Starting Problems, Starting with Throttle but Won't Idle Options

[nmkimosabe]

I will try to clarify the status and progress to date. The original mechanic had no clue and basically lied about what was wrong with the vehicle. He went so far as to say the engine was shot and I knew it wasn't. I found a new mechanic who has been diligently working on the car from top to bottom. Here's a pretty accurate list of work completed:
Compression tested out at approximately 110psi at each of the cylinders
Smoke test indicated vac leaks at the oil cap and valve covers --- repaired and retested
Throttle valve switch was cleaned and adjusted
Replaced the coil
Replaced the cylinder head temp sensor
Replaced spark plug wires, points, condenser, cap and plugs
Checked dwell and points
Adjusted valves
Rechecked double relay and found broken / overheated pin 88Y. Replaced with spare.
Cleaned the ground strap
Replaced the ECU with a spare and will retest original to see if it still works...may have misspoken about it being fried
Discovered distributor shaft end play in excess of 0.02 in. causing wander in dwell and erratic timing pulse when setting timing.
To purchase a rebuilt distributor
Hoping this extensive work results in my car returning to its original running condition.
I appreciate all of the input and suggestions during this journey.

[Superhawk996]

Given you had a worn distributor is there a reason you wanted to stay with rebuilt stock instead of going to a new 123 distributor?

The thing that bothers me here is your last update was
UPDATE: Well, the car finally was running better in the shop but then died when the car was taken for a test drive

This really doesn’t align with the bad distributor theory as a bad distributor doesn’t usually work then stop during a test drive. Usually when you get those kind of died instantly while driving failures, it’s electrical in nature.

As Wonki suggested, that could extend all the way into the ECU not failing until hot. You may want to reach out to @jeffbowlsby - at one time he was offering a test service of ECU’s in car and with the ECU test equipment but that may have been D-jet only ?

You’ve had a lot of parts swapped but I’m still not getting the sense that you have a mechanic that really understands L-jet. Could just be that you’ve had multiple problems masking other problems. (IMG:style_emoticons/default/confused24.gif)

I wish I had a better suggestion for you but there’s just too many questions I have that can’t easily be answered 2nd hand not knowing what he’s tested electrically and how he tested it.

Maybe Wonkipop has better suggestions - I’m not an L-jet guy and he is.

[fiacra]

I can't believe this saga took yet another turn. Hoping replacing the distributor FINALLY does it, but I'm not convinced yet. If you really want to stick with a stock distributor you can see if Bill at Sparxwerks has one in stock. If not, he can rebuild yours. Turnaround was quick for my distributor. I too would put in a vote for a 123 distributor. It makes sense if you already have to replace/rebuild the distributor.

At this point Gary I don't know what to say other than I admire your tenacity, and pity your bank account. I know it's a full day's drive away, but maybe rent a U-Haul car hauler, borrow a friend's truck, and put your car in the hands of the experts at PMB.

[nmkimosabe]

Given you had a worn distributor is there a reason you wanted to stay with rebuilt stock instead of going to a new 123 distributor?

The thing that bothers me here is your last update was
UPDATE: Well, the car finally was running better in the shop but then died when the car was taken for a test drive

This really doesn’t align with the bad distributor theory as a bad distributor doesn’t usually work then stop during a test drive. Usually when you get those kind of died instantly while driving failures, it’s electrical in nature.

As Wonki suggested, that could extend all the way into the ECU not failing until hot. You may want to reach out to @jeffbowlsby - at one time he was offering a test service of ECU’s in car and with the ECU test equipment but that may have been D-jet only ?

You’ve had a lot of parts swapped but I’m still not getting the sense that you have a mechanic that really understands L-jet. Could just be that you’ve had multiple problems masking other problems. (IMG:style_emoticons/default/confused24.gif)

I wish I had a better suggestion for you but there’s just too many questions I have that can’t easily be answered 2nd hand not knowing what he’s tested electrically and how he tested it.

Maybe Wonkipop has better suggestions - I’m not an L-jet guy and he is.

I appreciate you taking the time to respond. The mechanic now believes the electrical issue when the car died was possibly the burnt 88Y pin on the dual relay which was later switched. I've been as methodical and thorough throughout this process, and it has been quite aggravating. I've had many vintage Porsche's and never experienced this level of frustration. Stay tuned for an update this week.

[nmkimosabe]

I can't believe this saga took yet another turn. Hoping replacing the distributor FINALLY does it, but I'm not convinced yet. If you really want to stick with a stock distributor you can see if Bill at Sparxwerks has one in stock. If not, he can rebuild yours. Turnaround was quick for my distributor. I too would put in a vote for a 123 distributor. It makes sense if you already have to replace/rebuild the distributor.

At this point Gary I don't know what to say other than I admire your tenacity, and pity your bank account. I know it's a full day's drive away, but maybe rent a U-Haul car hauler, borrow a friend's truck, and put your car in the hands of the experts at PMB.

Thanks for the continuing moral support and I think (hope) we are close!

[wonkipop]

Given you had a worn distributor is there a reason you wanted to stay with rebuilt stock instead of going to a new 123 distributor?

The thing that bothers me here is your last update was
UPDATE: Well, the car finally was running better in the shop but then died when the car was taken for a test drive

This really doesn’t align with the bad distributor theory as a bad distributor doesn’t usually work then stop during a test drive. Usually when you get those kind of died instantly while driving failures, it’s electrical in nature.

As Wonki suggested, that could extend all the way into the ECU not failing until hot. You may want to reach out to @jeffbowlsby - at one time he was offering a test service of ECU’s in car and with the ECU test equipment but that may have been D-jet only ?

You’ve had a lot of parts swapped but I’m still not getting the sense that you have a mechanic that really understands L-jet. Could just be that you’ve had multiple problems masking other problems. (IMG:style_emoticons/default/confused24.gif)

I wish I had a better suggestion for you but there’s just too many questions I have that can’t easily be answered 2nd hand not knowing what he’s tested electrically and how he tested it.

Maybe Wonkipop has better suggestions - I’m not an L-jet guy and he is.

I appreciate you taking the time to respond. The mechanic now believes the electrical issue when the car died was possibly the burnt 88Y pin on the dual relay which was later switched. I've been as methodical and thorough throughout this process, and it has been quite aggravating. I've had many vintage Porsche's and never experienced this level of frustration. Stay tuned for an update this week.

yeah well, the dual relay is real important for having the fuel pump work in an L jet.
so........
lets see.

i can tell you another interesting story about "ECU"s.
going back 25+ years ago, and being an early adopter of CAD (thanks to my time in chicago, (IMG:style_emoticons/default/beerchug.gif) thank you america) i had a hot rodded 486 i ran my drafting and modelling software on. and one day it (IMG:style_emoticons/default/stromberg.gif) itself. i came in the office and fired it up and it ran for about 10 minutes. then kaput. if i remember right i went out for a coffee and cig or three and came back and switched it back on. fired up. ran for 10 minutes. kaput again. sat down and thought about it. right. somethings getting hot and when its up to temp is when if fails. rang my computer tach man nerd at that time. the late 90s were great. nerds door to door. he came and picked up the box and threw it in his ute and took it home. ripped it apart. found the crack in the circuit board. i said great. i have forgotten to back up for a fortnight or two and i have a masterpiece or three on it i need to retrieve. "no worries". he set the box up on his back verandah outside over night with a hard drive to down load all the data and fired it up first thing the next morning and before it could get hot enough to die he managed to get all the data off it. saved our arses. but not our bank account as we had to get a new machine. forced us to get a pentium. (IMG:style_emoticons/default/biggrin.gif)

moral of the story. if it runs and idles well etc but then when you head out the door and get 10 minutes down the road and it dies well.............and its an EFI system from half a century ago, you got to suspect some thing electrical.

and start testing and diagnosing. and resist spraying it with parts machine gun.

i hope this is the end of your troubles.
very frustrating as you say.

however - i would say this, L jet is very very simple and honestly not hard to get to the bottom of, if you get your brain into what it is. its a fairly limited set of things that can go wrong.

[fiacra]

It's funny how things always seem to circle back to the L-Jet dual relay. Having a spare one with you at all times is a good idea. I think you already have an extra one Gary but if you are in urgent need just let me know. They are often scarce, but still available. CIP1 is out of stock, but JBugs and FCP Euro still shows them as available. FCP Euro currently has the best price. I can no longer get them from my supplier in Europe.

I will also add that if you have a gremlin infestation in your L-Jet electrical system then having Jeff go through your FI harness or having him make a new one for you is a worthy investment. These >50 year old harnesses, especially the wiring exposed to the heat in the engine bay, can cause all kinds of hard to diagnose problems. I know it's an investment to get a new harness, but Jeff's work is top notch and I wouldn't hesitate to do it. I know that your mechanic thinks the FI harness is OK, but think of replacing the harness as a maintenance item at this stage in the life of your car. Given the work that I know you have personally done on this car, replacing the harness is well within your skill set. If electrical items are frying, who knows what is going on in the harness.

[nmkimosabe]

Given you had a worn distributor is there a reason you wanted to stay with rebuilt stock instead of going to a new 123 distributor?

The thing that bothers me here is your last update was
UPDATE: Well, the car finally was running better in the shop but then died when the car was taken for a test drive

This really doesn’t align with the bad distributor theory as a bad distributor doesn’t usually work then stop during a test drive. Usually when you get those kind of died instantly while driving failures, it’s electrical in nature.

As Wonki suggested, that could extend all the way into the ECU not failing until hot. You may want to reach out to @jeffbowlsby - at one time he was offering a test service of ECU’s in car and with the ECU test equipment but that may have been D-jet only ?

You’ve had a lot of parts swapped but I’m still not getting the sense that you have a mechanic that really understands L-jet. Could just be that you’ve had multiple problems masking other problems. (IMG:style_emoticons/default/confused24.gif)

I wish I had a better suggestion for you but there’s just too many questions I have that can’t easily be answered 2nd hand not knowing what he’s tested electrically and how he tested it.

Maybe Wonkipop has better suggestions - I’m not an L-jet guy and he is.

I appreciate you taking the time to respond. The mechanic now believes the electrical issue when the car died was possibly the burnt 88Y pin on the dual relay which was later switched. I've been as methodical and thorough throughout this process, and it has been quite aggravating. I've had many vintage Porsche's and never experienced this level of frustration. Stay tuned for an update this week.

yeah well, the dual relay is real important for having the fuel pump work in an L jet.
so........
lets see.

i can tell you another interesting story about "ECU"s.
going back 25+ years ago, and being an early adopter of CAD (thanks to my time in chicago, (IMG:style_emoticons/default/beerchug.gif) thank you america) i had a hot rodded 486 i ran my drafting and modelling software on. and one day it (IMG:style_emoticons/default/stromberg.gif) itself. i came in the office and fired it up and it ran for about 10 minutes. then kaput. if i remember right i went out for a coffee and cig or three and came back and switched it back on. fired up. ran for 10 minutes. kaput again. sat down and thought about it. right. somethings getting hot and when its up to temp is when if fails. rang my computer tach man nerd at that time. the late 90s were great. nerds door to door. he came and picked up the box and threw it in his ute and took it home. ripped it apart. found the crack in the circuit board. i said great. i have forgotten to back up for a fortnight or two and i have a masterpiece or three on it i need to retrieve. "no worries". he set the box up on his back verandah outside over night with a hard drive to down load all the data and fired it up first thing the next morning and before it could get hot enough to die he managed to get all the data off it. saved our arses. but not our bank account as we had to get a new machine. forced us to get a pentium. (IMG:style_emoticons/default/biggrin.gif)

moral of the story. if it runs and idles well etc but then when you head out the door and get 10 minutes down the road and it dies well.............and its an EFI system from half a century ago, you got to suspect some thing electrical.

and start testing and diagnosing. and resist spraying it with parts machine gun.

i hope this is the end of your troubles.
very frustrating as you say.

however - i would say this, L jet is very very simple and honestly not hard to get to the bottom of, if you get your brain into what it is. its a fairly limited set of things that can go wrong.

I love your story about the hot -rodded 486 and I have similar memories of those and the IT nerds running around the company offices. I would agree that L-jet seems like a simple system once you figure it out, but it does require a learning curve to understand it fully and how all the components work together. Of course, what doesn't.
I'm curious as to why you live in Antartica?

[nmkimosabe]

It's funny how things always seem to circle back to the L-Jet dual relay. Having a spare one with you at all times is a good idea. I think you already have an extra one Gary but if you are in urgent need just let me know. They are often scarce, but still available. CIP1 is out of stock, but JBugs and FCP Euro still shows them as available. FCP Euro currently has the best price. I can no longer get them from my supplier in Europe.

I will also add that if you have a gremlin infestation in your L-Jet electrical system then having Jeff go through your FI harness or having him make a new one for you is a worthy investment. These >50 year old harnesses, especially the wiring exposed to the heat in the engine bay, can cause all kinds of hard to diagnose problems. I know it's an investment to get a new harness, but Jeff's work is top notch and I wouldn't hesitate to do it. I know that your mechanic thinks the FI harness is OK, but think of replacing the harness as a maintenance item at this stage in the life of your car. Given the work that I know you have personally done on this car, replacing the harness is well within your skill set. If electrical items are frying, who knows what is going on in the harness.

Thanks for the offer of the dual relay but fortunately I had a spare probably because you told me months ago to have one just in case! Guess i need to get another one as my spare is now being used. I spoke with Jeff awhile back and once I get my car back, I think the next thing I will do is replace the wiring harness. I need to some research about installing one first. Looking at the harnesses on Jeff's site it doesn't look too difficult if one pays attention. Have a good weekend.

[wonkipop]

[quote name='nmkimosabe' date='Aug 29 2026, 12:02 PM' post='3270040']
[quote name='wonkipop' post='3270009' date='Aug 29 2026, 05:06 AM']
[quote name='nmkimosabe' post='3269962' date='Aug 28 2026, 04:26 PM']
[quote name='Superhawk996' post='3269857' date='Aug 27 2026, 07:08 PM']


[/quote]

I love your story about the hot -rodded 486 and I have similar memories of those and the IT nerds running around the company offices. I would agree that L-jet seems like a simple system once you figure it out, but it does require a learning curve to understand it fully and how all the components work together. Of course, what doesn't.
I'm curious as to why you live in Antartica?
[/quote]


(IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif)
north antarctica.
an internationally irrelevant island continent off the coast of antarctica on the edge of the southern ocean.
i live in the post industrial resort town of melbourne - thats mell bun not mel born.
antarctic research staff take their summer breaks here.

where the factory was that the first car in antartica was made.
sadly the old VW factory was pulled down last year.
i think someone managed to get the famous sign - a giant VW emblem.
it was lying on the ground at one stage.
i thought about it but decided it was a little large to fit on the garage wall.