ok guys, it's been a while since I've posted on here.. and that's because the camaro has been in progress.... but here's what's halted me cold, and I'm hoping some of you guys can help me out here.

basically, the car cranks, and at times coughs (like it wants to start), but doesn't fire.

I HAVE spark, fuel pressure, air. I've used a noid light to check both injector banks and have also done the resistance test on the injectors. TIMING IS GOOD (triple checked).

HOWEVER, it does run if I shoot some gas into the intake manifold prior to cranking. She runs for about 15 seconds and then sputters and dies.

here's my setup (in short):

355ci
HSR
36# Accel injectors
MSD blaster coil, distributor, wires
NGK plugs
solid roller cam (forgot the specs.. but it's something like 232*, 232*)
1.6 RRs
holley aluminum heads
double valve springs
SCAT rods, ROSS pistons (freshly put in bottom end)

Yes, I know that the PROM has to be tuned, and we have a modified prom from the previous engine that we're using for now.

I also just bought a second ECM that I'm going to swap out just in case if the old one is pooched.

Any thoughts guys?

thanks

 

only thing i could possibly think of would be ecm

 

keeslinger: my friend and I are thinking the same too... cause even if it's not getting enough fuel, it should at least still run even after shooting in that bit of fuel before cranking. At the very least, it'd run like crap, or lean (if it needed extra fuel)... that's why I picked up a second ECM to try out this wknd

 

Hm, had the exact problem once -- when was the last time you took a look at the Cat converter?

 

Happened to me when I had the distributor 180 deg out.

 

sonic2008: running straight pipes.. so no cat. Sorry, should've added that in my list.

viprklr: that's what we initially thought, but the timing is right. Also, when the car did run with the extra shot of gas, it ran fine (no misfiring, popping, banging).

 

It never pops/bangs/spits? I was thinking possibly timing, or valve lash. I have had the intake valves too tight before, and it would crank, and crank, but add some gas, and it would fire for a few secs, then die. Sometimes it would backfire out the intake.

Does it run smooth, like it should when you get it to fire/run for a few seconds? Or is it hard to keep idling until it dies?

I would say if the ECM doesnt fix it try barrowing a carbed intake/carb/HEI to to rule out the EFI if nothing else

 

Noid light shows injectors firing? fuel pressure in the lines?
but only runs when you put fuel down it's throat eh?
I'm not wise to fuel injection, but is there a way you can remove one fuel injector from the intake, and see if it's squirting? Crank it over and watch it spray fuel. (or not spray fuel, and confirm bad injectors or a plugged fuel rail or whatever)...

 

Maxxmitchell: she runs fine during the 15 seconds when the extra fuel is shot into the intake.... that is, until that fuel dies out. Let's put it this way, for those 15 seconds of idle, you wouldn't think that anything was wrong. Believe me, timing was one of the first things that came to mind, but it's definately not timing.

Sonix: yup.. noid light on BOTH banks work (pulses and lights us). Resistance is fine. Fuel pressure is there at the schraeder valve. I guess we'll have to try and yank up the injectors and actually physically see the fuel, because on paper, everything is fine.

 

Bad gas has it sat for awhile? too low of octane. just suggestions

 

keeslinger: gas was a fresh 91 octane (shell was the closest gas station).

I'm gonna be putting in the new ECM tomorrow morning (fingers crossed) as the battery is now charging. I think you can start to see why this one is kind of a mystery. My friend and I sat on this for a while, covering ALL the basics that we can think of (air/fuel/spark/timing/ground wires/etc...).

Hell, even if the PROM wasn't calibrated properly off the bat, it should still run lean or even just idle like crap. But it just dies, even after that 15s grace period with that shot of gas. That's why I'm now believing that it could be the ECM itself..

 

okay i agree ecm best of luck tommorow hope it works for ya

 

thanx.. will post if it is ecm...

 

Did you just build this combo?
If so, did you line up the cam gear on the correct timing mark and with the correct timing "dot"?

I've done that as well.
Experience is the best teacher.

 

Fuel pump?
Hook up a fuel pressure gauge to see if your getting fuel to the injectors.

 

ncgator: got fuel pressure. this is the puzzling part (which is why we're thinking that it could very well be the EMC). All the "basics" are covered..

 

Could this be a vats issue?

 

no, I don't think it's a VATS issue. From what I've read, part of the VATS kills the fuel AFTER the car has started. I could be wrong, though... but hey... it is worth looking into (on my end).

 

On my 89 killed the starter as well as injector pulse. Could jump the starter and add fuel and make it run but only so long as fuel was being added. Also a low oil pressue sensor that I think kills injector pulse.

 

viprkiller: a good friend of mine was the teacher (me the "apprentice). But he's really good, and I was there when the cam gears were put in. Everything was lined up good. I'm quite certain it's a fuel delivery issue... whenever it was running for that 15 second window, the car sounded great.

89rs: If the ECM swap doesn't solve anything, then I'll probably do the oil pressure switch. I'll know soon enough if it's the ECM, as the battery is on a charger right now. At this point, I'm looking at it as a checklist of sorts (in terms of replacing parts).

 

if you have fuel pressure at the schradoer valve then i would rule out anything with the fuel delivery system. i would agree to check the injectors. it sounds to me like the injectors are pluged or not fireing. if you put fuel down the intake and it runs that is telling me that the injectors are not fireing. now you said you tested the wiring on the injectors and it is showing that the ecm is trying to fire them?

i would check the injectors

good luck.

 

check the IAC, and ECM fuse or ECM

 

89_ho_rs: we checked the injector resistance and it checked out fine. They're brand new 32lb ACCEL injectors. I also used a noid light on BOTH the injector banks and the noid light tested out ok.

rayzor: well.. the battery is charged.. I just need to siphon the old gas out (year old gas), and plug in the ecm... <fingers crossed>

 

OLD GAS? This whole time?

 

Did you check it with a gauge?

Also, are the injectors the correct ohm'age for your car?

 

keeslinger: no, that was left over from the LAST time we tried to crank it (a year ago). That's why I was removing the old gas for a fresh batch

vw: yeah.. checked the fuel pressure with a gauge, and even pressed on the valve just to check beforehand, and gas squirted out.

Ok... UPDATE: changed the ECM and still the same... she coughs and wants to start, but doesn't. SOOoo... I decided to pull the spark plug from CYLINDER 1, and noticed that it was DRY. NO GASOLINE smell. The spark plugs are NEW, so this one still looked brand new. I'm calling the injectors on this one.. what you guys think?

 

High impedence vs Low impedence?

 

year old gas shouldn't matter id say injectors aren't firing

 

Did you check the injector fuses under the dash?

 

ncgator: I'll check the fuse. I just assumed that having passed the noid light test, that it would be ok. Yes.. careless.. but that's why I'm appreciating all the feedback thus far

vwdave: they're high impedence injectors. They're actually 32lb injectors, NOT 36lbs as I had earlier stated. But anyways.. yeah.. they're ACCEL P/N: 150132 high impedence 32lbs

 

Don't know if you fixed it or not. but try bypassing the oil pressure safty switch. The thing will give you fuel and what not for a second but shut of the fuel pump if it see's no oil pressure.