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914World.com _ 914World Garage _ Car running like crap
Posted by: saigon71 Apr 16 2019, 07:29 PM
Could use some "check this" help:
Running a 2056 D-jet.
Over the winter I adjusted the valves and changed the oil. It didn't need much else.
This Spring, I installed a new distributor cap and new set of points. Adjusted dwell to 50 degrees before setting timing dead on at 27 degrees BTDC.
The car was running awesome. 
All of the sudden, the car has developed a pretty serious intermittent miss. There have been times it runs flawless on a test drive, only to start sputtering the next drive. When the sputtering and bucking occurs, there is sometimes an audible "pop" or "knock" sound coming from the engine bay.
I've got a new FI wiring harness from Jeff Bowlsby installed.
So far I have done the following:
-Check fuel lines for kinks
-Added "Star-Tron" enzyme fuel treatment to fuel stored in tank for winter, have since added two tanks of fresh gas
-Fuel steady pressure at 31PSI (but I couldn't get the car to act up when I had the gauge attached)
-Verified point gap hadn't changed after setting dwell
-Verify that CHT is tight (CHT is almost new)
-Cleaned & adjusted trigger points
-Unplugged TPS - it did not make a difference
-Checked FI harness grounds at the back of the engine
-Pulled all 4 spark plugs to check for fouling - they all looked good
-Swapped the coil with a known good one
Any advice on other things to check would be appreciated.
Posted by: Minerva's 914 Apr 16 2019, 07:36 PM
I would check the points, it's a cheap and easy check and apparently the likelihood of a defective set of points is greater than one might imagine according to a long time friend that has been a 914 starwort for 40 years.
Posted by: Big Len Apr 16 2019, 08:01 PM
I would check the points, it's a cheap and easy check and apparently the likelihood of a defective set of points is greater than one might imagine according to a long time friend that has been a 914 starwort for 40 years.
Posted by: wndsrfr Apr 17 2019, 06:07 AM
I would check the points, it's a cheap and easy check and apparently the likelihood of a defective set of points is greater than one might imagine according to a long time friend that has been a 914 starwort for 40 years.
Put the old dizzy cap back on
Posted by: VaccaRabite Apr 17 2019, 06:30 AM
When the car is acting up, put a timing light on the different plug wires and see which one is acting funny.
I agree with the others that your issue sounds electrical. Could be a faulty plug wire.
Zach
Posted by: rgalla9146 Apr 17 2019, 07:29 AM
Not mentioned: plenum and intake manifolds for vacuum leaks or cracked hoses.
Posted by: dr914@autoatlanta.com Apr 17 2019, 07:44 AM
can you get it to do it when the car is stationary, or do you have to drive it and put a load on the engine?
Posted by: saigon71 Apr 17 2019, 10:39 AM
can you get it to do it when the car is stationary, or do you have to drive it and put a load on the engine?
I notice it most under load, but noticed it happening stationary as well when I rev the engine.
Posted by: Spoke Apr 17 2019, 10:56 AM
Does the tach bounce or jump when this happens? Sometimes that could signal ineffective burn or ignition issues.
Posted by: dr914@autoatlanta.com Apr 17 2019, 10:56 AM
so rev the engine and pull one spark plug wire at a time from the cap and try to localize it to a cylinder or two. If two diagonal cylinders, trigger points, if two on the same Side injector grounds if only one then switch the injector leads and see if it moves and switch the plug wire with another one
can you get it to do it when the car is stationary, or do you have to drive it and put a load on the engine?
I notice it most under load, but noticed it happening stationary as well when I rev the engine.
Posted by: saigon71 Apr 17 2019, 06:36 PM
Update:
The trigger to the poor running is turning the headlights on. Almost immediately, the car starts jerking and I hear the knock sound.
Battery is new. Resting voltage is 13.06, it is 13.6 running without lights and drops to 12.5 running with the lights on. Alternator belt seems fine.
Posted by: Spoke Apr 17 2019, 07:17 PM
Where are you measuring the 13.6V and 12.5V when running? At what RPM are you at? If 12.5V is at the battery, you have an issue. Also what is the voltage at the coil?
With the engine running at high idle like 2k, measure all 3 pins of the VR with respect to chassis ground. Not the engine but the chassis. D+ should be 13.5V, DF should be 6-10V and D- should be less than 0.5V. All voltages DC. Don't disconnect anything; just jam the DMM probe into the connector to the VR.
Posted by: saigon71 Apr 17 2019, 07:36 PM
Where are you measuring the 13.6V and 12.5V when running? At what RPM are you at? If 12.5V is at the battery, you have an issue. Also what is the voltage at the coil?
With the engine running at high idle like 2k, measure all 3 pins of the VR with respect to chassis ground. Not the engine but the chassis. D+ should be 13.5V, DF should be 6-10V and D- should be less than 0.5V. All voltages DC. Don't disconnect anything; just jam the DMM probe into the connector to the VR.
13.6 running without lights on, 12.5 running with the lights on. Both measurements taken at the battery, car idling at 1100 rpm or so.
I'll run your other tests tomorrow after work.
Posted by: Spoke Apr 17 2019, 07:37 PM
Where are you measuring the 13.6V and 12.5V when running? At what RPM are you at? If 12.5V is at the battery, you have an issue. Also what is the voltage at the coil?
With the engine running at high idle like 2k, measure all 3 pins of the VR with respect to chassis ground. Not the engine but the chassis. D+ should be 13.5V, DF should be 6-10V and D- should be less than 0.5V. All voltages DC. Don't disconnect anything; just jam the DMM probe into the connector to the VR.
13.6 running without lights on, 12.5 running with the lights on. Both measurements taken at the battery, car idling at 1100 rpm or so.
I'll run your other tests tomorrow after work.
Does the battery voltage come up w/lights on as RPMs rise?
Posted by: Olympic 914 Apr 18 2019, 07:46 AM
13.6 seems low.
Had a recent issue where it was charging at that and after a 30mi. drive the battery was too low to start the car. first I suspected the new radio amp I had installed was drawing too much. but then found that the alternator belt was loose. it was probably slipping more at higher rpms, replaced the belt ($10 insurance) tightened it up and its now charging at 14.1, no other changes.
I did read where you stated the belt on yours seemed okay.
will still be bringing my jump start box to Hershey.
and AAA card.
Hope you get it sorted.
Posted by: dr914@autoatlanta.com Apr 18 2019, 09:43 AM
13.6 is great, sounds like a grounding problem, check the battery neg to right firewall connection, the ground leads at the back of the engine case on top and the rear trans mission to bottom of the trunk floor
13.6 seems low.
Had a recent issue where it was charging at that and after a 30mi. drive the battery was too low to start the car. first I suspected the new radio amp I had installed was drawing too much. but then found that the alternator belt was loose. it was probably slipping more at higher rpms, replaced the belt ($10 insurance) tightened it up and its now charging at 14.1, no other changes.
I did read where you stated the belt on yours seemed okay.
will still be bringing my jump start box to Hershey.
and AAA card.
Hope you get it sorted.
Posted by: ctc911ctc Apr 18 2019, 01:22 PM
[quote name='dr914@autoatlanta.com' date='Apr 18 2019, 09:43 AM' post='2706434']
13.6 is great, sounds like a grounding problem, check the battery neg to right firewall connection, the ground leads at the back of the engine case on top and the rear trans mission to bottom of the trunk floor
[quote name='Olympic 914' post='2706413' date='Apr 18 2019, 06:46 AM']
Or, number 329 in the 700 TT book should be considered!
13.6 is the right potential for optimally charging Lead/Acid Batteries to maximize the life of the cells.
https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery
Posted by: saigon71 May 5 2019, 11:27 AM
Where are you measuring the 13.6V and 12.5V when running? At what RPM are you at? If 12.5V is at the battery, you have an issue. Also what is the voltage at the coil?
With the engine running at high idle like 2k, measure all 3 pins of the VR with respect to chassis ground. Not the engine but the chassis. D+ should be 13.5V, DF should be 6-10V and D- should be less than 0.5V. All voltages DC. Don't disconnect anything; just jam the DMM probe into the connector to the VR.
Damn this is frustrating.
I discovered I had an adjustable voltage regulator and bumped up the voltage slightly.
Still battling this problem. I installed a reman "Carquest" alternator from NAPA. Things got better, but the car still bucks when I drive it with the lights on.
Spoke: I measured the voltages as you suggested with the new alternator at 2000 RPM. These are my readings:
D+: 14.5V
DF: 3.2V
D-: negative 62 millivolts
Does the low reading at DF indicate I got a bad rebuilt alternator?
Posted by: saigon71 May 5 2019, 11:30 AM
Where are you measuring the 13.6V and 12.5V when running? At what RPM are you at? If 12.5V is at the battery, you have an issue. Also what is the voltage at the coil?
With the engine running at high idle like 2k, measure all 3 pins of the VR with respect to chassis ground. Not the engine but the chassis. D+ should be 13.5V, DF should be 6-10V and D- should be less than 0.5V. All voltages DC. Don't disconnect anything; just jam the DMM probe into the connector to the VR.
13.6 running without lights on, 12.5 running with the lights on. Both measurements taken at the battery, car idling at 1100 rpm or so.
I'll run your other tests tomorrow after work.
Does the battery voltage come up w/lights on as RPMs rise?
Battery voltage increases slightly with lights on as RPM's rise from 13.6V to 13.77V
Posted by: ejm May 5 2019, 12:05 PM
You need to check the voltage at coil terminal #15 and maybe at pin 1 of the white 4 pin FI harness plug on the relay board. High resistance somewhere will reduce voltage to the consumers. I would plug another ignition switch into the harness and see if the problem goes away.
Posted by: saigon71 May 5 2019, 12:57 PM
You need to check the voltage at coil terminal #15 and maybe at pin 1 of the white 4 pin FI harness plug on the relay board. High resistance somewhere will reduce voltage to the consumers. I would plug another ignition switch into the harness and see if the problem goes away.
Thanks Ed. 13.7V on terminal 15 of the coil. Which pin is pin 1 on the white 4 pin FI harness?
Heading out to swap out the ignition switch.
Posted by: saigon71 May 5 2019, 02:33 PM
I swapped out the ignition switch with a new one. Still acting the same.
Posted by: Spoke May 6 2019, 06:31 PM
Where are you measuring the 13.6V and 12.5V when running? At what RPM are you at? If 12.5V is at the battery, you have an issue. Also what is the voltage at the coil?
With the engine running at high idle like 2k, measure all 3 pins of the VR with respect to chassis ground. Not the engine but the chassis. D+ should be 13.5V, DF should be 6-10V and D- should be less than 0.5V. All voltages DC. Don't disconnect anything; just jam the DMM probe into the connector to the VR.
Damn this is frustrating.
I discovered I had an adjustable voltage regulator and bumped up the voltage slightly.
Still battling this problem. I installed a reman "Carquest" alternator from NAPA. Things got better, but the car still bucks when I drive it with the lights on.
Spoke: I measured the voltages as you suggested with the new alternator at 2000 RPM. These are my readings:
D+: 14.5V
DF: 3.2V
D-: negative 62 millivolts
Does the low reading at DF indicate I got a bad rebuilt alternator?
All those numbers look good especially the 14.5V on D+ and 62mv on D-. That D- reading is basically testing the grounding of the alternator. You should be seeing 14.5V or near it on the battery as well.
Was this with lights on or off?
Posted by: Spoke May 6 2019, 08:08 PM
BTW, what voltage do you have at the coil with ground referenced to the engine case?
Posted by: saigon71 May 12 2019, 10:40 AM
Does the tach bounce or jump when this happens? Sometimes that could signal ineffective burn or ignition issues.
Tach remains steady when it acts up.
Posted by: saigon71 May 12 2019, 10:58 AM
BTW, what voltage do you have at the coil with ground referenced to the engine case?
13.7 on coil terminal 15, 7.7 on coil terminal 1, referenced to the engine case.
Posted by: saigon71 May 12 2019, 11:30 AM
Update:
I've swapped out the distributor cap and points, I've swapped out all 4 injectors with known good ones. Replaced the ignition condensor. Ran a new battery ground strap from the negative terminal to the side of the engine bay. Tried a replacement voltage regulator. Swapped out the relay board with a known good one.
I just re-tested fuel pressure - it is 30PSI at idle, 29PSI at 4000 RPM.
Nothing has changed.
I'm still driving the car. She's missing now without the lights on sometimes. However, it is always much worse when I turn the lights on. The hesitation seems to be more prevalent at higher RPM.
Bump for some fresh ideas. 
Man this sucks, it's prime driving season.
Posted by: mepstein May 12 2019, 12:03 PM
Because of what I went through I’m still guessing electrical. I would pull every connector and spray with contact cleaner. Mine got better when I switched out the coil. I did the switch with other stuff but I have a spare if you want to try.
I had a friend help me go through the dizzy at the same time it started running right. I had already changed out all the fuel lines, filter, rebuilt the ingectors and checked the fuel pressure. I switched out the engine harness but it made no difference.
Posted by: oakdalecurtis May 12 2019, 12:14 PM
My 76 2.0 Djet would miss intermittently for years, couldn't find the problem, not for lack of trying. I finally pulled the dizzy and slid out the fuel injection points underneath it. Well well well. The points on one side had a piece of plastic debris behind them which would slide around and jam up the points, only intermittently. Maybe check your injector points. This problem would not have any relationship to lights on or power use however.......
Posted by: saigon71 May 12 2019, 06:12 PM
My 76 2.0 Djet would miss intermittently for years, couldn't find the problem, not for lack of trying. I finally pulled the dizzy and slid out the fuel injection points underneath it. Well well well. The points on one side had a piece of plastic debris behind them which would slide around and jam up the points, only intermittently. Maybe check your injector points. This problem would not have any relationship to lights on or power use however.......
Thanks for the response. I've swapped out the trigger points with no change to the problem.
Posted by: dralf May 15 2019, 07:41 AM
I have finally started working on a similar running issue with my 1975 that still has D jet injection. My engine would actually die while driving, I could restart it, and if the REVs were above 4000 RPM it would continue to run and die if the RPMs dropped. I does not do this all the time but is a scary situation on the interstate. My previous posts regarding this issue have suggested I replace the coil, some of the wiring harness, check grounding and points. Reading this post makes me wonder if I do not have an alternator / power to the coil issue. I am going to use some of the suggestions and checks from this post to look at my car for source of my problem.
Posted by: JmuRiz May 15 2019, 10:19 AM
Just a shot in the dark, how's the fuel filter (how old/dirty/clean etc)?
Posted by: 904svo May 15 2019, 10:35 AM
Just a WAG, check all the red leads on the battery connector you might have one of
the red wire with broken strands causing a intermittent problem.
Posted by: saigon71 May 15 2019, 10:39 AM
Duplicate post - oops. 
Posted by: saigon71 May 15 2019, 10:39 AM
I THINK (and hope) that I found what is causing the problem. I've gotten in contact with Odyssey about a warranty on this new battery.
This thread shows what is going on:
http://www.914world.com/bbs2/index.php?showtopic=338054
The video on post 5 shows the whole battery post moving.
Posted by: VaccaRabite May 15 2019, 07:13 PM
Its a weird problem, and I would assume that the post would cause all sorts of other issues, but the timeline matches. Do you have another known good battery you can swap in? If not swing by and grab one.
Zach
Posted by: saigon71 May 18 2019, 03:06 PM
Its a weird problem, and I would assume that the post would cause all sorts of other issues, but the timeline matches. Do you have another known good battery you can swap in? If not swing by and grab one.
Zach
Thanks Zach. I'm in the warranty process with Odyssey. They said it could take 7-10 days until I get my new batttery. I may run down to your place if I get time to test this bad battery theory. Plus, I've got some parts from Mark for you.
Youre right, the timeline fits. The problem definately gets worse under electrical load.
Posted by: Big Len May 18 2019, 06:41 PM
One weird problem Bob. It's a new one for me.
Posted by: saigon71 Jun 2 2019, 06:44 PM
I wanted to get plenty of driving in to make sure the problem was fixed before reporting back.
The loose battery post was the problem. Odyssey was great to work with to get a new replacement under warranty.
Relieved that it's fixed but frustrated that it took so long to figure out.
On the bright side - my alternator was on the verge of failure, so swapping that out probably saved me a future break down.
Thanks for all the help.
Back on the road (confidently).
Bob
Posted by: mepstein Jun 2 2019, 06:51 PM
Posted by: Dion Jun 2 2019, 07:53 PM
Nice one Bob. Glad they made good on the warranty for ya.
Happy motoring.
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