acechase99

finally got the car to crank over and start but the car wont idel it will run if im giving it gas but as soon as i let off it dies. code 34 comes up which is MAF sensor, could this really cause this much of an issue i unplug it and it does the same. their looks to be small wires in a diamond shape inside and one broken. any way to test these.

so far new fuel pump (45psi to rail)
new injectors
new filter
new fuel pump relay
new plugs and wires
cleaned the IAC
new ICM

any one have any ideas, could the ECM be bad if so does both the ECM and prom go bad or just the ECM and use the same PROM
thanks for any help

TwinTurboROC

Yes you need the MAF to idle correctly. IF the wire is broken inside its done. GET A NEW MAF. and take it from there. Get back to us if the problem persists or if anything new starts up after that.

TwinTurboROC

Oh as for the ECM, they do go bad from time to time. Look at your check engine light when you turn your ignition on. It should come on, go off, then come back on solid and stay solid if your prom is good.

What makes you think the ecm may be bad? The idle problem?

acechase99

i will order a MAF today hopfully they have one in the warehouse. i was thinking ECM problems when i was first having fuel issues which seems to be solved now. I still do not hear my pump prime of the 2 seconds when turn the key on but it fires right up as long as i am giving it a little gas.

acechase99

ok have a new MAF still does the same thing just no more code. it seems like it turns over a little quicker but still dies right away. any other sugestions. i have a small exhaust leak at the exhaust manifold ill be working on that in the mean time thanks

TwinTurboROC

Sounds like your IAC might still be a issue. Put a small matchbook between the throttle and the stop screw and see if the car fires up then. Btw did u reset the codes by discon the batt for about 1 minuet?

camarosrock1989

iTrader: (1)

I had the same problem and it was my TPS, replaced it and was fixed. My MAF has been unplugged for a while. I have heard many people replace theirs and doesn't make a difference. Even makes matters worse for some, after market MAFs are not made well either.

TwinTurboROC

Yeah but when one of the heated elements is broken, its BROKEN. lol. Ive never seen a TPS cause a idling problem before, Care to explain some more? (not trying to be a smart *** about it either), You can pm me.

acechase99

yea i disconnected the battery had to re-charge it. I adjusted the throtle by the asjesting screw and got it to idel but seems a little high (i will get the actually rpm when i get a chance to back out tomarrow) i figure i would try to re clean the IAC and put everything back to gether and see what happens when i try to drive it down the street.

question off this topic, the car came with some cheap after market headers that dont have a place for the o2 sensor is there any way to by pass this sensor or install it on the new headers. the stock exhaust has a nasty leak so im trying to figure out if i should try to put the headers on it or not. i live in texas so unfortantly i have to deal with getting safty inspections. for another 3 years until it is considered a classic

TwinTurboROC

The o2 senor is need, try to get it installed. You can have a o2 sensor bung welded in. I have seen on some cars that a o2 sensor will cause surging, and rich running at idle.

acechase99

ok first of all i would like tosay thanks for all the help. I messed with the throtle screw and can get it to idel less the around 3000 RPM and i cant find anyvacuum or intake leaks where it could be sucking in extra air. I noticed it takes about 3 nice cranks before it wants to try and crank all the way over im going to hook up the pressure gage tomarrow to see if it takes that long before it gets pressure. then it wasnt wanting to crank back over after letting it idel at about 3000 rpms for 3 or 4 minutes I dont know the next place to start

TwinTurboROC

Wait, its IDLING at 3000 rpms, thats not right, You will kill your car like that. Adjust it back down to where it runs at like 700-800 rpms. You may need to tweak your distrubutor to get it to idle right. DEFINATELY check to see what your timing is set at.

Before you adjusted could you keep the car alive, by just pressing the throttle lightly? Like just rev it up to about 1200 rpms and let it warm up.

Whats the year model make motor of your car?

acechase99

i backed the idel screw all the way back off and it still idels that high and cant find any vac leaks. I brought the crank to 0 and the distributor was at the number 1 plug how else can i mess with the distributor
89 firebird formula 5.7 TPI

TwinTurboROC

Definate intake leak. Heres what to do, get some carb clean, and spray around the intake area, the runners, even the vaccume to the brake booster. You can even take the brake booster vaccume line out and plug it w a big screw or clamp. Even the lower intake etc. Check the TB area. Spray and spay, avoid the headers and super hot areas. Youll hear the car rev up if it finds a bad spot.

Does the car do any idle control at all? maybe the IAC valve is bad. I forgot how much the iac ports in stock TB can alter but i dont thinkg 3000 rpms.

You know how to adjust timing?
That can affect idling, but not to 3000 rpms, you have some other issues right now.

Do the carb clean test and see. BTW do not over use this stuff, it can ignite.

Im gonna assume the car starts up and idles now on its own, without you giving it gass or w/e? But idles to high

acechase99

it starts rough normally it takes a good 3 cranks before it will give a little hickup then ill give it a little gas and it will start. ill try the carb cleaner tomarrow

what do you mean by idel control? i have cleaned the IAC but at about 75 dollars havnt been in a hurry to replace.

I know you can use a timing gun (may not me right term) but i brought the harmonic balancer notch to 0 and pulled the cap and it was pritty much right on the number 1 plug.

this is my 2nd one of these and I love this cars I picked this one up from a guy who decided to start ripping stuff out of it like the AC for some reason and completly screwed this car up hopfully i can bring it back to life eventually

TwinTurboROC

Well, i mean idle control, as in does it rev down, rev up, anything to say that the IAC is working. I know it may be hard to figure it out now, but hopefully when u get the idle down, you will hear it adjusting itself, and see the rpms drop.

Do that thing with the carb cleaner first. I did a quick write up on setting timing, you can do it after you bring the idle down. I am certain you have some kind of intake leak. Look around the throttle body area. Also have you removed the intake or the runners etc?

(just a quick side not. If your car is idling at 3000, what you can do is unplug the IAC connector. Turn the car off, You should see it almost all the way out because its trying to SLOW the idle. Now also, before you start the car, you can do ignition on, disconnect the IAC, and it should be fullly retracted because it wants to INCREASE the idle cuz the car is about to be started, just be carefull to not break it. This is just a free way of seeing if the valve is messed up, i would do that last if you dont find any intake leaks)

With the dizzy thing. Its called ignition timing. I dont know what your experience level is, but ill give a quick rundown.

Once you have the dizzy installed, you can adjust it by turning it left and right. on the crank pulley, there is a spot on the balancer with a slash across it. Thats the mark we use to time it. Normally what you do is connect the timing light or gun, to the number 1 plug wire. Then disconnect the tan wire (its by the panel underneath the wiper area, right next to the trany dipstick, there the black wire harness, there should be this white connector sticking out of it).

What that does it take the ECM out of controlling the timing (remember your cars computer can advance and retard timing). So now you can set your base timing. Look on the hood label. It should have info on what the amount of degrees should be.

Now looking down at the crank pulley from the DS side of the car, there should be a small tab sticking off the timing chain cover, right above the crank, Its got some V's or zig zags or kind looks like a mini saw blade.

That is the timing mark. Yours may be rusty. I suggest hitting it w some bp, and a small wire tooth brush. It normally cleans up the rust so you can actuall see the numbers.

Remember to do this this dizzy has to be loose, maybe a turn on the bolt that holds it down, just until you can turn it left and right.

Now you start the car up, the timing light should begin flashing, point it down at the "saw tab" and you should see the slash in the CRANK pulley moving around near it. What you need to do is turn the dizzy left or right (small movements) until that mark lines up with one of the V's. The Vs are have numbers next to them, 4 degrees 8 degrees 12 degrees... (I forgot what the exact numbers are).

Keep in mind, the correct way of doing this is with the car warm. But you can do it cold, and just keep adjusting it until the car is warm, in about 5 minuet intervals.

acechase99

yea it does have idel control it does not rev up and down i sprayed the carb fluid and it did rev up a little i figured since they are only 13 bucks i riped back apart the plentum and going to replace all the gaskets and doyble check the seating of the fuel injectors going out of town tomarrow so ill be back in the car tomarrow hopfully see some changes.

TwinTurboROC

if it did rev up when u sprayed you have an intake leak. Get them gaskets replaced. Lemme know how it goes.

acechase99

well the rain has not let up the last couple days hopfully can get back out to the car soon.

blackbeauty89

lotta good info on this thread. i'm having somewhat of a similar problem..sort of

crazyjc15

sounds like you IAC is stuck wide open. being that you car has MAF and not MAP, a vacuum leak will make it run rough and possible stall at idle. cleaning the IAC wont do much if its stuck. after you replace the IAC you may need to relearn idle position. there's a procedure for that, i dont have it on hand right now but if i find it ill post it here.

dubble checking you timing wouldnt hurt either.

acechase99

ok wouldn't the IAC throw a code.

ok got it back together and finally got the idel down its at about 700 rpm which I am about to double check but that sounds about what I have read before.

now I have the problem with the car not wanted to start back up after running for a few minutes but if I go back out after about 30 min it will start back up. when i first start it up it takes about 3 cranks before it finally turns over I have read possable starting with these cars even though it always cranks fine.
it was only running for a few minutes was not running really hot this is why I am confused if it was running hot then I could see why


UPDATE:
OK just checked and im throwing code 54 now, fuel pump circuit and I dont think i hear the pump priming and it is a brand new fuel pump filter and relay. could the oil pressure switch be causing this or do you think it is a bad ECM

TwinTurboROC

Progress good. Were the gaskets bad?
Did you reset the timing? Connect back the est conn?

With the no start check for spark, fuel pressure and fuel injector pulse.

I have seen iac that are bad throw NO codes. Does the car
Adjust idle? Turn on your headlights defoger and blower motor on high at around the same time. It should rev about 100-150 rpms up to compensate for the load.

acechase99

yea the gaskets were bad I had that same issue back 6 years ago when I had my last formula wish I would have remembered.

Ill run out ina few and see it it will turn over if it doesnt then I will check fuel pressure.

timing is good and the car does adjust idel a little i was able to drive it down the street and back no issues till i turned it off then tryed to restart it then NO GO.

ill try the hed lights and everything if it turns over and let you know
i am leaning to bad ECM from what i have read.
it was something like if you crank the engine and build up pressure the oil switch does something to get the fuelpump going by bypassing the ECM (sorry probable could of described that better but i think it makes some sense)
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ok so went out real quick and im not getting any pressure to the rail, if i run a hot wire to the g port aldl you can hear the pump and then the car will turn over and run for a lttle then die (it will go in gear and move up and down the drive way didnt attemp to take it on the road
Oh yea the inline fuse is good that's the first place I looked
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http://www.austinthirdgen.org/index.php?pid=35 i used this post and everything checked out and didnt have any faults at the wires i dont have a clue what else to check if i unplug the relay and jump the power wire with the pump it will get presure and start right up. this is the 2nd relay maybe a 3rd is a charm. if seems to start eerytime if i do that and drives well i managed to atleast take it around the block but when i parked it i noticed a small fuel leak at the fuel rail which looks like possable a bad O-ring so i guess time to rip the top end off again. but still no clue on the fuel relay issue.

acechase99

ok fuel leak fixed picking up relay today i had to order it last night, any one have any ideas if its not the relay it will start right up every time if i manually run the fuel pump no had cranking and will run fine. disconected the battery to charge it and now not throwing a code

acechase99

no luck with the new relay

blue iroc

I know this an old post, but did u ever fix your car? If yes can u let me know what was wrong with her. Your cars symtoms sound exactly the same as my car is experiencing right now.

Thanks,