Mechanics

COULD SOMEONE LET ME KNOW IF MY TEST RESULTS ON THE PRIMARY COIL CIRCUIT ARE CORRECT?

1992 Dodge Shadow • 4 cylinder FWD Manual • 224,834 miles

Hi Everyone and Happy Holidays,
Our 1992 Dodge Shadow left us on the side of the road the other night. We decided to do some back yard checks on the ignition system. Using a computer probe (like the ones sold at auto parts stores), we checked the primary connector to the coil. We connected the probe as directed (Red clip to the positive battery post and Black clip to the negative battery post), then disconnected the primary connector to the coil.
These were the results as we cranked the engine:

1) While touching the probe tip to the terminal to the Grey wire: the Green light and the Red light alternately flashed (I am thinking this is the signal from the computer).

2) While touching the probe tip to the terminal to the Green wire with an Orange stripe: the Red light glowed.

3) Then using a regular old test light, to jump the Grey wire to the Green wire with an Orange stripe: the test light flashed.

It seems to me that this type of testing was talked about on the site a long time ago, but I can’t find the discussion now. I am hoping that someone can let me know if these results are correct.
Thanks for everything
Avatar
Sunshine03
December 24, 2011.



Did you just simply check for spark at plug(s)? And do you hear fuel pump run when key is turned to on?

Tiny
Fixitmr
Dec 24, 2011.
Hi
Sorry I didn’t add this in the first Email. Just wanted to add; the fuel pump can be heard as it runs (both inside the car and at the filler cap). Using a spark tester and cranking the engine: there was a bluish orange spark at all four spark plug wires and at the coil wire. We were told the computer probe and test light tests to the coil connector were part of a thorough inspection of the ignition system – we just didn’t know if the test results were correct for this car. Also, each of the spark plugs had sooty deposits on the electrodes.
But just out of curiosity; are the computer probe and test light results correct?
Thanks

Tiny
Sunshine03
Dec 27, 2011.
I'm not familiar with that test. If you sqirt some fuel into intake will it run? Is timing belt ok?

Tiny
Fixitmr
Dec 28, 2011.
Hi again
Sorry this Email is so long; but this is what is going on…
The problem is that the other evening; after being parked at a store for a few minutes, the car wouldn’t start back up – all of this was sudden and without warning. The next day; we took the air cleaner off, and while watching the injector operate (as the car was trying to run) – it was spraying erratically, splashing fuel, etc. Thinking the problem was fuel related and since we had already replaced the fuel pump earlier this year – we replaced the one fuel injector and pressure regulator in the throttle body. Now the fuel being sprayed is a lot smoother, straighter, and more controlled – but the car still runs the same – terrible.
Basically, the car will not start unless the gas pedal is pressed. When the car does start it runs extremely ruff and keeps trying to die. Next, we did some checks on the ignition system – which led to the earlier Email
A few days ago; we hooked up a fuel pressure gauge and while the car was trying to run – the fuel pressure held at about 40 psi, but as the car died or was turned off the gauge needle immediately fell to 0 psi. The fuel pressure was the same with and without the fuel filter installed.
I guess the most aggravating thing is that earlier this year we had to do a bit of work on the car. The last thing we done was replace the oil pump. Some who visit this site often, may remember; we posted questions about the oil light coming on after replacing the oil pump - but in the end; when we replaced the oil pressure sending unit the light went off and stayed off; so-far-so-good. But here’s the kicker; the fuel pump was one of the first things we replaced after it went out. And it has worked fine - in fact the car has been running fine for some time now. And like a lot of people on a tight budget, we got the fuel pump from AutoZone.
We also gathered some computer codes by using the key cycle method; the codes are: 12, 13, 15, and 55
After finding out that code 13 was the MAP system and just to see what would happen, I disconnected the old MAP sensor, and then started the car – and believe it or not the idle got better. So like most people we got a new MAP sensor thinking we have fixed the problem. After hooking up the new sensor and starting the car – there’s no change. I even tried disconnecting the new MAP and starting the car – now the idle stays bad, this is crazy, and the computer has set the codes 12, 14, and 55.
After reading in the Haynes book that a code 14 may have something to do with the wiring, and being unable to make much sense out of the wire diagrams in the book; we tore into as much of the wire harness as possible and everything looks ok. We also found that almost every sensor under the hood is (in one way or another) connected to each other and to the computer. There were just a few wires that branched off and went through the firewall.
The car seems to be getting enough gas – as a matter of fact it is hard to keep it from flooding as it tries to start
A few other things we have done are: 1)Cleaning and gapping the sparkplugs.
2)Checking all hoses and their connections - they look ok.
3)The timing belt looks good, it’s tight, and the timing marks line up when you rotate the engine with a wrench.
4)The car is idling so bad that it is hard to tell where the timing marks are when using the timing light. After I get the wires bundled back up – I’ll try the timing light again.
This is just a thought, but could something be wrong with the computer. I have also heard that if the ignition switch or distributor goes bad strange things can happen to a car. I have to admit this problem has us stumped.
I really appreciate the help with this problem; this is the only car we have that was running good
Thanks for everything

Tiny
Sunshine03
Jan 2, 2012.
Is that a 2.5 motor?

Tiny
Fixitmr
Jan 2, 2012.
I own a 89 acclaim with the 2.5 and it's been great like you say. I also have an 87 ram with the 2.2 carbureted and loved that too! As far as computer goes you might just pic 1 up from scrap yard cheap although i've never experienced idle problems due to that. I would say distributor may be suspect. I dont have as many miles on mine so not been an issue.

Tiny
Fixitmr
Jan 2, 2012.
The spray from injector should be a perfect cone shape. I wonder about the IAC and the EGR? Both can really mess up mixture making it weak and causing rough running. And what about TPS?

Tiny
Fixitmr
Jan 2, 2012.