ok i ran ito a problem.
i rebuilt my fieros 2.5 engine. hooked it all up. it will start if you put abit of fuel in the intake but only for a second so i know the car will run. it also ran yesterday pretty good but once i turned it off. it didnt start again. i know my fuel pump is working. i replaced the fuel pump. still nothing, i hear it buzzing and when i unplug the inlet to the TBI. fuel just pumps out of the end. so its working. i also bought a new fuel relay. still no go. so i replaced the fuel injector thinking it was clogged. still nothing. so i got frusterated and took the whole TBI right out and cleaned real good. put it togeather and still no go. so i thought maybe the injector isnt getting any juice from the battery. so i pulled off the clip on top of the injector and pulled out the wires and placed them directly on the prongs on the injector still no go. so i hooked the injector to the battery and fuel sprayed out of the injector so i know everything is working. but still no fuel spraying out of the injector when i turn the ignition on. so no start. i replaced all the fues in the fuse box. still nothing. the tank is full of fuel.

what gives?!?! am i missing something?? i really need to get this car running soon. all the vacume lines are connected. throttle cable and everything.

just some info on the fiero if anyone would like to know and help rule out what could be the problem or if someone knows what could be the problem.

1986 fiero SE. no AC. 2.5 duke engine. all stock.
part i have replaced.

ignion coil,
plugs
wires
starter,
fuel pump,
fuel filter,
fuel injector,
fuel relay.
gasket for the TBI.
distribtor cap and rotor.

i was going to go get a fuel pressure guage but even if it has to high or to low of fuel pressure. shouldnt it still spray threw the injector?

Does it spray through the injector when cranking? If not then check the fuel injector circuit. Also, check to make sure you have spark while cranking

ill check the the wires. maybe i have a bad ground? and yes it doesnt spray when cranking it. and i have great spark when cranking. everything works. if i put abit of fuel in the intake. it will start up but use up all the gas that is in the intake tho. injector just doesnt spray.

First thing I would do is check fuel pressure.

None, look at the fuel pump circuit.

Good, look at the injector circuit.

Since you have replaced both the pump and the injector that leaves the wiring (unless you have some sort of blockage in the line) - don't rule out the regulator as well...

quote Originally posted by joshh44: ill check the the wires. maybe i have a bad ground? and yes it doesnt spray when cranking it. and i have great spark when cranking. everything works. if i put abit of fuel in the intake. it will start up but use up all the gas that is in the intake tho. injector just doesnt spray.

This may seem stupid, but have to taken a multi-meter to the wires yet? Typically I have found that situations such as your can be remedied by simply checking for voltage and impedance.

For example, if you have no power at a necessary point, check impedance from that point back to the next item in the chain.
Next check that item for voltage/impedance.
Still no juice, check the for power going to it, then impedance in the line going to it.

The reason to check impedance in the wire going to/from is to be sure it is not a split wire. This is how I solved a "no start" issue with a 3.0 Dodge I replaced the water pump on.

My first thought was that I had a timing gear off by one tooth and was going to have to tear the front down to the water pump to re-align. I stopped, thought, checked for fuel, knew I had air but checked anyway, then checked plug wires for spark. No spark.
Check rotor. No Spark.
checked ignition wire. No spark.
Checked coil. No wire connected.... opps...
put the wire back on....
turned key, VROOM...
Saved me hours and money.

I know you have spark, but you have no spray, the testing procedure is no different when working with any electrical part, only the voltage and impedance or the individual parts.You might find that you forgot to hook something up further back in the chain. You did just rebuild it!

------------------
Myke

PAST: 88 L4 5spd, 84 L4 auto, 88 L4 5spd, 87 L4 auto

Present: 84 L4 4spd, 88 L4 5spd

Future: Tomorrow will tell...

Just for reference, impedance in this case means resistance in Ohms on a plain volt-ohm meter.

Also, the module has a primitive timing circuit built into it so it will theoretically fire the coil even if the ECM isn't connected to it. However, the ECM won't fire the injector unless it sees pulses coming to it from the module. If it will sorta start and run as you pour fuel down the throttle body then that's a (rare) possibility.

Checking the injector circuit is easy. The pink wire at the injector should have 12 volts on it at all times that the key is in RUN. The other wire goes to the ECM. The ECM fires the injector by providing a ground path to complete the circuit. Power to the injector goes from the battery to fusible link A, then to the ignition switch terminal B (red wire), then out from there (pink wire) to the fuse panel, then to the injector.

JazzMan

Thank you for the clarification, Jazz. I was trying to be descriptive and general about the procedure.

Jazz gave to the entire circuit, It is as simple as making following back up the path to ensure everything is getting the correct power at all times. I would suggest following the power back from the injector. My experience, typical issues with power happen closer to the injector. (often a bad wire/connection, once the ground wire was bad/split, once it was the injector.)

Alternatively, Jazz has also suggested the module might be bad and that made me think... Most of my experience is with DIS (waste spark)... Is there a chance the module doesn't "know" where in the rotation the engine is and therefore is not sending a pulse? (like the CPS on the Dis?) Maybe a bad pick up? Could that cause such an issue? (did that make sense? would a bad pick up be able to shut off the injector?)

bad question, I know.. I understand how to fix, how to diagnose, but actual operation tends to be beyond me.

Myke

His '86 has a regular distributor, but that is an interesting question. The pre-DIS cars don't know where the crank is, they rely on the distributor to distribute the spark to the correct cylinder, a mechanical solution as the distributor is turned by the camshaft. A not-uncommon problem with the 2.5 engines is a sheared plastic cam gear, the simple test for this is to look in the oil fill hole while cranking and seeing if the rocker arms are moving up and down. If not, then the gear's gone.

JazzMan

Is your Check Engine light on when you turn the key to the run position? If the ECM isn't powered up you will get no injector pulse. The fuel pump may run via the oil pressure switch if you cranked it a lot, but the fuel pump should run for 2 sec when you first turn the key on (without cranking it).

There is an orange? wire with a single pin weather pack connector on it (near the battery area) that is the main power to the ecm. You might want to check that too, if it's crusty it could cause this problem. Also check grounds as someone stated up above.

Good luck, I know these kind of problems are aggravating.

ok i tryed some more options and still no go. ill check some wires and what not that you guys said. i havnt had a chance to try them out.

i took the wires out of the retainer clip that clips on the top of the injector. placed them right to the injector plugs to see if it was having a bad connectiuon. nothing.
my engine like doesnt come up. but when one of the wires was touching the injector housing and on the injector prong at the same time. fuel sprayed out of the injector when i didnt have it in run. but my engine light came on afew times but quickly whent away once i jiggled the wire on the injector.
another thing is when i put the car in run mode onm the ignition. the fuel pump keeps going. it doesnt stop after 2 seconds. what would cause that as well? maybe thats why the injector wont turn on i dont know. ill check for some corrosion on some wires and plugs. the fuel relay had so much corrosion on it. the fuel pump woildnt even turn on. once i replaced it. fuel pump is working.

Sounds like you've got some wiring problems for sure. The pump should come on for two seconds when turning the key to RUN but not cranking. If it keeps running then something's wrong.

You've got multiple problems going at one time, and when that happens there's no way to fix all of them at the same time since the different symptoms confuse the process. What you have to do is work the problems one at a time. By doing only one problem at a time you gradually convert all the unknown variables into known variables, systematically.

You will need a meter, do you have one? That will be essential to dealing with multiple electrical problems.

JazzMan

yes i do have a meter.

im having some terrible allergies at the moment so my mood on working on the car at the moment is very slim.
i took some medication to help so once that starts helping ill go take a look and check all the connections.
i did buy this car for $650 and it wasnt running when i bought it.
i got it to start afew days after i bought when i replaced the spark plugs and wires. i only drove it down the street and then up the driveway and its been there ever since i bought it which was afew weeks ago. the engine bay was very dirty and muggy. so i took care of that and its pretty clean now. vaccumed out alot of the dirt and leafs that were in there. im woundering if maybe i knocked something while cleanng it. or since its been sitting for awhile. some of the connections are corroded away,
i did yesterday found 2 wires that arnt connected to something. i have no idea where they go.
they look like ground wires because they have the metal ring clip on them. there by the transmission area. near the distribtor and ignition coil. my camera wont take photos. but it took some videos. so ill load up the video and you fellows can take a look.

Ground wires... mount to the the 17(?)mm bolt below the dist.....
Let's see if I can put the pic up here:

close up and pulled back a bit to show the dist.


I hope that worked....

Edit: YES, I have not tried to post pics with that photo server. coolness, so in the first pic, the bolt and wires are in the center of the pic.
In the second one, they are still centered, but I pulled back so you could see the location from behind the car (standing on the drivers side) on the top right hand corner, you can see part of the dist. My fuel filter is the rusty thing on the top left.

Myke

[This message has been edited by Myke (edited 06-14-2008).]

thank you!!
ill clean up the ground area and bolt them into place.
and it looks like your in need of a new fuel filter lol.

im just heading to the store. gotta pick up afew things for the fiero. like the air filter and such.

im going to clean up all the electirical grounds and plugs and what not. get them to have some good contact
hopfully ill find out what the problem is with my no starting situation.

quote Originally posted by joshh44: my engine like doesnt come up. but when one of the wires was touching the injector housing and on the injector prong at the same time. fuel sprayed out of the injector when i didnt have it in run. but my engine light came on afew times but quickly whent away once i jiggled the wire on the injector. another thing is when i put the car in run mode onm the ignition. the fuel pump keeps going. it doesnt stop after 2 seconds. what would cause that as well? maybe thats why the injector wont turn on i dont know. ill check for some corrosion on some wires and plugs. the fuel relay had so much corrosion on it. the fuel pump woildnt even turn on. once i replaced it. fuel pump is working.

To me, that sounds like your ecm is not providing the ground path for the injector.

As far as the ecm not knowing where the crank is, or not recieving a reference pulse, that seems to be already shown not to be the case. The same reference for the injector is used for firing the spark plugs. If it will start when he pours a little gasoline into the throttle body, then the ecm is seeing the reference. That doesn't mean the ecm is internally doing what it needs to do to ground the circuit. I really think you have an ecm problem--or in the wiring between the dist and ecm.
I did have a problem once with a bad wire coming from the distributor on an 84, which is basically the same as his non-dis engine. The wire looked ok, but the conductor inside the insulation had parted. Can't remember what color this wire was, but it ran from dist to coil.

The fact that the injector sprayed when he touched a ground to it, also seems to indicate the injector is 'ok'.
Josh, you want to be careful grounding the injector tho, it is really just a little solenoid and not designed to be energized continuously for very long.

I have the exact same problem with my 88--just haven't had the time to check it out fully.

[This message has been edited by maryjane (edited 06-14-2008).]

So MJ, your basically on the same plain as the rest of us. You think he should start testing the ground back to the ECM as (i agree with you here) his injector sprayed when he grounded it proving the circuit is good on the power side.

MJ, As I stated before, most of what I work on is DIS. Is there anything other that the ECM or a bad connection that could cause this? I forgot what Jazz said, but I think he mentioned the module sends a pulse to the ecm? Could this circuit be disconnected somehow, or otherwise not "talking" to the computer?

Sorry, just full of questions today. Don't mean to hijack your post, Josh!

------------------
Myke

PAST: 88 L4 5spd, 84 L4 auto, 88 L4 5spd, 87 L4 auto

Present: 84 L4 4spd, 88 L4 5spd

Future: Tomorrow will tell...

haha no worrys.
ill hook up thos ground wires right now and take alook around for any bad wires or connections.

if my ECM is bad. do i have to get another one of the same year of car or would any year of car work as long as its a 4cly?

Maybe some of the power wires are grounding out somewhere.

grounding out? what does that mean?

One of the 12v wires from the fuel pump touching bare metal causing it to short, continue running and blow the fuse.

oh that could be it.
i just removed the ECM from the car. and i took the cover off to check inside and i found one of the prongs that the plugs plug into got burnt. just one tho and so when you plug it in. that one wire isnt going threw the ECM. so im in the process of doing a temporarly fix until i can buy a new ECM. im hoping that is the problem.
ill check under the car for any bare wire touching any metal.

If you have determined that the ecm is fried, you will need to replace it with one from a like vehicle. If you have an auto transmission, the new ecm has to come from an auto as well. You also cannot use an ecm from an 87 or 88. They had a dis engine--yours has a distributor.

Go to The Ogre's Cave to check out the ECM section.

ill check the auto wreckers for some fieros if there is any of the same year. and mine is a 5 speed.
i really want to get this car on the road as soon as possible. its my daily driver car.

quote Originally posted by joshh44: ill check the auto wreckers for some fieros if there is any of the same year. and mine is a 5 speed. i really want to get this car on the road as soon as possible. its my daily driver car.

Shouldn't have to be just a Fiero, as long as the part# is correct-and the trans and ac options are the same. Ya still need to ensure you have no wiring issues so you don't fry another ecm.

[This message has been edited by maryjane (edited 06-15-2008).]

yeah im going to try one last time today and im going to search the whole intire car for any shortages. bad connections, wires not pluuged in. broken/cracked wires.

im going to start at the front of the car. and work my way back.
im hoping the ecm isnt fried but so far it looks like it is. im going to buy some end connections for the wires and some new wire as well. replace any bad old wires if i find any.

about the ECM. can they come out of a different car??
mine doesnt have AC, or powerlocks or power windows. its a 5speed with cruise control.

ive heard that some 2.5s wont start if the a/c is on and some even die at idle
just maybe make sure your ac is off and the compressor is not constantly running

edit<sorry didnt catch the last where you dont have ac>
neither do i

[This message has been edited by BlackGT Codde (edited 06-15-2008).]

quote Originally posted by joshh44: about the ECM. can they come out of a different car?? mine doesnt have AC, or powerlocks or power windows. its a 5speed with cruise control.

Yes, the ecms in Fieros were also used in other GM products from the 80s. There is a tag on your ecm that will have the part # on it. For your year and options, the only sticking point would probably be your shift light, which is illuminated by the ecm--if you have a shift light. There is a list of ecm part #s in The Ogre's Cave, and a larger one at fierosails/fierosecrets website.
Check the pff mall as well, someone is always parting out a Fiero there.
You must get one from a similar eng family, the same transmission. One from a car with an a/c 'might' work--I'm not sure what difference that would really make. One from an automatic transmission car will not work, as it will have TCC lockup.
pwr locks/windows etc have no effect on the ecm.

Cruise control probably is an issue.

87-88 will definitely not work. Check the mall here at pff and try to find one from your same optioned vehicle and ask if the ecm was working before they started parting it out.
Then, there is always The Fiero Factory and The Fiero Store. Ed Parks will bend over backwards to help you out.

well with the cruise control. i dont need it all that much. i mostly do city driving anyways so i can remove the cruise control. thats not a problem.
and i dont need the shift light eather. i never pay attation to that anyways. ill do some searching around and check out thos websites

Looking at the Pontiac Parts manual and an on-line vendor, 1226864 is the service p/n for the ECM which is used on the 85 - 86 Fiero 2.5 L engine. This ECM is found on some other GM cars (mostly Duke engines) in 85 - 86. For the PROM installed in the ECM, one p/n listed for the 86 - 5 spd is 16052973 (code 2975FAU).

Before you shell out $$$$ for an ECM, you really need to test the wiring, make sure you have a good power \ ground and make sure the SES light isnt just burnt out.

im checking the wires out right now. i just came in to check the board for any more info on what i need to do.
so far so good with the wiring. going to test some things with the volt meter and see how she is.
i might need to replace the ground straps. they dont look to bad but they dont look so good eather.

and my SES light isnt burnt out i dont htink. its on when i start the car. and it doesnt flash or change eather when i check the ECM for trouble codes. its just a constent light that is on. and the fuel pump doesnt shut off as well. its always on. even after i replaced the relay.
one of my budds thinks the coolent temp sensor is bad. which is why its idling very high when its running. its running alittle rich but nothing to worry about at this point. and i was reading somewhere that the coolent temp sensor is one of the more importent sensors on the engine. i think i mught just replace it for the heck of it. im sure it hasnt been change to a new one in the fiero lifetime. any of the sensors for that matter. i took the O2 sensor out and check it out. it looks alright. but not up to my standards. might go replace that while im at the auto store. is there any other main importent sensors that i should look and check that would explain the weird high idle.

when you 1st start uyp the car. it revs up to 3500 and sometimnes 4000 rpm. and you just tap the gas pedal and it slowly brings it back down to 2500 and sometimes to 2000 rpm. i checked the timing. and its in perfect spot where the stock timing is. it runs really nice and smooth. no misses or anything. sounds really good besides a small hole in the muffler and a annoying ticking sound. its most likely the rocker arms. tho there all tq. down to specs from what i got out of the haydens manual. 24in lbs which i think is the tq. for the rocker arm bolt. someone would kindly help me fix that problem that be sweet. but my main focus is trying to get the idle down to where it should be and fix electric bug somewhere in the car. its not that big of a car. and the whole intieor is out of the car at the moment. so finding wires shouldnt be to difficult.

not a 4cyl guy, but the high idle is usually a vacuum leak. check the egr valve gasket and also the tbi gasket, they are know n to leak on 4's. you can spray water at the base of the tbi, if the idle drops as the water seals the voids, it is the gasket.
form a previous post, here is the fuse block layout:

hey thanks for the photo of the fuse. i really needed that so badly. i cant even read what fuse numbers go where and what the fuse is for. now i know time to print this sucker.

and i replaced the TBI gasket and the EGR gasket. but ill give it a shot with the water. if it is leaking. is there some kind of gasket maker i can throw on there? i dont want to spend another $30 on some more gaskets that i just bought when i can spend $5 and make a gasket.

wait! i have some make your own gasket stuff and i havnt had a chance to use it. its

Fel-Pro Sealing material pack.
it comes with.

1. cork-rubber sheet. 10" x 8 5/8" by 1/8th" thick
1. cork-rubber sheet. 9 1/8" x 8 5/8" by 1/16" thick
1. rubber-cellulose sheet. 9 3/4" x 8 5/8" by 3/64" thick
1. rubber-fiber sheet. 9 1/4" x 8 5/8" by 1/32" thick

i also have a roll of Fel-Pro Karropack sheet (tan fiber) 36" x 18" by 1/32" thick.
it was on sale for $3 so i snatched it up. never know when something like you might come in handy.

i had to take the EGR off because i ad to get at the bolt to take the valve cover off to do some rocker arm adjustment. and i found some like of liquid substence inside the intake area were the EGR goes into. looks kinda like water but its kinda blackish in color because of the left over carbon build up that i couldnt remove in the tight areas. im hoping its not a cracked head or else ill be alittle angry. just lapped the valves to the head, ported the head out a tiny bit, replaced all the valve seals. and cleaned out all the carbon build up. and had to take it into a shop to remove a broken exhaust bolt that was stuck to it. and i replaced the head gasket and everything as well. geah,. i would hate have to pull the head off again. was a royal pain in the kisser. broken bolts and such.