‘74 1.8L L-Jetronic Cold Start Low Idle, Mystery solved! Options

[Van B]

Well, emissions sticker is there… its also gone forever. It was sprayed over when new with corrosion protection. So, not likely it would survive any attempt to reveal it.
Engine number is EC008741, but that’s the best I got. Other than it’s a US spec with the low compression pistons that provide a whopping 76hp/91ft lbs… to the crank.

[wonkipop]

@wonkipop retarding further is just sparking later and sending the exhaust out while it’s still burning.
Also, there’s no mechanical difference between blocking both the advance and retard distributor port or leaving them open to atmosphere. Either way neutralizes them. But blocking does ensure nothing gets in the port. However, I think you would want to block the port on the TB to avoid air leak.

Testing your cold start theory wouldn’t be hard. But it would be time consuming given the need for a cold engine. You would have to start the car, get it warm, pull the retard port, set air screw for correct warm idle, pinch/block line from TB, and confirm timing is correct. Then, stare at the car outside in the cold for several hours while you wait for it to cool down completely*, and start it again to see what happens.

I’ll try it tomorrow and report back.

*or go do something else

was thinking plugging the hose so it does not leak air into the throttle body.
you pull the lines off the distributor end to take the distributor out of the equation.
as you say the ports don't need the blocking, its the hose. you leave the hose on the throttle body ports.

i think all that would happen is the car will start just fine and theoretically should idle faster. a quick experiment is what i was thinking. then just put the line back on the distributor when finished. the retard is not there at fire up, it starts on 7.5 btdc regardless of hose on or off, vacuum kicks in shortly or immediately there after. so just go out there when its cold, pull the line off the dist. plug it. fire it up and see what happens.

thanks for explanation re hot exhaust. now i get it.

[wonkipop]

Well, emissions sticker is there… its also gone forever. It was sprayed over when new with corrosion protection. So, not likely it would survive any attempt to reveal it.
Engine number is EC008741, but that’s the best I got. Other than it’s a US spec with the low compression pistons that provide a whopping 76hp/91ft lbs… to the crank.

sounds like an owner/dealer that knew about the dreaded battery/hell hole corrosion problem even in 1974 and did some proactive work!? (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/beerchug.gif)

never mind.

there is one more thing you can look for when you get a moment.
these engines get white stamped numbers on their tin ware.
the number ought to still be there with a bit of luck.
if you look down on lhs side of engine between the air cleaner and the heater fan you might be able to see it. might be either 604 or 605. or it could be some other number.
its down near the snap in cover for the alternator adjustment hole.

there is a chance its on the right hand side of the tin near the battery. but more likely its on the left hand side.

there is one other thing you can look for which is the little white tuning sticker.
usually on tin on top of engine on left hand side. it might not be there any more.
fairly fragile. if it is there take a snap of it and post it up.

thanks for all the info so far. its fairly useful. trying to work out why there was an EC-A engine that had california and 49 states and then there was also an EC-B engine with the same. starbear and i have the EC-B one.
and then there is also an EC-B which had only 49 state. its fairly weird what was going on. we are trying to work out what the differences were. don't think we can ever work out the why!

yeah - the horsepower from these engines is frightening. (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/beer.gif)
i took mine out for a run this morning. hit the streets early before the post lockdown zombies got on the roads. went for a run down by the docks and opened her up.
acceleration almost made my head move but maybe it was the gear changes.
i'm trying out one more theory with mine which is the gas might have gone off.
we have been restricted/locked down here so i've basically had 3/4 of a tank of gas in it for the last 4-5 months i've slowly used (i've lost track of time!) and i am wondering whether the octane has dropped. it can happen.
i will see what a cold start next weekend is like on some topped up fresh gas?

[ClayPerrine]

I haven't looked at the availability of the Datsun stuff in a long time. Sorry.

But I do know there were a lot more Datsuns made with L-Jet than 914s. So the wrecking yards should have some of them.

Clay

[StarBear]

@Van B

yours is the splitting image of the setup on mine. (IMG:style_emoticons/default/beerchug.gif)

@Van B if you want/need a new tune up sticker (on the tin to the left of the oil filler neck I made some reproductions. PM me and I’ll mail one to you. ps: my car was produced 11/73 and has a 605 engine tin stamp; wonkipop car produced 1/74 and has a 604 tin stamp. There’s a current thread on this topic too.
@wonkipop if the photos are of your engine looks like your sticker has cracked/flaked. I think I sent you one or two some months ago?
(IMG:style_emoticons/default/beer3.gif) (IMG:style_emoticons/default/driving.gif)

[Van B]

I’m gonna say it says 604. I almost lost what was left by wiping it lol.

Oh and @starbear I would love to have a sticker! Someday soon, I want to restore this engine and make it look all clean and new again

[StarBear]

I’m gonna say it says 604. I almost lost what was left by wiping it lol.

Oh and @starbear I would love to have a sticker! Someday soon, I want to restore this engine and make it look all clean and new again

Yep; looks like 604 to me. Consistent with wonki’s.
For the sticker just pm me with your mail address. Will mail you one. (IMG:style_emoticons/default/piratenanner.gif)

[wonkipop]

@Van B

yours is the splitting image of the setup on mine. (IMG:style_emoticons/default/beerchug.gif)

@Van B if you want/need a new tune up sticker (on the tin to the left of the oil filler neck I made some reproductions. PM me and I’ll mail one to you. ps: my car was produced 11/73 and has a 605 engine tin stamp; wonkipop car produced 1/74 and has a 604 tin stamp. There’s a current thread on this topic too.
@wonkipop if the photos are of your engine looks like your sticker has cracked/flaked. I think I sent you one or two some months ago?
(IMG:style_emoticons/default/beer3.gif) (IMG:style_emoticons/default/driving.gif)

(IMG:style_emoticons/default/behead.gif)
(IMG:style_emoticons/default/whack_3.gif)
i do have to put that sticker in.

[wonkipop]

calling all 74 1.8 owners reading this thread.


wonki + starbear are trying to work out some history stuff for mr b (jeff bowlsby).
(because 74 1.8s are the best 914s right? (IMG:style_emoticons/default/driving.gif) )

if the info is still on your car this is what we need.
cars have to be unmodified and reasonably original (don't have to be in show condition, need to be unmolested).

1. Vin date.
2. engine bay emission sticker (image).
3. engine tune up sticker (image).
4. painted number on engine if its still there (image if you can).
5. distributor vacuum hose set up from dist to throttle body (image).
6. part number on the throttle body if you can read it. (image of TB).

thanks - keep those 1.8s going. (IMG:style_emoticons/default/driving.gif)

[Van B]

@wonkipop
I did your experiment today and here’s what I found:

-marginally improved kickover
—initial RPMs surged a little higher (900-1000RPM)
—seemed to start quicker
-warmup idle still sluggish (700RPM)
-off idle and low RPM throttle response did improve
—liked the improvement enough I think I will leave it for a while

Also, I have my idle set for 850 RPM

[wonkipop]

@wonkipop
I did your experiment today and here’s what I found:

-marginally improved kickover
—initial RPMs surged a little higher (900-1000RPM)
—seemed to start quicker
-warmup idle still sluggish (700RPM)
-off idle and low RPM throttle response did improve
—liked the improvement enough I think I will leave it for a while

Also, I have my idle set for 850 RPM

i got the thought from vw porsche themselves.
they had two versions of the 50 state 1.8 floating around in 74.
one of them did not use the retard plumbing on the dist/TB.

did not even know there was that second version until i started doing some digging on a question for mr. b.

don't know the why of it, when the different versions kicked in or anything about it much other than there were two versions. (at least).

far as i can tell the difference was they either introduced or abandoned retarded idle.

i would have thought they needed the retarded idle for california - period.
it had harsher NOx standards in 74 than the 49 states.
but it turns out even that logic does not hold as unretarded idle versions have cali certification. and i have worked out the example in question that demonstrates that is unmolested, unchanged and the way it came. the tune up sticker proved it.

(IMG:style_emoticons/default/confused24.gif)

main thing is it worked for you. to some extent. (IMG:style_emoticons/default/beerchug.gif)

thats why starbear and i are after that information listed above from owners.
its fairly interesting in the context of L jet and its introduction.
914s and 412s being the first cars anywhere to get it.

[L-Jet914]

calling all 74 1.8 owners reading this thread.


wonki + starbear are trying to work out some history stuff for mr b (jeff bowlsby).
(because 74 1.8s are the best 914s right? (IMG:style_emoticons/default/driving.gif) )

if the info is still on your car this is what we need.
cars have to be unmodified and reasonably original (don't have to be in show condition, need to be unmolested).

1. Vin date.
2. engine bay emission sticker (image).
3. engine tune up sticker (image).
4. painted number on engine if its still there (image if you can).
5. distributor vacuum hose set up from dist to throttle body (image).
6. part number on the throttle body if you can read it. (image of TB).

thanks - keep those 1.8s going. (IMG:style_emoticons/default/driving.gif)

By VIN date do you mean production date?

[L-Jet914]

Well, emissions sticker is there… its also gone forever. It was sprayed over when new with corrosion protection. So, not likely it would survive any attempt to reveal it.
Engine number is EC008741, but that’s the best I got. Other than it’s a US spec with the low compression pistons that provide a whopping 76hp/91ft lbs… to the crank.

My emission sticker on my (my father's) 74 had some overspray from a trunk hinge repair done before my time. I used isopropyl alcohol on a q-tip to remove the overspray paint and it removed the paint and didn't harm the sticker. I learned the trick from a friend of mine.

[Van B]

Yeah, this is 48yr old ziebart rustproofing… it ain’t coming off.

[L-Jet914]

Yeah, this is 48yr old ziebart rustproofing… it ain’t coming off.

Ah okay. No worries. I didn't know it was undercoating/rustproofing.

[wonkipop]

Yeah, this is 48yr old ziebart rustproofing… it ain’t coming off.

extreme hell hole paranoia - and in 1974! ha. (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/av-943.gif)

[wonkipop]

calling all 74 1.8 owners reading this thread.


wonki + starbear are trying to work out some history stuff for mr b (jeff bowlsby).
(because 74 1.8s are the best 914s right? (IMG:style_emoticons/default/driving.gif) )

if the info is still on your car this is what we need.
cars have to be unmodified and reasonably original (don't have to be in show condition, need to be unmolested).

1. Vin date.
2. engine bay emission sticker (image).
3. engine tune up sticker (image).
4. painted number on engine if its still there (image if you can).
5. distributor vacuum hose set up from dist to throttle body (image).
6. part number on the throttle body if you can read it. (image of TB).

thanks - keep those 1.8s going. (IMG:style_emoticons/default/driving.gif)

By VIN date do you mean production date?

well both if you can work it out.
the date on the vin sticker.
and if you have your karmann # by all means.
(IMG:style_emoticons/default/beerchug.gif)

EDIT
its great you got your dad's car.
(IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)

[Van B]

@wonkipop
I did your experiment today and here’s what I found:

-marginally improved kickover
—initial RPMs surged a little higher (900-1000RPM)
—seemed to start quicker
-warmup idle still sluggish (700RPM)
-off idle and low RPM throttle response did improve
—liked the improvement enough I think I will leave it for a while

Also, I have my idle set for 850 RPM

Alright…. That didn’t work. I guess the car wasn’t really cold when I tried it the other day. But today the car didn’t even try to start and then became instantly flooded. Total shitshow! Theeennnn I realized that even when I tighten the distributor, it can still move enough to alter timing slightly if it’s bumped or nudged.

Oh and the seatbelt interlock started messing up and so I had to fix that before I could continue on setting the car back to the way it was.

Bottom line: leave the hoses on.

[wonkipop]

@wonkipop
I did your experiment today and here’s what I found:

-marginally improved kickover
—initial RPMs surged a little higher (900-1000RPM)
—seemed to start quicker
-warmup idle still sluggish (700RPM)
-off idle and low RPM throttle response did improve
—liked the improvement enough I think I will leave it for a while

Also, I have my idle set for 850 RPM

Alright…. That didn’t work. I guess the car wasn’t really cold when I tried it the other day. But today the car didn’t even try to start and then became instantly flooded. Total shitshow! Theeennnn I realized that even when I tighten the distributor, it can still move enough to alter timing slightly if it’s bumped or nudged.

Oh and the seatbelt interlock started messing up and so I had to fix that before I could continue on setting the car back to the way it was.

Bottom line: leave the hoses on.

(IMG:style_emoticons/default/biggrin.gif)

ah well
good thing you are the guinea pig before i go in mucking about in a month or so. (IMG:style_emoticons/default/beerchug.gif)

---

that fugen seat belt interlock screwed with me 30 years ago.

there was a relay still in the circuit under the passenger seat.
there wasn't one anymore after i got through with it.

[wonkipop]

@Van B

attached the definitive on how the cold start valve works.
your observation it only opens during cranking 100% right.



i found some more from same source regarding AAV being responsible in the main for fast idle warm up. i'm favouring my mechanic's instinct that its the AAR closing too fast in the case of my car for the idle stumble. link to source.

http://www.914world.com/bbs2/index.php?aut...;showentry=2520