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Discussion Starter #1 (Edited)
Heres my story i got a 1996 fleetwood with a stock lt1 it ran fine until i noticed the temp light came on so let it cool down and next day i tryed to start it, it cranked but wouldt come on. The reason it overheated because the water pump bearings went out from what i seen and got so hot it melted the side of the optispark so since i seen that i then replaced the following-optispark/harness,water pump,temp sensor,icm,coil,cam position sensor,cam seal/opti seal. Now still cranks but no start? I get no spark from the spark plug wires and coil?? I even swapped the pcm thinking maybe it was bad but still nothing. I checked fused there good but did replace the ignition fuse but still nothing?? What can i check now??
 

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May have fried the ignition control module if overheated. It is bolted to front of head (right side as you face engine from front). Get that sensor checked at Autozone for free. In my experience, if bad, need an AC Delco part. Generic crap from China will throw engine codes. Also, cocobolo95 has suggested in past to double check that you ensure wires were put back onto opti in correct positions.


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Discussion Starter #3
Yes the coil was replaced and is ac delco and also the wires are correct because i marked them when i took them off
 

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Discussion Starter #8
That was actually the first 2 things i replaced and still no luck so i then went ahead and did the opti and other stuff to it
 

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I know you said coil was Delco, but ICM too? Might sound weird but try unplugging ICM currently bolted in and try plugging in old one and give it a shot. I have seen ICM from store be completely shot even out of the box


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Discussion Starter #10
Sorry i ment to say the coil is ac delco but the icm is another brand. I will try to plug in the old one just to see what it does because i still have it
 

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Have you tried checking for codes? Codes for opti low & high resolution pulses missing, as well as both icm codes, don't light the check engine light. Or the service engine light, depending on which one 96 fleetwood has.

I'm not sure, but I think fleetwood can check codes without an obd 2 scanner. If not, get an obd 2 scanner. Get one that can also read real time sensor data.

So check codes, and even though engine doesn't run, with ignition switch on, you can read some of the sensor data. As an example, if coolant temp sensor is reading way off, car won't run.

Lets start with the opti you bought. If it's anything besides Delco, GM, or Delphi, there's a 50-50 chance of it being bad right out of the box. If you want to diagnose the opti low & high resolution pulses, the only 100% way of checking the square wave output of opti, is with an oscilloscope.

Luckily, you can buy a PC based scope for around $70. Get it on ebay, amazon, etc.

Now for the overheating. If you melted the opti cap, you might have damaged the engine. At the very least blown head gasket or gaskets. Do a compression test and a leak down test of cylinders to confirm.

If engine is good to go, lets get a fuel pressure tester and see what key on prime pressure is. There's a schrader valve on fuel rail to attach tester hose to fuel rail. Pressure should be around 43 psi @ key on prime.

Buy a new set of injector lower o-rings and install these when replacing fuel rail into intake.

If you have the opti low res pulse missing code or the 2 icm codes, they keep pcm from opening the fuel injectors. So, you need to remove fuel rail from intake. With catch cans under the injectors & a fire extinguisher at hand, have assistant crank engine. Are fuel injectors spraying fuel?

All this should keep you busy for awhile.
 

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Forgot to add, body control module sends pcm a 50 hertz fuel enable signal. This is when opti & icm codes are not set. And when vats security system is all in order. It's a 50 hertz square wave. Scope can show this also.

So, when you turn ignition switch to on, does security light come on for several seconds? Then go off again? This means everything ok with security system. If light stays on, engine won't run because pcm stops injectors from spraying. Good write up of vats security at www.shbox.com

# 25, 26, & 27 in how to section.
 

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Discussion Starter #13
Thanls for that info cocobolo95 the security light not on the dash at all. Someone also mentioned to me check all my ground wires. Can somebody tell me where are all the ground wires that could effect this issue??
 

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Did you do the engine tests I recommended to see if you have blown head gaskets?

You probably need to change the light bulb for the security light. This involves removing the instrument cluster. I'm not sure if fleetwood has it's own service manual, or if fleetwood uses the caprice/ roadmaster manual. But you need to find out and gget the factory service manual. It will have wiring diagrams with all grounds & power wires.

As a stop gap, you can download the 96 F-body service manual at the following link. While the lt1 engine & transmission will be mostly the same as your fleetwood, there will be differences. www.mediafire.com/?40mfgeoe4ctti

I give good advice. I don't always hit the nail on the head, but I know what tests to run and where to look for trouble. If members would do the tests I suggest, they would confirm or eliminate specific problems they are having.

The compression & leak down tests are very important after you overheated your engine enought to melt the high temp plastic parts of your opti. These tests need to be done to eliminate mechanical problems that will keep engine from running, if blown head gasket/s are found.

After doing those tests, move on to testing fuel pressure @ key on idle. If good get a code scanner and scan for codes. If opti or icm codes are present, fuel injectors will not open. Fix the security light. You need it. When light works, when key turned to on, security light comes on, then goes off after several seconds. If security light stays on, either solid or flashing, fuel injectors won't open.

Troubleshooting involves a step by step test of components. If components test good they can be eliminated as a cause of problem. You move on to the next test. And so on. Installing a new part does not eliminate that part as a suspect. And part changing doesn't always fix a problem. There can be problems with power wires, grounds, connectors, splices, fuses, etc.
 

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Discussion Starter #15
I did not do the test you recommend due to work and not having those reader tools but just gathering as much info as i can and getting familiar with it so when i do get a day off i can try to attempt to do so
 

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Yeah i too was going throught the same troubles as you. I did the same as you. My 95 fbird would stall after about 5 minutes of running. One of the last things i did was to get a new pcm. Still stalled out on me. I felt like i was going in circles and toughing money to the wind. It turns out that it was the icm. After all because i got a a cheap non delco icm. Then had heard not to use the knock offs . So i put the original ac delco back in and was having the stalling issuses. Put all kinds of parts in try to figure whats killing the motor and it end beening icm. So i put the cheap icm back in and has been running great now. Planning on getting the ac delco one soon. But have not yet. Hope this helps you. Thats what i would do my friend.
 

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If you got a multi meter. You can back prob the white wire going to the icm. With the red lead prob. Then black to the cars body. Have the meter set on a/c voltage scale. On a low scale. Like my meter starts at 20 volts then 120. So i used 20 scale. You then turn the ignition on to try and start it. You should see a flash reading of any thing from 2 to 4 volts. If you are see a voltage pules in that range. And have no spark out of the coil under the icm. It most likely the icm bad. Try this 1st my friend before you go checking & burying a bunch of un need instrument tools etc. You can thank me later ;) good luck
 

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Discussion Starter #18
Hey thanks. I will swap the old icm just to see what it does because i did test it and it was still good. Going to do the wire teat like tou said this weekend and see what it says and will report back
 

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Discussion Starter #19
Its working now!!!!! It ended up being the cheap no name brand icm i bought new. All i did was plug in the old stock icm and it fired right up. Wow thanks all for the help and recommendations means alot
 

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Yeah that is awesome. Your welcome! Im glad i could pass some good info and tips. O by the way for the icm. It is recommend to put the white past on the back of the icm& the aluminum plait the icm and coil blots to. If you dont have the white past a substitute for it is dielectric grease. That is what i used . have not had any issuses. Keep it rubber side down my friend lol.
 
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