Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

> 75 914 with D-Jettronic, need help diagnosing stuttering
Rant6
post Nov 19 2013, 01:45 PM
Post #1


Newbie
*

Group: Members
Posts: 8
Joined: 18-June 12
From: Daytona Beach, Florida
Member No.: 14,574
Region Association: South East States



Hi folks. I have a nearly all original 1975 914 with the 2.0 engine. The car has 93k miles on it, and I have owned it for almost two years. I have been troubleshooting one particular problem for quite some time. The car runs perfectly with one exception. The engine hesitates or stutters often. It is a hard stutter, that is, it actually feels like maybe the ignition is cutting out for a fraction of a second, and so it causes a bucking sensation when driving the car. There are few discernible circumstances where this always occurs or never occurs. It seems to be random, and it can occur under easy acceleration, steady throttle, or off throttle (usually VERY slightly off throttle). It can occur under cold or hot conditions. It happens every time I drive the car, sometimes infrequently, but more often it happens constantly. It seems to happen most often in the middle of the RPM range, that is from about 2500 to 3200 RPM.
Some of the emission control stuff has been disconnected or removed from the car including the charcoal canister, the distributor vacuum retard, (I don't think there was a vacuum advance because I can't find where the hose would have connected to), the vacuum line to the decel valve, and an electrical 2-prong plug that goes into the intake plenum. I have done the following things:

Fuel injector cleaner
New plug wires
New plugs
New rotor/cap/points
New air cleaner
Re-attached the electrical plug in the intake plenum (this caused the idle to surge up and down 1200 RPM, so I disconnected it - what is this thing?)
Re-attached the vacuum line to the decel valve
Replaced the circuit board in the throttle position sensor, and aligned.

I really thought the last item was going to be the fix, but it had no effect at all.
Can anyone offer some possible causes?

Thanks,
Mike
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
TheCabinetmaker
post Nov 19 2013, 02:54 PM
Post #2


I drive my car everyday
*****

Group: Members
Posts: 8,339
Joined: 8-May 03
From: Tulsa, Ok.
Member No.: 666



I agree. tps!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Rant6
post Nov 19 2013, 03:06 PM
Post #3


Newbie
*

Group: Members
Posts: 8
Joined: 18-June 12
From: Daytona Beach, Florida
Member No.: 14,574
Region Association: South East States



I did look at the fingers on the TPS, and one of them does ride very close to the edge of its associated strip. I'll take a closer look to see if it is losing connection. If I disconnect the TPS, will the car still run?

Thanks,
Mike


User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 12th July 2025 - 11:22 AM