It still sounds to me like you might have a bad ECM.

quote Posted by Lou6t4gto 07-14-2008 will a ecm out of a 87 GT 5 speed work in a 86 SE 2.8 auto ??? just for test purposes ???

Did you try swapping the ECM's? You can use the 87 GT 5 speed "temporarily" just for a test. I wouldn't put a lot of miles on the car with that one though.

I'd do this before I started tearing apart the fuel injection.

------------------
Marc in sunny Titusville, FL

• 84 SE son's car, loaded
  
• 85 Coup w/V6 transplant
  
• 85 GT newly on the road
  
• 86 SE/GT "The Chameleon" - big plans!

I tore into mine last night and removed the upper intake, only to realise the smaller EGR tube that runs from the lower manifold into the backside of the throttle body had come loose, so it was sucking in way too much air. could that cause a problem like what we are seeing here?

It certainly couldn't help things.

just thought I might use it for 5 min, just to see IF thats the problem. IF it'll run with the 87 GT ECM , I'll just take it back out & get the correct one. No one wants to stick their neck out & answer "COULD IT BE THE Pressure Regulator" ?

In my opion, it may be. If it's not letting enough fuel through, yout initial prime (the pump hums when you first turn the key) may build up enough pressure to let some through and start the car, which them lets off some of the pressure. Then you may not be getting our pressure to build and continue running, therefore choking it out. Get what I mean? A partially clogged fuel filter would have a similar effect.

------------------
Jay Brintnell
Southern Ontario Fiero Association
Yellow 85 Notchback(A.K.A. GodFearN)

quote Originally posted by Eclipse: I tore into mine last night and removed the upper intake, only to realise the smaller EGR tube that runs from the lower manifold into the backside of the throttle body had come loose, so it was sucking in way too much air.

It's not an EGR tube, but...

Did you have a high idle speed?

& the only way to check the pressure regulator is..... ?? if I remove it, can I tell by looking at it ? maybe a hole in the diaphram ? any way to check spring pressure ? I'm asking sooo many questions because I'm TRYING to LEARN. Thanks

ok, here is something that will get your blood boilin or make you feel really dumb. do you have enough gas in it? maybe your gauge is lying to you.

im facing the same dilema. but my setup is totaly different than anyone elses on this forum. i am going to test my shrader valve and see what it reads. it will fireup only after the pressure has subsided and i then let the pressure build back up. it will fun for however much fuel is in the lines. then its outta gas. and wont get anymore going. i dont understand why it is doing this. it was driving fine the night before. the first and most obvious step i skipped was putting some gas in it. it says there is 1/8th tank, but my needle could be lying to me now. never has before. im also replacing my plugs since they are previously fouled from pouring gas into the cylinders. i will eventually findout what the deal is on mine. and i will note it on here for a future reference to anyone who needs it.

------------------
1987 Fiero GT built by my brother, merlot566jka, 3500 LX9 from 06 Malibu, WOT-TECH.com 1280 grind stage 3 cam, LS6 valve springs, 1227730 ECM conversion, Darrel Morse solid aluminum cradle mounts, Truleo headers modified to fit the 3500, 36# inectors, 70mm 4.3 throttle body adapted to 3500 intake, ported heads, upper and lower intakes, lightly polished, tcemotorsports.com crank trigger wheel, CenterForce dual friction clutch, Flowtech Afterburner muffler, 2.5" piping, cat deleted, EGR deleted, SinisterPerformance tuning, C6 Corvette exhaust tips. projected to be 35 MPG with a guesstimate of 250 hp to the wheels

I put in 4 gallons after cleaning the tank. I don't think the gauge works at all. but , HOW could it be able to build 44 pounds pressure if there wasn't enough gas to run ??

Patrick, thank. You are right, my typo. It was the "Throttle Body Idle Air tube". No fast idle, just runs for 2-3 seconds and dies altogether. There is fresh gas in teh tank.

I'll continue hunting tomorrow:}

Lou, Good luck!

[This message has been edited by Eclipse (edited 07-16-2008).]

I am not 100% familiar with that engine, but I would suspect the map sensor is bad or the MAF sensor is bad or unplugged. As far as the FPR is concerned you should be able to pinch off the fuel return line and try to start the engine if you think it is just bleeding off the fuel pressure. Make sure the map sensor is plugged in and its vacuum line is plugged in and not clogged. Also check the MAF sensor for corrosion on the plug.

Hope this helps. Good luck.

I know WHERE the Map sensor IS, but I am not familiar with WHAT IT DOES. & the MAF ??? what is it ?? and WHERE is it ?? thanks

from just breifly scanning through a few posts it sounds like you have clogged injectors..setting for 9 yrs will do that

What you might try to do is put some techron in the tank and tap on the injectors as a friend trys to start it ..use a ratchet extension or something to be able to reach them ..of course it might not work on all the injectors so you will just maybe be able to get it barely running with it missing but...once it runs and warms up ..alot of times the other injectors may start working with you nudging them along by tapping on them ...I have done this many times on different cars that have set and it usually works ..

Erik, all of the injectors wouldn't die at once would they? if there was 1 or 2, or even 3 fowled injectors, wouldn't the car at least try to chug along on the others?

quote Originally posted by Eclipse: Erik, all of the injectors wouldn't die at once would they? if there was 1 or 2, or even 3 fowled injectors, wouldn't the car at least try to chug along on the others?

Well if the car has set for that long the fuel in the injectors are all gummed up by now so yes, all of them are likely fowled. If you can get a few to start working using the method I mentioned then it may get the others to at least start firing as the engine warms up with you nudging them along by tapping on them and running techron to help..it may take a while to unfowl them and its not guaranteed that they will completely become unfowled.

If it was mine I would just pull the intake and pull the fuel rail with the injectors, take each injector and connect up a spare injector wire clip, ground one side of the injector wire clip rapidly supply and remove voltage to the other side and see if the injector clicks then connect a short length of fuel hose to the injector inlet clamp it with hose clamp dump some techron in the fuel hose injector inlet, apply a few pounds of pressure to the inlet with a air compressor on low pressure settting ( be sure to clamp the air tip to the fuel hose so it doesnt go squirting out techron all over you ) while you supply and remove voltage to the injector rapidly ..This works really well to clear up the injector IF the injector is salvagable ..every now and then an injector will be junk so its not a guarantee but worth a try concidering the cost of new injectors

I didn't see any response if the fuel pump running. it is possible for it to prime the system, but not run during start and or run - the ECM needs the signal from the Oil Pressure Sending unit. - jumper the pump at the Data link, and listen for it running, if its running, try to start the car leaving the jumper hooked up.
if the fuel pump is running, check the fuel pressure regulator - yes, this could cause this problem. Pull the Vac hose off the FPR, and look for fuel, it there was a hole in the diaphram, fuel would pass through the vac hose.
Also check the pressure at the valve, and check to see how long it takes to drop off - after an hour, it should only drop 10 - 15 psi.

if the fuel pump is running, and no troubles with the FPR, than pull the injectors, it's really not that hard to do.

for this time being while i am trying to figure out my fuel system problem, i am going to hook some wires up to a resistorized LED to show when the fuel pump is on. sorta like a 12v test light.....

------------------
1987 Fiero GT built by my brother, merlot566jka, 3500 LX9 from 06 Malibu, WOT-TECH.com 1280 grind stage 3 cam, LS6 valve springs, 1227730 ECM conversion, Darrel Morse solid aluminum cradle mounts, Truleo headers modified to fit the 3500, 36# inectors, 70mm 4.3 throttle body adapted to 3500 intake, ported heads, upper and lower intakes, lightly polished, tcemotorsports.com crank trigger wheel, CenterForce dual friction clutch, Flowtech Afterburner muffler, 2.5" piping, cat deleted, EGR deleted, SinisterPerformance tuning, C6 Corvette exhaust tips. projected to be 35 MPG with a guesstimate of 250 hp to the wheels

UPDATE: This afternoon I removed the intake top, the Fuel Rail, injectors. the inside of the rail had some rust, the injectors were really cruddy. I cleaned everything with carb cleaner (the injectors sprayed insid the inlet & blew out with air) , checked all the injectors by touching current to them, THEY ALL CLICK. checked the pressure regulator (applied vacuum to the port, could hear something move , but No air leak ). One thing I thought strange, when I removed the intake & return lines, (I had tried to start it 3 hours before) but when I unbolted them , there was absolutely NO Pressure. is that normal ??? thanks for your input.

i believe the pressure dies off after a little while. that is kind of the same problem ive been facing.

------------------
1987 Fiero GT built by my brother, merlot566jka, 3500 LX9 from 06 Malibu, WOT-TECH.com 1280 grind stage 3 cam, LS6 valve springs, 1227730 ECM conversion, Darrel Morse solid aluminum cradle mounts, Truleo headers modified to fit the 3500, 36# inectors, 70mm 4.3 throttle body adapted to 3500 intake, ported heads, upper and lower intakes, lightly polished, tcemotorsports.com crank trigger wheel, CenterForce dual friction clutch, Flowtech Afterburner muffler, 2.5" piping, cat deleted, EGR deleted, SinisterPerformance tuning, C6 Corvette exhaust tips. projected to be 35 MPG with a guesstimate of 250 hp to the wheels

Posted on 7/6/08 - If I am not mistaken, the Fiero has a cold start injector. After a few seconds, the fuel to this injector is shut off. Your main injectors may be stuck or gummed up with varnish. Just a guess but if it will continue to run on starting fluid, etc. it sounds like an injector issue to me. Keep us posted.....

Still believe that you have an injector(s) problem........ Hope cleaning them works for you.

You posted earlier about the oil turning black. Well your starter motor does turn the engine over, and although you've changed the oil, 9 years of stilling will leave all sorts of crud through the engine, so that does not sound unreasonable; that what little running you've had would blend this old stuff in with the new. Regarding your starting issue, i would have guessed fuel injectors. To have more than 2 fail, although unlikely, is possible. They've sat for 9 years!! The pre-squirt injector is enough to get the engine started and thats it. Hopefully you cleaning up the fuel rail and injectors works once you get it back together.

Lou,

You should check for an Injector pulse with your test light. I dont know how much disassembly you have done already, but if the sensors (especially the TPS) are all connected, unplug one of the injectors and connnect your test light between the 2 terminals. When you crank the engine it will blink every time the Injector fires (if the ECM is sending the signal). There is an injector test light called a NOID light that you can get at Autozone etc., but a conventional test light will work as long as you can get it connected at both terminals.

As someone mentioned above, you don't know if the ECM is receiving reference pulses from the ignition system. Just because the tach works does not mean the signal is making it to the ECM. If you see RPM on a Scan Tool, then you know the signal is getting read by the ECM (i know... maybe borrow one?).

Also you said the TPS was new. That does not mean the circuit is intact. If there is a bad connection between the TPS and the ECM, the ECM may think the throttle is wide open, and the injectors will be shut off (Clear Flood Mode).

I think you should make sure there are no problems with the engine control system before tearing into it mechanically. Did you ground the diag connector in the console and check for codes? (there may be more now from working on it, this would have been better to do early on). I know you said electrical work is not your thing, but I would hate to see you throwing parts at it.

Just my...say 5 cents or so. I hope this helps you.

I DID test before getting into it. it showed NO Codes. ok, the Lid is not bolted up yet, so I'll check the plugs going TO the injctors for pulses, I a 12 volt test light will work, right ? HOW do I check the tps ??? all I did was change in a KNOWN GOOD Sensor, made no difference. What size is the Bolt/Stud (had a 10mm nut on it,small stud. that holds the flange on the EGR Tube coming from under the inake To the EGR?? I lost one into the GREAT VOID of the engine compartment. Thanks

Yes a 12V test light will work.

Sorry, I missed that you checked for codes. I tried to open the service manual link that Sidecar posted, but it is being blocked (I'm at work), oh well.

If you have a schematic from the other testing you did at the ECM (did you get one from 88IronDuke?), you can test the TPS by backprobing the wires at the ECM. With the Key on, Connect your Digital Volt Meter black lead to the TPS ground (black wire), and the red lead to the Signal (dk blue wire). With the throttle closed you should have less than 1 volt DC. If so, this is not the problem. Normally the voltage will be less than a volt with the throttle closed, and go close to 4.5V or so at WOT. If you slowly press on the accel pedal you should see the voltage go up. If the voltage is high before you even touch the gas, you have a wiring problem (assuming the sensor is good, or not stuck).

I'd give you the ECM pin numbers, but I can't find a schematic. If I find it I will edit this, or someone else can chime in.

I also hope I'm not leading you off on a tangent - I think more likely the suggestion made by Sidecar might be more important to check based on the symptoms. But it is harder to check for the reference pulse to the ECM without a scan tool. You can probably backprobe that circuit with your meter, but I'm not sure what to look for. Did you check the continuity of the 4 wires between the distributor and the ECM?

EDIT to be less stupid (me): If you had an injector pulse when you cranked with the test light connected in place of an injector, then you have a reference pulse, and you can ignore all of the blabbing I did here. Sry, just realized that.

EDIT to add TPS info:
D12 Black = Ground
C13 Blue = Signal
C14 Gray = 5Volt Ref

[This message has been edited by Jakesdads86gt (edited 07-17-2008).]

I checked 3 of the plugs going to the injectors, they DO pulse the test light. haven't put the lid back on yet. WHAT size is the bolt holding the EGR Tube to the exaust ? lost one, & don't need a leak at this point. Thanks

Try jumpering 12 volts to pin G in the ALDL connector (goes directly to the fuel pump). Run a piece of wire from the positive on the battery to this terminal and the pump should run continuously. See if that makes it stay running. If it does then there is something going on with the fuel pump relay circuit.

I think someone already suggested that but I didn't see if you tried it or not.

[This message has been edited by Jakesdads86gt (edited 07-17-2008).]

thats one of the first things I tried, That was 2 months ago. I'll try it again now that I know the injectors ARE NOT the problem. This is really getting frustrating.

first did you try to block off the fuel return line and see if it started.

The map sensor senses vacuum pressure and tells the ecu to start the run map.

The Mass Air Flow senses air flowing into the engine and adjusts the air fuel mixture, if it is unplugged or not working the engine will start but then die very shortly.

Haven't blocked the return yet.(Tomorrow) I already changed the MAP,(no difference) I wish I had a pile of sensors to "borrow" to change these out, 1 by 1 is getting expensive. something is definitely shutting off the fuel flow. I want to see what the Pressure gauge does when, ON, starting, AND shutting down. (tomorrow)

OK, I put the pressure gauge back on, when I turn the iign ON it goes to 40PSI, runs for a second or 2 (staying at 40 PSI, shts down, still holding 40 PSI. I gues that rules out the pump, filter, lines & regulator. Back to: somethings shutting off the pulses to the injectors. new MAP, TPS, cleaned injectors.( I wouldn't think crimping off the return line is neccesary since it Holds 40 PSI no matter what). so, now to change out the ECM (out of my 87 GT stick.) WHAT ELSE ?

I am in the same boat. Car sat for 10 years. New gas, started right up and has started every time for the past year. Car is started and driven in and out of the garage about 5 time a week. Never any problem. Last Sunday it drives out of the garage fine but the return trip it fires up nice but stalls and had to be push it into garage. I can get it to run at 2000 rpm if I pump the throttle very fast. The engine sputters, runs very rich and back fires a little but won't idle. When I turn on the key I get gas to come out the fuel line. I have yet to crank the engine and see if fuel comes out. I have gas and pressure to the injector rail.

Has O2 sensor been checked

I hope you find the problem soon and look forward to your answer

HOW do I check the O2 sensor ??

The IAC controls the idle circuit. At idle, the butterfly in the TB is closed. The IAC allows air to come through a "bypass" orifice in front of the butterfly. If you look in the front of the TB, you will see a hole in the bottom of the TB. this is the orifice that the IAC controls. A small plunger on the IAC moves out to allow air into the intake. If it is not opening, it may cause it to die at an idle. When it does start, will it rev? Can you open the throttle slightly to increase rpm's? Grasping at straws.......

TOUCH THE THROTTLE & IT DIES IMMEDIATELY. The throttle only works WITH the ether spray.

I would test the TPS and its connection


Have you checked for spark? A weak coil or ignition module or crappy connections could cause the symptoms

pull a plug wire, stick a screw driver into the plug end and hold it about a half inch away from a gound and then crank the engine over ..it should have a nice white spark if not its time to investigate the ignition ..even so, your module could be on its way out so you might want to test it as well

[This message has been edited by Erik (edited 07-19-2008).]

plugs are sparkin' right untill the engine stps spinning. module was the first thing replaced.