brettmc

What started the opti replacement:

https://ls1tech.com/forums/lt1-lt4-m...g-episode.html

I put the new opti on. I cranked for the car for a second before installing water pump. Idled it about 20 minutes last night as I filled up the radiator. It had a couple of misses but nothing sounding bad. Tonight, I refilled the radiator and cranked her up to go for a road test. Let it idle for about 5 minutes while I checked for leaks. Then it died...tried to restart immediately but it just turned over. Tried again an hour later, still no start.

At this point, frustration level is high and my hand is itching for the lighter and gas can.

I checked everything I knew to check on this ****....even the opti venting and dowel length. The opti I installed is a lifetime warranty Advance Auto unit. I sure don't enjoy the idea of taking that sumbench apart again.

Anyway, I'm taking suggestions on the next course of action.

Oh, and thanks for listening....

Gojira94

iTrader: (4)

Your other thread mentions you don't know the age of ignition components except the new plugs. See if the coil is any good. Could be simple as a coil, coil wire, or ICM.

Coil resistance check for obvious failure here:

http://shbox.com/1/coil_testing.jpg

And see if the ICM ground is good, with a buddy's help with the cranking part of the test:

http://shbox.com/1/4th_gen_tech2.html#opti_test

And last (or maybe first) check the ignition fuse.

Could be other things, but see where your spark is first...

Speedy

Sounds like the coil, or the icm. Test the coil as said above, check for loose wiring in that area also.

brettmc

i'll check those in the morning. thanks.

gregrob

iTrader: (8)

Your advanced auto opt is your first mistake, I've seen several of them bad out of the box. Secondly, are you using thread sealer on the wp bolts?

brettmc

It quite possibly might be the opti again and if that proves to be the problem, there won't be another stock one goin in.

The 4 long wp bolts got a dose of black silicone. The other 2 didnt....

Adam1203

iTrader: (5)

i notice a lot of people once they have an opti problem they seem to have the problem over and over and over again. which leads me to believe there is more then something wrong with just the opti.


i know its expensive but i find it a good practice to replace all ignition components once you replace something on high millage cars.

brettmc

7.15 on the 20k ohm setting for the 3 terminals inside the coil:



Good?

Speedy

That's normal. What's the primary? .1? If so it looks good. Just tap the thing a few times to see if it goes nuts while you're testing. FYI, I have had problems with an MSD coil in the past. Left me waiting for a tow truck. Car just misfired got weaker, slowed down and died over 5 miles. Took me forever to figure it out. I had spark directly from the coil, but little to nothing at the plug. I thought it was the opti so I changed that, but no luck. Changed the ICM, no luck. Even got a coil, halfway installed it, tested it and decided that wasn't the problem so put the MSD back in! Had all the guys here scratching their heads too, LOL! After testing with an inline spark tester I finally did change the coil (all the way this time) and it ran like new.

After seeing your information about the optis, I don't think they are the problem. Your first opti didn't seem to have any obvious serious problems, the second is new and it still doesn't run. I believe it is either the coil or the ICM, both inexpensive parts and it wouldn't hurt to change both.

brettmc

I live alone so I had to rig up a solution for the ICM test. I have 2 wires each about 4 feet long with alligator clips soldered to each end. I used one for the ground and one for the C terminal in the ICM plug. I got voltage on the multimeter set at 200AC.

brettmc

NO part is too expensive to get this headache to stop...

brettmc

replaced the ICM and coil and now it runs. However, it's doing something now that it didn't do before. At idle, it pops softly thru the intake, which brings idle down for a second. it also backfires thru the exhaust occasionally. Could it be the tune? If it was tuned with a bad coil and/or ICM, could the tune be off now?

brettmc

BTW, thanks for the tips on replacing coil and ICM.

pro94lt

I won't say how many autoparts store optis I went through via LIFETIME WARANTY exchange and a ebay one in the middle of it all. You could have your wires crossed I recently had the number 2 and 8 crossed and it sounds similar to your description. Pull the belt and tensioner and check it out It's an easy check that won't cost you any more money.

brettmc

It's got an AI 200cc head pkg with their 230/236 comp cam and valvetrain. Too much idling? Maybe the beast needs to stretch its legs?

Gojira94

iTrader: (4)

Just looked at your coil test pic. By any chance are you running an MSD 6AL box or similar? If so, did you play with the timing on it or is it just set static for the vehicle application with dipswitches? Is the PCM mail order or dyno tuned for your mods? What plugs did you use and what gap did you set them at?

You may end up wishing later that you did a different opti but I don't think this one is your immediate cause. If you take it for a stroll, you'll definitely know if you crossed 2 plug wires. I did it last time around with #4 & #6. Discovered that error right away.

edit: your tuner would likely have spotted weak/erratic spark while tuning if you had an ICM on the way out.

brettmc

no msd box. the shop that installed the h/c/i also tuned it. it's funny how it wasnt doing this with the old coil and icm...and i didnt touch the wires between the old and new coil/icm.

Gojira94

iTrader: (4)

Ok, so if you give it light- mid throttle does it stop popping above 1000-1100? If you haven't deleted your AIR injection, make sure the tube to the CAI/ intake box isn't off and causing the MAF to get a bad reading, or a sensor that isn't hooked back up after the opti install.

If nothing else obvious presents itself, take it for a near-distance drive for 15-20 minutes on surface streets and see if you can elicit an SES light.

brettmc

AIR has been deleted. I'll check the sensors and see if the popping stops off idle.

Speedy

At least the car is running. Can you locate which cylinder is popping? Check the wires, then check for a cracked/damaged spark plug, possibly due to the initial backfire. Check for any vacuum leaks, especially the EGR system because if it's supposed to be blocked off and it isn't you will be lean and backfiring. You should be pulling a steady 17-22 inches testing with a vacuum gauge (directly off the manifold) perhaps a little less if you have a big cam.