5th injector testing

Ian_G · 12-30-1999, 06:07 AM

Hey Y'all,

Well the only problem I'm having with my '73 2L is cold starting. It really seems like trying to start a car without a choke.

I've looked all over but cannot find a FAQ or tech page about testing the 5th injector and it's operation. Can anyone out there either point me to a page or suggesting testing techniques?

Thanks all
Ian

JP Noonan · 12-30-1999, 07:56 AM

The cold start valve (5th injector) gets +12v when the starter is running, but only gets a ground from the thermo time switch at 50 or so degrees F. Unless you only have the problem at those temps it is not the CSV, it is most likely the failure of the aux air regulator to open. Try soaking the AAR in PB Blaster or Liquid Wrench it MAY loosen things up (IMHO WD-40 is about as good as a 5th of Vodka, well, no not even that good, i.e. it is mostly alcohol). If the problem is below 50 degrees then try injector cleaner, but usally the CSV's don't get blocked up (it is a fairly low tolerence valve more than an injector) they leak.

If unplugging the AAR on the intake side cured the problem ten it is the AAR. Unfortunatly you can't leave the car like this for long or it will idle at 2500+ when warm.

Ian_G · 12-30-1999, 09:25 AM

You speak of AAR (Aux Air Regulator). I'm away from the car but can you give me an idea of where it is. I'm imbarrased to ask as I've become VERY fimiliar with the FI.

My problem is when it's <50F and the engine is COLD. Then you just have to spin the engine and ease on the throttle to get her to go. Once it's caught it runs like any other FI. This reminds me of an old Triumph I had sans choke. I had the "racing" (HA!) carbs and they can without a choke. So you just used your foot a little to ease some extra fuel into her while starting. Not a great thing.

Thanks
Ian

BTW The reason WD-40 is mostly alcohol is that the WD stands for Water Displacing. Oil floats on water right? Well it won't push the water off a surface as a result. So you bust the surface tension with an alcohol and then float a light oil onto the surface. I've a BS in Chem and it always striks me as funny when folks use WD as an all purpose light oil. Duh, use it to get the water off, even in water, and THEN lightly oil.

JP Noonan · 12-30-1999, 06:56 PM

"The AAR by any other name"... Seriously you probably just call it something else. Look at the Dave Darling 2.0L hose diagram, it is on there. Basically it is a vaccuum leak that lets the car idle when cold. Inside the AAR is a heat sensitive spring/valve "thingy" that as it heats up (either from the heat given off by the motor or by it's internal heater) closes the vac leak. It has two hoses going to it (13mm dia. I think) one from the air filter the other goes to the intake by the CSV, there is also a red wire coming from it that gets +12V to power the heating element.

However you say that the problem doesn't occur above 50 degrees (or there abouts) it IS most likly the CSV. To test it see if it gets a ground on one of the wires going to it (this is the one from the thermo time switch located under the air distributor) the other gives the CSV +12 only when the starter is running.

I think you mentioned awhile ago that the motor was receintly rebuilt? The thermo time switch is easy to leave out during a rebuild.

JP Noonan · 12-30-1999, 06:58 PM

Sorry for the repeat, I guess Brian is a faster typer...

We shall see who has the faster car though

Dave at Pelican Parts · Dave at Pelican Parts's Garage

The AAR only has one wire going to it. The ground path is through the case of the AAR, into the manifold, into the engine block. The one wire gets +12V when the fuel pump is running; the power is taken from the fuel pump circuit.

--DD

Ian_G · 01-01-2000, 04:30 PM

Hey y'all,

Weel I'm here putting in my Y2K time (we're running 100% coverage until 1/4/00) and reading all the responses.

I have located the AAR and CSV. I'll be testing both. I do know that I connected the thermo to the AAR. I go over all the connection from the ECU and FI diagram.

Anyway I'll test the CSV and AAR tomorrow. I's got to be one of those. It does start just takes awhile and runs fine the second it catches.

Peace
Ian

Pritchard · 01-03-2000, 09:39 AM

The CSV will not operate unless two things happen: 1-the yellow wire to the starter must have 12v going through it (ie. the starter is in use) and 2-the Thermo Time Switch is closed. This switch closes at 34 degrees F on my car.

To test the TTS, I removed it from the car and placed it in the freezer. I tested for continuity (from the spade connector to the housing of the switch) every minute or so until the switch showed continuity.

You probably already knew this. I just wanted to type some. Good luck.

Pritchard