D-Jet Conversion not going as planned., Car starts but will not run. Options

[slapshot]

Thanks to all that contributed. It sure is great to have so many people willing to help. (IMG:style_emoticons/default/beerchug.gif)

I'm still working on getting it to idle at the correct RPM. I need to dial in the nob on the ECU. Cylinder 1 plug shows I'm running rich.

Tangerine directions

Do you have the disassembly instructions?

[emerygt350]

Now you can get down to the fun of d-jet. Set your timing now that it's running.

What you want to do then is reduce all vacuum hoses to only the necessary (mps, aar). When the car is cold the aar should put it around 1600rpm. As it heats and the aar closes it should drop to 900. If it isn't than you have a vacuum leak somewhere and or your timing is too advanced.

Common leaks are the various hoses of course, the plenum, the plenum runner sleeves, and the injectors. The intake gaskets can also leak of course. I like carb cleaner to chase leaks, many others here like smoke machines.

[FlacaProductions]

I've read that "canned air" (Dust-Off for cleaning out computer keyboards) is a good, non-messy way to chase vacuum leaks.
It uses a refrigerant that doesnt burn well....spray at things...if the idle drops....BINGO!

the can even has a little straw so you can get real close without getting real close....

its dry too, no wet anything....

[JamesM]

How sensitive is that inner screw? If I move it could it cause damage to the engine?

No more than risk of that than where you are currently.

But fiddling with the MPS wont get you a known good MPS, it will just potentially get you closer (or might do nothing at all)

Save time and start with a known good, calibrated, tested MPS.

[brant]

Agreed

Don’t touch the MPs any more until you have a wide band AFR

Really hard to set them correct
Really really really easy to mess up the settings

[rjames]

You can make a cheap homemade smoke 'machine' very easily that will be more accurate than spraying canned air. Do this before moving to the MPS.
And if you have to move the to MPS, yes, you'll need a wide-band AFR to set it correctly for YOUR car. Even if someone were to calibrate an MPS for you, unless they did so while it was installed in your car and reading the AFR, it likely won't be set correctly for your engine.


Also, do you know if they changed the cam on your car when they ditched the FI for carbs?

[brant]

Did you set the timing with a strobe light yet?

Also with the distributor vacuum line removed?

Otherwise you high idle is just the timing

Set all the basics again before touching anything

[JeffBowlsby]

Even if someone were to calibrate an MPS for you, unless they did so while it was installed in your car and reading the AFR, it likely won't be set correctly for your engine.

^^^THIS.

So often overlooked. No two engines are alike in terms of wear and therefore fuel needs. I have documented multiple NOS MPSs of the same part numbers and are calibrated similarly, but differently, and small variations matter as the calibration is sensitive. Best way is to tune it to your specific engine with an engine dyno, EGA analyzer or WBO2 sensor.

[slapshot]

I have a smoke box and pushed smoke through it today. Found that the intake to 3 and 4 were leaking between the head and air intake bad. I had a new gasket and fix it. I need to do a better job making the top of throttle body air tight. There was too much smoke coming out of it for me to tell if there were leaks around it.

I haven't set the timing yet. Thanks Brant for reminding me that I need to disconnect the vacuum.

I have opened the MPS a couple times but I haven't touched the adjustment screws yet. I do want to put a new paper gasket in it to fix the leak but I don't know how to disassemble it to remove that diaphragm and if it can be done without moving the adjustment screws.

[emerygt350]

You can do that without moving the screws. It really is super simple. Tangerine racing has a little instruction sheet Chris ships with his kit. Perhaps ask him for a copy? It really is so simple you don't need it but you will eventually want the tool, so maybe buy the tool and get the instructions?

[slapshot]

Also, do you know if they changed the cam on your car when they ditched the FI for carbs?

The previous owner does not know if they changed it when he switched to carbs. He had it done back in the 80s.

[slapshot]

You can do that without moving the screws. It really is super simple. Tangerine racing has a little instruction sheet Chris ships with his kit. Perhaps ask him for a copy? It really is so simple you don't need it but you will eventually want the tool, so maybe buy the tool and get the instructions?

I requested the instructions. Is it as simple as just pushing on the inner screw to pop the diaphragm out?

[brant]

I would get the tuned first

You can’t expect it to give you baseline until everything is set

But I would use blue hylomar on the MPS gasket
Have done so before
It’s non hardening but creates a seal

[rjames]

You can do that without moving the screws. It really is super simple. Tangerine racing has a little instruction sheet Chris ships with his kit. Perhaps ask him for a copy? It really is so simple you don't need it but you will eventually want the tool, so maybe buy the tool and get the instructions?

I requested the instructions. Is it as simple as just pushing on the inner screw to pop the diaphragm out?

After you open the MPS there are 4 screws that hold the diaphragm in place. Once you remove those screws, the diaphragm will be loose and will drop out into your hand.
Replacing the gasket (or cleaning it up and trying to reseal it) doesn't require touching the adjustment screws at all.

In depth info that covers 95% of everything you could ever hope to know about the MPS can be found here.

[slapshot]

After you open the MPS there are 4 screws that hold the diaphragm in place. Once you remove those screws, the diaphragm will be loose and will drop out into your hand.
Replacing the gasket (or cleaning it up and trying to reseal it) doesn't require touching the adjustment screws at all.

In depth info that covers 95% of everything you could ever hope to know about the MPS can be found here.

Good to know. Mine wasn't loose and with my nail the retaining washer didn't want to come out. I stopped there not wanting to damage it.

[emerygt350]

After you open the MPS there are 4 screws that hold the diaphragm in place. Once you remove those screws, the diaphragm will be loose and will drop out into your hand.
Replacing the gasket (or cleaning it up and trying to reseal it) doesn't require touching the adjustment screws at all.

In depth info that covers 95% of everything you could ever hope to know about the MPS can be found here.

Good to know. Mine wasn't loose and with my nail the retaining washer didn't want to come out. I stopped there not wanting to damage it.

Wait for the instructions... Pbanders site linked above is good too but probably more than you need at the moment.

[slapshot]

With the smoke test, I get smoke coming out each side of the throttle shaft. Is there a bushing kit for this? Is it rebuildable or can I pack with grease?

[brant]

It’s rebuildable
But no kit
A difficult job with custom sized bushing and often involves cleaning the bore of the throttle body ID. Then making a custom sized throttle plate to fit the new ID

A job best left for a rebuilder/machinist to do

[emerygt350]

It’s rebuildable
But no kit
A difficult job with custom sized bushing and often involves cleaning the bore of the throttle body ID. Then making a custom sized throttle plate to fit the new ID

A job best left for a rebuilder/machinist to do

I sent mine off to be rebuilt by a member here. Turned out very nice. If you are interested I can pm the info. Normally the shafts don't leak much and won't affect anything until you get picky about fine tuning so you may want to leave that job for later.

On a d-jet it's all about controlled vacuum leaks. Your idle adjustment screw on the throttle body can compensate for the air coming in around the throttle shaft for the time being.

[slapshot]

Now the BIG issue. I am working on setting the timing. Remember that I started with a great running car with carbs that I did all the work to get it working good, did all the carb tuning, installed and setup new 123 dist, etc. So its this isn't my first time. I set TDC based on plug 1 on the rotor, follow the instructions from 123 website, set app to 20 deg for all RPMs, try to start the car but it wont start. I guess I had the dist too loose and it slid up and out of the groove so the rotor wasn't turning. Here's where it all goes bad. I set TDC and verify by using a leak down test (easier than removing the valve covers) to verify the valves are both closed. The issue is TDC for #1 is about 180 degrees off what it was before. I have double, triple, quadrupled checked this and pulled the valve cover off to verify the valves are loose. What am I missing here? Is it possible that the dist gear moved? The dist didn't pop out of its hole that I know it just slid up a bit. Could the 123 internal drive slipped? Could I have had it wrong with the carb and ran it all summer? I think I've lost my mind.