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My 94 fleetwood has 168k on it, had to replace opti back in Nov, put maybe 3k on it since then. Was running fine up thru Monday night when I got home from work. Went to go to the store Tuesday afternoon and nothing, just cranks away. My dad just left from looking at it, he doesn't have an obd1 scanner to be more accurate but from the tests he did its getting spark thru the coil and into the opti but not sending it out to the plugs and I also have no injector pulse.

Anyone had this problem before or have and idea as to what else it could be? Like I said, I have had zero trouble since replacing the opti and all of the sudden this happens.
 

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Well, I was bored sitting in the house so I just went out and changed the coil and Ignition control module and still does the same thing. I even tried to bang on the gas tank. It smells like fuel under the hood but I still have no clue what the deal is. Someone has changed the coil in the past as one of the hex bolts was replaced with a philips head bolt
 

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Got to check the two basics. Spark & fuel. FP gauge quickly rules in/out that being the issue. If FP is good, move to ignition

Apparently the icm or coil was not the issue

BTW stock coil would have been riveted on so any replacement coil is held on by small nut/bolt. Of which any PO could have changed
 

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Got to check the two basics. Spark & fuel. FP gauge quickly rules in/out that being the issue. If FP is good, move to ignition

Apparently the icm or coil was not the issue

BTW stock coil would have been riveted on so any replacement coil is held on by small nut/bolt. Of which any PO could have changed
I'm gonna run down to Harbor Freight in the morning and grab one. What should it read with key on? Also would crank position sensor cause any problems?
 

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Anything with a CPS is most likely OBD-2. A '94 will not have a CPS. Half way through '95 maybe. You can easily tell by seeing it on the bottom of the timing cover. Confirm either way before buying a scanner. If you do have a CPS issue (doubt it) it will likely throw a P0336 code. But it will not show up on the HVAC diag reader. Any big parts house will let you use a reader. An OBD-2 reader, they don't keep OBD-1 laying around.

Depending on what replacement Opti you got, and who installed it, it could very well be that. Especially if it doesn't have an AC Delco yellow transluscent cap (stronger, less flexing, better quality, and which indicates good chance of better quality optical reader, screws that stay tight....) If you did a new IC and ICM I'm sure you used the correct thermal paste. I'm also sure you read the 1/2 dozen painfully detailed threads on Optis and Opti rebuild.

And don't get tunnel vision, eyeball errthin under the hood. Dad's eyes always good to add.

Also: bad gas.
 

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My 94 fleetwood has 168k on it, had to replace opti back in Nov, put maybe 3k on it since then. Was running fine up thru Monday night when I got home from work. Went to go to the store Tuesday afternoon and nothing, just cranks away. My dad just left from looking at it, he doesn't have an obd1 scanner to be more accurate but from the tests he did its getting spark thru the coil and into the opti but not sending it out to the plugs and I also have no injector pulse.

Anyone had this problem before or have and idea as to what else it could be? Like I said, I have had zero trouble since replacing the opti and all of the sudden this happens.
It's worth asking....what brand of Opti did you use? Anything with something other than the Mitsu Optical sensor is going to be a crapshoot and could fail quickly. Also be sure to check the condition/operation of your Vent Harness for thje Opti.

So, getting back to your no start. I used to have link to a very good troubleshooting thread but it appears to no longer be on the web :frown2: However, there are many threads here and in the Stickies that could help you trace out your issue and find the culprit. It could be something big like a bad Opti or something as simple as a broken wire in the harness. you need to troubleshoot it and not throw parts at it. Use a methodical process to trace down the issue.

If you google "LT1 No start Diag" will will find lots of hits on various sites and for various car platforms. It's ok to use a troubleshooting link from a Corvette site....it could help you figure this out. To me it sounds like youve narrowed it down to the Opti. Think you said you got nothing going out to the plugs so that is where i would focus my concentration.

Look at the circuit for the Opti and there are troubleshooting steps to verify if the signals are coming and going into the Opti as it should. If you find a signal not going, it could be the sensor and/or it could be a bad wire or terminal. At this level of the weeds you are going to need a DVM (meter) and know how to use it to check for things like Voltage and continuity. GL and let us know what you find.
 

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If you have fuel pressure and no pulse to injectors and no spark at plugs, then opti is bad.
AIP has a decent one I hear for $100.

Nab
 

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so spark into the opti but no spark out of opti .my guess is the opti is filled with engine oil.. remove the lower venting hose see if oil or other crap flows out .

new opti may have been poorly made bad rotor bearing seal.. I tested a new opti it had the rotor bearing seal leak .. spectra brand .

if that is with no mess leaking out then the opti cable may have gotten water in the opti by poor seal... that will kill the optical sensor and no pulse to PCM to turn on injectors .

any deep puddles/car wash ETC..
 

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I'm gonna run down to Harbor Freight in the morning and grab one. What should it read with key on? Also would crank position sensor cause any problems?
You need a FP gauge that has a fitting to screw on to the Schrader valve. When you turn the key on, engine off, the gauge should immediately snap up to around 42 psi when the pump primes then drop to around 35 psi. If engine would start it should be 43.5 psi with the vacuum line pulled off the FPR. With that vac line on it should be about 37 psi

If you have a CPS that should not prevent the motor from starting if it was bad, just throw a code

The lower $ off shore Opti is a crap shoot
 

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Discussion Starter #10
You need a FP gauge that has a fitting to screw on to the Schrader valve. When you turn the key on, engine off, the gauge should immediately snap up to around 42 psi when the pump primes then drop to around 35 psi. If engine would start it should be 43.5 psi with the vacuum line pulled off the FPR. With that vac line on it should be about 37 psi

If you have a CPS that should not prevent the motor from starting if it was bad, just throw a code

The lower $ off shore Opti is a crap shoot
I think it may be the fuel pump. My brother in law took me up to get a pressure tester, I used the only hose that would attach to the valve and got zero psi. I can't even hear the pump prime anymore, we could when we first looked at the car yesterday afternoon
 

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Discussion Starter #11 (Edited)
so spark into the opti but no spark out of opti .my guess is the opti is filled with engine oil.. remove the lower venting hose see if oil or other crap flows out .

new opti may have been poorly made bad rotor bearing seal.. I tested a new opti it had the rotor bearing seal leak .. spectra brand .

if that is with no mess leaking out then the opti cable may have gotten water in the opti by poor seal... that will kill the optical sensor and no pulse to PCM to turn on injectors .

any deep puddles/car wash ETC..
not sure the brand, it was a freebie from a friend of a friend but I do know it was brand new. Unfortunately I don't have access to a jack right now to get my car high enough to slide my big ass under the car to pull the vent tube and I can't get my big hands to it from up top

update

I tried the jumper wire trick as the pump wasn't priming. I tested with gauge hooked up to schrader valve. Just discovered the gauge set I got from HF could use some teflon tape lol. Held power to the pump for 5 seconds and gauge stayed at 40psi until I let off and dropped to 0 as my quick fix leak solution was a paper towel zip tied to the hose. The pump still doesn't sound like it should though.

I went back out and tested the relay which was good and I found out that the pump wasn't priming because in the dark last night I forgot to bolt down two wires on the coil. Pump primes again but still doesn't start. At this point I'm thinking its opti or pcm
 
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