I've been trying to diagnose a problem and thought I fould it, but now I'm at a loss and could really use some help. Before I get started, I have performed some searches for similiar symptoms and am wondering if the problem could be with the OPTI. I'm not sure though, so I'd love some opinions before I drop the money that I don't really have on a Delteq system to replace it.

Last week my idle became rough after the car warmed up. When in drive, the tach was registering 500RPM and the idle was so rough that the dash rattled. I took a look at my plug wires (I have the taylor OVC wires) and noticed that the number 6 wire was nicked. Here's a pic for reference.

http://jodydavidson.home.comcast.net/car/wire.jpg

I just finished replacing the wire and took the car for a road test. Unfortunately, the problem still remains. FYI, I did have the battery disconnected for a couple of hours as to reset the PCM.

Until the car warmed up it seemed to idle OK. Once warm, It still had the rough idle at 500RPM in drive and I know that RPM is too low. If I put the car in park it goes up to 650RPM and smooths out a bit.

When driving, between 2000 and 2500 RPM there was definately a loss of power and I also noted a noise. Now I'm at a bit of a loss as how to describe this noise. It may be a knock. The best way I can think of to describe it is a repeated clicking or ticking noise. This is only present between the 2000 to 2500 RPM range and there is definately a loss of power associated with it. When the car is between 2500 and 3000RPM there is no ticking, but the power feels like it is surging. Above 3k the car felt OK. (Speaking of knock, I am using an LT4 knock module.)

As I mentioned, I thought it was the number 6 wire, but I replaced it and that didn't correct it. I drove the care appx. 200 miles with the wire in this condition. Is it possible that because this wire was bad it may have fouled the plug? I've got the AC Delco platnum plugs and they've got around 5k miles on them. I'm hoping it isn't the OPTI, as my budget is not in a place to buy the Delteq system right now.

One thing I've thought about doing is getting a data logger to see what the computer is doing while this is going on. This is unchartered territory for me though. I do have a laptop but don't have a cable yet, and I'm not sure which one to get. This car is a 95 and the emissions sticker under the hood lists it as ODB1. I seem to remember reading somewhere that some of the 95's actually had an ODB2 connector. Here's a picture of the connector.

http://jodydavidson.home.comcast.net/car/odb.jpg

If someone could identify this as an ODB1 or 2 connecter I'll get a cable ordered to do some data logging.

Thanks in advance for any ideas you may be able to offer.

Joe

 

I just thought of one other thing I forgot to mention. I don't have the stock ciol. I'm currently using an MSD Blaster Coil. Could it be taht the coil is acting up and causing this problem?

 

I'd buy a Scanmaster if I were you. I have mine mounted in the diagonal vent on the dash, and can't imagine not having it now. Are you throwing any codes at all? Clicking or ticking noise could definately be a coil arcing, or another plug wire arcing somewhere. Go out at night sometime and crank it up and raise the hood. If you're arcing anywhere you'd almost definately be able to see it.

 

I too have an MSD Blaster Coil. Its been arching between the magnetic metal thing around the coil and the the coil itself, and I've heard the clicking noise, I dont really have that bad of a hesition or power loss as ive been driving it like this for a bit (sitting right now under snow though). Like DonHood said pop the hood at night and look carefully around the coil and all your wires for possible arching.

OBD1 connectors are 12 pin
OBD2 connectors are 16 pin

Your PCM is OBD1 w/ a OBD2 connector, you can order a cable from AKMCables.com and download FreeScan (in the Computer/Diagnostics section) which is, as the name implies, free. You can also make the cable yourself but if your not handy and dont have decent soldering skills and/or time to waste I would recommend just buying one from Andrew at AKMCables (good guy).

Good luck

Ian

 

Well, I took a look under the hood last night and didn't see any arcing anywhere, but this clicking noise only seems to occur when the car is actually on the road. When it is in park it revs through the RPM range just fine and I don't hear the clicking.

I'm going to go get a GM coil this morning. I seem to remember some posts in the past about problems with the MSD blaster coil.

Does anyone else have any thoughts about what I should check?

 

OK, so today I tried a new coil. The clicking noise I had reported is gone, but the idle is still rough and now is present throughtout the RPM range. At times the engine surges and feels like it is running right of a couple of seconds and then runs rough again. I checked the grounds at the coil adn they look OK. I've also inspected teh wires. They look OK as well and there are no signs of arcing.

My OPTI did get wet when my water pump went out last summer, but it seemed to be working OK. When I changed the water pump I did switch over to an electric pump. I'm wondering if the WP seal in the timing cover may have leaked oil onto the OPTI. While I was under there today I did notice some oil. It was too high up to have been from the pan, and the front of the intake looked OK.

Should I chalk it up to a problem with the OPTI?

I told myself recently that when it went out I was going to get rid of it once and for all and replace it with a Delteq. I cannot help but wonder if I jinkex myself.

Is there anything else that anyone can think of, before I replace the entire ignition system?

 

It could very likely be the opti. You should def. get an AKM cable, it helps a lot just to make sure all your sensors are working. OBD1 with OBD2 connector. I got one for programming mostly, but it helps out as a scanner too.

If all else fails, before spending a bunch of money, take it to a shop and have them diagnose the problem. They have a lot of equipment the typical DIYer can't afford. If you have access to an oscilliscope you can check to make sure you're getting a constant signal from the opti, it's not too difficult.

It's harder to diagnose the cap & rotor, you can't just check resistance across each terminal as you turn the engine over, because usually it only bridges when the engine is under high load (and the spark plug gap has more resistance). But that ticking sounds an awful lot like knock, which means the cap & rotor 99% of the time, aside from actual problems inside the chamber.

I believe you can get an entire new opti for what, 230 something from whoever it is that sells those parts wholesale around here? That would be my route. The opti really is a good system, it's placement was just not thought out very well. GM could have used a convential distributor shaft and stuck all that stuff on there and it probably would have been much more well received. Imagine if all you had to do was replace the cap & rotor every 50k miles, and it was near the top of the engine? Wouldn't bother me too much.