 Fuel pressure and spark but won't run |
|
|
|
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. |
|
|
| Groosh |
 Jun 5 2016, 01:24 PM
Post
#1
|
|
Member  Group: Members Posts: 50 Joined: 21-October 11 From: Dexter, MI Member No.: 13,702 Region Association: Upper MidWest  |
Hi. I recently bought a '74 1.8 and am looking for help to get it running. It has the original fuel injection and ran late last year according the previous owner.
Here's what I know after reading many posts in the forum and working on it. Thanks to everybody who contributes, I couldn't have gotten this far without your help. - The dual relay is bad I believe. After wiring it all back up, there is power from the ignition to both the start wire and run wire but no power to the fuel pump. I'm jumping the pump currently to test - All relays in the board work - Fuel pressure gauge shows 35psi on startup. I didn't install this gauge but seems to work ok - Will fire with starting fluid I'm thinking I must be pretty close and suspect the car isn't getting fuel but the gauge shows pressure? |
   |
 
|
  |
Replies
| timothy_nd28 |
Jun 5 2016, 01:59 PM
Post
#2
|
|
Advanced Member Group: Members Posts: 2,299 Joined: 25-September 07 From: IN Member No.: 8,154 Region Association: Upper MidWest 
|
Rich's test is a good one, it's testing if your fuel pump turns on and it's also testing if part of the dual relay is working.
|
|
|
|
| Groosh |
Jun 5 2016, 02:10 PM
Post
#3
|
|
Member Group: Members Posts: 50 Joined: 21-October 11 From: Dexter, MI Member No.: 13,702 Region Association: Upper MidWest |
QUOTE(timothy_nd28 @ Jun 5 2016, 11:59 AM)  Rich's test is a good one, it's testing if your fuel pump turns on and it's also testing if part of the dual relay is working. The relay isn't working as far as I know but I'm jumping the fuel pump right now. Power is getting to the relay properly from the ignition but not turning on the pump. Will that alter something else? So if it fires under starting fluid, has fuel pressure but apparently no fuel, maybe it's as simple as a clogged filter? |
|
|
|
Posts in this topic
Groosh Fuel pressure and spark but won't run Jun 5 2016, 01:24 PM
The Cabinetmaker An inline pressure gauge will show pressure in the... Jun 5 2016, 01:28 PM
Groosh
An inline pressure gauge will show pressure in th... Jun 5 2016, 01:30 PM emoze NO - if it fires on start fluid but won't run
... Jun 5 2016, 05:16 PM r_towle Stick a pencil in the round intake end of the air-... Jun 5 2016, 01:35 PM Groosh
Stick a pencil in the round intake end of the air... Jun 5 2016, 01:42 PM Groosh
Stick a pencil in the round intake end of the air... Jun 9 2016, 12:45 PM jim_hoyland And the 6 pin connector is plugged into the AFM ? Jun 5 2016, 02:08 PM timothy_nd28
Hi. I recently bought a '74 1.8 and am lookin... Jun 5 2016, 02:16 PM Groosh
Hi. I recently bought a '74 1.8 and am looki... Jun 5 2016, 05:23 PM ejm
- Will fire with starting fluid
Oh. There is one... Jun 5 2016, 05:44 PM timothy_nd28 I'm not sure if I can see the jumper from 88Y ... Jun 5 2016, 06:24 PM Groosh
I'm not sure if I can see the jumper from 88Y... Jun 9 2016, 12:48 PM Twonicks001 I know this sounds overly simplistic but it had me... Jun 5 2016, 07:34 PM motorvated If the injectors are not firing, you might want to... Jun 6 2016, 06:33 AM Groosh
If the injectors are not firing, you might want t... Jun 9 2016, 12:46 PM r_towle Without more accurate testing I would strongly sug... Jun 9 2016, 12:53 PM timothy_nd28 Adding new parts just confounds the problem. Remo... Jun 9 2016, 01:01 PM Groosh
Adding new parts just confounds the problem. Rem... Jun 10 2016, 01:05 PM timothy_nd28 Also if you don't already own these, run to Ra... Jun 9 2016, 01:23 PM timothy_nd28 Okay, use one of the jumper wires you just bought ... Jun 10 2016, 04:05 PM Groosh
Okay, use one of the jumper wires you just bought... Jun 11 2016, 06:53 AM timothy_nd28 Okay, jump pin 85 at the dual relay to the negativ... Jun 11 2016, 07:15 AM Groosh
Okay, jump pin 85 at the dual relay to the negati... Jun 11 2016, 10:08 AM timothy_nd28 What about pin 10 at the ECU? Jun 11 2016, 11:54 AM Groosh
What about pin 10 at the ECU?
I'm not gettin... Jun 11 2016, 12:14 PM timothy_nd28 We need to make sure that you are indeed probing p... Jun 11 2016, 01:30 PM Groosh
We need to make sure that you are indeed probing ... Jun 11 2016, 02:02 PM timothy_nd28 We might as well check some other wires, I'm s... Jun 11 2016, 02:22 PM Groosh
We might as well check some other wires, I'm ... Jun 12 2016, 11:24 AM timothy_nd28 Pin 14 and 33 are two of the four injectors. Disc... Jun 12 2016, 07:25 PM timothy_nd28 The resistor pack should look similar to this:
O... Jun 12 2016, 07:43 PM Groosh
The resistor pack should look similar to this:
... Jun 13 2016, 07:02 AM timothy_nd28 Old meters like that are awesome! Go ahead an... Jun 13 2016, 10:13 AM Groosh
Old meters like that are awesome! Go ahead a... Jun 20 2016, 07:17 AM timothy_nd28 For injectors 4 and 1, is this 12volts at the fuel... Jun 20 2016, 08:18 AM Groosh
For injectors 4 and 1, is this 12volts at the fue... Jun 20 2016, 09:13 AM timothy_nd28 Since the injectors all have continuity, the probl... Jun 20 2016, 09:54 AM Groosh
Since the injectors all have continuity, the prob... Jun 23 2016, 08:17 AM timothy_nd28 So you have 12volts on pins 14,15,32&33? Jun 23 2016, 03:38 PM Groosh Thanks to all of Tim's work, I have a repaired... Oct 5 2016, 05:26 PM Groosh Well, I started back at the beginning of our testi... Oct 18 2016, 02:35 PM timothy_nd28 Try deflecting the air flow meter flap with the ig... Oct 18 2016, 03:59 PM Groosh
Try deflecting the air flow meter flap with the i... Oct 19 2016, 02:02 PM timothy_nd28 Cool, much better results than last time. Oct 19 2016, 07:58 PM timothy_nd28 Car is almost ready to run. I would do one more te... Oct 19 2016, 10:48 PM Groosh
Car is almost ready to run. I would do one more t... Oct 22 2016, 07:35 AM timothy_nd28 Ok, I'm very glad that you did this test. Fir... Oct 22 2016, 10:09 AM Groosh
Ok, I'm very glad that you did this test. Fi... Oct 22 2016, 11:53 AM timothy_nd28 Cool, not sure what your issue was with the previo... Oct 22 2016, 04:18 PM Groosh
Cool, not sure what your issue was with the previ... Oct 23 2016, 12:09 PM timothy_nd28 The ECU uses the spark signal to fire the injector... Oct 23 2016, 12:34 PM Groosh
The ECU uses the spark signal to fire the injecto... Oct 23 2016, 12:37 PM timothy_nd28 Verify you do have 12 volts present at the positiv... Oct 23 2016, 12:39 PM Groosh
Verify you do have 12 volts present at the positi... Oct 23 2016, 12:44 PM timothy_nd28 Remove the distributor cap and rotor, and manually... Oct 23 2016, 12:47 PM Groosh
Remove the distributor cap and rotor, and manuall... Oct 23 2016, 03:08 PM timothy_nd28 Yah, time to replace them. Oct 23 2016, 03:11 PM Groosh
Yah, time to replace them.
Happened to have a se... Oct 23 2016, 03:50 PM timothy_nd28 On the ignition coil, you should have 3 wires on t... Oct 23 2016, 06:12 PM Groosh
On the ignition coil, you should have 3 wires on ... Oct 24 2016, 03:05 PM timothy_nd28 Just to make sure, did you pull all the wires off ... Oct 24 2016, 04:58 PM Groosh
Just to make sure, did you pull all the wires off... Oct 24 2016, 05:12 PM timothy_nd28 That indicates that the coil is good. So, you have... Oct 24 2016, 08:07 PM timothy_nd28 After checking the ground strap, take your voltmet... Oct 24 2016, 10:55 PM Groosh
After checking the ground strap, take your voltme... Oct 25 2016, 02:00 PM timothy_nd28 Reattach wires to the ignition coil. Turn the eng... Oct 25 2016, 02:17 PM Groosh
Reattach wires to the ignition coil. Turn the en... Oct 25 2016, 02:48 PM timothy_nd28 Silly question, but are the points in the closed p... Oct 25 2016, 02:52 PM Groosh
Silly question, but are the points in the closed ... Oct 25 2016, 03:24 PM timothy_nd28 Yes. Now check the resistance between the negative... Oct 25 2016, 04:10 PM Groosh
Yes. Now check the resistance between the negativ... Oct 25 2016, 04:32 PM timothy_nd28 That's fine, thanks for telling me. Repeat th... Oct 25 2016, 04:57 PM Groosh
That's fine, thanks for telling me. Repeat t... Oct 25 2016, 05:01 PM timothy_nd28 Redo the test from the 2nd paragraph from post #69 Oct 25 2016, 06:19 PM Groosh So I've been working with Tim and he has been ... Oct 26 2016, 04:29 PM Frankvw That is good to hear. Thanks for the update. Inter... Oct 26 2016, 11:18 PM Groosh Since it's 60 degrees in Michigan, I've at... Feb 24 2017, 11:17 AM Groosh Another warm day and another attempt. This time it... Mar 24 2017, 12:32 PM mark04usa :Qarl: Glad to hear that you've had sucess. Th... Mar 24 2017, 01:30 PM timothy_nd28 I love happy endings. :beer2: It's be... Mar 24 2017, 02:13 PM |
12 User(s) are reading this topic (12 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 23rd November 2024 - 06:35 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.