CAREFUL), new ones are available and they're not that expensive. The Cap'n |
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| billd |
Oct 20 2005, 09:33 PM
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#4
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Member Group: Members Posts: 327 Joined: 25-May 05 From: Palo Alto, CA Member No.: 4,145 |
Thanks guys. I'll clean the throttle switch and see how it works.
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| smg914 |
Oct 20 2005, 10:11 PM
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#5
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Sahara Beige Steve Group: Members Posts: 1,962 Joined: 22-February 04 From: Tampa, FL Member No.: 1,695 Region Association: None  |
If that doesn't work, it could be something as simple as bad ignition wires or maybe you need new spark plugs.
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| 914GT |
Oct 20 2005, 10:25 PM
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#6
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Senior Member Group: Members Posts: 1,100 Joined: 11-October 04 From: Tucson Member No.: 2,923 Region Association: Southwest Region |
Maybe check to see if you have timing too advanced.
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| BMartin914 |
Oct 20 2005, 10:55 PM
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#7
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||| Group: Members Posts: 1,408 Joined: 30-May 04 From: Oregon Member No.: 2,128 Region Association: Pacific Northwest |
I have dealt with the same problem in the past.
The solution ended up being replacing the FI trigger point wires from the distributor. They were frayed so bad they were shorting or causing inconsistencies with the resistance. Frayed wires at the MPS can cause a simililar problem. But if you just restored the d-jet... (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) |
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| bd1308 |
Oct 20 2005, 11:35 PM
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#8
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
if its the 74 model, I have one for uber cheap...brand new (but without box)
my grandmother bought it for a xmas gift.....but i ended up wrecking my 914. b |
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| michelko |
Oct 21 2005, 02:04 AM
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#9
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Senior Member Group: Members Posts: 867 Joined: 30-November 03 From: Germany, Lambsheim Member No.: 1,404 Region Association: None |
Had the same problem,
adjusting the Throttle position switch cured that. My advice: clean it and adjust it to factory spec´s (idle switch 2 ° opening etc.) (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_flagge6.gif) |
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| motorhead |
Oct 21 2005, 07:57 AM
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#10
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Member Group: Members Posts: 67 Joined: 11-September 05 From: tehachapi, ca Member No.: 4,784 |
mine had the same problem shortly after purchase. dead spot at mid throttle. the tps had a bad spot in the contacts. replaced the switch, adjusted to spec, haven't touched it in about 15 years. thinking back, it was probably the only easy thing I've ever done on the little beast.............
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| billd |
Oct 21 2005, 08:35 AM
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#11
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Member Group: Members Posts: 327 Joined: 25-May 05 From: Palo Alto, CA Member No.: 4,145 |
Its definitely the throttle switch. I removed the connector to the throttle switch and drove the car a bit. The problem is completely gone. It does hesitate a bit though.
I then pulled the switch off and cleaned it with electrical contact cleaner and an eraser. Replaced the switch and the problem is still there. I fear that the groove worn in the contacts is so deep that the flat spot I have can't be fixed by cleaning. Did someone say they have one cheap? |
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