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Discussion Starter · #1 · (Edited)
Fixed it!

FIXED IT! THE NEW COIL WAS SHOT!

(Posting updates at end of thread)

I am still having issues with my 87... here is what it is doing.

Cold fires right up sounds great, runs great, smooth, etc.

gets up to factory temp 210-220 and she dies won't start.
Doesn't give any codes anymore.

Things I have tuned up, fixed, and checked along the way.

replaced fuel regulator diaphram (was leaking)
MAF is clean
New MAF relays
New fuel pump and filter
new coil, wires, plugs, module, cap, rotor
holds fuel pressure

I don't want to through parts at it... but I am not sure where to look next. I have heard people talk about the oil pressure sending unit causing problems... should I try that?

any help is greatly appreciated... I really want to drive!
 

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Wire up an idiot light to see if the pump is getting power when it runs for a while. When it causes the problem also check on the fuel pressure. After that, check if you are cranking and getting a blue spark
 

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always drop back to the basics of compression,
air flow in and exhaust out of the engine,
ignition spark, strength and timing,
and fuel delivery,volume and pressure
oil pressure and temp
cooling,temps and fluid levels (fuel,oil,coolant)
computer controls and sensors
obviously compressions ok, so that only leaves the remaining potential problems

Id check for fuel pressure is steady and spark is consistent first and verify the spark plug condition as clear pictures of the plugs numbered by cylinder can give a great deal of info
id check for vacuum leaks , and loose battery connections and loose grounds,the symptoms would make me think its ignition , sensor, CPU,or fuel related

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=1401

http://forum.grumpysperformance.com/viewtopic.php?f=80&t=728

http://forum.grumpysperformance.com/viewtopic.php?f=70&t=202

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=168

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=596

http://forum.grumpysperformance.com/viewtopic.php?f=70&t=2798&p=7622#p7622

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=3954
 

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Discussion Starter · #5 ·
Found it... I think

Well everything is in order... pressure, spark, no codes...

However, it appears that the central Cat is toast super heating the exhaust... I am guessing that has toasted the o2 sensors as well. The engine is actually pushing exhaust out before the coupling into the cat... :thud:

I don't exactly know why that causes it to die when hot... Maybe someone can enlighten me.

Time to save some pennies for an exhaust system cat and back.
 

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Well everything is in order... pressure, spark, no codes...

However, it appears that the central Cat is toast super heating the exhaust... I am guessing that has toasted the o2 sensors as well. The engine is actually pushing exhaust out before the coupling into the cat... :thud:

I don't exactly know why that causes it to die when hot... Maybe someone can enlighten me.

Time to save some pennies for an exhaust system cat and back.
If that is the case, drive it for a while with it dumping straight out the manifolds before the cats. If the problem goes away, it is the cats.
 

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if your running rich the cats tend to heat up, if your running EXTREMELY RICH the cats melt and clog, if the cats are partly melted thats more than likely allowing the engine to run untill heat expands the crud in the cats and chokes the engine, melted cats are a RESULT of a fuel control problem not the CAUSE, a bad fuel pressure regulator, or defective injectors or defective sensors can cause the problem, as always theres ways to TEST & VERIFY, before you go throwing money at the problem by buying /installing random parts
pulling trouble codes helps but its not the ONLY source of info

"the symptoms would make me think its ignition , sensor, CPU,or fuel related"
 

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Discussion Starter · #8 ·
Never give up.

Again thank you for the help!

I have talked to a few local shops and the conclusion is that even if the cat are toast that they will not cause the engine to die @ temp.

I hate tossing random parts at the problem I am not sure what to do next other than take it in to a shop.

I have no doubt it is a "simple" problem I just haven't found it yet.

:huh:but I am persistent. I have built several carburated chevys and have work on many imports so I don't any problems wrenching...

I just am not sure what to do next... since it runs perfectly when cold.

I was thinking about throwing a oil switch at it since I have read of people having similar problems with it.

Thanks again! :D
 

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I was thinking about throwing a oil switch at it since I have read of people having similar problems with it. :D
That was going to be my next suggestion. Should be simple to prove without buying anything. Let the engine warm up and "shutoff" then insert jumper on the low oil pressure fuel shutoff sensor plug and see if motor re-fires
 

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If it is the cats disconnecting them will help verify the problem. After which you can chase it down to the root cause
 

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Discussion Starter · #11 ·
More

I went back to the basics!

at 205 degrees the spark quits...

it has a new coil, module, cap, rotor...

could the capacitor cause this problem... I did not replace it yet....
 

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Discussion Starter · #12 ·
the capacitor housing is trashed oem broken apart... rusty... went through hell and back five times...:smack
going to get a new one... let ya know how it turns out. :spanked:
 

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Discussion Starter · #13 ·
still no spark... has power to the coil... uhhh. I feel like I am chasing my tail. I guess I can check the ground... or maybe the new coil or module is bad... but it is the same issue that grounded me to begin with. :thud:
 

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Discussion Starter · #15 ·
Puzzled

In a good way I think... :crazy: I have got her running hot or cold. But I am not totally sure the how or why of it... Spark, fuel, ..... all good and running strong... I am not holding my breath though.

It is probably because I made an appointment for the local pros to take a look at it. :laughing:

all I can figure is I miss diagnosed the spark in the day light... sorta doubt it... but I have made one or two mistakes before.

The fuel system was / is dirty and I have been cleaning it with lucas injector cleaner... perhaps it was the major issue along with the other minor ones...

:huh:

It has been a long strange trip. All I can do now it take it out and run it. And hope I don't have to call AAA.


Enduro is enduring... :smack
 

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The fuel system was / is dirty and I have been cleaning it with lucas injector cleaner... perhaps it was the major issue along with the other minor ones...

:huh:
If you tried dancing around a fire at midnight with a chicken tied to your head and it works, you can declare that as a cure too. If you suspect your injectors and I'm not sure why, take them out and have them sent out for testing or better yet, replace the old multecs with Bosch 3s.
 

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Discussion Starter · #17 ·
ignition problem

Never heard of this scenario before... here is what is happening.

has power to the distributor.

fires runs great... more power than ever.

randomly dies... no spark at all.

I pull one plug wire hold it away, have someone crank it over. then it starts sparking again after a few cranks.

shut it off... put the plug wire back on... fires up and runs fine... until it does the same thing.

it is definately in the distrib. I am going to have the new coil and module checked... if it is not that then the only thing left that isn't new in there is the pickup... but I don't think that it could be the issue. :crazy:
 

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Discussion Starter · #18 ·
If you tried dancing around a fire at midnight with a chicken tied to your head and it works, you can declare that as a cure too. If you suspect your injectors and I'm not sure why, take them out and have them sent out for testing or better yet, replace the old multecs with Bosch 3s.
I dance at the fire every tuesday to worship the vette gods with tar and feathers covering me head to toe. :devil: cluck cluck bawk bawk. :rolling:

I am going to replace the injectors they are due... I wanted to be sure it was the cause of this engine drama... and as my previous post... lol! that is not the problem...

Thank you all for your patence and help! it has made this adventure much more endureable... hahaha.

and thank you for the links grumpy! super helpful! :D
 

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I pull one plug wire hold it away, have someone crank it over. then it starts sparking again after a few cranks.

it is definately in the distrib. I am going to have the new coil and module checked... if it is not that then the only thing left that isn't new in there is the pickup... but I don't think that it could be the issue. :crazy:
What color spark?

Why can't it be in the pickup?
 

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Discussion Starter · #20 ·
Spark is blue and will arc a 3 -4 " gap with ease... when it sparks. I guess it can be the pick up.... that is why I asked... ;) i suppose it could be all rusty and nasty in there... time to look... brb

:D
 
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