Hey all my name is John. I have been using 914 as a resource for a while but just registered (I have questions). So I have a 73 2.0 hand me down from dad. And I have idle issues. History: 86 dad snapped spark plug. Got what he could out of it and then tried to vacuum the head thru the spark hole. Was worried that not every thing was out so never started it again, and forgot to drain the tank. It sat in garage and storage until 2008 when he gave it to me. First thing I did was run a borescope in the cylinder , couldn't see jack. So dropped the motor pulled the head and the cylinder was clean as a whistle. Did some work over about three years sourcing parts and such. And got it to run in 2010. Then moved to SC. Got it here six months later and started on it some more. No I have had down time from work and have started tinkering again after 2 years. I have replaced all hoses,injectors and seals, yesterday I opened and freed up the aar. All this I and I have gotten the idle down from 4K to just under 2k. I can get it down to about 1100 but I have to remove the hose from the MPS? ( the Can on the right wall). The second I get the hose near or on the nipple the engine throttles up th 2 k. And runs smoother. At 1100 it sounds rich a lot of back firing. ( exhaust ignition). Any ideas gents?

Click to view attachment btw here is my beauty.

The two most likely causes of a high idle in D-Jet, when everything else is adjusted and working, are vacuum leak and advanced timing. With a car that's been sitting for a long time, however, you REALLY need to go over everything -- all the sensors, all the wiring, valves adjusted, timing, fuel pressure, all potential seals/hoses, etc. etc. D-Jet works well and is not too hard to troubleshoot - except when it's been neglected for a long period of time. Then it can be a lot of "fun" to track down issues.

I know you said you replaced hoses and seals, which is good, but start trying to identify which ones maybe you didn't replace. Nothing is more frustrating (and fruitless) than chasing a symptom randomly or one with multiple root causes. So do your best to eliminate the variables:

1. Confirm timing.
2. Check to make sure there really are no vacuum leaks.
3. Connect that MPS again - can't really run without that, things go super-rich -- make sure it's functional
4. Verify ALL the sensors and various D-Jet components are serviceable and functioning correctly.

and most of all:

5. Read this website: http://members.rennlist.com/pbanders/djetparts.htm. That will help put a lot of this together so you can understand how things work. Good troubleshooting info there.

And

Yeah I'm really not wanting to drop the motor again but probably need to do it just to Make sure fine tooth comb it. Thanks beat navy. Hooah. Prior army myself.

You don't need to drop the motor to do any of this! In fact it's best if you don't. You need to be able to fire it up and test things.

Go through that website from Mr. Anders and familiarize yourself with all the D-Jet components, how they work together, and how you KNOW they are working. Everything from the "big kahunas" (MPS and CHT) that will screw everything up to the more minor stuff like AAR and Ambient Air Temp sensor.

Give us feedback and we'll help.

Very pretty car, too!

Did you replace the manifold gaskets? Air intake gaskets?

Welcome fellow SC resident!- just down the road in Bluffton-

When I first got my car 7 years ago - I had a high idle - it was 3 fold
1. vac leaks- will always cause high idle-
- common leaking points is open AAR, intake manifold leaks and throttle body leaks, and vac hoses connected to plenum and t.b.
2. lean running due to MPS was going bad or not calibrated correctly when rebuilt
3. timing set correctly- your advance is off and valves should be adjusted.

- a hunting idle is also sign of very lean running car- checking plugs can clue you in to how rich or lean your car is running.
- when an MPS fails it usually goes rich flooding the car out so it would not start. but I have had one go bad the other way so lean that when unplugged it actually ran, otherwise would not start it was so lean - that MPS I rebuilt and recently retuned it. and now runs great!!

nice color too btw! take a drive once its on the road and come down to 3rd Saturday cars and coffee at the Bluffton campus of USC-B near Sinn City!- sorry I mean Sun City

reading back thru it seems if you have evaluated all the hoses and seals that next thing is timing, advance etc- check the advance plate motion in the distributor- it could be sticking- if you pull the vac hose off the distributor it should speed up, put it back on and will slow down a few hundred rpm. if so its probably working fine, if not that's the next thing to check along with overall timing. you should be closer to 900 rpm- although mine is about 100-1100 right now when warm and my next project is setting valves and then rechecking my timing- but because ive been tuning the newly rebuilt MPS that may need a tweek or 2 yet as well. -

don't pull that vac hose off the MPS its going way rich and will flood out fouling up your plugs. - 2 things you cant do and have the car run 1. CHT cannot be disconnected(cylinder head temp sensor). 2. MPS connected.

Make sure that you don't have any hoses that go directly from the air cleaner to the manifold. There should always be some kind of component in between, like the AAR or the decel valve.

--DD

Unmetered air. Check for leaks at the phenolic gaskets between the runners and heads.4K idle = a lot of air.

4k idle can only be a huge open hole below the butterfly (throttle body). Only so many places it can be. Timing, valve adjust, etc are important, but no way causing that high of an idle. It's a massive air leak, bigger than leaky injector seals, phenolic blocks, etc. Something is open.

I think it WAS 4K before he started hunting down leaks and replacing hoses/seals. It's now about 2K, which still implies timing and/or additional leaks.

It was a missing injector seal dut that was fixed. Before the post. Thank you all for the help. DD your every where haha. And when I do get it fully on the road I'll come done to bluffton. So as an update I was working on timing today. New points set the gap but noticed the primary copper wire was broke free of the plate so I sandwiched it between plate and points. Probably needs replaced. Put a timing light on it and was still off a little. Is the green or black hose the advance? (Newbie question I know ). I did pull a vacuum on the Mps and it held 18-20 psi for 10 min. Aar has been opened and freed. Throttle body and cold start have been resealed wit liquid gasket. Because I could find any. Just to let y'all know this is a 73 wit 26k original miles on it so never rebuilt never pulled apart (till now). Other than the hisses and fuel pump , oil and filter, and front clip. Everything is original. Shoot the four rubber rings on it are 83' rounded edge radials.

Do you know Gunn1? OU812? Your style is so similar.

83 feet of tire?

You can't just sandwich that wire between the plates. Good spark depends on that braided wire having a quality soldered connection.

I have to keep hunting for a leak I capped the throttle body and it kept running. So I think I'm gonna cap it and try a fog or liquid spray to see if I can't find it. All hoses on vacuum side are a kit from AA so routed per their cheat sheet that I still have . Do you guys recommend clamps on all?

Hahah no I don't. It was a Johnny on the spot fix. There was no way I was going to get a distributor today, so I made due. It was foreign pretty well. Plus got a wedding in less than a month. So new distributor will only be after that. 1983 rubber ! Dad worked for BFG.

Of course I cold re solder it I suppose. I am a electrical technician.

So your car is running ok (aside from the fast idle) with that braided wire just sandwiched between the distributor advance plates?

When I saw it loose my heart sank. But I tried a temp fix of sandwiching it between the points bracket and the top advance plate. And so far it's working. But I'm gonna solder it tomorrow.

Did you only replace the ONE injector seal or all EIGHT of them?

Too similar Rand.

Al 4 seals and the 4 bushings. $2.57 at autozone.

Do y'all recommend hose clamps on all vacuum hose ends?

I don't. It's my understanding if you use the correct size hoses that are in good repair you shouldn't need clamps.

so found that I had a poorly seated injector. Fixed that and still have a high idle once the engin warmed up I was around 2800. Going to vacuum test all my vacuum hoses. I put my box of gloves over the throttle body and rpm drops to 1900 rpm. But still runs. Sprayed every thing I could get to with starter fluid and no rpm drop or raise. Take the th box back off and rod go back up. Sprayed some starting fluid in to the throttle body and it lowered the rpms. I'm so confused at this point. The car sounds really good no back firing. I've found no obvious leaks.

when you sprayed that in there it became more rich and slowed the rpm, this is what I would expect, you have have eliminated all the leaks so either your advance is off- meaning timing not set correctly or its running too lean still. - you might be having to try a different MPS, - can you get an O2 reader or install one? when did you set the timing? I didn't see that on the thread but maybe recheck that again, a former member used to say re-verify everything .

I replaced the points yesterday and set the timing that way then checked it at 3k rpm today with the advance disconnected. And orange/red line was in the notch

Troll needs to die, not be fed.
Does this really bring you enough jollies to keep this up?

Assuming the box serves as a reasonable plug for the throttle body, you still have a good-sized vacuum leak. Like a hose that isn't plugged in, or a fairly sizable crack in the manifold. (There are two "support columns" inside it, and the manifold can crack around where they are.)

Find the leak(s).

--DD

So this morning I pulled the manifold. After a painstaking process of sealing all ports I was able to pull a vacuum on it. Leak wise I think I'm good. I am going to pull the distributor. And give it a good cleaning along with re lube and double check my timing. im flattered that Rand thinks I'm trolling. I could think of better ways to waste my time if that was the case I.e. Driving my car.

The only vacuum hose you need is the one from the manifold to the MPS. Unplug all the other hoses, and securely cap every opening.

How's the idle at that point? If it's still high, you need to start hunting through the manifold, the intake runner pipes, the injector seals, and so on. (But first double-check the caps on all of the hose fittings.)

If comes down with that, then add one part back on at a time. When you add a part that sends the idle skyward, you have just found the source of a leak.

How's the PCV hooked up? Does the valve work?

--DD

DD I really appreciate your help. So what I did today. Reinstalled the the manifold after perssure testing. Then pulled the distributor after realizing I needed to set it for 3500 rpm not 3000 and because I need to fix the cable in it so I did that redid all my timing steps and now I'm at 1900 rpm consistently. I can turn the distributed and bring the rpms down but I start to get back firing as I do. I did however drive it around the block. So it was nice to drive it around.

That is toast, soldering does not work. check with AA for an aftermarket points plate.
Mike


ps: get a Pertronix and replace the points, you won't need that ground strap.

Did you try spraying starting fluid around all the hose connections, manifolds, the idle will increase when you find the issue.

I have sprayed starting fluid and nothing. The solder is holding but it's only secondary the plates are actually connect via the black points around the plate

"Black points"? I think they are plastic numbs used to interface with the lower plate which makes them slip.
.

Which ecu are you using?

It is all original parts. It has 26,000 original miles on it. The only things new are fuel lines and hoses, an accel coil, and a fuel pump that I purchased used for 80 dollars from a guy that restored Vw bugs.

They didn't seem plastic though I didn't test conductance however it is a metal on metal hub and there is a connection path from clip to ball to top plate as well. And the metal clip on the opposing side.

The ball is greased not a reliable ground. All original, you stated you had to find the parts?
Are the FI parts mix and match or are we working with a specific MY FI system?

This is a great story without an ending - My 2.0 is doing the same thing - hovers at 2K while it holds -20 of vacumm. Occasionally surges down to 1K, vacuum is then -15.

Might write this up in a new thread.

Do not use starting fluid to find leaks. It is flammable. Use carb cleaner and spray generously on every part of the intake. Every hose, Every intake runner all over the plenum.

When you covered the throttle body, did it create a massive vacuum? Like others said, you still have a vacuum leak. Vacuum leak with DJET == open throttle.

One other tip when working on the 914 engine in the car, remove the engine lid. There's 2 10mm bolts holding it on. You'll be pleasantly surprised how much more access you have. It's a one man job to remove and replace the lid although a second set of hands helps.

Disagree. If there wasn’t a good connection the car wouldn’t run at all.

Does the ECU match the the MPS?