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Fiero no start - what's your guess on the problem? by tjthorson
Started on: 11-04-2013 07:36 AM
Replies: 15 (1228 views)
Last post by: Fiero_Mark on 11-12-2013 03:41 AM
tjthorson
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Report this Post11-04-2013 07:36 AM Click Here to See the Profile for tjthorsonClick Here to visit tjthorson's HomePageSend a Private Message to tjthorsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Guys,
I have been working on cars for over 25 years.... Rebuilt engines, rear ends, etc.... I have a Fiero (that I actually need to sell) that is driving me nuts. Give me your thoughts on what you would do next.....

Car cranks - no start. spark tested at coil and on two plugs - all good. Compression at least 130 in back three cylinders. Car was running - and just died out. Car did have fuel pump being backfed through ALDL connector. Found the problem there - pin was corroded and broken in the fuel pump relay plug in the engine bay. Now has fuel pump prime on key "on". Fuel pressure >35lbs. (gauge leaks, hard to get accurate reading.)

Steering column replaced due to key not moving to "start" - PO had a toggle switch override. New steering column and ignition switch (should be unrelated - but Im telling all).

So - fuel injectors must not be firing, right? I suspected backfeeding the fuel pump through the ECM might have damaged it, so I replaced that. Still no start. Trying to follow the service manual. I do have an old OTC4000. I noticed I do NOT have any RPM indication on crank. Manual says to apply 12v to 3rd wire on one of the plugs from the ignition module - should show RPM on OTC. Not only does it NOT show RPM, the fuel pump runs.....

Thoughts? Is there another sensor on this thing Im not aware of - crank sensor or something that keeps the injectors from firing?

And - if you know anyone looking for an 85GT 4 speed with low original miles, and a ton of new parts... Let me know.

------------------
Todd Thorson
Current Fiero - NONE!
http://www.toddsplace.com

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Gall757
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Report this Post11-04-2013 08:42 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Prove to yourself that the injectors are not firing by spraying starting fluid in the throttle body and cranking. If the car runs for a few seconds you know there is no fuel getting there. '

With no RPM showing on cranking, the more likely problem is the ICM or pickup coil in the distributor, or associated wiring.

[This message has been edited by Gall757 (edited 11-04-2013).]

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tjthorson
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Report this Post11-04-2013 09:19 AM Click Here to See the Profile for tjthorsonClick Here to visit tjthorson's HomePageSend a Private Message to tjthorsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

Prove to yourself that the injectors are not firing by spraying starting fluid in the throttle body and cranking. If the car runs for a few seconds you know there is no fuel getting there. '

With no RPM showing on cranking, the more likely problem is the ICM or pickup coil in the distributor, or associated wiring.





Already replaced the ICM - did not replace the pickup coil, although it looks pretty rusty.

But - if the ICM or pickup coil were bad - wouldn't I also have a no spark condition?????

I get spark firing at the coil - and at the plugs....
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Gall757
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Report this Post11-04-2013 09:55 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Perhaps.. Do the starter fluid test first, and then you will know.
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Old Lar
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Report this Post11-04-2013 10:01 AM Click Here to See the Profile for Old LarSend a Private Message to Old LarEdit/Delete MessageReply w/QuoteDirect Link to This Post
Fuel, spark, one or the other isn't working. ECM, distributor.
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theogre
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Report this Post11-04-2013 10:04 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by tjthorson:
But - if the ICM or pickup coil were bad - wouldn't I also have a no spark condition?????

Even if you have spark... No ref signal (No RPM on scanner) = ECM will not ground injectors and will not start.

See my Cave, HE Ignition and Ground "Myth" notes

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Fiero_Mark
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Report this Post11-05-2013 04:27 AM Click Here to See the Profile for Fiero_MarkSend a Private Message to Fiero_MarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hello All -

This is my first posting of any consequence on the Pennock forum. I have gotten so much help and important information by reading this forum for a couple of years now that it is time for me to step up and return a little bit to the community.

tjthorson, I think that I have the answer to your "cranks but won't run" condition. I think that much of the following chronicle will sound familiar to you.

I have also been going through an epic battle with my 88 Formula. I decided to write everything down because the problem had become so deep with regard to the number of remedies attempted and theories explored, and staggering contradictions.

The problem is the car cranks but will not run. No pops, backfires, smoke. Nothing. Nada. Zilch. Zero.

The car we are talking about is an 88 Formula, 2.8 V6, Auto trans., approx. 140k miles. For the past two years since returning it to roadworthy status (and before) the car has always run excellent. It regularly has been getting as much as 33 MPG, and when starting, the motor runs as soon as you turn the key. Never missed a stroke. It is (was) that good. There are many new or virtually new parts, most less than 12-18 months old.

** How The Problem Started **

When I started the car one morning for a trip from Lynnwood to Bremerton, the motor cranked for about 5-8 seconds before it started. This was highly unusual since the motor usually runs almost instantly upon turning the key. However, the motor continued to run normally and I commenced the trip with everything appearing normal. The rest of the trip would be on the freeway, and the car ran well the whole time.

About an hour and fifteen minutes into the trip, and while at a highway speed of around 65 mph, the motor suddenly lost power, ran weak and a little rough for about 20 seconds, and then died on the way down an off-ramp where I managed to coast the car off the road and onto the shoulder. My gut reaction was that I ran out of fuel, but my normally accurate gauge read 1/4 tank. I tried starting the motor several times with long periods of cranking with absolutely no indication of firing. Absolutely dead. It remained like that ever since it died. I had the car towed to my parents place in Bremerton --> $100.

** What Was Done After It Died **

-- Whenever I turned the key, the fuel pump ran for 2-4 seconds and shut off in the normal fashion.

-- Poured about 1.5 gallons of fuel in the tank. --> Still no fire

-- Disconnected fuel line in engine bay, turned key and my father said he saw fuel squirting out of the fuel line (more about this later). So it appears that there was sufficient fuel in the tank and fuel being delivered to the engine. --> Still no fire

-- Removed a sparkplug and grounded it, then cranked engine and observed big bright spark in plug. Also true for second plug. --> Still no fire

-- Replaced the inline fuel filter with a new filter. --> Still no fire

-- Replaced the Ignition Control Module (ICM) in the distributor with a new unit --> Still no fire $50

-- Replaced the ECM (computer) with a new (remanufactured) unit --> Still no fire $109

-- Aligned the timing marks on the front of the engine on the compression stroke, removed distributor cap and observed rotor pointing directly at no. 1 cylinder --> timing is correct

-- Sprayed starter fluid in throttle body while cranking. --> Still no fire. Not even a cough, backfire, pop, or smoke. Nothing.

-- Removed sparkplug and observed that it was wet after starter fluid --> Strange!

-- Connected a fuel pressure gauge borrowed from OReillys both in the fuel line and at the Schrader valve on the engine. Both readings indicated zero pressure - the gauge didn't move at all, which made me wonder if I was doing the measurement right. Quizzed my 95-year-old dad about what he actually saw when he earlier watched the disconnected fuel line, and asked him if it really squirted strongly. He said that it kind of dribbled and bubbled. --> It MUST be the fuel pump, RIGHT??

-- Pumped out 4 gallons of fuel and dropped the fuel tank and installed new fuel pump and in-tank filter. Reinstalled tank with 4 gallons of fuel --> Still no fire $85

-- Earlier I poured in 1.5 gallons of fuel. I just now pumped out 4 gallons of fuel, therefore there was 2.5 gallons in the tank when the motor died and the fuel gauge indicated 1/4 tank. --> the gauge was correct and I didn't run out of fuel.

-- Bought new fuel pressure gauge and checked pressure at Schrader valve and got 40 PSI from new fuel pump --> Still no fire

-- Removed new ECM and reinstalled original ECM --> Still no fire

-- Checked for spark with inline spark-checker tool and plug installed --> got blinking light on two different cylinders, no fire.

-- Again sprayed starter fluid in throttle body --> Still no fire or any hint of fire

-- Observed tach in cockpit while cranking. Indicates zero, does not move other than a slight initial twitch. --> is this a clue that the ECM is not receiving reference pulses?? But the distributer/pickup coil is new and there is spark!!

-- Inserted jumper in ALDL diagnostic terminals and observed code 12. I also noticed a rapid clicking sound that appeared to be coming from the top of the engine. Didn't sound good. Removed the diagnostic jumper and the rapid clicking stopped. --> Is the clicking sound a clue?

-- Did a compression check and got 110+ psi.

** The $64.000 Question **

--> How do you mix air, fuel, and spark in an enclosed chamber and NOT get fire????

** Answer To The $64,000 Question **

--> You don't get fire when you actually have no spark due to a bad coil. Replace the coil and the motor will run.

In my case, a good spark was observed in the sparkplug while it was removed and grounded on the exhaust header. A sparkplug checker tool also indicated spark with the sparkplug installed. But the truth is that the plug was not firing when it was installed in the motor and under compression.

When I changed the coil the engine ran perfectly again.

Just to be sure, I reinstalled the suspect coil and the engine would not start. I rechecked for spark with the sparkplug removed and observed a good spark. I put the replacement coil back in and the engine started and ran well. So, a bad coil can cause a no-spark condition when the plug is installed and under compression.

I am betting that this will work for you, too.
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tjthorson
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Report this Post11-05-2013 07:42 AM Click Here to See the Profile for tjthorsonClick Here to visit tjthorson's HomePageSend a Private Message to tjthorsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
AWESOME! That is EXACTLY what I have..... I tried starting fluid - and still not even a sputter and the plugs are wet now.

So - it cant spark under compression.... Amazing.....

I owe you a lunch sir after I replace that coil and that thing fires.... This thing does have a recent coil by the PO - its one of those red "super" holley ones....

------------------
Todd Thorson
Current Fiero - NONE!
http://www.toddsplace.com

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Fiero_Mark
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Report this Post11-05-2013 01:39 PM Click Here to See the Profile for Fiero_MarkSend a Private Message to Fiero_MarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
Please let us know if this works, since you mentioned a recent coil by the PO.

I should also tell you that my many long cranking attempts to start the engine (it took me 30 days to figure out my problem due to the car being 80 miles from home) likely resulted in fuel draining into the crankcase and diluting the oil. My engine first started a little hard with some misfiring due to the buildup of glop in the cylinders, then evened out, but with a whining noise. I shut down and changed the oil and the whining subsided. The car now runs strong and "perfect" again, and again starts almost instantly.

So if this is also true for you, then beware of running the engine for very long when (if) it starts, and immediately do an oil change.

Good luck!

- Mark
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Francis T
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Report this Post11-05-2013 02:22 PM Click Here to See the Profile for Francis TClick Here to visit Francis T's HomePageSend a Private Message to Francis TEdit/Delete MessageReply w/QuoteDirect Link to This Post
For you and others with possible ign problems I'll post the below document again:

Your’s could be a common problem and don’t cost anything to check.
Try this:
Watch the tach when cranking if it don’t move you're not getting pulses from the distributor. If so, it could be a faulty module in it or more likely simply corroded connectors at the base of the distributor. Reseating those connectors a few times could clean the pins some and also do the same to the connectors on the coil etc. These cars are old, and old connectors corrode. Such can also manifest itself as intermittent misfires, and engine cutouts.

BTW: lots of folks keep replacing modules and coils thinking they are bad because the new ones FIX the problem, when in actuality the fact that they simply unpluged the connectors and repluged them into the new unit cleaned the contacts enough to make it work again, at least for a while. It's smart, to replace those old connectors with new ones.
BTW: Cliphouse has those connectors
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tjthorson
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Report this Post11-07-2013 06:25 PM Click Here to See the Profile for tjthorsonClick Here to visit tjthorson's HomePageSend a Private Message to tjthorsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Fiero_Mark:

Please let us know if this works, since you mentioned a recent coil by the PO.

I should also tell you that my many long cranking attempts to start the engine (it took me 30 days to figure out my problem due to the car being 80 miles from home) likely resulted in fuel draining into the crankcase and diluting the oil. My engine first started a little hard with some misfiring due to the buildup of glop in the cylinders, then evened out, but with a whining noise. I shut down and changed the oil and the whining subsided. The car now runs strong and "perfect" again, and again starts almost instantly.

So if this is also true for you, then beware of running the engine for very long when (if) it starts, and immediately do an oil change.

Good luck!

- Mark


mark. new coil $29 at napa. started up on the first blip of the starter. YOU are the nan. PM me a paypal address. im going to send u some lunch money. thanks everybody! ill rekist the car for sale as soon as i put it back together

------------------
Todd Thorson
Current Fiero - NONE!
http://www.toddsplace.com

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Fiero_Mark
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Report this Post11-08-2013 01:48 AM Click Here to See the Profile for Fiero_MarkSend a Private Message to Fiero_MarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hey Todd! YAAAAAY!!! WE WON!!!

Believe me, I know how you feel. Thanks for letting everyone know.

This may sound kinda corny, but hearing that my first serious post on the forum helped someone to solve an extremely mysterious, aggravating and thorny problem is a very gratifying reward of it's own. With all the help this forum has been for me, it feels good to send some back the other way.

Thanks, but no need for lunch money. Our success is my reward.

I need to learn how to post pics, so I thought that everyone might like to see my ride, so here we go …



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tjthorson
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Report this Post11-08-2013 09:47 AM Click Here to See the Profile for tjthorsonClick Here to visit tjthorson's HomePageSend a Private Message to tjthorsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sweet ride! Unfortunately for me - once I get this car put back together now, it will be sold. Its the last Fiero in the garage for now..... This red one is #7 that I have owned since the late 80s when got my first one.

Sorry for the spell errors - I typed that on the phone in the garage last night - wanted to let you know right away. In hind sight, it all makes sense. Wish I would have figured it out before buying the ECM - but I guess the new owner gets 2 good ECMs.... And - I did fix the steering column issue, and the fuel pump issue in the process.

Thanks again. Ill pass it along to someone else somehow!

Todd


 
quote
Originally posted by Fiero_Mark:

Hey Todd! YAAAAAY!!! WE WON!!!

Believe me, I know how you feel. Thanks for letting everyone know.

This may sound kinda corny, but hearing that my first serious post on the forum helped someone to solve an extremely mysterious, aggravating and thorny problem is a very gratifying reward of it's own. With all the help this forum has been for me, it feels good to send some back the other way.

Thanks, but no need for lunch money. Our success is my reward.

I need to learn how to post pics, so I thought that everyone might like to see my ride, so here we go …



[This message has been edited by tjthorson (edited 11-08-2013).]

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Custom2M4
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Report this Post11-10-2013 12:27 PM Click Here to See the Profile for Custom2M4Send a Private Message to Custom2M4Edit/Delete MessageReply w/QuoteDirect Link to This Post
Glad to hear you got it fixed. If your interested in making a donation for the help, perhaps to the forum itself would be a good cause as well. Cliff (the owner), has saved my buns a few times just by having this forum and community still operational after so many years.

Too bad you have to sell, maybe one day we will see you again, for a longer stay. Cheers,
Chase.

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tjthorson
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Report this Post11-11-2013 07:30 AM Click Here to See the Profile for tjthorsonClick Here to visit tjthorson's HomePageSend a Private Message to tjthorsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Custom2M4:

Glad to hear you got it fixed. If your interested in making a donation for the help, perhaps to the forum itself would be a good cause as well. Cliff (the owner), has saved my buns a few times just by having this forum and community still operational after so many years.

Too bad you have to sell, maybe one day we will see you again, for a longer stay. Cheers,
Chase.



Thanks. I certainly have in the past - been around here a long time.... Like I said - this red one was my 7th fiero in my short 43 year life - Im sure its not the last.....

But - good reminder - Ill send along another donation today!

Oh- And FrancisT - forgot to respond to you. That's great advice as well. I knew it didn't apply to me because I did replace the module, and I cleaned those wires (they were pretty green) and still had not start. But - great advice to anyone searching later one and gets this thread.

------------------
Todd Thorson
Current Fiero - NONE!
http://www.toddsplace.com

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Fiero_Mark
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Report this Post11-12-2013 03:41 AM Click Here to See the Profile for Fiero_MarkSend a Private Message to Fiero_MarkEdit/Delete MessageReply w/QuoteDirect Link to This Post
I also would like to say that FrancisT's advice is indeed wise advice for anyone else reading this thread, and as he says, it costs nothing to check and clean the connections.

Unfortunately, I forgot to mention in my "chronicle" that one of the many things I did was clean all my connections and treat them with a deoxidizing electrical contact treatment called "DeOxit". Also, like Todd, *nearly* all my parts were new (except the coil!), and my harness connectors are in fairly good shape. So I knew that the problem was not connectors.

Knowing that the connectors were good while seeing a good spark in the plug indicated that reference pulses were being sent to the ECM. Knowing all this, coupled with the belief that we had good spark, etc., etc., is what made this problem so very, very difficult to figure out. I finally replaced the coil because it was the only part that had not been replaced (because all indications were that it was good). Bingo.

My apologies for the huge photos of my car. I have a lot to learn about posting on the forum.

Good idea to buy Cliff a beer! I shoulda thought of that ...

- Mark
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