I’ve been trying to get this thing running since it came home last fall and am running out of ideas and patients. Originally I thought all it was a bad fuel pump. Even though it WAS bad it’s not the issue. I’ve replaced; fuel pump & tank, starter, battery, crank position sensor, both coils, ignition control module, plugs, wires, vacuum lines, checked the fuses, fuse links look good AND rebuilt the TB. I put the TB back on last night thinking that the problem would be solved only to be right back where I left off 4 months ago – no start. It cranks, I can see the rockers going, I can hear the fuel pump & see fuel going into the TB but it won’t run. If I crack open the throttle it will half ass run for a few seconds but not right and if I let it go it pops/backfires up the TB. I checked each plug wire and they are on right and each spark. The only things I haven’t changed are the Manifold Air Temp, Manifold Air Pressure, the Coolant Temp Sensor and the ECM itself. Will one of these cause it not to run? I hate to throw parts at it not knowing the issue TOO LATE!! LOL but there’s not much left to replace. I also got a fuel pressure gauge but couldn’t find my tubing bender to put the adapter on so I skipped it last night. ideas?

Have you checked cylinder compression?

quote Originally posted by 2.5: Have you checked cylinder compression?

Yes i did. I don't recall what it was exactly but they were all the same and what the GM Manual said they should be. This car only has 21500 original miles on it. It's been sitting forever due to the dead fuel pump but i suspect that it was something else and the fuel/pump/tank were victims of it sitting for years with 1/4 tank of gas. When I replaced the pump I used a sending unit assembly from my spare parts, i think it originally came from a GT but as long as it's the correct 4cyl pump that shouldn't matter, right?

Do you get a good volume of fuel from the fuel line?

I had a similar issue and my injector in the TB was bad (88 2.5). It wouldn't function, but it looked ok visually (it didn't leak and was putting out some fuel).

https://www.fiero.nl/forum/A...130314-2-115604.html

[This message has been edited by jaskispyder (edited 04-09-2014).]

quote Originally posted by jaskispyder: Do you get a good volume of fuel from the fuel line? I

Before the rebuild i thought it was dumping in too much fuel but apparently that is normal. The PO said he replaced the injector too.

what if you pour gas down the tbi as it is trying to run? That will tell you if it is starved for gas.

Did you reset the IAC?

BTW, one day it was fine, the next it was bad (the injector)... so, it was frustrating me.

[This message has been edited by jaskispyder (edited 04-09-2014).]

quote Originally posted by jaskispyder: what if you pour gas down the tbi as it is trying to run? That will tell you if it is starved for gas. Did you reset the IAC?

I didn't pour in gas, didn't think it was safe with the occasional pop/backfire up the TB. I cleaned the IAC and screwed the pintel in. Shouldn't it reset itself? In the thread you posted there was mention of grounding the blue wire on the injector. I'm not at home now but how do you do this, just stick something in the back of the plug?

Edit; and I feal your pain in your thread. I told my wife the car either needs to start soon or start looking for a new home.

[This message has been edited by DLCLK87GT (edited 04-09-2014).]

quote Originally posted by DLCLK87GT: I didn't pour in gas, didn't think it was safe with the occasional pop/backfire up the TB. I cleaned the IAC and screwed the pintel in. Shouldn't it reset itself? In the thread you posted there was mention of grounding the blue wire on the injector. I'm not at home now but how do you do this, just stick something in the back of the plug?

I would just dribble some gas down the TBI when it starts up (or to get it started). Or get some Ether spray. There is a procedure to reset the pintle, but I think I need my manual. I believe I just back probed the connection and grounded it to the tbi.

Have a fire extinguisher handy and don't put your face over the TBI

quote Originally posted by jaskispyder: Have a fire extinguisher handy

That goes without saying no matter what you're fixing on these damn cars

If it tries to run then you have all the things needed to run, just not at the right time or amount. Just because the rocker arms go up and down does not mean they are doing it at the right time. I think the cam drive gear is fiber, you may have lost a tooth on it so the cam is out of time or it could just be randomly turning. I will guess you have the ignition timing set right. With that low of mileage the cam gear should not be bad, but I guess you never know. Do you know how it quit running in the first place? Larry

quote Originally posted by trotterlg: If it tries to run then you have all the things needed to run, just not at the right time or amount. Just because the rocker arms go up and down does not mean they are doing it at the right time. I think the cam drive gear is fiber, you may have lost a tooth on it so the cam is out of time or it could just be randomly turning. I will guess you have the ignition timing set right. With that low of mileage the cam gear should not be bad, but I guess you never know. Do you know how it quit running in the first place? Larry

I am guessing the cam gear is fine, unless it happened to skip, but usually it just breaks apart.

So... I am guessing fuel, right now... at least that would be step one for me.

quote Originally posted by trotterlg: Do you know how it quit running in the first place? Larry

I got the little old lady only drove it to church on sunny Sundays story. Apparently she drove it until the fuel pump died, had it replaced under warranty then some time later it died again and she parked it. The kid i got it from got if off his buddy and neither could figure out the issue and gave up. He moved out, his parents told him to take the car with him but he didn't want to so i scored it for $500. Seemed like a good deal at the time, now i think i want my money back.
If it's the cam gear I'll set it on fire myself!

So you have spark at the plugs?
I'd say re-check setting timing as best you can.

[This message has been edited by 2.5 (edited 04-09-2014).]

quote Originally posted by 2.5: So you have spark at the plugs? I'd say re-check setting timing as best you can.

Timing light indicates spark on each wire, have to imagine the plugs are sparking, both new. And this is an 88 2.5 with DIS, no timing to set. At least not by me.

It can't be the cam gear. You are getting some fire so the cam is turning. The gear won't skip a tooth.

Maybe a valve is hanging open. Check compression. Oil the cylinders - one squirt in each cylinder.

[This message has been edited by phonedawgz (edited 04-09-2014).]

quote Originally posted by phonedawgz: It can't be the cam gear. You are getting some fire so the cam is turning. The gear won't skip a tooth.

OK then i'll put my matches away.

quote Originally posted by phonedawgz: Maybe a valve is hanging open. Check compression. Oil the cylinders - one squirt in each cylinder.

Did and did. When i got it i put some marvel mystery in each when i changed the plugs. Compression was good on all 4. I changed the valve cover casket when i pulled the EGR off to clean it and replace the gaskets, the top end was nice and clean.

[This message has been edited by DLCLK87GT (edited 04-19-2014).]

quote Originally posted by DLCLK87GT: Timing light indicates spark on each wire, have to imagine the plugs are sparking, both new. And this is an 88 2.5 with DIS, no timing to set. At least not by me.

What sensors tell the ECM when to time spark, maybe one of those is bad?

[/b]

quote [B]Originally posted by 2.5: What sensors tell the ECM when to time spark, maybe one of those is bad?

It's the crank positioning sensor and the ICM and I replaced them both with no change.

Did you pull the console and check for damage to the main harness?
I had one that sat a long time and mice had chewed up a few wires to the ecm.
It had basically the same symptoms you are describing.

I

With the key on I ground the injectors blue wire and get the "click". Then with the key on I ground the ALDL "G" pin, pump comes on, ground the injector and it sprays nice and steady. Unhook everything, crank it over and I can see the injector pulsing fuel into the TB. The TB blade is closed so the fuel is just spraying on top of it.
Edit, no I didn't pull the center console to look for damaged ECM wires but will this weekend just to rule it out.

[This message has been edited by DLCLK87GT (edited 04-09-2014).]

Did it run afterwards?

I was thinking may be the module but he is getting spark. Sounds like a crank sensor but that is new.

no it was the same, it'll crank, cough & sputter but wont run. It wants to but just can't. It sounds like the timing is way off but apparently the cam gear is either good or bad and the rockers are going so it's good.

So it's getting fuel & I have spark but still wont run. Will a bad IAC do this? I'll have to try resetting it after work. How about any of the sensors?

Plugged up cat? Plugged up exhaust with mouse nests?

From reading your first post. I'm reminded of working on a sbc350.
If the timing is off by 180*, they will act similar to what you're describing.
Maybe the cam gear was replaced and they only checked for tdc.
Remember that the duke uses the wasted spark system too.

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1988 Fiero 2.5

quote Originally posted by 2.5: Plugged up cat? Plugged up exhaust with mouse nests?

hmmmm... anything is possible. The kid who had it before me replaced the cat. I think he read on here that could be an issue so he hacked it off and half assed on a new one. I'll pull the O2 sensor and see what happens. I'm also going to get another crank sensor and swap that out....again. Running out of options. If none of that works I'll pull the console and see if anything looks chewed or cooked. After that I dunno what to do ....maybe start looking for a L32

[This message has been edited by DLCLK87GT (edited 04-10-2014).]

I just pulled the O2 sensor and no change so it's not the CAT.
I did the diagnostic "ground" and only get 1 blink, then 2 blink and I hear no clicking from the IAC.
So, me being me, I got pissed and started it and mashed my foot down. It started, it ran, but it's popping, chugging, reeks of gas and sounds like the stereotypical WW1 fighter coming in for a crash landing.
WHAT AM I MISSING HERE????
Very frustrating because I got this for my wife to show her how cool these cars are and this is turning into a huge POS. HELP ME BRING HER OVER TO THE DARK SIDE!!!!
It's not helping that this one is the "newest" of the 3 with only 21500 original miles on it, it shouldn't be this hard.....should it?
And FYI, I was going to replace the crank sensor again but nobody has one and it's on back order. When I do go get it I'm going to bring the original ICM and have them check it to see if it's good. I have a hard time believing that the old and new ICM & CPS all bad but again, running out of ideas. Will also check the ECM tomorrow for bad wires or mouse nests. HELP!

Are the wires in the place from the coil packs to the right plugs? Also, do you have spark on each cylinder? It sounds as if they aren't firing in the right order. Just my 2 cents. Sometimes when people troubleshoot a problem and get annoyed, they put stuff back in the wrong place. Also, how old is the gas in the tank? Ethanol blends degrade pretty quick. If it's been in there without any fuel stabilizer for a while, and the only thing it will do is gunk stuff up, and you're car won't run properly.

[This message has been edited by imabaddude (edited 04-12-2014).]

quote Originally posted by phonedawgz: It can't be the cam gear. You are getting some fire so the cam is turning. The gear won't skip a tooth. Maybe a valve is hanging open. Check compression. Oil the cylinders - one squirt in each cylinder.

Wrong.... 88 DIS duke and gets timing from Crank wheel.
You can have dead cam gear and the brick will still give spark.

ECM will not ground injector w/ no ignition. If you get a spark... likely not a brick problem. Wiring or ECM w/ problems.

ECM love to die and act like no ignition... meaning no ground to injector.
Car is getting warm to hot ever when parking. Heat/cold cycles alone can kill ECM regardless total miles driven. The coating on ECM board or weak solder joints can cause dead ECM.
If so, Get another ECM.
also See my Cave, ECM Heat

plugs wires... Only matters that 1 4 to bottom coil, 2 3 to top coil.
Iffy wires or plugs can kill coils and ICM
See my Cave, DIS Ignition

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Check the CTS, I think it is the problem, verify the plug too .

quote Originally posted by theogre: Wrong.... 88 DIS duke and gets timing from Crank wheel. You can have dead cam gear and the brick will still give spark. ECM will not ground injector w/ no ignition. If you get a spark... likely not a brick problem. Wiring or ECM w/ problems. ECM love to die and act like no ignition... meaning no ground to injector. Car is getting warm to hot ever when parking. Heat/cold cycles alone can kill ECM regardless total miles driven. The coating on ECM board or weak solder joints can cause dead ECM. If so, Get another ECM. also See my Cave, ECM Heat plugs wires... Only matters that 1 4 to bottom coil, 2 3 to top coil. Iffy wires or plugs can kill coils and ICM See my Cave, DIS Ignition

the valves are moving so cam gear not dead.
Brick all new; crank sensor, coils and ICM.
Injector spraying.
vacuum lines new.
plugs and wires new.
Did NOT change out MAT, IAC,CTS,MAP could one of these be the issue?
I'll go get a new ECM if that's what you think. I'm just asking because the local P & P is going to rape me for one (and who knows if it's any good), and a reman one at the parts store is close to $100. BUT if that's what it takes I'll happily shell that out to bring her back to life.

Doesn't sound like the ECM. ECM is $90 at advanceauto.com and they have coupon codes so it will be cheaper. Just google coupon codes for advance autoparts. It still sounds like the wires are put in the wrong order, If they aren't try them in different spots, maybe the coil was put in backwards or something to where you think they are right, but they aren't. IDK, I haven't had a duke with DIS. Don't put any new parts on it, stop, take a step back and think. Your check engine light comes on when you put the key in the one position, so your ECM is working, it primes the fuel pump, and you are getting fuel, you are also getting spark. So, the issue has to be timing related, or it could just be the gas in the tank is rotten. When I bought my fiero it had sat and the gas was rotten and needed to be drained, when I started it, it ran like crap and popped and backfired, and would die, but after I got the old gas out and put new gas in it sorted out.

[This message has been edited by imabaddude (edited 04-13-2014).]

quote Originally posted by imabaddude: Doesn't sound like the ECM. ECM is $90 at advanceauto.com and they have coupon codes so it will be cheaper. Just google coupon codes for advance autoparts. It still sounds like the wires are put in the wrong order, If they aren't try them in different spots, maybe the coil was put in backwards or something to where you think they are right, but they aren't. IDK, I haven't had a duke with DIS. Don't put any new parts on it, stop, take a step back and think. Your check engine light comes on when you put the key in the one position, so your ECM is working, it primes the fuel pump, and you are getting fuel, you are also getting spark. So, the issue has to be timing related, or it could just be the gas in the tank is rotten. When I bought my fiero it had sat and the gas was rotten and needed to be drained, when I started it, it ran like crap and popped and backfired, and would die, but after I got the old gas out and put new gas in it sorted out.

I tried putting wires on backwards just for the hell of it, it was the same if not worse. Gas tank, pump, gas and filter are all new. I agree that it sounds like the timing is way off but the ECM is the only part directly associated to timing that I haven't changed. Well that and the cam gears. I'm going to go get another crank sensor today and try swapping that out again, and inspect the new coils and ICM. If no change then the ECM has got to be it. If i swap that out and it still wont run, I'll have to bing it somewhere or just admit defeat and sell it.
Edit to add that i haven't changed out all teh sensors (see above) but don't think they will cause it to NOT run to this degree.

[This message has been edited by DLCLK87GT (edited 04-14-2014).]

The mystery deepens. Tonight I pulled the "brick" and put on another - new - crank sensor, cleaned and re-lubed the plugs with dielectric grease, put new heat sink paste on and put it all back together. And for the umpteenth time, checked the plug wires to make sure they were in the correct place. Tried to fire it and the same as before, will half ass run if I floor it but sounds like the timing is way way off. OK THEN!
Next step was to replace the ECM and this is where it gets interesting. I started fiddling with the center console...hey, it's not attached. It took me 30 seconds to pull it off and expose the ECM which was also, not attached. It was plugged in but not bolted in. I pulled it out and it's got a "PRIORITY MAIL" sticker on it and on the service tag, hand written "84" so obviously it's been replaced already but the "84" has me wondering if the PO was smart enough to go through the trouble of replacing the ECM, but stupid enough to put in one from an 84???!!!!!
the sticker on it reads;
SERV. NO. 1227748 ALWK
855992 M810162764

Anybody know how to decipher this? I Goggled it and got back info about cross referencing GM ECM's but it didn't tell me much other than they were in 86 - 95 GM cars, sort of ruling out the 84 thing but it still has me scratching my head. I've replaced just about everything there is, and it looks like so did the PO. At first I was excited to see the 84 and said out loud "well there's your problem!!" but maybe not....
Edit to add; some more searching tells me this IS the right ECM, used in 87-88 Fieros. can these be checked to see if they are good?

[This message has been edited by DLCLK87GT (edited 04-19-2014).]

You may be on to something... I'm not sure of the numbers, so it may or may not be the right one. Probably want to change it anyway. Have you checked all your grounds?

I wonder if the ecu is from a 2.8 and not for the duke, if it's been changed you never know.

quote Originally posted by Neils88: You may be on to something... I'm not sure of the numbers, so it may or may not be the right one. Probably want to change it anyway. Have you checked all your grounds?

Oh HELL YA!! I've replaced old and added several new grounds including one from the ICM to the frame, replaced the starter and negative battery leads as well. Its well grounded.
I just cracked open a nice cold 90 minute IPA and was staring at the ECM. I started to think about the "priority mail" sticker that was placed over the little door that exposes the "chip" inside. So with nothing to loose I pulled the door and the chip underneath. The chip is from Singapore. Suppose GM was using Singapore chips back in 88 or is this; A: a rebuild unit, or B; did somebody try one of those super HP increasing chips and FUBAR'd it??
Either way I'm going to go order a new on in the AM. Just thinking out loud.

quote Originally posted by DLCLK87GT: Originally I thought all it was a bad fuel pump. Even though it WAS bad it’s not the issue. I’ve replaced; fuel pump & tank... I also got a fuel pressure gauge but couldn’t find my tubing bender to put the adapter on so I skipped it last night. ideas?

Did you ever check the fuel pressure?

I'm reading your thread for the first time, and the symptoms remind me somewhat of the problems I was having with my '84 as posted HERE. Fuel sprayed from the injector. It would run, but just barely, unless I unplugged the MAP from the harness. Something was amiss.

quote Originally posted by Patrick: I disconnected the fuel filter (it was very clean inside) and connected a fuel pressure gauge onto the end of the fuel supply line. I then jumped terminal "G" at the ALDL connector with 12v from the cigarette lighter to run the fuel pump. The gauge showed a grand total of 4 lbs pressure while the pump was running, and immediately dropped to zero when the power was cut. I suspect that short chunk of flexible hose inside the tank has rotted. Whether it's that or the pump itself which is to blame, it looks like the tank needs to be dropped.

I know you've replaced the fuel pump etc, but unless you've actually checked the fuel pressure with a gauge, you'll never know if you are indeed getting enough fuel pressure for the engine to start and run properly.

quote Originally posted by DLCLK87GT: SERV. NO. 1227748 ALWK 855992 M810162764

The 1227748 aka 7748 was used in several different vehicles. In Fiero's they were only used in the 87-88 2.5.

ALWK refers to the PROM that was originally in the ECM. The ALWK prom wasn't used in a Fiero. http://www.exatorq.com/ludi...d1/fieroprom.html#L4

Now just because the sticker on the outside says ALWK that doesn't mean the prom inside is an ALWK. Take the cover off and compare the PROM with the chart from the link above.