elementaltoad

I have a 1988 TPI 5.7 liter firebird formula, i started it when i got home and it ran and started fine. i took it too the gas station to fill it up with87 octane, which is what ive been using. After i got home i let it idle for a bit and turned it off to check fluids, since i just got it. After checking oil and trans fluid for contamination i noticed the radiator took in more coolant, which should be right since it sat for a while before i bought it. however as i went to start it again it cranked and will fire, die,fire,die, fire and after a few cycles of that it will quit trying to start. so i tried it again and it did the sam thing, so i pumped the gas thinking it might coax it, but it just bogged out and puffed smoke from the intake, but the smoke didnt smell odd, just like the engine had flooded. However i smelt the smell of what i take to be wiring, most likely ignition? but i know the smoke couldnt have been collant since there are no signs of contamination and it did not smell sweet. It ran fine the other day with the exception of the gas tank building up pressure (clogged return line or charcoal canister i assume) so i vented the gastank and it started up perfect, idled fine and warmed up and i could spin the tires off all day with no problem. But now it refuses to start and only boggs out with me pumping the gas, any help would be extremely appreciated, my guess is ignition if anyone can help me go from there. thanks again

Willie

Sounds like the MAF power relay is bad. Swap it with the MAF burnoff relay and see if your engine will start. If it does, the relay was the problem. FYI, both relays in 1988 are identical.

elementaltoad

i removed the relay, and attempted to start the car, it will fire once but then just try to turn over, i wasnt sure which relay it was so i disconeccted one at a time trying to start after removing each one to no avail. Which i assume means my MAF sensor itself is bad?

elementaltoad

i removed the MAF and checked for visual damage and i see none, so i hooked it back up, relays too and tried to start, no such luck, it will only fire,die,fire as i said, now if i hold the starter on it will keep firing so i am getting fuel and aparently air. So my last resort is either the MAF, or IAC.

Willie

Well, let's see. Removing only the MAF power relay is equivalent to disconnecting the MAF. The engine should have run. It doesn't. Although your symptom can be caused by a bad MAF, your engine did not continue to run after start up without the MAF. I'm leaning towards a bad ignition module. Any other ideas guys???

Willie

elementaltoad

my idea was ignition originally also, as alot of times the assinine placement of plug wires and such tends to crack and dry up the silicon boots. ill run and try the dissconect once again straight from the MAF wire and think of some more symptoms.

elementaltoad

Ok i left the relays plugged in, and disconected the MAF straight from the back of the port on the MAF itself. I cranked it and it would fire but only so long as i held the ignition on, i could get no idle on its own, so if there is this "limp home mode" on my 1988 formula 350 then i would assume a no run condition with MAF taken out of the loop would imply ignition problems?

elementaltoad

some simple symptoms

-No start condition
-When key is turned SES light as well as the normal gauges light up
-when cranked it will fire, but only so long as key is kept turned
-when key is let go, sometimes it will stumble,die,stumble,die and repeat, then finaly give up
-other times it will fire but when key is let go it simply dies
-started fine until recently, when the starting got bad
-ran fine, but would stumble at idle sometimes
-no funny smells on crank
-gets proper air and fuel
-suspected MAF, however symptoms persist with MAF disconected
-checked MAF for damage, no visual damage
-checked relays, no visual damage
-coil looks worn
-starter cranks fine, ignition switch was suggested to be faulty
-ignition module which i am not familiar with was also suggested defective

angel71rs

Ignition module in these years had 2 outputs. One to coil for spark, another to computer to let it know it was running. Computer ouput could be bad, so puter wouldn't know engine was running, would feed no fuel. Check to see if there are 2 plugs connected at base of distributor. If you follow one, it will go to coil, other goes into firewall. If connectors are ok, pop module out and take it to Autozone for testing.

I used to own an 89 Formula 350 twin cat. I took it for a test drive and was impressed. Next day I called seller to talk turkey. He told me it wasn't running, it has just quit. He was asking 4,700. I offered 4,000 as is. He said yes, I went for it with a tow truck. It had spark, fuel pressure, so I had module tested. Guy tells me "bad news, it's no good". I told him, nope that's good news, 35 buck module saved me hundreds.

elementaltoad

alright ill have the module and ignition switch tested then, would be acheap route to start. Where is this module at by the way, i know alot about these cars but unfortunetly i'm retarded when it comes to hands on stuff since ive never actually owned one before.

elementaltoad

well angel the deal is i can crank the car and it fires up, i can rev the engine and all so long as i have the key turned all the way and the starter engaging, but when i let the key go it will instantly die, like nothing besides the starter will prodice electricity after i let it go, almost liek the car returns to an off state. I am accusing either the ignition switch or module for being partially or completely faulty probably a combo of both knowing my luck, but when i put the key in it is sort of touchy, and will not do the ding if i dont have it completley in, but when i let the key go the lights on the dash are still on. Maybe just a faulty ignition wire from the switch?

elementaltoad

hmm the switch works fine, starter is fine, rotor,cap,wires, plugs all fine, ecu fine, possibly the electronic spark control, or ignition module? i would think these because they are probably bypassed until the car starts? and as soon as i let the starter disengage it will die, leading me to believe a component that takes over for the starter ( i assume sending energy or a signal) fails to take over and the car dies, odd thing is sometimes it will idle,die,idle,die and then quit alltogether.

elementaltoad

TPS, MAF also good, as the car will fire and rev as i give it gas while the starter is engaged BUT only while starter is engaged.

elementaltoad

Trouble Code 42 indicates that there may be a malfunction in the Electronic Spark Timing (EST) system.

During cranking, the timing is controlled by the ignition module while the ECM monitors the engine speed. When the engine speed exceeds 400 RPM, the ECM sends a BYPASS signal to the ignition module which switches the timing to ECM control. The ECM calculates what the timing should be then "tells" the ignition module via the EST circuit.

An open or ground in the EST circuit will stall the engine and set a Code 42. The engine can be re-started but it will run on ignition module timing.

The conditions for setting this code are:

* System in BYPASS mode but the ignition module is still controlling timing

- or -

* Engine speed > 600 RPM with no EST pulses (ECM controlled timing) going to the ignition module for 200 msec.


Typical causes for this code include:

1) BYPASS line is open or grounded
2) EST line is open or grounded
3) PROM or CALPACK not seated properly in the ECM
4) Poor connections between ignition module and ECM
5) Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise)
6) Faulty or incorrect ignition module
7) Faulty ECM


sounds similar to my issue, as it will only run with starter engaged, anyone else agree?

elementaltoad

ok starter engages, singnal to ICM, signals coil, coil chargers, releases and the engine fires up, ECM/o2 sensors/MAF all being bypassed in this proscess. After realeasing key as the engine fires, the ECM should engage, and later on as it reaches operating temp the o2 and maf should kick in, thing is it never has time to idle, etc. giving me a clue that the ECM itself may be at fault, it was a slow dying process, one in which the car would intermitantly idle or not, and sometimes refuse to start. SES light signals when key is turned on, but i dont think it is workin any ideas?