Author |
Message |
Laithallos Samba Member
Joined: August 08, 2018 Posts: 4 Location: San Diego
|
Posted: Wed Aug 08, 2018 1:30 pm Post subject: Type 3 Runs horrible |
|
|
Okay So I have a 69 squareback with the stock D-jetronic Fuel injection system. it took a while to get it running right but when I did it ran beautifully. so about a week ago I was hearing a slight popping out of my exhaust at idle. I decided to do a full ignition overhaul. replaced the plugs with NGK B6HS plugs new wires, new cap new rotor, new point and condenser. still had the popping. and one day while driving it just lost all power couldn't even get out of its own way. letting it idle and pulling the wires one at a time the idle did not change on cylinder 3 and 4. I checked for spark at the plugs nice and strong I did a compression test on all cylinders all 145psi. I redid the valve adjustment all within spec .006 I have pulled the fuel injectors all 4 are not leaking and opening and closing like they should. I checked the oms on the throttle switch and its working properly, I have the early build 69 so its only the two wire throttle switch so it only sees idle has no potentiometer to record off idle position. my fuel pressure is at 28psi. I'm at a loss. oh and I also redid my timing to make sure everything was okay |
|
Back to top |
|
|
raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21462 Location: Oklahoma City
|
Posted: Wed Aug 08, 2018 10:14 pm Post subject: Re: Type 3 Runs horrible |
|
|
For the record....there is no potentiometer in any of the throttle switches. They are off/on switches only. There are also no ohms or resistance to check.
That is one of tbe worst features of the books. Resistance has nothing to do with TVS operation or adjustment. It only tells you if you have poor connections or wirn out,switch paths.
If two injectors on one side are not injecting....which is what it sounds like....its typically a bad ground at the case centerline. Ray |
|
Back to top |
|
|
Intrinsic Samba Member
Joined: November 16, 2011 Posts: 262 Location: Clearwater, FL
|
Posted: Thu Aug 09, 2018 6:01 am Post subject: Re: Type 3 Runs horrible |
|
|
Since the problem seems isolated to cylinders 3 and 4, could this be a bad trigger point contact? They are located in the distributor, in a chamber underneath the breaker points and advance plate. |
|
Back to top |
|
|
Laithallos Samba Member
Joined: August 08, 2018 Posts: 4 Location: San Diego
|
Posted: Thu Aug 09, 2018 6:56 am Post subject: Re: Type 3 Runs horrible |
|
|
All 4 injectors are working properly, now I've inspected the trigger points before when I had a rich condition. They seemed okay and I know parts fail unexpectedly all the time so know my question is, I didn't see an adjustment for them. So what do I look for besides burn marks and where can I find new replacement trigger points |
|
Back to top |
|
|
KTPhil Samba Member
Joined: April 06, 2006 Posts: 33820 Location: Conejo Valley, CA
|
Posted: Thu Aug 09, 2018 9:08 am Post subject: Re: Type 3 Runs horrible |
|
|
Laithallos wrote: |
All 4 injectors are working properly, now I've inspected the trigger points before when I had a rich condition. They seemed okay and I know parts fail unexpectedly all the time so know my question is, I didn't see an adjustment for them. So what do I look for besides burn marks and where can I find new replacement trigger points |
Are you saying it drives fine now? Or do you still have the problem?
On the early models, the injector ground is not at the center, there are paired ground points on each side near the heads (not sure exactly where, but look for them).
Maybe you bumped off a hose while working on it. This FI system does not tolerate any vacuum leaks. First check the hose from the MPS to the IAD. A loose hose here will also cause the "rich condition" you said you had.
I would suspect the ignition system next. Your problem seemed to start (or get much worse) after you did your ignition service. You say the injectors are working... can you verify spark at each cylinder?
Suspect the FI last... it's almost never the issue. Randomly replacing FI parts gets expensive, and rarely solves anything. |
|
Back to top |
|
|
Mike Fisher Samba Member
Joined: January 30, 2006 Posts: 17961 Location: Eugene, OR
|
Posted: Thu Aug 09, 2018 10:38 am Post subject: Re: Type 3 Runs horrible |
|
|
Unbolt the pairs of injectors & watch them spray fuel on top of the engine to see that they all are spraying similar cones of fuel. $5 Remote Starter Button from Harbor Freight lets you work alone! _________________ https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold
Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey |
|
Back to top |
|
|
raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21462 Location: Oklahoma City
|
Posted: Thu Aug 09, 2018 12:23 pm Post subject: Re: Type 3 Runs horrible |
|
|
Intrinsic wrote: |
Since the problem seems isolated to cylinders 3 and 4, could this be a bad trigger point contact? They are located in the distributor, in a chamber underneath the breaker points and advance plate. |
Actually not quite. The trigger points fire diagonal pairs....not side to side pairs. So of 3 and 4 on the same side are not firing....its not the trigger points. If even on cylinder on each side from each paired set is firing....it's not the trigger points.
However its most commonly the grounds from the injectors that cause one whole side to go out. Ray |
|
Back to top |
|
|
rosevillain Samba Member
Joined: December 28, 2005 Posts: 1283 Location: roseville, ca
|
Posted: Thu Aug 09, 2018 1:20 pm Post subject: Re: Type 3 Runs horrible |
|
|
raygreenwood wrote: |
Intrinsic wrote: |
Since the problem seems isolated to cylinders 3 and 4, could this be a bad trigger point contact? They are located in the distributor, in a chamber underneath the breaker points and advance plate. |
Actually not quite. The trigger points fire diagonal pairs....not side to side pairs. So of 3 and 4 on the same side are not firing....its not the trigger points. If even on cylinder on each side from each paired set is firing....it's not the trigger points.
However its most commonly the grounds from the injectors that cause one whole side to go out. Ray |
The early injection systems ground the injectors, in pairs, to an upper cylinder tin mounting screw. One ground per side, with the ECU ground at the case split. |
|
Back to top |
|
|
Laithallos Samba Member
Joined: August 08, 2018 Posts: 4 Location: San Diego
|
Posted: Fri Aug 10, 2018 9:32 am Post subject: Re: Type 3 Runs horrible |
|
|
I've checked all 4 injectors the grounds are good and I have unbolted them and cranked all 4 are spraying as they should and I've checked spark at all 4 spark plugs at the distributor, then with a screw driver at the plug ends grounded to the case, then finally all four plugs out and the side electrode grounded to the case all 4 are getting spark so I have spark and fuel and air the compression test came back 145psi on all 4 cylinders. This is why I'm at a loss it should be running fine but it's not. Also I checked for vacuum leaks none found. My rich condition was caused by a bad cylinder head temp sensor that's fixed. It was running great for 3 weeks before this happened |
|
Back to top |
|
|
Abscate Samba Member
Joined: October 05, 2014 Posts: 22503 Location: NYC/Upstate/ROW
|
Posted: Fri Aug 10, 2018 2:19 pm Post subject: Re: Type 3 Runs horrible |
|
|
Smoke test that sucker and find the intake manifold leak.... _________________ .ssS! |
|
Back to top |
|
|
raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21462 Location: Oklahoma City
|
Posted: Fri Aug 10, 2018 7:57 pm Post subject: Re: Type 3 Runs horrible |
|
|
rosevillain wrote: |
raygreenwood wrote: |
Intrinsic wrote: |
Since the problem seems isolated to cylinders 3 and 4, could this be a bad trigger point contact? They are located in the distributor, in a chamber underneath the breaker points and advance plate. |
Actually not quite. The trigger points fire diagonal pairs....not side to side pairs. So of 3 and 4 on the same side are not firing....its not the trigger points. If even on cylinder on each side from each paired set is firing....it's not the trigger points.
However its most commonly the grounds from the injectors that cause one whole side to go out. Ray |
The early injection systems ground the injectors, in pairs, to an upper cylinder tin mounting screw. One ground per side, with the ECU ground at the case split. |
Yes....as I noted.....it can be a ground causing bo th on one side to not fire....but not the trigger points. Ray |
|
Back to top |
|
|
KTPhil Samba Member
Joined: April 06, 2006 Posts: 33820 Location: Conejo Valley, CA
|
Posted: Fri Aug 10, 2018 8:27 pm Post subject: Re: Type 3 Runs horrible |
|
|
Abscate wrote: |
Smoke test that sucker and find the intake manifold leak.... |
X2
|
|
Back to top |
|
|
Laithallos Samba Member
Joined: August 08, 2018 Posts: 4 Location: San Diego
|
Posted: Mon Aug 20, 2018 10:36 am Post subject: Re: Type 3 Runs horrible |
|
|
So. It turned out to be a bad manifold pressure sensor causing all this. can't find one and its over $500 to get it rebuilt so I'm just going to ditch the Fuel injection and go with a carburetor kit |
|
Back to top |
|
|
raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21462 Location: Oklahoma City
|
Posted: Mon Aug 20, 2018 11:18 am Post subject: Re: Type 3 Runs horrible |
|
|
Laithallos wrote: |
So. It turned out to be a bad manifold pressure sensor causing all this. can't find one and its over $500 to get it rebuilt so I'm just going to ditch the Fuel injection and go with a carburetor kit |
Stop it! Its not that hard.
First...whats "bad" with it?...and did someone tell you its bad...or did you test for it?
If it leaks vacuum....is it either of the two o-rings?...or the diaphragm...if it has one?
And...no...you cannot actually get it rebuilt for $500 and have it be generally usable. It will cost $500...and be so far out of whack adjustment wise that you may never get it running unless you have lots of tuning experience.
Does your 69 have the style of MPS with the big slotted aluminum screw in the back filled with epoxy?...(which is actually the outer full load stop)?
If so you can buy a replacement diaphragm kit...a very well built one...with new o-rings.
http://www.tangerineracing.com/mpsdiaphragm.htm
For $154.00...thats a steal. It even comes with adjusting tools and a new plug for the back that allows work through adjusting of the main armature.
With just a little care...you can remove your diaphragm....and duplicate the center and outer screw settings by counting the number of turns...installing the diaphragm and be done and probably be within 10% of where the original adjustment was ...in about an hour.
If the coils read improper resistance...but are just a little high...that can be fixed...usually....by re-flowing the solder on the wires on the inside....5 minutes. If one or more coils do not read resistance...or if teh guts are rusted...only then is it shot.
You give up too easily. There are only 23 live wires and four main sensors in the system (depending on year)....then the trigger points.
Ray |
|
Back to top |
|
|
KTPhil Samba Member
Joined: April 06, 2006 Posts: 33820 Location: Conejo Valley, CA
|
|
Back to top |
|
|
Mike Fisher Samba Member
Joined: January 30, 2006 Posts: 17961 Location: Eugene, OR
|
Posted: Mon Aug 20, 2018 11:47 am Post subject: Re: Type 3 Runs horrible |
|
|
Tram adjusts my '69 MPS AFR with a small screwdriver while he has his 02 sensor clipped to my tailpipe. _________________ https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold
Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey |
|
Back to top |
|
|
|