Ok, the plot thinkens and gets even harder to diagnose.....
I bought a new ICM today. I just went out and set up the shop lights, a fan, and grabbed the tools. I hopped in the car to pop the deck lid button, and before I got out, I put the keys in the ignition to test what it felt like doing today.
When I turned the key to the on position, the fuel pump turned on for 2 seconds and then went off. When I tapped the key to start, to test if it would come on for an additional 2 seconds, the car started. It ran for a couple seconds and then quit.
Cranking the car, the fuel pump comes on every time like it should, and the car sputters, like it wants to start. This is the exact symptoms I had 3 months ago when I was sure the car was out of gas, and the cause for dropping the tank 4 times looking for problems with wires, rubber fuel lines, plugged sock, and replacing the fuel pump.
In the video last night, the fuel pump was NOT coming on while cranking in any way, and it never attempted to start.
In the video below, taken tonight, the fuel pump is coming on as it should, so the problem above has went completely away, replaced by one that the car starts for a few seconds and now dies.
I honestly do not know if anyone begins to understand how EXTREMELY p'd off and frustrated I am at this point and time. I have found myself restraining my self from taking a sledge hammer to the car... I would hand someone $500 cash to make this problem go away.
NOTE: NOTHING on the car was touched between yesterday's video, and the one below. In fact the decklid has remained closed since the video last night, and never reopened
[This message has been edited by JohnWPB (edited 09-30-2014).]
May I suggest something different, that it might be the ECM connectors. The ECM uses a card edge with copper plating and the connector that plugs onto this has weak contacts. The combination of these two can create an intermittent nightmare that is almost impossible to diagnose. The copper fingers on the card edge can oxidize creating a very light film. This can be easily cleaned with a pencil eraser. The connector is much harder to deal with because the pins are only rated for a couple of inserts, that is, disconnecting and the reconnecting it to the ECM. There are kits to replacing all of these pins but for now you might want to try to bend the pins out just slightly enough to make a tighter contact with the ECM. I have used pins from my wife's sewing kit to accomplish this. Once the pins have been pulled out slightly you might want to spray them with Deoxit electrical cleaner, but make sure you wipe up any excess fluid in the connector. Do NOT use this on the ECM.
My 2 cents. Nick
I second Nick's suggestion. I talked to one of the guys who was on a team that went around to dealers to work on "Problem" Fieros back in the day. They got called in after none of the dealer mechanics could solve issues. He said most of the time what fixed whatever issue they were called in for was cleaning the contacts to the ECM.
Ok.... ECM unbolted.... I do not see how the plugs come loose. I certainly do not want to mess something up! I see no clips to release, or anything to "squeeze" like a normal style plug to release.
Check the fuse links and contacts on the c500 area specially the one for the Ecm .
If it were a fusible link, say blown, I don't think that would cause the intermittent problem I am having. I will definitely look at the contacts though. I am taking plugs apart everywhere, and inspecting them, and spraying with contact cleaner.
[This message has been edited by JohnWPB (edited 09-30-2014).]
Push the connector towards the ECM to take pressure off of the metal clip, slide a small screwdriver between the metal clip and the plastic connector on the ECM side of the metal clip and then pull the connector off backwards.
I doubt this is an ECM problem. This seems to me to be a fuel pressure problem. Buy a fuel pressure gauge from Harbor Freight or borrow one from your parts store and see what the fuel pressure does when the trouble is happening. My guess is that it falls off quickly after the engine starts.
I think this because the engine doesn't just stop but instead gets progressively worse and then quits. But don't make assumptions - use the fuel pressure gauge and see if this is indeed the problem.
The fuel pressure should read about 42 psi minus intake vacuum. So with the engine not running 42 PSI ish. Take 10 PSI for the 10 PSI vacuum with the engine running at idle.
A Googled pic of the connector so ignore the text
---- Edit - maybe I am hearing things that weren't there. Not sure if it coughed while it died or did it just 'shut off' die. A cough die would make me suspect fuel pressure was dropping. A cut off die tends to be more electrical. Still would be worth it to have a fuel pressure gauge to see what is happening fuel pressure wise. At $19 it is cheaper than a tow. Make sure the gauge goes up to 50 PSI.
+1 on the idea that this problem is not the same as the last problem. Two separate things to fix. Both of them intermittent. We know with this problem when it is happening - the ICM is producing a signal that is getting to the ECM, and the ECM is seeing the signal.
I am not one big on thinking this is an ECM pin problem. Since we know the signal is making it to the ECM if the problem it would have to be on the ECM injector output. GM has two banks of injectors. Each bank is wired to two pins. So you would have to have 4 pins going bad and at the same time for this problem to be bad Injector output pins. If only 3 went bad the engine would still run but you would have a substantial 3 cylinder miss.
btw,when GM went to later OBD1 ECMs such as the 7730 they dropped it down to only one pin per bank. So GM didn't see the need for extra pins at the ECM due to bad connections.
With it you can see what is happening with your ECM. You will have to take the Lt. Blue secondary terminal retention clips off to be able to probe the terminals of the connectors. You also need to power this test probe, you can use the power to the Cig Lighter socket for that.
You will be able to see the ignition pulses come into the ECM. You will be able to see if the ECM is firing the injectors. You will be able to see if the ECM is turning on the fuel pump relay
Use the WHITE pin locations for the stock Fiero 1227170 ECM. The Yellow pin locations are for the 7730 swap. You have the 7170 ECM as I can see it in your pictures.
While this shows a DIS ICM, the wire colors and functions are the same as the distributor mounted ICM.
The Purple/White wire is the ignition signal coming from the ICM - Terminal B5 on your ECM. When probing with the engine running or cranking the light should go between green and red. This will indicate your ICM is sending a signal to the ECM.
The White wire on B4 is where the ECM is returning the signal to the ICM. The ECM controls advance once the engine is above 400 RPM. Once over that the ECM will be sending the signal to the ICM. Again you should be able to see the signal here. Note - When cranking the ICM runs on it's internal signal and ignores the White wire. But remember the Purple/White wire MUST be getting a signal during cranking or the ECM won't be injecting fuel since it doesn't see the engine as turning over.
The Tan/Black wire on D5 is the one that ECM uses to tell the ICM that the engine is indeed running over 400 RPM. So once the engine has started the ECM will change the signal on the Tan/Black wire to indicate to the ICM that the ECM will be controlling advance.
Injectors - D14 & D15 and C15 and D16. Lt. Blue and Lt. Green. Don't be surprised if GM swapped things around . Many (most) times each wire coming from the injectors has both a Lt. Green and Lt. Blue wire spliced on it and then connects to the ECM. It really doesn't matter since you should get the same reading on all 4 of the wires. Key on engine oif the probe should read high (red) on all 4 pins. Engine running or cranking you should see the ECM bring the pins down to the low state and the light should flash to green for just a short pulse and then return to red. Each time the light flashes green that indicates the ECM was pulsing the injector.
All these tests are to be done with the connectors plugged into the ECM and using the test light probe, back probing until the metal tip connects the proper terminal inside the connector. No light on the probe indicates you haven't yet touched the metal terminal. Once you have you should see one of the lights come on.
[This message has been edited by phonedawgz (edited 10-01-2014).]
Whew, that is a lot to process! I am no electrical guru, but that looks like I could probably do it if I take my time and look the diagrams over well.
In the mean time, I did take the ECM apart, and I am not sure what people above are talking about by cleaning the edge connector. The edge connector is unused completely. In fact it is covered in a soft plastic resin, as well as the rest of the board to keep from shorting out from moisture ect.
The plugs go into the other end, and are not flat connectors, but "square wires". I sprayed the pins with alcohol, and then used a soft brass brush and went over all of the pins good. I dried it all off with my heat gun set to low. This was pretty much preventive maintenance, as all of the wires, plugs, pins were shiny and new looking with zero corrosion.
As for the car when it dies, it has never "coughed" and yes, I do know what you mean by that. It usually just up and dies quietly haha.
Anyhow, I have to pick up that electrical tester and a fuel pressure gauge tomorrow, and the saga will continue.
[This message has been edited by JohnWPB (edited 10-01-2014).]
while you're there, dont forget to reseat the chip. ...and is that a factory OEM chip or a Mod Chip?
Now you tell me I have no clue honestly
I will get the fuel pressure tester today..... I also have that new ICM to put in today, and will be getting the new coil in the mail as well.
Also, still curious on this:
quote
Originally posted by npdimonte:
The ECM uses a card edge with copper plating and the connector that plugs onto this has weak contacts. The copper fingers on the card edge can oxidize creating a very light film. This can be easily cleaned with a pencil eraser.
There was an edge connector, along the entire end of the PC board, but it is unused. Does this differ with Fiero ECM's?
[This message has been edited by JohnWPB (edited 10-01-2014).]
Originally posted by infinitewill: The problem was that the previous fuel pump had non-submersible fuel line which dissolved and left quite a bit of debris in the tank and it would constantly get sucked into the pick up tube and starve for fuel.
infinitewill, how long did it take for that to happen??
Sorry, I did, but honestly it seemed quite remote, but another person mentioned it as well, so you were right to begin with
The last time the tank was dropped, I put purple cleaner in it, and washed it out really, REALLY well. I then took my industrial shop vac, put a filter over the end of the hose, inserted it in the exhaust port of the vacuum and the other end in the gas tank. I let it blow that warm air in the tank for a good hour to ensure it was COMPLETELY dry. When I changed the fuel sending unit for the "more modern one" from the Fiero store, I replaced all of the rubber lines with fuel rated lines.
The new coil came today, but I am taking a couple days off from the car and will put it on this weekend, as well as the new module.
I went to Harbor Freight today, the only fuel pressure kit they had said it did not fit GM. I went next door to the part store, and they wanted $60 for a tester. If it was something that I would use all the time, I would not think twice about it. But I am not a mechanic, and cant justify $60 for a one time use tool. I will try Autozone this weekend and see if they have a loaner.
[This message has been edited by JohnWPB (edited 10-01-2014).]
Perhaps your new fuel pump relay isn't up to par? Or maybe the connection is so-so and needs to be cleaned?
May I make a general trouble-shooting suggestion? Now that the thread is long it really takes time to go through to see what others have suggested and what your results have been. Could you perhaps 'edit' the first posting to include a little table at the very bottom that Lists all the things you've tried in One Place? That might help others to see something that has been missed. Conditions can sometimes play a role ... does the failure happen when engine is Cold or Hot or when raining, etc. My daughter had a car that would fail only above a certain Outdoor temp, whether the engine was Hot or Cold.
Sorry, I did, but honestly it seemed quite remote, but another person mentioned it as well, so you were right to begin with
The last time the tank was dropped, I put purple cleaner in it, and washed it out really, REALLY well. I then took my industrial shop vac, put a filter over the end of the hose, inserted it in the exhaust port of the vacuum and the other end in the gas tank. I let it blow that warm air in the tank for a good hour to ensure it was COMPLETELY dry. When I changed the fuel sending unit for the "more modern one" from the Fiero store, I replaced all of the rubber lines with fuel rated lines.
The new coil came today, but I am taking a couple days off from the car and will put it on this weekend, as well as the new module.
I went to Harbor Freight today, the only fuel pressure kit they had said it did not fit GM. I went next door to the part store, and they wanted $60 for a tester. If it was something that I would use all the time, I would not think twice about it. But I am not a mechanic, and cant justify $60 for a one time use tool. I will try Autozone this weekend and see if they have a loaner.
Auto Zone, Pepboys, Advanced auto and maybe Napa. You might be able to get an adapter to make the HF one work.
lol you said youre not a mechanic with all the work you did on this car!!! Then you go and buy a 2nd fiero?? $60 for something you're gonna need means $30 per Fiero!!! or just sell it on ebay when youre done for $30 (net) That makes it $15 per Fiero
**** HF says "Fits most systems (except for Bosch, CIS-Jetronic and GM throttle body systems)" You Dont Have GM TBI. You have GM MPI
[This message has been edited by Alex.07.86GT (edited 10-01-2014).]
Originally posted by Alex.07.86GT: Auto Zone, Pepboys, Advanced auto and maybe Napa. You might be able to get an adapter to make the HF one work.
I tried NAPA and Bennit Auto Supply and neither had any type of adapter. I will try a few other places......
quote
Originally posted by Alex.07.86GT: lol you said youre not a mechanic with all the work you did on this car!!! Then you go and buy a 2nd fiero??
That was a statement that I am going through the motions, and expressing my limitations I guess hehehe.
As for the second Fiero, It's a no brainer. I need a new gauge cluster, new center console, and a few other parts. The Fiero is $400. It also has a brand new Grand Am brake kit from the Fiero Store with something like 100 miles on it, with SS lines (Before the engine blew). So it will be a true bolt on replacement for my car.
When I am done with the car, the junk yard will pay me $400 and come pick it up. (I did this a couple years back with another Fiero that another member on the forum and I stripped parts off of).
quote
Originally posted by Alex.07.86GT: **** HF says "Fits most systems (except for Bosch, CIS-Jetronic and GM throttle body systems)" You Dont Have GM TBI. You have GM MPI
I bought the HF kit, and brought it home. There was one adapter in the kit that fit, but it did not press the valve stem in the center of the schrader valve. It was in too deep in the adapter, and didn't even touch the one in the center of the schrader valve, let alone press it down the 1/4 inch or so needed.
As for updating the first post, I will try to do that tonight. I am on the way out the door to work now.
What is this attached to the distributor mount? I noticed the ground was probably not that good on it. Whatever it is, I need to know what it's called to get a new one It looks like some sort of capacitor maybe?
Thanks for the link to the fuel pressure tester. That is the one I bought, then took back LOL! I guess I was doing something wrong. It sure seemed like the one adapter that fit, did not depress the valve stem core thingy.
I am on my way now to get a new fuel pump relay, and to re-purchase the HF pressure tester. I will put all of that on, along with the new module and coil when I get back.
[This message has been edited by JohnWPB (edited 10-02-2014).]
What is this attached to the distributor mount? I noticed the ground was probably not that good on it. Whatever it is, I need to know what it's called to get a new one It looks like some sort of capacitor maybe?
Thanks for the link to the fuel pressure tester. That is the one I bought, then took back LOL! I guess I was doing something wrong. It sure seemed like the one adapter that fit, did not depress the valve stem core thingy.
I am on my way now to get a new fuel pump relay, and to re-purchase the HF pressure tester. I will put all of that on, along with the new module and coil when I get back.
GOOD! cause I was about to send you some money to bu the $60 one
What is this attached to the distributor mount? I noticed the ground was probably not that good on it. Whatever it is, I need to know what it's called to get a new one It looks like some sort of capacitor maybe?
Thanks for the link to the fuel pressure tester. That is the one I bought, then took back LOL! I guess I was doing something wrong. It sure seemed like the one adapter that fit, did not depress the valve stem core thingy.
I am on my way now to get a new fuel pump relay, and to re-purchase the HF pressure tester. I will put all of that on, along with the new module and coil when I get back.
It's your Tach Filter. It filters the high frequency interference generated by the solid state HEI so the tach sees only the firing pulses and not the interference. Can't get it anymore, but Rodney Dickman has them: Fiero Tach Filter
[This message has been edited by Robertzep2 (edited 10-02-2014).]
I just quickly read through your post... Have you replaced your ignition coil? I had this exact problem last Fall. I was driving home from a long ride. The car died on the expressway and I coasted to an exit ramp. Let it sit and it started up. Drove for a bit and it died again; sat and it started. Got back on the expressway, determined to get home, and it died again about five miles from the house. Pulled to the berm, let it set and tried starting it. No go. Called Insurance company and got it flat bedded home. I spent the next day troubleshooting. I put my timing light on the coil wire and aimed in the back window. I watched the strobe pulse, and thought; good I have spark. Replaced ICM and thought I am good to go.... The car would not start. I replaced my distributor with a new one, and thought I am good to go.... The car would not start. Replaced the ignition coil and it fired right up and has ran good ever since. So, even if the ignition coil outputted a spark it was too weak and cause all my issues. Another clue, when it was having problems I heard a high pitch in my radio. I even put all my old parts on with the new ignition coil and it runs fine.
[This message has been edited by Robertzep2 (edited 10-02-2014).]
Funny you mention the coil, as I just replaced it today. I put in a new coil, new ICM new Distributor Cap, new Rotor and a new fuel pump relay. (All of these, except the coil, were new already, with around 100 miles use on them)
I used an inline spark checker today, and I am getting spark, but it would still not start.
So, It all came down to the fuel pressure, and I was SOOooo hoping that the pressure was non existent or really low. At least I would then know it was just a matter of dropping the tank to fix it. The car does not want to cooperate however, and the fuel pressure is perfect.
So, I have air, fuel, and spark..... THE three things needed for an engine to run, however mine is not running. It is not a timing issue, as I just timed it, and it runs perfectly when it starts (and would not cause the car to die going down the road). Plugs and wires are new, even if they were "bad" it would not cause the engine to just die while driving down the road. The fuel pump turns on when I turn the key on, and turns on again while cranking. The tachometer goes to around 400 RMP or so while cranking.
I am so over this......
[This message has been edited by JohnWPB (edited 10-02-2014).]
You have fuel pressure and spark, but no fuel is getting through the injectors. You either have shorted injectors, no 12 volts to the injectors, or no ground pulse to the injectors. The ground pulse comes from the PCM/ECM, the 12 volts comes from the fuse box at key on.
Check for 12 volts at the injector connector with key on, if you have 12 volts check for ground pulse at injectors.
My guess is shorted injector, and can be diagnosed with a DVOM
when it doesnt start, will it start with starter fluid?
I replaced all the stuff above last night, and cranking and cranking the car does not want to start. Next is to test if the car will start with starter fluid.
I just went to test that..... and tapped the key and the car started. It is running, and idling perfectly. Fuel pressure is at around 35 with the car running.
Now, how to test further since it now wants to run. I know the problem is still there, and just waiting to cost me ~$300 when it dies on the side of the road somewhere.
@Steve I will test the injector when I figure out 2 things, first how to do it, and second when the car decides not to want to run again. Testing now would be pointless, as they are tend to work perfectly at noon, on the 1st Friday of the month.
[This message has been edited by JohnWPB (edited 10-03-2014).]
the wires on the right look like they were squished. you might have more damaged/squished wires. test those wires. while its running wiggle all your wires & connections around.
Distrib/coil wires to ECM or wires from ECM to Fuel Injectors should be top priority.
Probably when there is a blue moon, or when big foot shows up, too.
John, I applaud your efforts, and have learned a lot by reading this thread. Of course, you're probably no better a mechanic than I am. I'm just curious, but by now wouldn't a mechanic have fixed this for less cost, time, trouble, and effort? Usually, this odd problem you're having would be my luck.
I'll give it my best shot, but sometimes it's easier to run it by the [good] mechanic and get the problem fixed. Sometimes some humor, too. I had a good laugh watching them drive my truck around and around the lot, with one mechanic hanging off the side of my truck, looking for the source of the noises. Later, they used some sort of hydraullics to boince my truck up and down in the bay while listening for noises. My son wanted to be in the truck for this.
I'D BE DRIVING it on 4 jack stands @ 40mph in my yard waiting for things to happen!!!
I started the car, let it get up to temperature for a week, then restart... then cool completely and restart no problem. I did this for 3 days straight, and all seemed fine. I drove it for 4 days this last time, all over the place, and even to its first car show / meet. Never a problem. Then the 5th day, it did it again, and got towed home.
As for taking it to a mechanic, can you imagine how long at $80 an hour it would take to get them to just this point of what has been ruled out. I would agree if say it was a known problem, like a water pump gone bad, a bad starter, take it and have someone else fix it However, when it is a totally random intermittent problem, it makes it extremely hard to diagnose.
There are a lot of people posting and helping in this thread that I trust far more than some mechanic that asks a Pontiac what? When you tell him what kind of car it is
I just need to read up and figure out how to test the injectors, if it is even possible when the car is running as good as it is at this particular point in time.
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