Edited due to initial thoughts of the problem being tested and eliminated...scroll down because I'm still stuck:

I've seen lots of posts regarding opti diagnosis, but none mentioning to check the high resolution line (purple or purple/white) coming into the ECM from the Opti. It should read 0.5 - 1.5 volts during crank. If it doesn't, the ECM isn't telling the injectors to open because the Opti is bad.

Has anyone heard of this? I'm going to check it tonight and post again later.

 

I have not heard of this but it makes sense.There is an electrical signal being sent to the ECM. I though I would toss this out to you though have you check your oil pressure sending unit? If the ECM does not see it rise on startup it will shut down the fuel I believe.You could check this with a pressure gauge on the fuel rail.Just a thought.

 

Update:

Checked the wiring diagram when I got home, a problem with the high resolution line sets DTC 36, which is the big one for the Opti.

Too bad I can't check trouble codes...

Good idea about the oil line. Someone else suggested the same idea with the coolant. If my Opti's ok I'll move there next.

 

I can't comment about a voltage that might be readable on that line, but I can offer the following:

If there is a problem with either optical pickup in the Opti, there will be a corresponding code set. I don't have my manuals with me right now, so I can't look up the codes, but if you have no codes set, the optical portion of the Opti is probably functional.

IIRC (going from memory here), a loss of high-res data won't kill the engine. The ECM can operate with only the low-res input from the Opti (albeit not as optimally as with high-res data also present).

Your symptoms suggest either of two possibilities to me:

1. A fault in the "Run" circuit of the ignition system. Sounds as though it's possible you have power to the ignition system when the switch is in Crank position, but not when it's in Run position.

2. A similar fault in the fuel pump power circuit, causing the fuel rail to be pressurized during Crank, but not pressurized during Run. I'd suggest you check for 12VDC at the pump when in Run position.

Good luck. Keep us posted on what you find.

Be well,

SJW

 

I did not mention it earlier but the fuel pump relay may be a good thing to check. In my 93 it is on the pass side underdash near consul.It is energized when the oil pressure come up.

 

Simple check is to not fully release the key to the run position, keep a little pressure on the key. by letting it back off enough to stop the starter engagement but still turning it slightly, you can easily rule out the ignition switch contacts. Once the car got to where yours is ie: run for a second or so then die we figured out the above trick, I had to drive it this way to the shop about 6 miles or so, my fingers were killing me but a new ignition switch in my 240k Acura was all it took to fix.

 

Edited for brevity:

Went through the troubleshooting flowchart in my Helms manual and signs point to a bad Optispark. however the car starts up and runs flawlessly later that day.

So here's the revised question (which may require a new thread): if my Optispark is only moist due to my pressure wash and is causing an intermittant start problem, will running the car for awhile and perhaps driving it around dry it out and fix this?!?

 

Ahh the dreaded 16&36 not good at all.That means the optical part got wet and unless you have good towing package it HAS to be replaced.Once they do this it will not last. Yes they can dry out especially the 95&up but now you have to worry about rust. Do not risk it and welcome to the "I have replaced my Opti" club we meet at the bar on friday night.

 

Well, I'm on my second Opti already.

Drove the car around for 1/2 hour. I'll let it run for awhile and shut it down.

 

Glad you found the problem but just for refernce if you suspect a F/P problem hook up a FP gauge and it will tell the tail. Sticking a gauge o there will enable you to see if you are looosing FP or not. This would have eliminated the VATS, Fuel pump, and the FP relay. It is posible that you just had some condinsation in the connector and when you pulled it it solved the problem. I would just run it untill it dies if it where me.

 

actually, I am hopeful...

are you saying that, after fiddling about with the test lead area, it started? perhaps jostling that connection did the trick...

 

The car doesn't run anymore.

This time when it tried to die I gave it gas and I could keep it running (although sputtering and backfiring) for a few seconds until it crapped out.

So maybe it is the fuel pump after all? Why would it run fine yesterday and now it does not? If the opti is bad would it sputter like that or not run at all?

 

This is classic opti problems. You can check the fp as suggested, but I'll bet a steak dinner you need to install a new opti before its fixed right.

 

Code 16, 36 and backfire and sputter till it dies=Opti sorry

 

I'm half relieved half pissed. At least if it's the opti I can fix it, even though it's a pain in the ****. It's better than this continuous troubleshooting that's getting me nowhere!

Can I put on my old one that was fine even though it's been sitting in the garage for three years, or is that a horrible idea and I should suck it up and get a new one?

 

Well at least open the old one up. Why did you change it? I would at least put a cap and rotor on it and seal it with RVT if it is a good one. If it is not rusted inside the optical portion should be good if it worked when you took it off.You need and E5 Torx driver and E4 socket to do this. The socket can be hard to find.(it could be E4 driver E5 socket but I think I was right the first time senior moment here)

 

Ok, it's back to being funny.

Went to a buddy's shop and borrowed his tech tool to read codes.

Plugged the tool in and established communications, got the following codes:

72 A/C something or other. I ripped it out, no surprise here.

28 QDM error. What's the QDM? Not listed in my Helms.

No 16 or 36.

The best part? The car started right up again. Even without the codes is my Opti fried? I'm driving it to the shop while I have the opportunity.

AAAAARRRGHHH!

 

If the optical section of your Opti was failing, I'd expect you'd get Code 16 or 36. So I doubt there's a problem with the optical section.

The backfiring/stumbling/no-start symptoms you're getting suggest an ignition-related fault of some kind. Just to be sure about this, as FD2BLK advised, definitely get a FP gauge on there and monitor the FP while the car's acting up. If the FP's okay, that points more strongly toward an ignition-system fault.

It could be that the high-voltage side of the Opti is damp. It could be that the connections to the Opti, ECM, coil controller, etc are intermittent.

A backfire into the intake usually means one of two things:

1. Spark occurring at the wrong time (firing cylinder(s) while the intake valve is open).

2. Valve train mechanical failure (would not be intermittent).

There's a slim chance that an extremely lean A/F ratio could cause this, but I seriously doubt it.

If this all began with the first time you tried to run the car after the power-wash, I'd say it's highly likely that you got moisture into someplace where it doesn't want to be -- in the Opti, a harness connector, etc.

I don't have my manuals here, but a quick Google search turns up two sites that list:

Code 28 is Quad Driver Module #3. Air conditioning Clutch relay and/or cooling fan relays. Check with digital Ohm meter, replace if less than 18 Ohms. If relays OK, potential ECM failure.

I'd say there's a good chance the 28 is tied to your removal of the A/C system.

My best guess: Moisture in the high-voltage section of the Opti.

Good luck.

SJW

 

You said you HAD a code 16 and 36 so you must have reset it.I still say opti is bad I would bet it will die again.In its death march the opti will fire sometimes and die at other times better get the old one out and get it ready.

 

I never actually had a 36 or 16 code, I just probed the lines with a DVM and assumed based on what the manual defined as the problem I assumed those codes would be there. I wasn't able to check codes until today when I borrowed the scan tool and only had the two listed above.

I just tried to start the car again and it is back to the run for 2 seconds then stall.

The issue happened once months ago and then everything was fine until recently, which is why I assumed it was the powerwash ruining my Optispark. I was convinced of this based on everyone's input until I saw no opti codes today.

I will check all of the voltages on the circuits handled by QDM tomorrow and look for shorts. I have a large current draw which could also be explained by a problem in the fan or A/C circuits. Then it's full diagnosis of the ignition system and perhaps ultimately replacing the ECM. However, would problems with the ignition system or ECM be intermittant?

There are many connectors dangling unplugged in the engine compartment from the gutting, I'll also trace all of them back and remove them from the harness.

I just can't believe it's the fuel system since twice in two days the car has ran flawlessly for an extended period of time. Those types of problems are not intermittant...it HAS to be electrical.