Engine first start attempt., Couple vacuum leaks, Finally adustable idle. Options

[VaccaRabite]

Do the Cam break in before you run the engine too much more. You want the engine turning about 2.5 - 3K for that anyway (IIRC).

Jake used to say to the do that cam break in the first time you got the engine to fire. As soon as you got it running just break in the cam then and there.

Zach

[Olympic 914]

Do the Cam break in before you run the engine too much more. You want the engine turning about 2.5 - 3K for that anyway (IIRC).

Jake used to say to the do that cam break in the first time you got the engine to fire. As soon as you got it running just break in the cam then and there.

Zach

That was my original plan. but with the RPMs being uncontrollable and not knowing whether it was running too lean or what, I didn't want to melt the heads or seize the KB pistons.

As it was the paint was cooking off of the Triad muffler.

The rpm I remember seeing was 2000 rpm for the cam break-in, and I couldn't get the engine down to that number.

I don't have a head temp gauge right now nor do I have a AFR. gauge.

Jake has a shop full of gauges and tools and would be better able to tell if something bad was happening and shut it off before it destructed the engine. If the engine had only required a few adjustments I would have continued with the cam break-in.

I do have a Autometer wideband AFR coming in the mail in a day or two. (maybe today!) and also a Dakota digital head temp gauge, probably in a week or so. once these are installed and I can see what is really happening I will complete the cam break-in.

Its not like I will be sitting around twiddling my thumbs as I wait on parts. I just got the new condenser and rev-limiting rotor yesterday and will be again pulling the distributor to install these, check for free movement of the advance plates and do a static set on the timing.

Thanks for all your suggestions,

[jcd914]

Zach is right do the cam break in.
3000 rpm for cam break in is fine.
20 minutes running lean with no load at 3000 rpm is fine.

Not getting the cam broken right away is bad in the long run.

It is the starting the engine that is the hardest on the cam, so each time you stop to restart to test something else you are risking the life span of your cam and lifters.

Jim

[gereed75]

I have had a very bad experience doing a static 2000 rpm cam break in for 20 minutes. Engine temps can get very hot doing this. If you are committed to doing it static, I would recommend several shorter periods while monitoring engine temps carefully. Maybe four five minute periods with a cool down in between.

Flame suit on.

Good luck with troubleshooting.

[ChrisFoley]

And I sanded and painted the plenum myself, So should not be any holes rusted through.

The problem with 2L plenums isn't rust holes. Stress cracks can form on the underside, especially around one of the tubular reinforcements.
Such stress cracks may be nearly invisible even after sanding, and only open up under high manifold vacuum.

[ChrisFoley]

We always do cam break-in with carbs unless the FI setup was working on the same engine before the rebuild.
Diagnosing FI faults while trying to break in the camshaft can be disastrous.

[gereed75]

Interesting Chris. If I understand you correctly you mount carbs to run the engine for the breakin and then mount the unknown FI and do the final tune??

What procedure do you use for the actual cam run in to avoid the heat of just having the car set there and run with minimal airflow?? Thanks

[ChrisFoley]

Interesting Chris. If I understand you correctly you mount carbs to run the engine for the breakin and then mount the unknown FI and do the final tune??

Yes, that way I know I can get the engine running quickly, check for oil leaks, get the timing close, and do the cam break-in without delays or letting the engine idle for any length of time.
I prefer not to start/stop the engine more than 2 or 3 times before setting the rpm up to 2500 and let it go for 20+ minutes.
I can set the rpm with the idle speed screws so I don't have to hold the throttle myself.
It's not important if the mixture is less than ideal as long as its not so rich or so lean to have trouble running. Without any load it takes very little energy to hold the elevated rpm.

What procedure do you use for the actual cam run in to avoid the heat of just having the car set there and run with minimal airflow?? Thanks

The oil gets hot but the engine doesn't overheat. It's not working hard enough to really get the heads that hot, and the fan is spinning fast enough to remove that much heat effectively.

[Dave_Darling]

3,000 RPM is a vacuum leak. A pretty good sized one. Double-check that all of the fittings on the manifold are plugged when you're doing your "only the MPS" test. No other hoses, no open fittings on the manifold. If you have the head vents plumbed to the manifold, or the oil breather plumbed there, you need to remove those and plug them. (And the head vents should never be hooked up to the manifold anyway.)

And I agree, just run the engine at the 3000 RPM it wants to run for 20 minutes. Then start figuring out what is keeping the idle up.

--DD

[Olympic 914]

Back at it again today.

Pulled the distributor checked that the advance weights were free and moved smoothly. put in the new condenser and rotor. replaced distributor static timed it at the 5 degree mark.

Disconnected and plugged all of the vacuum lines to the plenum except the MPS.

They were both vacuum hoses to the distributor, cold start valve hose that goes to AAR, Line that tees off and goes to the decal valve and the other line to the decal valve.

Turned the key and it started right up, AND again went to 3200 rpm.

Set the timing at the 27 deg mark ( it was only a 5-7 degrees off anyways ) Still running at 3200. since the air filter was off and I could access the throttle body I put my hand over the throttle body and the revs faltered a little but stayed up.

squeezed the hoses on the plenum to see if there was any change, None. Didn't notice any movement on the stubs from the plenum either.

Left it run for about 5 minutes while I did this and then chickened out and shut it down..

Next step is going to be removing the plenum.

Damn, this is frustrating. Looks like I will also need new intake runner hoses since I messed these up a little sliding them back on the intake runners to get them off of the plenum, with a big screwdriver.

[Olympic 914]

Planned on hooking up the Autometer AFR to see what it was doing but they sent me the wrong unit and I have to return it.

So I don't really know what AFR its running at.

[Java2570]

I have the same setup as you do with the cam, heads, etc. When I went to start it last summer, I had the opposite problem of not enough air. I got discouraged and took a bunch of time off from working on it. I'm just now starting back up on getting mine running. I was just curious, since you seem to have a large amount of air getting in, if maybe the MPS is leaking? I think you mentioned that it was a rebuilt unit but I've had a couple I've redone with Tangerine kits start leaking because I didn't seal it well, etc.
Maybe something else to double check anyway.....good luck!

[914_teener]

It is important to know what ecu you have.

Are you saying that you have a 1.7 ecu when you said it ran fine back in 89?

[Olympic 914]

It is important to know what ecu you have.

Are you saying that you have a 1.7 ecu when you said it ran fine back in 89?

Yes


The ECU was the same in 1973 for the 1.7 and the 2.0 it was an 037

The difference was the MPS was a 049 on the 1.7 and a 037 on the 2.0

And the TS2was a 012 on the 1.7 and a (NLA) 017 on the 2.0 with a 270 ohm ballast resistor.

All that being said

I pulled the plenum off and did a quickie plug of all of the holes then sunk it in the laundry tub and put air pressure to it. I did expect to find some leaks around where I duct taped the holes shut but I was looking for a new leak.

And I found it... (IMG:style_emoticons/default/piratenanner.gif)

As others had mentioned it is leaking around one of the tubular supports that go through the middle of the plenum. one of the top ones. I expected to find a gaping crack but until you put air to it you can't see it.

Now I have to figure out how to fix it.. With my welding skills I will probably burn a hole through it so I was thinking either trying to sweat some solder in there or JB weld.
Unless someone has a good 2.0 plenum they would like to offer up...

Of course I will test this one before I put it on...

[ChrisFoley]

I like solder better, but JB weld will work.

[Olympic 914]

Went with the JB weld.

It looks like these plenums were put together with the support pieces being separate and added when the top and bottom of the plenum was welded together. looking inside the support piece you can see a ring about 3/16 - 1/4 down on the tops and bottoms (sorry no picture) mine was leaking from that connection. I cleaned it up with a little stone in the dremel and spread some JB weld around in there. I did both support pieces top and bottom, even though only one was leaking.

This was the culprit




Then got some of those rubber freeze plugs to plug the holes to the intake runners and just used pieces of hose with bolts and such to plug the rest of the vacuum ports.

Then another dunk in the laundry tub of water , putting air pressure to it. NO leaks from the plenum, but a few bubbles from around the bolts I had used to plug the hoses. Then the Duct tape I had used to seal the top blew off of where the throttle body mounts.

This gave me some confidence in the repair, but thought another test was in order. (since I bought those rubber plugs I may as well use them)

Cut a gasket with no hole and bolted the throttle body down to hold it. Then hooked the mity vac pump up and drew 10 in of vacuum.



It held vacuum for over 5 minutes, although it did slowly leak down, probably from one of the numerous plugs and connections I had made.

I am confident enough in this to say it is repaired. In operation this plenum will never be required to hold a sealed vacuum, and the MPS will adjust for any minuscule amount of air that may leak from the various other connections.

It is a lot of extra work but I am happy it isn't something I did wrong when building this engine, OR something that I should have foreseen.

Now I just have to wait on the new gaskets to put everything back together. If it was not for this I believe it would have just started and only required a touch of tuning to run good.

I bought this plenum off of ebay and can only imagine the headache it must have caused the PO, May even have been the reason another teener owner changed over to carbs.

I will update this when everything is back together and thanks to all who made suggestions on things to check.

[Olympic 914]

Back from a little vacation to OBX, my new intake tubes and gaskets were in the mail when I came home.

Put it all back together with the plenum repaired with JB weld I expected the best.

Well, it started right up, and again went to 3000+ (IMG:style_emoticons/default/sad.gif)

But this time I let it run to finish the cam brake in. Set the timer and while it was running I started pulling and plugging vacuum lines again. most had No effect. but when I pulled and plugged the line from the throttle body to the dizzy the rpms increased so I plugged that one back on.

Then I tried spraying starting ether around the connections and noticed a little stumble at the throttle body, I put the new gasket on dry so maybe that was leaking a little. also sprayed around the intake runnners to the head and got a definite stumble on the driver side. I just had that off. maybe the gasket didn't settle right there, Its hard to get to the bottom bolt in the middle.

Also when I depressed the clutch the rpms would go up considerably, So I guess the clutch is releasing, at least.

After 15 min I shut it off and when I went to start it again.... NO buzz from the fuel pump.. (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/ar15.gif)

So of course it won't start now.

Damn this sucks, you would think that I stole a backpack full of rocks from Pele.

Now track down the fuel pump problem.

Checked the easy things first. fuse on relay plate is good and power is there. also switched the relays but fuel pump still doesn't run.

Where does the power come from that runs the pump for a few seconds ??

My fuel pump is front mounted and the wires run through the cabin, so I think I will put a couple spade connecters in line there and run power to the fuel pump to see if it will run. better than pulling the tank.

Then I get to remove the intake system again.

I need a vacation from this thing...

[VaccaRabite]

you can't do it now with a busted fuel pump... After you found the leak in the plenum, did you try covering the throttle body with your hand again? Did that have any effect?

You found a leak on at least one intake runner, and at the throttle body. Both of those make sense, and are easy to fix.

For the throttle body make sure the mating surfaces are CLEAN. You can use a very thin smear of RTV or anaerobic gasket sealer on that seal. Key here is thin. Like the kind of thin that covers the part, but only just covers the part, and does not squish out boogers when you tighten it down. Same with the intake runners, though I suspect a bent runner or plenum pipe is to blame there.

Also, I bet CASH MONEY that you throttle cable is wrapped around your clutch cable, and when you press in the clutch you are also opening your throttle a little. Very common.

Zach

[Dave_Darling]

Agreed with all of the above.

D-jet runs the pump the following way:
The ECU sees the "key is on" signal from the ignition switch, by way of the relay board and the "power supply" relay on the relay board. (See your relay board diagram from Haynes or Pelican for which is which.) When it sees the power go from "off" to "on", it will ground a wire that connects to one of the pins on the fuel pump relay, closing that relay and sending power from a fuse on the relay board to the pump.

So, you need to make sure that the ECU is seeing power. You need to make sure that the correct fuse on the relay board (I forget which but you can trace the circuit on the diagram or just check both) is good. And you need to make sure that the relay closes and that you get power on the pump wires.

And of course, make sure the pump's ground connection is good....

--DD

[Olympic 914]

On the cable issue, normally I would have taken that bet and been counting my money ahead of time, But I thought I better check it anyways.

Well I know the cables were run correctly as I had checked them with a mirror, But when I removed the throttle body and there was slack in the cable the throttle cable fouled on the clutch clevis. So you win this one.

One down.

Next the fuel pump. I cut the wires in the cabin going to the fuel pump and installed spade connectors then I was able to power the fuel pump separately and happily it did run. both of the wires going back into the harness are shorted or grounded. one IS the ground and the other is the power to the fuel pump. So my ground is good.

Also tried starting it with the fuel pump jumpered it would not start.

Checked the CHT and it showed 1260 ohms at the 90 degrees in the shed plus the 270 ohms of the resistor I had installed for a total of 1530 ohms. I don't know what the head temp is though because of the outside temp and the fact that it had just run.

Power to the coil with key on.

you can't do it now with a busted fuel pump...

Also, I bet CASH MONEY that you throttle cable is wrapped around your clutch cable, and when you press in the clutch you are also opening your throttle a little. Very common.

Zach