When you have the A-B jumper in and start the car, that is usually used for setting the timing. With the A-B jumper in, the engine runs on just the distributor timing, and not the ECM's programmed advance timing. If your timing was way off perhaps it would only run with the A-B jumper in.

im not sure.. all i know is that the car started damn fast and smooth with the pins in

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"proud'862M6"

So stick it back in and see if it runs good with it in again.

when ur timing a 2.8 where should you point the rotor when you have the engine on TDC?

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"proud'862M6"

So here is a second thing to try. When you turn the key to ON, with A-B jumpered, the Idle Air Control valve runs to close the valve. Once started the ECM re-adjusts the IAC to keep the engine running. Perhaps the problem is with the IAC allowing too much air in the intake. Just to try and see what happens, jumper A-B and turn the key on. Wait till you see three 12 flashes and then unplug the IAC on the engine. Then try starting the engine. The engine should start hard if at all. You should have to hold the throttle open some to keep the car running or at best the engine would run well below normal idle with your foot off of the gas. If the engine is running faster than that you have a serious vacuum leak.

With a serious vacuum leak you would most likely had a fast idle problem especially when the engine was warmed up before.

The IAC is the lower of thse two connectors on the throttle body. Unplugging the IAC leaves it where the ECM had it and prevents it from being adjusted. Plugging it back in re-allows the ECM to control it. You might get a SES (Service Engine Soon) light by doing this test. If so the SES code can be cleared by disconnecting the battery for 30 seconds when you are finished.

so i unplugged the IAC and it barely ran i would hold the throttle open and it would sputter and die ... but even after that.. the ECM never flashed any other code besides code 12 ??????

Well that's good I guess. It shouldn't have ran good. If it did that meant you had a big vacuum leak. So plug the IAC back on and just verify again the engine seems to run good with the A-B jumper in, and doesn't with it out.

So if that's still the condition then it's really sounds like you want to verify the timing is correct or not. The A-B jumper changes the timing.

Any chance you have a fuel pressure gauge and can verify the fuel pressure at about 40 psi, key on engine off?

no it runs bad with and without A and B jumpered... i even messed with timing and everything seems to be in order...

so today i got a free ECM to try.. sadly it made no difference... interesting thing though, i was messing with timing tonight and i got it on TDC and put the distributor in with the rotor facing towards the intake... i put the cap on and then my wires, and i put them all in order... but it doesnt even try to fire until i turn it completely to the right side of the car.. which i think is advacing it way to much...but its not even firing where the rotor was when i put it in? now ive done this before countless amout of times on my Fiero and i just dont know what the deal is with this thing.

Take out the #1 plug. Either put a compression gauge in the hole or your assistant's finger. Turn the crank clockwise until either the compression gauge starts moving or your assistant starts making a weird noise. Then continue forward till the mark on the crank pulley aligns with the 10deg before spot on the marker. Stop there. Do not turn the crank backwards to get to that spot.

Now look at the dist. It HAS to be aligned to point at the #1 tower. If you can rotate the distributor to get it so the rotor is pointing to #1 that's fine. (loosen the hold down bolt) If you can't get the distributor to rotate enough to point at the #1 plug you might have to take the hold down bolt out all the way, then lift the distributor. As you lift it note how far the rotor turns. Before putting the dist back in put the rotor pointing in a position so when all the way back in, the rotor is pointing towards where the #1 tower is supposed to be. When installing the distributor you most likely will have to rotate the crank to get the distributor to drop in all the way. Then again rotate the crank clockwise till you are on compression and then continue till you are at 10* before tdc on the compression stroke.

Just as a double check pull the rotor off the dist shaft now and make sure the rotor points the same way as the notch on the shaft.

Now with the crank either still at, or back at 10 deg before tdc on #1, do a minor turn on the distributor to align the prongs and points of the reluctor and stator below the rotor. Get the points of each to point exactly where the other is. Snug down the hold down bolt. Now re-check to make sure the rotor is pointing to the #1 tower. Double check the firing order of the distributor. It turns clock wise. The firing order is 1-2-3-4-5-6 Now put the spark plug back in, reassemble the distributor and start the engine.

You will have to put the timing exactly on with a light after this however this procedure WILL align the distributor close enough to start the engine.

So i put the harmonic balancer on 10 BTDC and everything you said to do.. Now it tries to start and has plenty of spark and it fires every once in awhile but doesn't start. we took the spark plugs out and cleaned them and they were black.. we put them back in after we clean them..and we tried starting the car. at first, the engine fired and almost ran. we tried cranking again and all we could smell is raw fuel...my dad pulled the spark plug and it was soaked and dripping gas ...why is it flooding so fast? it was only the second crank and it just flooded it out.

replace the plugs

while they are out put 3 squirts of oil in each cylinder

they are NGK Iridiums and i just bought them... should i get rid of those?

Didn't you say they were black?

Black as from driving or black from trying to get the engine to start.

Properly gapped?

black from trying to get engine to run...but the motor floods out in the first two cranks

Make sure your MAP vacuum line is connected. Also try electrically unplugging the MAP sensor.



The MAP sensor determines how much air is in the intake manifold which the ECM uses to determine how much gas to squirt into the intake.

If the vacuum line isn't connected the ECM will think your intake is full of air (usually caused by having the throttle wide open) and dump all kinds of gas into the intake. So make sure the vacuum host to the MAP is connected/

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Electrical disconnected - So then the ECM doesn't have the MAP to use to calculate how much gas to squirt in. So the ECM relies on some major limp mode tables to try to get the engine to run. The thought here is the major limp mode table won't be dumping way too much fuel and at least you can get the engine to start so you can procede to trouble shooting.

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What if both don't work and the intake is still getting way too much gas? - Well is an injector stuck open? One of the 6 or perhaps the cold start injector?

btw - if the engine runs by electrically disconnecting the MAP? Major limp mode? Yeah it's not going to run good with power or anything but at this point I'm just looking to get it to run.

ok i will check into that.. i was just looking in my haynes repair manual and i was just suspecting the map sensor...

I'm not quite to saying it's bad, I just want to see what happens if the ECM doesn't see it. But yeah, give it a try.

Check to make sure your EGR valve is clean and free to move up and down.

[This message has been edited by phonedawgz (edited 12-17-2010).]

I had the exact same problem.... fuel fouled plugs.... I had just got my car and got 5mpg then it would not start, some ass who had my car before me put a bb in the MAP vac line so it though I was WOT all the time!!! Took forever to find that stupid thing!

How about a jumped timing chain? Symptoms sound similar to mine when chain had jumped one tooth. After I corrected the timing by rotating the distributor, the engine ran but was down a bit on power.

So i unplugged the Map sensor and it started up so i replaced the Map..guess what? MY CAR RUNS!! haha ya ...so another fiero back on the road! thanks for all the advice and knowledge..

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"proud'862M6"

So it was all a bad MAP? Cool cool cool

ya we had it running and we tried plugging the MAP back in and it shut the car down...so we kinda figured that was the problem

Well it makes sence. The MAP is the thing that ECM uses the most to determine how much gas to inject.

Yea, so next thing is replacing the timing chain....found out that its looser than im comfortable with.... then i need to buy poly bushings

Wow...this thread read like a murder mystery....a tip of the hat to phonedawgz for all the help....with this kind of assistance folks can keep their Fieros ticking.

No joke!! when i started this thread, i didn't think anyone would respond...but i was wrong.. best decision i made while fixing my car.. thanks

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"proud'862M6"