I have a 5-6K miles on msd opti and coil. 7k miles on tune up. 1 o2 is brand new the other has 7k miles on it. new air filter, cleaned the maf, pulled and clean the tb.


Well the car will start right off sometimes. Other times it'll drain the battery and never start and will backfire through the intake. Other times it'll start but after cranking on it till the battery is nearly dead.

I had a buddy say he thought it was the maf but I doubt that? These cars will run with the maf unplugged won't they? It just resorts to a standard table in the pcm doesn't it? Is there a way to test the maf?

He said it could be the ICM also? Can that be tested?

Oh The car will not run for **** without the msd6a hooked up. And once the car is started and running for a couple minutes it runs great and it will fire on demand until it gets overnight cold.

 

Also Once the car is started and running for a couple minutes it runs great and it will fire on demand until it gets overnight cold. Spark seems to be jumping around and may not be firing properly. Which explains why sometimes it'll get lucky and start.

Fuel pressure also has checked out and there is no major leak down in the fp over nite. Car still has about 10psi of fp overnite.

 

No ideas?

Been doing some reading and it seems to me that if the ICM is bad then the injectors don't get the go ahead to fire from the PCM? Is this accurate?

 

could be a weak battery or bad ignition switch

 

battery was checked at orielly. if the ign switch was bad it wouldn't crank at all? It'll crank all day long until the battery is drained.

Only seeing about a 1.5v drop while cranking from 12.1 volts to about 10.5-10.8 while cranking.

 

If you took the fact that there is a 6-8k mile old msd opti out of the equation and I still had the problems I think alot of people would be screaming opti.

I am starting to think maybe just maybe the msd is going bad? Or maybe the rotor is faulty? It was installed february of 2007.

 

[QUOTE=DAFAIC;5886822] if the ign switch was bad it wouldn't crank at all?


NO..... my ignition switch was bad and the car would crank over but not start. Sometimes it would start and run on only a few cylinders and other times it would run fine.
The best way to tell is, turn the key forward until the started is about to ingage if the lights in the dash go out when you turn the key to crank the started its probably bad.
Also every time you try to start the car and it doesen't start, turn the key all the way off like you are taking the key out and try again.
I've read all kinds of weard thing the switch will do.

 

My 8k mile old MSD opti is dead or dying. I found that you can check whether the optical sensor is functioning properly by checking the pulsing ground on the non pink wire on the unplugged #1 injector while trying to start the car.

After a few other tests to confirm signal is moving from one side of the plug to the other it is confrimed that the opti is bad.

Sent MSD an long *** e-mail last night. They prolly won't do anything since it's been in the car 2 years and a month but only 8k miles.

 

Have you scanned it? Loss of the low res pulse signal from the Opti will shut down the fuel system, but it will also set P1371. There are also codes for a shorted or open circuit to the ICM. An intermittent problem with the Opti pulse signals can be due to a dirty or corroded Opti harness connector.

 

The car wouldn't run over 3,000 rpms when it was running without the msd 6a plugged in.

while cranking the car the light on the test light wouldn't flash while testing pulsing ground, then it would flash for a second or too. the car would stumble, and then it would quit flashing and the car would quit trying to start and just turn over.

I unplugged the opti and plugged it back in and check all the wires. and they all tested fine.

Harlan Hynes wrote the following. This is what I did and everything checked out. When I got to checking the pink wire/blk it had ground like it is suppose to. Now I couldn't unplug the opti and test at that end because it's an MSD and it's hard wired.

"OPTI testing

If you failed the injector pulse test we must make sure that all the power is getting to the opti.

With the test light and the car on KOEO, unplug the opti connector at the optispark and test for hot at the red wire at the opti. do you have hot?

If yes. Next step

if no, the pos feed comes from the computer. Check that the PCM is sending the signal, if not then you might have a faulty PCM



Next, using a multi meter on volts scale, test the red/black and purple/white wires for 5 volts. Do you have 5 Volts?
Yes, next step
No, The 5 volt reference is provided by the PCM, possible PCM failure or PCM power feed problem


Next, test the pink/black wire for ground. Do you have ground?
Yes, then the optical sensor is not working and is probably bad. based on the other tests run this is causing your no spark condition. It’s time to replace your opti. You can also check for corrosion or damage to the opti connector and replace as needed.

No, the ground is provided by the PCM, possible PCM failure or PCM power feed problem."

 

Well pulled the opti off tonight. While I was looking everything over piece by piece I noticed the coil contact on the cap was dirty. Went over and jerked the coil wire off and sure enough the opti side was soaked in coolant and the metal contacts were rusted. Cleaned the opti contact and put it back in.

So the speed shop that installed the opti didn't do the following...
1. use new water pump gaskets and didn't bother putting any sealer ontop of the old gaskets.
2. didn't use the o-ring that came with the opti. I had 2 so never thought twice about that.

So I installed the o-ring, used an old coil wire from before the morosos to test with, installed the battery, and did a test fire and the car fired just like it use too. It starts so quickly you can't hardly get off the key fast enough.

So I'll try again in the morning and if it does it again I am going to clean up the water pump mounting area and put it back together.

 

Well got the car back together. It fired right off the first time. Let it warm up then realized a hose was leaking. Turned car off. Fixed that. Second time starting was a little slower. Didn't tighten one of the bleed screws enough so I turned the car off and tightened it and checked some other stuff. 3rd time started the car took about 4 seconds to start. Went for a drive and everything seemed good.

Came home jacked the car up and put the muffler back on as the car has been running muffler less for a while. Rolled it off the ramps tried to start it and nothing. Now it wont start. Tried both the other icm and coil and with and without the msd 6a box and still no crank.

Car started up fine 3 times and then went down hill!?!?!?!? Any ideas???

 

Injuneer
There are no codes
and only a pending code for the driver O2 as the heater on the O2 is out.