I have an '86 4cyl 5spd Fiero, and just went and put some new ACDelco plugs, and the NAPA High Mileage wires on it. This is the first time I've actually changed spark-plugs, so I stuck to a manual and followed it closely. Gapped the plugs to the 1.5mm specified in the service manual, routed the wires all the same, one at a time to make sure I didn't screw up... Then I turned the key.

Right away the engine started to chug, letting out pulses rather than the nice smooth flowing sound I'm familiar with. So, I immediately killed it, went back, pulled all the plugs (carefully) re-checked the gaps, put them back in and made sure all the wires were on nice and tight. Turned the key again.

And the same thing happened, I let it run for a little bit this time, hoping that it was just something the ECM had to re-learn or something, and sure enough the idle smoothed out, though it still sounded a little bit odd, but judging by the fact that one of my orriginal sparkplugs was cracked in half, I wasn't sure if it was right or not... So, I took it for a test-drive around the block, and the SES light pops on.

My SES light was on sporratically beforehand, which I was told was a code 35, and just required pulling out the IAC, cleaning it and its socket, and putting it back in, which I also did just after changing the sparkplugs, but before starting the car... (Yeah, I should have done one thing at a time) But, the light always went away as soon as I started going down the road before. Now, it comes on as I start going down the road.... I've got about 2 hrs to get this taken care of, please, someone help me figure out what I screwed up....

Plug gap is .060 in. on 4 cyl and .045 in. on V6. Try that.
Check to see that all wires go to their correct plug and distributor cap positions. (in the manual)

That's as quick as I can be

[This message has been edited by fyrebird68 (edited 01-21-2009).]

quote Originally posted by fyrebird68: Plug gap is .060 in. on 4 cyl and .045 in. on V6. Try that. Check to see that all wires go to their correct plug and distributor cap positions. (in the manual) That's as quick as I can be

1.5mm is .060 in :P I'll go double check the wiring... but, the engine should run nightmarishly if that's wrong shouldn't it? But, I'm not one to take chances, so I'll go check now.

Twilight, when you replaced the IAC did you disconnect the battery cable? if not the ECM will still recognize the problem. After 25 years just cleaning the IAC is not enough it might need replacing. Your wires should be in order and the Gap is not critical on fuel injected engines it just the heat range. The SES light can come on and off with just the smallest vacuum leak and read no codes.

Jim

[This message has been edited by FieroJimm (edited 01-21-2009).]

quote Originally posted by FieroJimm: Twilight, when you replaced the IAC did you disconnect the battery cable? if not the ECM will still recognize the problem. After 25 years just cleaning the IAC is not enough it might need replacing. Your wires should be in order and the Gap is not critical on fuel injected engines it just the heat range. The SES light can come on and off with just the smallest vacuum leak and read no codes. Jim

No, I didn't disconnect the battery.. Well, from the looks of things, it's safe to take it out on a trip? I gotta be somewhere pretty damned soon here, and would hate to miss it... but, if my engine is at risk, I'd rather hold off. None of the codes seem like something that is a problem, in fact, acording to my service manual, the 45 may be caused by an intermittent coolant reading... which, my code 15 says isn't working... SO, replacing that should be all I need, right?

[This message has been edited by Twilight Fenrir (edited 01-21-2009).]

make sure all your wires are on tight on the plugs and cap. Push down real hard. I dont want to patronage but I have done many tune ups and the last one i did i spent about an hour just making sure everything was on tight (V8). It would not start for the life of me until everything was on snug.

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'86 2m4- Auto, Daily Driver
'87 GT - 5spd, Project Car
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So now you'd better stop and rebuild all your ruins,
For peace and trust can win the day despite of all your losing

quote Originally posted by FIER086: make sure all your wires are on tight on the plugs and cap. Push down real hard. I dont want to patronage but I have done many tune ups and the last one i did i spent about an hour just making sure everything was on tight (V8). It would not start for the life of me until everything was on snug.

Oh yeah, I did that... I reafed and pushed untill my fingertips hurt, on each and every connection point.I'm 99% sure they're all on there...

I had somone come out and watch the intake with the cover taken off, and they said they could not see the stream of fuel coming from the injector. I've never seen a TBI system, I'm used to Carburetors, or magical boxes that just makes the car run (Every other form of injection) But, from what I understand, there should be fuel coming out of that armature that sticks out over the intake on the Throttle-body, right? The flapper on the intake also doesn't move, though it does when I push on the gas pedal. Is it supposed to be that way?

I know the IAC has its ownn air-flow, but does it completely bypass the primary intake? How does fuel get into the engine then?

Try about a table spoon full of gas down in the throttle body, press on the gas pedel once then release. Try the key to see if it will run about 2-3 seconds. If so you have a fuel supply problem,relay, filter, or pump.
Good luck

quote Originally posted by josef644: Try about a table spoon full of gas down in the throttle body, press on the gas pedel once then release. Try the key to see if it will run about 2-3 seconds. If so you have a fuel supply problem,relay, filter, or pump. Good luck

.... Seriously? Will it combust just poured down there? Doesn't it have to be atomized? Should I pour it in there, then get in my car, press the gas and try to start? Or, have somone dump it right in there while I turn the key?

You can have someone else pour it in but make sure they are not leaning over the engine when you try to start it. Also never put a second shot of gas in before opening the throttle and checking for flame......... do either of these wrong and you could have flames shooting up to someones face or arms. If it turns out to be a timing issue.

One thing that no one seemed to mention is that you could have the firing order right but, have started at the wrong terminal on the distributor.... it might still run but the timing would be way off.

Good Luck
Scott

Any chance your distributor moved (rotated) did you check if it was tight ? If it turned on ya while putting on the wires could cause these issues. Are all you vacuum lines still on, didn't accidently knock one off did ya ?

quote Originally posted by Sebringdcp: You can have someone else pour it in but make sure they are not leaning over the engine when you try to start it. Also never put a second shot of gas in before opening the throttle and checking for flame......... do either of these wrong and you could have flames shooting up to someones face or arms. If it turns out to be a timing issue. One thing that no one seemed to mention is that you could have the firing order right but, have started at the wrong terminal on the distributor.... it might still run but the timing would be way off. Good Luck Scott

Well... I guess I'll go do that then..

As for the pegging, again, I removed one wire at a time, and put it back on... So, everything is onn the same terminal it came off of.

I do have a can of starting fluid... Would that be better than pouring gas down there?

Fuel pump bad, Fuel pump Relay, Fuel filter, Fuel injector, ECM,......But start by checking fuses !

quote Originally posted by Mike Gonzalez: Fuel pump bad, Fuel pump Relay, Fuel filter, Fuel injector, ECM,......But start by checking fuses !

Fuses win, I'll go check them right now...

I vote Fuel Filter! When you turn on the key, can you hear the fuel pump? You can take your fuel line apart at the fuel filter then place a bottle, jug or bucket on the line, turn on the key and see if it is pumping! Sounds like it steadily got worse and it had nothing to do with your tune up. Just coincidental!

Edit to add - Too Late!

[This message has been edited by katatak (edited 01-21-2009).]

Dont know on the IAC, but you ECM needs to have time to "learn" with the new wires, plugs n such. You may wan to disconnect the battery for 15 minutes to reset the ECM and force it to "relearn" Also you may try running it long enough to get to operating temp and see how it does then.

Does it only run bad at idle? Does it clean up say at 2000 RPM?

Edit to add: How did that happen - posted twice? only made one? Wierd!

[This message has been edited by katatak (edited 01-21-2009).]

quote Originally posted by Mike Gonzalez: Dont know on the IAC, but you ECM needs to have time to "learn" with the new wires, plugs n such. You may wan to disconnect the battery for 15 minutes to reset the ECM and force it to "relearn" Also you may try running it long enough to get to operating temp and see how it does then.

Yeah, I was thinking about trying that. But, there is definitely something amiss with my IAC, and I'd like to get that out of the way before I go trying to make the computer re-learn something that is wrong.

quote Originally posted by katatak: Does it only run bad at idle? Does it clean up say at 2000 RPM?

I don't know :P I'm out of opportunity to take it out on the road, but while it was sitting I pushed on the gas peddle, the engine reved up hard at first but cleaned up after just a few seconds, when i took my foot off the gas the RPM's dropped, then the engine died. Sounds like it was suffocated.

If you were closer id give you an IAC, I got 3 2M4's out there one has to have a good IAC. The suffocating thing doesnt sound good. Not sure the IAC would do that. Im going to go look at service manuals in a minute see if I can find anything on the IAC. Have you checked the timing ? might have changed with new ignition parts.

I think you are on the right track with the IAC. If the pintel is adjusted out to far the car will not get enough air to idle right. The ecm only knows the previous adjustement / position of the pintel prior to your cleaning of the pintel. The ecm will constantly adjust the fuel for the air flow but may be confused. I would do what Mike suggested - disconnect the battery for a few minutes. Then reconnect and start the car. This will clear all your codes and let the ECM relearn the IAC position. There is a thread on here that outlines the process for adjusting the IAC correctly. I will see if I can fnd it for you.

Service manual say check ground straps IAC is sentitive to operating voltage, Ignition timing and EGR. Nothing specific I could find on the IAC though.

Ok, read this thread almost all the way to the bottom posted by Chicken Mcnizzle!

https://www.fiero.nl/forum/Forum2/HTML/085438.html

There is another way too. I think it's by Dodgerunner - I'll go find it.

+ for you Katatak for diggin up good info !! That search thingie doesnt do me much good.

Here's another one - about the same with a way to test the IAC itself and another version for adjusting it while installed.

https://www.fiero.nl/forum/Forum2/HTML/090637.html

I'm learning too!

quote Originally posted by katatak: I hear ya Mike, I usually get tired of reading the endless threads and do not ever seem to be able to find the answer I am looking for. Once in awhile I get lucky. I just don't have the patience to dig too much ....lol

Yup, with you there for sure !

Back to buisness....................Any updates.........Or are you out cruisin cuz its running so good now ?

I think he had something to do......

quote Originally posted by katatak: Ok, read this thread almost all the way to the bottom posted by Chicken Mcnizzle! https://www.fiero.nl/forum/Forum2/HTML/085438.html There is another way too. I think it's by Dodgerunner - I'll go find it.

Well, that's certainly the comprehensive answer I was looking for Thank you VERY much for digging that up.

quote Originally posted by Mike Gonzalez: + for you Katatak for diggin up good info !! That search thingie doesnt do me much good.

Seconded

quote Originally posted by Mike Gonzalez: Yup, with you there for sure ! Back to buisness....................Any updates.........Or are you out cruisin cuz its running so good now ?

No, no updates at the moment... I've lost my light source (wiring in garage started on fire while I was working >.> ) Got it taken care of, no harm done :P But I don't want to push it till I can replace my band-aid with proper work, so I'm not gonna go plug in my 2k watt worklights. Testing and working will unfortunately have to wait untill tomorrow morning. But, with all the information Katatak pulled up, I don't see how it can not work

Well if your gonna burn down the garage GET THE FIERO OUT !!!!!! We have time invested in it !!


Glad nothing was hurt, keep us posted on what the fix is.

I agree, Fiero's already have a bad rep when it comes to fire! Keep us posted on your progress.

Pat

quote Originally posted by Mike Gonzalez: Well if your gonna burn down the garage GET THE FIERO OUT !!!!!! We have time invested in it !! Glad nothing was hurt, keep us posted on what the fix is.

lol, the circuit breaker is off, so there's no power out there at the moment :P Besides, if I wanna get the Fiero out, that means I'm gonna have to lift that big heavy garage door... then push the car out while trying to keep it from rolling away :P Not to mention, pushing it back in there tomorrow morning to get back to work... no... no... it's fine where it is :P

quote Originally posted by katatak: I agree, Fiero's already have a bad rep when it comes to fire! Keep us posted on your progress. Pat

Will do I always manage to find the odd little problems in everything I do :P

Okay, just ran out and reset the IAC a few minutes ago... The Duke is running smooth as silk... albeit at 1500 RPM.... Idle just won't go below that. I looked under the air-cleaner and watched the pintle as it reset itself, it didn't fully extend... I could just barely see the tip poking forward, but probably not enough for normal idle. I've got the car sitting with the - battery cable unplugged, I'll go back out there after a shower and see if it takes care of it. But, I'm betting I've got to replace that IAC. No big deal. I had to go to NAPA to pick up my new clutch master cylandar today anyways :P

I think that should take care of me, I'll post back if anything crops up, thank you all very much for your input.

When I changed out my distributor and got it put in back in wrong the first time , and then finally corrected it my engine would not start either because I flooded the heck out of it.

I am not sure if a bad IAC could cause a failure to start.
Sorry I cannot contribute more than that.


One lesson I learned (about 3 times now LOL) it to NOT change more than one thing at a time. Because if you do and the car fails to run right or run at all it becomes a Mo Fo to figure where the problem is. Don't do as I did and not follow my own lesson!

I learned the hard way changing sensor pigtails and not testing the car after changing each one before going on to the next.
This is not a lecture but an observation that can save you grief.

Check to be certain you have spark on all 4 cylinders, a guy not long ago here had a brand new DEFECTIVE distributor cap, you cannot trust anything these days!
Also are you absolutely certain you have the wires in the right order and #1 in the proper position on the dist cap?

For the heck of it disconnect the connector from the IAC and try it.
Sparx22

[This message has been edited by sparx22 (edited 01-22-2009).]