Ive seen a lot of threads recently that made me want to say "DOH!" so im thinking it might be nice to have a general repair guide, a refrence guide like the ogre's cave but for step by step trouble shooting. Ive been working on this all afternoon and while im not a plus whore, it sure would be nice if this ever helps someone if I could get one. Also anyone please point out errors or places I could better elaborate. Im not aiming for a every situation guide, just one to the common problems you see over and over again. I may turn this into a point and click interface to eliminate the lengthy scrolling in the future if theres enough interst in it at all. Also all my formatting is cut out on the Forum, so in word format its easier to read

Note, I am not a ASE certified mechanic in all areas, please consult one before actually doing anything in this guide. There, now if you blow yourself up, don’t try to sue me.

Preface:
Visit www.fiero.nl and click on Pennocks Fiero Forum (PFF) for the largest and most helpful Fiero site on the internet.

Common terminology: Using the proper terms can get you better answers faster

Cranking is when the engine is turning over.
IE: When I turn the key the engine cranks but does not start

Firing is when the engine starts up, or tries to.
IE: When I turn the key the engine cranks but does not fire

KOEF means Key On Engine Off and the associated abbreviations can save time.
IE: Volt light is illuminated with KOEO, whats wrong?
Abbreviations: TB=Throttle body, FP= Fuel Pump, LIM = Lower Intake Manifold, SES= Service Engine Soon (light), IAC= Idle Air Control(valve), TPS= Throttle Position Sensor, CTS Coolant Temperature Sensor,

BASIC TROUBLESHOOTING PROCEDURES:

1: When you look at your car does your wallet tremble?
Yes: Good, that’s to be expected GOTO 2
No: Take out some money, lay it on the intake manifold and set it on fire. GOTO 1

2: Are you on your wife’s good side?
Yes: Good, you need to be to own a Fiero GOTO 3
No: Buy her some flowers and GOTO 1

3: Are you ready to get your hands dirty and bleed for this car?
Yes: GOTO appropriate heading for problem
No: Sell it!

For Starting problems GOTO 4
For Battery problems GOTO 9
For Running problems, GOTO 11
For SES light issues, GOTO 12

STARTING PROBLEMS:
Preface: If the starter is cranking the engine over, then it is working properly, just because an engine will not start does not mean the starter is faulty, its only job is to crank the engine over:
4: Put key in ignition, car in park (or clutch pressed in) and turn:
A: Car starts: What the hell are you doing here then? GOTO 3
B: Nothing happens GOTO 5
C: Engine does not crank but rapid clicking noises are heard GOTO BATTERY ISSUES
D: Engine cranks but does not fire or attempt to fire GOTO NO START DIAGNOSTICS
E: Engine starts but runs very rough GOTO RUNNING PROBLEMS

5:Turn headlights on and try to start car again
If headlights do not work, or dim or go out when turning key then GOTO BATTERY ISSUES
If headlights remain at previous state regardless of key position
THEN:

Automatic: put the tranny in neutral and try again,
Manual: Verify that the clutch switch is being fully depressed and try again
Start: examine and replace safety switch if necessary (on tranny with auto)
No Start THEN:

Jumper the yellow and purple wires at the clutch switch, or on the tranny connector with an auto and try again
Start: Faulty switch, replace
No Start: THEN:

Verify 12V on small wire to starter motor with key in start posistion, and 12V with clean connections on large wire to starter motor and ground to engine at all times. Assuming all are true remove and test starter motor.

6: NO START DIAGNOSTICS
6a: Basic rule of thumb engine’s need 3 things added in the right proportions:
Spark, Fuel, and Compression, we will now narrow the problem. Some assumptions will be made, but this will encompass the likely culprits. More in depth problems may be overlooked, but are not in the scope of this guide

6b: CHECK COMPRESSION/CAM TIMING
When the car last ran was it shut off normally?
Yes: assume timing chain and physical internals intact GOTO 6c:TEST FUEL
No: THEN:
Remove the distributor cap and verify that the rotor is turning when cranking the engine.
No: Timing chain is broken, seek professional help. Then find a mechanic
Yes: Hope that the problem is not a jumped timing chain and continue

6c:TEST FUEL
Don’t assume the tank is full just because the gauge says it is, they tend to be faulty. If the car has sat for more than 6 months the gas may have gone bad and the tank will need drained and refilled, along with the filter replaced.
** A key step to diagnosing a fuel based problem is to remove the fuel pump fuse, and feed the engine some starting fluid while cranking. If it starts or acts differently, the problem is likely in the fuel system. If no change continue or jump to 6e:TEST SPARK

Turn the key to the run position but don’t try to start. Listen for a humming in-between the seats. This will be the sound of the fuel pump running
Hear noise: GOTO 6d or jump to 6e
No Noise: Take the gas cap off and listen while someone cycles the key.
The FP will stay on for 2 seconds after the key is in the run position, then shut off until the key is in the start position, or the key has been turned off for at least 4 seconds, then back to the run.
Hear noise: GOTO 6d or jump to 6e
No noise: GOTO 6d ONLY
6d:Verify flow to fuel rail
If you have access to a fuel pressure gauge THEN:
Hook it to the Schrader valve and cycle the key. If you have 40PSI (or 15 PSI for the 4cyl) then you can assume the engine is getting fuel. GOTO 6e:TEST SPARK
If you do not have access to a fuel pressure gauge THEN:
Poke the center of the Schrader valve and gas should shoot 2-3’ into the air.
A: Nothing comes out: GOTO 8:FUEL PUMP DIAGNOSTICS
B: Little comes out or low spray: add gas and re-check, or test with fuel pressure gauge
C: Large stream comes out vigorously GOTO 6e:TEST SPARK
D: Large stream comes out and sprays you in the eye: What the hell were you thinking? I told you it would shoot 3' in the air, common sense should tell you not to stick your face over it. Now go flush with running water and call a doctor.
6e:TEST SPARK
If you have access to timing light: GOTO 6f ELSE GOTO 6g
6f:Hook timing light to plug wire #1 and power/ground. Have someone crank while you watch the timing light. Does it light?
Yes: Check spark strength with 6g THEN GOTO VERIFY TIMING
No: GOTO 7
6g: Remove a spark plug wire and lay it on the intake manifold so that a spark can arc to the engine. You may need to insert a screwdriver and space the metal 1/8” off the engine. Crank engine, dont hold the dang thing, it will hurt... trust me.
No spark: GOTO 7
Weak looking spark GOTO 7 and make best guess as to fault
Good looking consistent spark: 6h: CHECK PLUGS

6h: CHECK SPARK PLUGS
Pull plugs and look at them, they should be gapped properly, clean, not oily or sooty. If any of the above are not true, or as a last resort, replace plugs to rule out fouled plugs. Fouled plugs are a likely culprit if the engine was running badly before complete failure to start, or if the engine has sat for a long time and will not start ASSUMING all the above tests passed.

7:NO/WEAK SPARK DIAGNOSTICS
Preface: Many things can cause a vehicle not to spark, for this guide, unless otherwise noted, assume it is revering to a distributor based system, not the 87-88 4cyl’s DIS system.

7a: Eliminate cap/rotor and wires/ plugs
Remove the lead coming from the coil from the distributor end and lay it on the intake.
A: Sparks clean and consistent: inspect/replace cap/rotor and or wires
B: Bad or no spark continue

7b: TEST COIL
The only way to test the coil we will cover is to test all connections with an ohm meter, no 2 places on the coil should have 0 resistance between them, including testing to the coil output pole. If 2 connections have 0 resistance assume faulty coil and replace (~$15) otherwise try to swap with known good coil. Coils will usually miss then completely fail when hot, then when they cool down they will work properly until they run for a few minutes and get hot, but this is not a rule.

7c: TEST IGNITION MODULE
Remove module and take to auto parts store to be tested (~$FREE)
If it tests bad, replace (~$30) ALWAYS coat the bottom with dielectric grease and make sure the surfaces are clean. It its very important or the new module will likely fail.
If it tests good, the likely culprit will be the coil, though other possibilities might include a faulty ECM or faulty wiring.
Ignition modules will almost always be a dead failure, they will drop dead and never work again. Again, this is not a rule, just a commonality.

IF all above pass, seek professional help

7d: DIS notes 87-88 4cyl
The DIS will not spark without input from the crank sensor. The crank sensor should output a pulsing signal and can be tested with a multimeter. You will usually either see something or not if it’s a dead no start problem.
The ECM will not fire the injectors without input from the DIS module. If you are getting spark and fuel, but not injector pulse, look into this system after verifying wiring.

8: FUEL PUMP(FP) DIAGNOSTICS
Preface: The FP relay is backed up by the oil pressure sending unit, which has a switch that closes at ~4PSI to turn on the pump, should the relay fail. This can explain long starts, as the FP will not turn on until the engine makes 4PSI. Also, should the relay fail and the FP not turn on, you should inspect this circuit for failures as well.

Assuming you know the FP is not running:
8a: Check the fuse, it will be in the top row, second from the driver’s side.
A: Fuse bad: replace
B: Fuse good: Continue
8b: Check FP relay. It is on the drivers side firewall near the air filter (V6). Use your Haynes manual to determine which wire to watch for 12V on to ensure the ECM is sending the signal to activate it.
A: No signal GOTO ECM DIAGNOSTICS
B: Signal for 2 seconds CONTINUE
8b-b: If the car is equipped with AC, swap the relays, they are interchangeable and right next to each other (assuming AC relay known good)
A: FP runs- Replace relay
B: No change CONTINUE
8c: Jumper power straight to FP harness. It is located on the firewall mid way up, around the middle and has a 3 wire connection. Jumper 12V and ground to it using the diagram in the Haynes manual for reference. BE CAREFUL OF SPARKS
A: No run, replace pump/wiring. Always replace pickup sock with pump (total ~$45)
B:FP run, inspect wiring harness for breaks.

9:BATTERY/CHARGING SYSTEM DIAGNOSTICS
Preface: If the starter is cranking the engine over, then it is working properly, just because an engine will not start does not mean the starter is faulty, its only job is to crank the engine over. Also just because a battery is dead does not mean it is bad, nor is the alternator necessarily faulty.

9a:Turn key on- engine off (KOEF)
A:VOLT warning light on, all systems appear to work: CONTINUE
B:VOLT warning light NOT on with KOEF and power is in the cabin, inspect wiring/alternator
C: Certain systems not receiving power GOTO 9e
D: Here from “STARTING PROBLEMS” CONTINUE

9b oes the car start?
A: No: THEN GOTO 4 if from 4, then continue
B: Yes: AND battery is going low when parked GOTO 9e
C: ELSE 9g

9c:Turn the headlights on and turn the key to the start position:
A: Rapid clicking noises heard, and/or headlights dim and go out: GOTO 9d
B: Nothing happens, headlights stay bright: GOTO 5
C: Car starts normally: GOTO 9g
D: Car cranks normally but does not fire/or spits and sputters: GOTO 6

9d:Check/Clean battery cable connections ground wire connections and starter connections if starting problem. Then END or CONTINUE

9e: Battery is low. Test and recharge.
A: Battery tests bad – replace
B: Battery tests low needs recharged: GOTO 9f
C: Battery tests fine, fully charged: remove and test starter if starter related problem
D: If not starter problem, clean and test fusible links and junction post near battery

9f: Recharge battery and investigate low status. May simply be lights left on, or could be a faulty alternator sapping power, or a power leak somewhere. GOTO INVESTAGATING POWER LEAKS (if included in diagnostic list)

9g: Not sure what other problems commonly exist. Please suggest for expansion.

10: VERIFYING TIMING
The timing procedure is outlined in the Haynes manual. Make sure you are jumpering pins A&B of the ALDL connector, and reading off plug wire #1 If the engine does not start, and all other avenues exhausted, the timing could be 180* out. Swap the plug wires across from each other on the distributor. IE 1 to 4 2 to 5 and 3 to 6. This will effectively rotate the firing order 180* without having to pull the distributor

11: Running problems:
WOW… where to start here, umm, you own a FIERO get used to it… I’ll elaborate more in the future when I think of some common problems.

Common notes.
If you are experiencing high idle and or glowing exhaust, there is likely a vacuum leak. The most common culprits are a cracked EGR tube (from valve to intake) and if the intake has been off recently, a misplaced IAC feed tube. There is a black pipe about ½” diameter that runs from the back of the TB to the LIM, when the TB is moved, it can fall out of place un noticed. This creates a giant vacuum leak. Replace and its solved.

12: INFORMATION ON THE SES LIGHT
The code “12” if pulled from the SES light simply indicates that the ECM is functioning. It will always be there, and if it is not, there is a problem.
The SES light is not the all knowing god of repair. If a sensor is faulty but still within specifications, the ECM will not register the fault, and not set a SES
The SES light is not always the accurate source of the problem. Example. A vacuum leak can force the engine lean, the o2 sensor then reads lean all the time. The ECM sees this and assumes the O2 is faulty and trips a O2 sensor error. Same thing with the mix and a sticky EGR valve
Code 34… get used to it, its gonna be there. It indicates a fault in the EGR control solenoid, it will likely not effect drivability. There are pages on repairing this on www.fiero.nl in pennocks fiero forum under TD&Q. Use the search function.

[This message has been edited by 86GT3.4DOHC (edited 04-17-2006).]

How could I forget trannys? lol

13: TRANSMISSION PROBLEMS
Automatic GOTO 13k
Stick: Continue

13a: Does the tranny shift into gears with the engine off and car sitting level?
A: Yes - GOTO 13e
B: Somewhat, but not all the way into gears - GOTO 13d
C: Into some, but im blocked from a gear CONTINUE

13b: Does the car shift into all foward gears?
A: No - GOTO 13c
B: Yes - Try shifting into a foward gear before reverse gear, also try rolling the car a bit before trying to shift. - if this does not work GOTO 13c

13c: Inspect the shifter cables, but the problem is likely internal to the transmission.

13d: Does the tranny shift into all gears on either the front or the rear direction of the shifter? IE 1,3 and 2,4 (plus 5 and R depending on tranny)
A: Yes: adjust or replace selector cable
B: No: GOTO 13c

13e: Does the car shift into all gears with the engine running?
A: No gears - the clutch is not disengaging GOTO 13g
B: Yes but reverse grinds - the clutch is not fully disengaging GOTO 13g
C: Some gears, but other gears (not reverse) grind - syncro's likely worn and clutch not fully disengaging GOTO 13g
D: Yes - No problems GOTO 13f

13f: Does one or more gears grind while shifting with the car moving?
A: Reverse - Reverse is not syncronised, and will always grind unless the car is stopped, only shift then.
B: Yes - The syncros for that gear are likely worn out. There is nothing you can do short of rebuilding. You can try replacing the tranny fluid with syncromesh, as it should have anyway. This may help get more miles out of it.
C: If some gears are blocked, there is likely internal tranny problems.

13g: Clutch hydralics
Preface. The shifter pedal on many Fieros is prone to bending. There is a U bracket that the master cyl rod attatches to. Ensure this bracket is square and parallel with the pedal before begining. If not, replace it.

Inspection: Check the master cyl fluid level. Is it empty?
Yes : you have a leak GOTO 13h
No : CONTINUE

13h: Squeeze the rubber boot on the slave cyl. Do you feel liquid inside it? Remove and look also
A: Yes: the slave cyl is bad. Replace and GOTO 13j
B: No: This is a likely sign that the slave is in ok shape, but not definitive CONTINUE

13j: Park the car on a clean surface, or lay cardboard under it allong the drivers side front to back. Pump the clutch pedal vigorusly. Do you see droplets of brake fluid on the surface anywhere?
A: Yes - investigate and repair the leak
B: No - GOTO BLEEDING CLUTCH (or return if here from another step)

13k: Need some auto tranny stuff

14: BLEEDING CLUTCH:
Before bleeding clutch be sure the pedal and master cyl push rod are in good shape and not bent.
Preface: There is a lot of controversy around the proper method for bleeding the clutch, but the most successful seems to be as follows:

Park the car on a level surface
Remove the master cyl cap and top off the fluid
remove the bleeder and let the car sit.
Drink a beverage.
watch for air bubbles coming out of the bleeder
top off master
drink a beverage
when bubbles have stopped flowing, and fluid has been flowing for 60 seconds (or reasonable amount of time) replace the bleeder.
Tap the slave cyl vigourously with a ratchet or wrench
open bleeder and let fluid pass to remove any remaining bubbles.
GOTO 13j
(ADVANCED BLEEDING METHOD)
If for some reason the above is not working for you, this is a simular method.
proceed as above, but do not remove the bleeder.
open the bleeder, and compress the slave rod.
Close the bleeder and slowly release slave rod. It is very helpful to have someone gently push on the clutch as you do this, it seems air gets sucked in if you allow it to release too quickly or dont force it out
repeat several times.

If you are not sure that you have full bleed, remove the slave cyl from the tranny and support it, allow it to move to full extension. At this point, the pedal should be rock solid, as there is no where for anything to move. You can also increase the system pressure to make leaks more obvious this way, but be careful not to push too hard and blow out the slave or lines.

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Boost is like Venereal Disease, one night of passion can result in weeks of pain (and work.)
Its not always about who gets to the finish line first, its who looks good when they get there. 'Course it doesnt hurt to have both.
http:\\www.myspace.com\keeptherubbersidedown

Nice, I like it Especially the writeup on the clutch bleeding, not a lot of people remember to let out on the slave rod slowly because their hand might be in pain from having to hold it so long because you can't get the bleeder to thread in (personal experience ) I might've given you a plus too

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[This message has been edited by JamesCurtis (edited 02-17-2006).]

You care too much, and I think thats awsome. Come help me and my friend justin swap cradles from and 85GT to an 86GT this Sunday!

quote Originally posted by darkhorizon: You care too much, and I think thats awsome. Come help me and my friend justin swap cradles from and 85GT to an 86GT this Sunday!

Cover gas and give me someplace to sleep and maybe a little food?

Tempting, but I dont think I would play that card for my friends car, I will save that for the 3800 swap this summer. check your PM's

And for New Fiero Owners, we must be Sub-Dummies at least myself. . . . (Lost in Translation)

Is there a table somewhere that translates all the three/two letter codes into the actual meaning? I am constantly running into this. (I know EGR)
Also the Haynes manual does not always list them.

I really want to translate this and find out where the parts are located.

" If you are experiencing high idle and or glowing exhaust, there is likely a vacuum leak. The most common culprits are a cracked EGR tube (from valve to intake) and if the intake has been off recently, a misplaced IAC feed tube. There is a black pipe about ½” diameter that runs from the back of the TB to the LIM, when the TB is moved, it can fall out of place un noticed. This creates a giant vacuum leak. Replace and its solved. "

Thanks
Hager

[This message has been edited by Mr.Chipps (edited 04-16-2006).]

Nice write up, Keep up the good work--we`ll get you a publisher..
Mr. Chipps they usually post those meanings in the front of the manual, pain in the butt to page back & forth, this may help with some.

https://www.fiero.nl/cgi-bin/main.cgi?cua

https://www.fiero.nl/cgi-bin/main.cgi?ECMCodes

quote Originally posted by 3800superfast: Nice write up, Keep up the good work--we`ll get you a publisher.. Mr. Chipps they usually post those meanings in the front of the manual, pain in the butt to page back & forth, this may help with some. https://www.fiero.nl/cgi-bin/main.cgi?cua https://www.fiero.nl/cgi-bin/main.cgi?ECMCodes

Thanks,

Thats exactly what I was looking for. And with good definitions.

Hager

quote Originally posted by 86GT3.4DOHC: Common terminology: Using the proper terms can get you better answers faster .... LIM = Lower Intake Manifold

this one always gets me....
there is only ONE intake manifold.
the other two peices are the upper plenum & lower plenum.
the TrueLeo is NOT a intake manifold. it is a plenum.
Edelbrock makes a manifold.

quote Originally posted by Pyrthian: this one always gets me.... there is only ONE intake manifold. the other two peices are the upper plenum & lower plenum. the TrueLeo is NOT a intake manifold. it is a plenum. Edelbrock makes a manifold.

I believe that is your own opinion as i see no dictionary definitions that support you

ple·num (plnm, plnm)
NOUN:
pl. ple·nums or ple·na (pln, pln)
1. An assembly or meeting with all members present.
2. A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere.
3. The condition of being full; fullness.
4. A space completely filled with matter

vs

man·i·fold (mn-fld)
NOUN:
1. A whole composed of diverse elements.
2. One of several copies.
3. A pipe or chamber having multiple apertures for making connections.
4. Mathematics A topological space or surface.

quote Originally posted by Kohburn: I believe that is your own opinion as i see no dictionary definitions that support you ple·num (plnm, plnm) NOUN: pl. ple·nums or ple·na (pln, pln) 1. An assembly or meeting with all members present. 2. A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere. 3. The condition of being full; fullness. 4. A space completely filled with matter vs man·i·fold (mn-fld) NOUN: 1. A whole composed of diverse elements. 2. One of several copies. 3. A pipe or chamber having multiple apertures for making connections. 4. Mathematics A topological space or surface.

lol - NICE

no, I am going by what the parts are called in any parts/repair manual.

but that varies from car to car based on what that particular manual writer deicded to use. seeing as I am currently working in the technical documents department I can tell stories about some of the crap i've run across when updating military manuals for aircraft.

as for common use - people use the words almost interchangably.. but techically speaking the 3 peices ontop of the heads form one single intake manifold - its just 3 components that bolt together to make it up.

[This message has been edited by Kohburn (edited 04-17-2006).]

quote Originally posted by Kohburn: but that varies from car to car based on what that particular manual writer deicded to use. seeing as I am currently working in the technical documents department I can tell stories about some of the crap i've run across when updating military manuals for aircraft. as for common use - people use the words almost interchangably.. but techically speaking the 3 peices ontop of the heads form one single intake manifold - its just 3 components that bolt together to make it up.

Speaking of ple... err uhh intake man... uh should I just call it a mani-num? Hows your TDC one working out? got some new news on my turbo Im emailing to you...

quote Originally posted by Kohburn: as for common use - people use the words almost interchangably.. but techically speaking the 3 peices ontop of the heads form one single intake manifold - its just 3 components that bolt together to make it up.

yes, I agree with this. technically speaking, the upper plenum, lower plenum & intake manifold, make up one unit which could be called a intake manifold. I'll give the thread back...call it what ya like

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1985 Fiero SE - Plain Red V6 Coupe
3.1 Crane272 MSD 4.10-4spd DarthChip Borla
D.A.M.M. - Drunks Against Mad Mothers

quote Originally posted by 86GT3.4DOHC: Speaking of ple... err uhh intake man... uh should I just call it a mani-num? Hows your TDC one working out? got some new news on my turbo Im emailing to you...

the plenifold is getting a few reinforcements and then tuning - its been working out so-far, but was developing a few stress cracks near the throttle body

quote Originally posted by Kohburn: but was developing a few stress cracks near the throttle body

ah HA!

Carry on....

quote Originally posted by ryan.hess: ah HA! Carry on....

:P they were superficial - but i wanted to fix them and make it stronger before relying on it for any long trips