ive got an 89 IROC 350 b2l, and it was running a afew days ago. today it wont. it turns over, has plenty fuel pressure, has spark, but for some reason all the injectors wont fire, at all. theyve got pressure at the rail, but they just wont pulse. All of them. its not the ecm, ive already switched chips out and it did the same thing. it starts with ether, but ether enters the cylinders through the air intake, not the injector. any help would be awesome. someone told me the ign module, but im reluctant to shjell out 40 bucks till im sure, cuz it gets spark, but no fuel is shot into the cylinders.....ive spent hours on this, please somebody tell me whats wrong.

One more question... Should the injectors have a constant 12 volts as long as ythe battery is connected? thanks

[This message has been edited by silverstreakII (edited May 21, 2001).]

 

The injectors shouldn't have 12 volts, that would be way to much. Im sure Vader or someone could tell you how much power they should be getting. What happens when you turn the key?

 

sorry, the key has to be turned....im using it for an engine swap, its been wrecked. the VATS key has to be in, but we still have to use a remote starter switch.... but the 12 volts is with the key on..

 

A problem I just beat my head against the wall for a month over. My car would start fine cold but not restart hot. Fire a little ether in and she would start. Turns out one injectors was going to ground after she got warm. All injectors share a common ground so electricity finds the path of least resistance. So the one injector was stealing the power from the other 7, not allowing them to fire. Once you got the engine to catch, the alt put out enough juice to supply power and fire the injectors.

------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

Please don't pass bad information. The injectors do have 12 volts to the all the time, it comes straight from the fuse panel. It's the ground that is switched from the ECM.
I had the same thing happen with my engine after a swap. I bought used, cleaned injectors from a shop. None would fire at all, I replaced them with new SVO injectors and all is well. Go figure.


------------------
86 Camaro Sport
383 Speed-O-Motive Crate Engine, Raptor 700R4 Tranmission, Trick Flow Twisted Wedge G2's, 58mm Accel TB, 3.73 Auburn Pro, SLP Cold Air Induction and Headers, Dynomax Cat-back, Serpentine Belt Setup, Dual IROC Fans, Jamex springs, 16" IROC Rims, 36mm/24mm Sway Bars, Global West Steering Brace. Hotchkis Rear LCA's,Panhard Bar and SFC's.
My Camaro Project

 

Check the injector fuses. They are worth a try. I have seen them get blown by intermittant injector shorting problems. If they are blown, then one or more of the injectors or the injector wiring is bad (shorting). Have you checked the injector circuits with a noid light? If so, do you get ANY injector pulse?

Definately do not replace the ignition module if you are getting spark at the plugs. That componant is nothing more than a transistor and it either works and facilitates the coil firing, or it doesn't.

Hope that helps

------------------
Matt

1987 GTA L98 MD8 GW6

"Stop Lights timed for 35Mph are also timed for 140Mph"

 

Sorry, your wrong about the ignition module. It does fire the injectors below 400 rpm for starting purposes, then the ECU takes over from there. Yes it also provides spark to the plugs.



------------------
86 Camaro Sport
383 Speed-O-Motive Crate Engine, Raptor 700R4 Tranmission, Trick Flow Twisted Wedge G2's, 58mm Accel TB, 3.73 Auburn Pro, SLP Cold Air Induction and Headers, Dynomax Cat-back, Serpentine Belt Setup, Dual IROC Fans, Jamex springs, 16" IROC Rims, 36mm/24mm Sway Bars, Global West Steering Brace. Hotchkis Rear LCA's,Panhard Bar and SFC's.
My Camaro Project

 

you also might check that all the connections to the coil are plugged in tight. had a similar problem with a 88 2.8 blazer tbi, had spark, fuel pressure, replaced ecm, no injector pulse, for s--t's and giggles I checked the coil wires and one was very loose (unplugged) plugged it back in and it started back up no problem ever since. Hope you get it figured out.

what happened is the ecm never saw the engine turning over, for all it knows it thinks that your sitting there with the key on. also check the signal wire or wires from the coil to the ecm to see if there shorting out or broken.

------------------
89 Iroc 350 TPI,
Forged pistions
Comp roller Cam .510 lift 230dur
Flowmaster exhaust
Dart Iron Eagle heads 200cc runners 64cc chambers
MINI RAM SOON!!!!!
stock TPI for now 24# inj

[This message has been edited by AaronIROCZ (edited May 23, 2001).]

 

Actually I'm not - read my comment closer - but whatever. He really needs to check for injector pulse at the harnesses above all else. That will tell him whether or not the entire system is functioning properly. You must start with the easiest and most simple diagnostics checks in a situation like this and narrow down your list of possible causes. BTW - the ECU is more accurately referred to as an ECM.

 

actually its most accurately called ccc or c3, but since we all know what we are referring to, lets not jump on everyone. but the problem is now solved, the computer needed to reset with the aldl and once i did it it started right up. weird huh? thanks for the help guys

 

Yes that is wierd. Just FYI - CCC was the old carbed computer system.

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, Home-made cold air system w/ K+N cone and AFPR, TB bypass, AirFoil, !AIR, !A/C, 2300 stall.

"Stop Lights timed for 35Mph are also timed for 140Mph"