Problem with fuel injection, Advice needed |
|
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. |
|
Problem with fuel injection, Advice needed |
cal914 |
Mar 28 2017, 03:04 PM
Post
#1
|
Member Group: Members Posts: 319 Joined: 12-April 12 From: United Kingdom Member No.: 14,366 Region Association: None |
Hi there
Just put our 1970 914 back to fuel injection from carbs and it purred for the first 30 minutes in slow moving traffic but then it began to cough and then was quickly nearly kangarooing down the street. It was fine idling but trying to pull away and driving it, it sounded as though it was misfiring or coughing or not running on all cylinders. What's the checklist for trying to solve the problem? Thanks! |
jcd914 |
Mar 28 2017, 03:15 PM
Post
#2
|
Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
I would start with fuel pressure.
|
zipedadoo |
Mar 28 2017, 03:34 PM
Post
#3
|
Member Group: Members Posts: 135 Joined: 23-January 14 From: Arizona Member No.: 16,921 Region Association: None |
Check the throttle position sensor. Adjust, clean or rebuild.
|
Dave_Darling |
Mar 28 2017, 07:14 PM
Post
#4
|
914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
Ignition. Always start with ignition. Also make sure the basic engine is in good shape, valves adjusted and decent compression, etc.
--DD |
Jeffs9146 |
Mar 28 2017, 07:16 PM
Post
#5
|
Ski Bum Group: Members Posts: 4,062 Joined: 10-January 03 From: Discovery Bay, Ca Member No.: 128 |
If it starts and runs fine when it is cold then starts sputtering check the CHT sensor.
|
mgphoto |
Mar 29 2017, 12:01 PM
Post
#6
|
"If there is a mistake it will find me" Group: Members Posts: 1,339 Joined: 1-April 09 From: Los Angeles, CA Member No.: 10,225 Region Association: Southern California |
Where there any mods to the engine, cam, displacement?
|
cal914 |
Mar 29 2017, 01:12 PM
Post
#7
|
Member Group: Members Posts: 319 Joined: 12-April 12 From: United Kingdom Member No.: 14,366 Region Association: None |
Took the car out again today,fine for the first 20mins then the problem returned.The engine has had no mods done to it and prior to fitting the Fuel Injection the car was running great
Thanks for any help that you can give |
Frankvw |
Mar 29 2017, 01:15 PM
Post
#8
|
working on my first 914 ! Group: Members Posts: 652 Joined: 13-April 16 From: Holland, the Netherlands Member No.: 19,896 Region Association: Europe |
Did you change the fuelpump from the low pressure carb pump back to a higher pressure FI fuel pump again ?
|
boxsterfan |
Mar 29 2017, 01:25 PM
Post
#9
|
914's are kewl Group: Members Posts: 1,776 Joined: 6-June 03 From: San Ramon, CA Member No.: 791 Region Association: Northern California |
Sounds like CHT sensor.
|
Rand |
Mar 29 2017, 01:26 PM
Post
#10
|
Cross Member Group: Members Posts: 7,409 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
If it had a carb pump, would it run great for 20 minutes?
Have you checked the CHT as suggested yet? |
mepstein |
Mar 29 2017, 01:41 PM
Post
#11
|
914-6 GT in waiting Group: Members Posts: 19,322 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region |
Mine used to do that -intermitted bucking. I almost parted the car. I tried a bunch of things but I think it was just bad electrical connections.
|
cal914 |
Mar 29 2017, 01:43 PM
Post
#12
|
Member Group: Members Posts: 319 Joined: 12-April 12 From: United Kingdom Member No.: 14,366 Region Association: None |
Are the CHT sensor still available to buy new
|
cal914 |
Mar 29 2017, 02:14 PM
Post
#13
|
Member Group: Members Posts: 319 Joined: 12-April 12 From: United Kingdom Member No.: 14,366 Region Association: None |
Just found out The CHT censor was brand new out of a packet , that's one thing eliminated
|
mepstein |
Mar 29 2017, 02:25 PM
Post
#14
|
914-6 GT in waiting Group: Members Posts: 19,322 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region |
I can't be sure but I think it was the wires around the tach and making sure the timing was correct that eliminated the bucking. I pulled off all the ground wires and cleaned them as well as the wires for the coil, ect.
I had done the chts but it didn't fix it. |
mgphoto |
Mar 29 2017, 02:39 PM
Post
#15
|
"If there is a mistake it will find me" Group: Members Posts: 1,339 Joined: 1-April 09 From: Los Angeles, CA Member No.: 10,225 Region Association: Southern California |
Are all the FI parts original and proper according to the rennlist site?
|
cal914 |
Mar 29 2017, 03:16 PM
Post
#16
|
Member Group: Members Posts: 319 Joined: 12-April 12 From: United Kingdom Member No.: 14,366 Region Association: None |
All the parts are original with NOS Bosch fuel injectors , we had 3 sets to choose from
|
JeffBowlsby |
Mar 29 2017, 03:47 PM
Post
#17
|
914 Wiring Harnesses Group: Members Posts: 8,548 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
There are several FI troubleshooting guides here:
http://bowlsby.net/914/Classic/TechNotebook.htm And if you determine that you need a new harness...let me know. (IMG:style_emoticons/default/wink.gif) |
mgphoto |
Mar 29 2017, 04:07 PM
Post
#18
|
"If there is a mistake it will find me" Group: Members Posts: 1,339 Joined: 1-April 09 From: Los Angeles, CA Member No.: 10,225 Region Association: Southern California |
Your FI points in the distributor have grease on them.
|
McMark |
Mar 29 2017, 04:18 PM
Post
#19
|
914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Did you take the fuel tank out? Pinched fuel lines underneath are a common problem.
|
cal914 |
Mar 30 2017, 01:11 PM
Post
#20
|
Member Group: Members Posts: 319 Joined: 12-April 12 From: United Kingdom Member No.: 14,366 Region Association: None |
Yes ,removed the tank and cleaned, the sock was all clear.On top of the ECU there's a grey knob that turns and clicks is there a best position for the knob to be to help with the running of the FI
|
Lo-Fi Version | Time is now: 15th June 2024 - 03:41 PM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |