nitroheadz28

iTrader: (3)

I'm on the parkway in 6th doing about 1800RPM and the car jerks and rpms dip down to 14-1500. It did this 4 times on my way to class and almost gave me a heart attack the first time haha.

The only thing remotely similar I've experienced was on my 87 Fiero when the ignition module would be faulty the tach would dip to 0 for a second and the engine would fire back to life but never this violent jerking.

96 LT1
MSD Opti/ wires and everything 1yr/ 6k old
New waterpump 1yr/6k old and no coolant around the Opti
New clutch less than a yr and 5k old
Edelbrock shorties
PCMforless tune
SES light is on but an autozone scanner wouldn't link to read it.

Everything looks and sounds fine when I pulled into campus, it only happened in 6th when cruising just barely on the throttle.

thompson

iTrader: (4)

Bypass the msd box on the ignition, Let the opti work on its own. You should be able to unplug the opti from the box and plug it back into the harness. They will do this when the opti is weak.

shbox

Where does it say he has an MSD box???

OP, at this point everything would be a complete guess at what might be wrong. Get some scan results.

nitroheadz28

iTrader: (3)

What can I troubleshoot if the pcm wont link with the scanner? I will take it to my mechanic for an oil change and see if he can do anything tomorrow.

shbox

It might have been the scanner, but your going to troubleshoot that connection, first, if it won't work.

nitroheadz28

iTrader: (3)

I took it out for a quick romp on my break, put 15 miles on it and it didn't do a thing. Looks like its just when I cruise on the highway, hopefully I can get it figured out tomorrow because I have a 500 mile road trip planned halloween weekend

DisasterFormula

iTrader: (1)

My car did the same thing when my opti was dying.

nitroheadz28

iTrader: (3)

On the way home everything was fine as well.

I stopped by autozone and took one of their little scanners myself. I tried 5 times making sure it was jammed up into the port and *no link*.

Hopefully when I take it in for an oil change my mechanic will be able to scan it, blah I wish I had a stock pcm with hptuners lol.

shbox

A lot of OBD-II scanners rely on the +12v supply on the DLC pin 16. Make sure yours is working. The lighter fuse powers it. I am also assuming you don't have an OBD-I conversion.

nitroheadz28

iTrader: (3)

The PO deleted the cig lighter because he said it kept blowing the fuse and he couldn't figure it out, its on my to-do list to tackle..

So I took the car in for an oil change and scan, he managed to read it. Heres what I have:



Also I found out that both my trans and rear end are leaking. Its a new strange rear with about 5k on it, wtf!?





Goddamnit!!!!!!! Only had the car 2 months, got run off the road a month ago/ hit a hydrant because of a reckless idiot. Now all of this

RamAir95TA

iTrader: (2)

Your "transmission leak" is motor oil, not trans fluid. Might be rear main seal, dipstick, intake manifold, OPSU, etc.

A leaking rear isn't a big deal. Just change the fluid and put on a new gasket (assuming it's coming from the cover).

The DTC 16 and DTC 36 are not good. Having both of those codes usually means opti instant-death syndrome.

nitroheadz28

iTrader: (3)

Thats what I just read searching through forums and whatnot.. Apparently the engine wont even run with an active code 16... Most likely culprit is the opti/ wiring/ or possibly low voltage.

My optima was deeply discharged 3 weeks ago, I revived it but it hasn't been the same since. I'll try a new battery this weekend. Its a new MSD opti so WTF, the PO gave me the receipts for all the parts. Like $600 in tune up parts last year

Still reading up on DTC 34.

Also I'm not sure if this is related, but the car just started making a new noise 2 days ago. I hear it most clearly in 3rd while off the throttle letting the engine brake. It sounds like air whooshing, like my old grand prix as it was getting into boost.

I forgot to add that the engine idles at about 850-900 now as it has a vacuum leak.

DisasterFormula

iTrader: (1)

What MSD really stands for is Might Suddenly Die. If you want a good Opti, you want AC Delco, Delphi is second. Anything else is hit or miss. Me, I'm running a new Cardone distributor with a Chandler Motor Sports cap and rotor and I haven't had any problems the last 1500 miles or so. A lot of people don't have luck with Cardone. Accel is cheap, chinese made garbage.

Optima, I've heard a whole heckuva lot of bad things about them since they moved their factory to Mexico. My car has had a Duralast for about 4 years now, judging by the stamp on the side. When it dies, I'm probably going to buy a Diehard battery from Sears from what I've been seeing from them.

shbox

Opti or opti harness is your problem. The MAP code (in your case) is generally a result of the engine performing in an unexpected manner (like your situation that causes a sudden lowering of RPM [or even dying] due to another issue). I would not worry about that one.

nitroheadz28

iTrader: (3)

Thank you gentlemen.

Yes I've heard the same about Optima, I bought the car with a red top in it- its 1.5 years old.

Now realistically speaking, if I buy a spare opti asap and go on that road trip and it dies on me. Is it possible to swap out roadside with basic tools and a set of sockets and whatnot?

This pisses me off, I have a receipt right here just for the ignition components-

$428 MSD Opti
$38 MSD Coil
$95 MSD Wires

Give me a friggin break! Is there any way to rule out if its the opti or not?

DisasterFormula

iTrader: (1)

It can all be done from the top of the car, but being able to crawl under helps quite a bit. You have to drain your coolant and pull the alternator, water pump, smog pump, pump bracket, and crank pulley off to get at the opti. A lot of people will say pull the crank balancer off but I didn't feel the need to; I was able to squeeze the opti in there pretty easily with the balancer still on. You'll need a 15mm deep socket to get off one of the water pump bolts and to get the one behind the power steering pump off, you can just use a regular 15mm socket on an extension.

I would suggest biting the bullet to go ahead and replace it w/ a good AC Delco, but if you decide to take the spare around with you until the MSD craps out on you, go ahead and open the spare up and loctite the rotor screws. E4 socket to take the cap off.

Easiest way to rule out the opti is going to check voltages and grounds on your opti harness to make sure they're correct then ohm the harness.

nitroheadz28

iTrader: (3)

Ah crap! Now I see why everyone rags on lt1s and optis =(. Is there a vendor on here or a source that has the best price?

Thank you I appreciate it.

Speedy

Believe me, they aren't bad. Just ditch the MSD parts and use AC Delco.

nitroheadz28

iTrader: (3)

I read somewhere that MSD will rebuild the opti if its past warranty (1 year- mine is a little older) for $150, does anyone know if thats true?

I mean $550 is a good chunk for a new Delco unit- and I'm not the kind of guy to skimp on these kinds of things. But with being let go from work, my beater throwing a rod and having to part it out, having this accident in the T/A, and now this... Things are definitely rough.

I'll do some more reading on how to check the opti and harness, I need to buy a multimeter

Ok so I checked and the most MSD charges for an opti rebuild is $122+ shipping. Seems hit or miss, but its the cheapest option. Only thing is having to wait 2+ weeks, why did my grand prix have to blow up?

I read that Delcos are all reman and basically crap, you have to find a NOS one which is hard if not impossible and delphi is the choice for stock.

Getting ahead of myself anyway, multimeter first to check all this crap before I start throwing $$$ at this pig.

DisasterFormula

iTrader: (1)

You can usually get OEM parts on GMpartsdirect.com.