 75 still running rich, 75 still running rich |
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| brooks944 |
 Jun 26 2017, 02:19 PM
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#1
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Member  Group: Members Posts: 249 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States  |
My 75 is running rich and fouling plugs after just a few miles. One of the members spent several hours helping me check and figure out the FI a couple of years ago and that made a difference (both on the car and how much I value your experts here). I have 2 extra 'brains' is it time to change that and check? One is from a '75 and one from a 74, does that matter? Both are for a 1.8 which my car is. Fuel injectors are rebuilt as well as the cold start valve. Most vacuum hoses changed. Thanks for any input.
Rick |
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| brooks944 |
Jun 29 2017, 11:36 AM
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#2
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Member Group: Members Posts: 249 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
OK, got the HF fuel injector kit and measured pin 13 to battery negative after warming the car up. The fuel pressure was about 32 psi, but bouncing from 30 to 40. At higher rpm (3k plus), steadied at 32 psi. After the car warmed up I measured pin 13 to negative battery post and it read 67 ohms and was increasing as the car cooled. is it the CHT sensor? Appreciate everyone's help.
Rick |
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| malcolm2 |
Jun 29 2017, 11:44 AM
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#3
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States 
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QUOTE(brooks944 @ Jun 29 2017, 12:36 PM)  OK, got the HF fuel injector kit and measured pin 13 to battery negative after warming the car up. The fuel pressure was about 32 psi, but bouncing from 30 to 40. At higher rpm (3k plus), steadied at 32 psi. After the car warmed up I measured pin 13 to negative battery post and it read 67 ohms and was increasing as the car cooled. is it the CHT sensor? Appreciate everyone's help. Rick Man, you are on it. I meant to post a pic of my fuel pressure set up. You might want to find a way to have the gauge on there all the time. Sensor seems good. Check out the chart. at 67 ohms your cylinder head must have been over 300*f. you got 1300-ish ohms at 75*F. That is what you should expect. Pressure seems right too. Mine jumps around too. I am in the same range 30-40. You said it felt smoother, have you driven any? still smooth? Maybe you can pull a plug and check the electrode, post a picture. Hey, what about that ECU question? You did or did not swap one out? Are you sure the 75 spare ECU is mounted and not the 74? BTW, here is my FP gauge DIY permanent installation. http://www.914world.com/bbs2/index.php?s=&...t&p=2437471 |
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Posts in this topic
brooks944 75 still running rich Jun 26 2017, 02:19 PM
Marty Yeoman Check the pin count on the ECU. Some have six and ... Jun 26 2017, 02:25 PM
jim_hoyland
Check the pin count on the ECU. Some have six and... Jun 26 2017, 02:40 PM brooks944 Not sure what that you mean, thanks for replying... Jun 26 2017, 02:32 PM brooks944 Probably a dumb reply, but do you have pics of wha... Jun 26 2017, 02:38 PM Marty Yeoman Sorry My Bad. I meant AFM not ECU
Check this out ... Jun 26 2017, 02:46 PM brooks944 Thanks, is the probable issue the AFM instead of t... Jun 26 2017, 05:09 PM malcolm2 So, did this just happen? Did something change, or... Jun 26 2017, 05:56 PM brooks944 The injectors were rebuilt a couple of years ago a... Jun 27 2017, 08:31 AM malcolm2
The injectors were rebuilt a couple of years ago ... Jun 27 2017, 10:54 AM brooks944 Also, the 75 has seven pins (I also have a 74 and ... Jun 27 2017, 08:38 AM malcolm2
Also, the 75 has seven pins (I also have a 74 and... Jun 27 2017, 10:47 AM white1975 cht sensor is bad I would say if the afm is not s... Jun 27 2017, 11:02 AM brooks944 Tim did help me check out the maf, it worked fine.... Jun 27 2017, 12:20 PM malcolm2 Here is a simple test for you to try....
study up... Jun 27 2017, 12:57 PM brooks944 Here are some pictures of the spark plugs, probabl... Jun 27 2017, 02:26 PM Root_Werks As some have stated, could be CHT, my money is on ... Jun 27 2017, 03:15 PM brooks944 Thanks, what do I need for a vacuum leak. Changed... Jun 27 2017, 03:45 PM malcolm2
Thanks, what do I need for a vacuum leak. Change... Jun 27 2017, 03:55 PM timothy_nd28 Hi Rick, I've been following this thread but ... Jun 27 2017, 05:51 PM N_Jay
My 75 is running rich and fouling plugs after jus... Jun 27 2017, 06:39 PM brooks944 Clark, I got 1.376k ohms when pin 13 was connected... Jun 28 2017, 12:43 PM malcolm2
Clark, I got 1.376k ohms when pin 13 was connecte... Jun 28 2017, 02:29 PM brooks944 Tim, good luck on your test and thanks for your he... Jun 28 2017, 01:45 PM malcolm2
if you can find a way to check your fuel pressu... Jun 28 2017, 02:46 PM malcolm2 Just had a thought.... when you pull the hoses on ... Jun 28 2017, 02:59 PM 914_teener I just use the screw tee hole on the driver side f... Jun 28 2017, 07:16 PM malcolm2
I just use the screw tee hole on the driver side ... Jun 28 2017, 08:27 PM brooks944 Also, I did change the ECU yet. I have what seems... Jun 29 2017, 11:39 AM brooks944 Thanks. Did not change the ECU yet. It did run s... Jun 29 2017, 12:27 PM brooks944 Here is a couple of pictures of the plug from cyli... Jun 30 2017, 12:10 PM malcolm2 So who has more ideas about running rich? All 4 c... Jul 6 2017, 06:47 AM Bartlett 914
So who has more ideas about running rich? All 4 ... Jul 6 2017, 07:33 AM |
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