Now I did it...

1979 242 DL, automatic, K-jet. I carefully degreased and washed the engine with a garden hose focusing on the lower portion of the block (not the intake side), and now the car will start and sort-of run with starting fluid and pumping the gas pedal, but will not idle and runs erratically with my foot on the pedal.

I checked the obvious stuff like cap/rotor, and coil which seem ok.

New plugs, cap/rotor, wires have not fixed the problem. I dont see any disconnected hoses/plugs. I presume these cars dont have a CPS, which seems to be the faulty part on later models.

Not sure where to look next? Any ideas are greatly appreciated.

Thanks!
-Mike

First let it dry out.

The Ignition system' ICU is located on the passenger front fender mounted right by the Washer fluid body. It is black retangular box, with a plastic cover...the cover can be slid off to reveal the ICU.

There are 2 sets of bundled wires coming out of the bottom of the box... one set leads almost immdediatly to a small connect held by a bracket to the wheel well. Which then continues on past the Alt and under the front of the engine.

1)You could have gotten that connection wet.

2)those wires from the engine side of that connector run Under the Crank shaft and plug into the distributor. If you have the original wiring harness, the insulation may be in not that great condition....Also if you were degreasing the engine----those wires where they pass under the front of the engine really get soaked with leaking oil...which eats at the insulation. They are in a sheath but that may be cracked and when you washed the engine you forced water into that sheath.

Dry it out

Look in the mirror.

I have read this RWD and FWD for more than 15 years, and have seen this tale far too many times.

You could spray everything heavily with WD40 -including inside connectors - that is what it is for - Water Dispersant formula #40 - it is NOT a lubricant.

Looking at your engine in the dark is a good idea.

Was the coil wire included in your new wires? I found one of mine to be burnt where it was snapped into a clamp on the firewall.

The best advice I got was to pull every connector apart (check for water - maybe use a hair dryer also) clean the contacts and apply dielectric grease - zip tie any that you can.

I did this when my car was running ok, so I did one a week so I could know where to look if things went bad.

Disconnect, clean, top off, and charge your battery - it has taken a beating. Low voltage could be an issue.

I use a spray bottle filled with kerosine (paint thinner is good also) and rags for cleaning metal (it leaves a slight protective coating, and WD40 or silicone spray and rags for plastic parts Ols socks are great for getting in nooks and crannies.

My Volvo dealer will do lost of stuff (for good money!) but they will not wash or steam clean an engine!

With the engine off, remove plug from ignition computer (grey box) and make sure it is dry. Also any and all electrical connections on the engine and the fuse rail. Some water may have gotten in any of these connections. You did not say if the car was running fine before the wash.

I'm glad you told us you just washed the engine.

Kinda gives us a clue what the problem is. (:-)

Here a small thought for you to think about when it comes to water or rain.

Imagine how easy it would be to find moisture if it were colored and not clear!
Imagine the mess the world would look like after ever shower though!
Red, white or blue colors for America would look different. Especially, if it rotated into different parts of the country.
Of course the Northeast really liked lots of the white stuff last year!

Now working with that thought, about color, think about high voltage and how it jumps around on water.

Back in the old days of old "cathode ray tubes" operated with very high voltage much like our cars ignition systems. That stuff comes out of nowhere!
Big safety rule was to keep one hand in your pocket, even after you had turned the set off!

It would be silly, but I bet, if you lean on the car with the engine trying to run with some wet hands and rubbed those ignition wires, you could find a bad spot!

Actually I prefer to use the darkness of night to seek out bad wires with a mist or fog from a spray bottle.

Your car is pretty old but reliable when it comes to a fuel system compared to pumper carburetors! The pedal does not work like that on your car.

Even since then, our cars fuel system was changed twice, but guess what, the ignition components out there on the engine, didn't!
Removing the breaker points was the last change back in the early 70's. Just after the alternators came out to replace generators and vibrating contact points used for voltage regulation.

Because it's so cheap to replace parts on these cars, nothing got changed!

Funny you mentioned CPS's over Hall Sensors. CPS has questionable events on our cars today!
Maybe not so great?
Take a CPS fired ignition setup but then having a tachometer that uses a signal out of the alternator?
Four individual coils, one for two spark plugs. All this on their "special built Chevy V8" in a Range Rover! They are not known for any kind of inexpensive repairs! Ask my sister-in-law, she got rid of it!

Bottom line is, keep fresh and cheap ignition components on the car. I myself, find lots of these and new air filters in the junk yards. I have drawers full.
It seems that they get change just before the car is sold.

This is a cheaper way yet, but they don't fix other poor maintenance issues.

Work on your wiring connectors with some anti corrosion goop.
This way you will not be getting red or blue in the face with frustration.

Sweat equity is "clear" by the way! (:-)
I agree, A clean engine bay, is a badge of pride!

Phil

You are correct there's no CPS. Do you have the Green Manuals?

Ignition when water is involved would have been my first guess too. You seem to have eliminated that and it does start and run. So at least the ignition is working.

It's possible the problem has nothing to do with the washing. Pumping the throttle should have no effect since there also is no carb or accelerator pump. It could just be causing the air meter plate to wiggle.

It is common for the fuel filter or injectors to be clogged on an older engine. The kjet system requires a special hook up for a fuel pressure gauge to test it properly. You can test the injector spray pattern and flow with just some plastic hose and soda bottles. Also if the in-tank pump is not working and the tank is less than half full it can cause a fuel delivery problem. The main pump could also be failing.

The other common problem is vacuum leaks including around the injector's O-rings.

Just some ideas. I would recommend downloading a set of the factory manuals.

Lots of great ideas here, thank you very much to all.

I'll start going through these items over the next week, and post back with any solutions.

I did find a few cracked vac lines during the last inspection, and it seems my auxiliary air valve is in-op (that is, it does not open/close when I apply 12v to it).

The car was running pretty well before I washed the engine back in January. The car has been sitting in my quasi-heated shop for the last month after washing while I replaced the front suspension bushings/struts etc. so if there is any residual water, it is likely buried deep within a wire sheath as suggested.

I'm coming up to speed using the green books, interesting that they changed something under the hood nearly every year during the early days of the 240.

Thanks again!
-Mike

Hold on here!
Back up to that auxiliary air valve! This valve bypasses the throttle plate just like the IAC on the LH systems but no clicks!

On my '78 that unit has a heating element inside it. It will slowly close to decrease the amount of idle air on the cold engine, as it warms up. This slows the engine because while the engine warms up the friction inside the engine lessens.

This auxiliary air adjustment works with control pressure regulator. It also has a heating element which make CPR adds more fuel pressure to the top of the air flaps control piston. This restricts its upward movement against the incoming air allowed up though the fuel distributor to the injectors.
In other words it "leans out fuel" to run leaner.

These two items need to be timed together by their actions to work properly, But only one is adjustable.
The auxiliary air valve.
The CPR unit and its heater is made to be mimicking how the engine is suppose to warm up under the hood or in a laboratory originally for fuel ratio let alone emissions.
The AAV amount of air is supplemental. This is to allow adjustment of mixture from a starting point within the range of the CPR.


If you look into the top port you will see a sliding vane that should be partial open to the opposite side approximately a 3/32" to 1/8" on a 60 degree day. In some manuals this "rough opening" is set with the shank end of a twist drill. It is open more on a colder day.

There is a stud sticking up with a nut on it. This is a loose fit pin in the housing.
It will feel like it shifts a pivot point of the vane, when it's the tension between a bimetal spring of the vane.

It takes a few trials and errors, to blend the two operations in to one. Once you see it cycle during several warm ups, you get the hang of which way you move the vane to raise or lower the revs.
It works for me to be about 30 seconds or a minute the idle starts lowering itself.
Outside temperatures and the engine actually heat soaking the components, it compensates well!
I use this as a GOOD FOR THE CAR...TIMER. It works with the engine to allow piston expansion and oiling before driving. The O2 sensor adjusts the ECU and it works the frequency valve for overall running mixture.
The colder it gets, the longer it takes to reach a slow down and comfortable idle zone.

Once you get these "dialed in" just keep clean fresh fuel in it!

How long has this car sit again!....Not good!

Phil

Thanks for the info re: Aux Air Valve, mine is open just barley when cold, I'll hook up 12v for a few minutes and see if it closes.

I discovered that both the large vac hoses from the Aux Air Valve were cracked, as was the hose from vac advance, and the three way valve. In short, I have to replace all the vac hoses (as has often been recommended, but I was too suborn to comply). During washing the engine and changing fluids, changing the V/C gasket I must have disturbed the mostly-sealed state of those hoses. I'll post back afterwards to see if that fixed the problem.

One problem (kinda) solved, and now a new problem... I posted in the 200 series forum.

I cant thank you all enough!
-Mike