Tech...this is not a hardcore question but I know the ones that can help are in this section. I have done the whole 1-ton build up with coilovers...ya know..the new average build. Well for my drivetrain...I went with a 5.7L Vortec out of a 97 truck and a built Turbo350 and Stak 3spd. My harness and ECM are from Howell. My problem now is....it wont start. As soon as I turn on the ignition..the check engine light starts flashing and never stops. I am getting fuel but no spark. I have triple checked everything and it is all correct according to Howell's instructions. Anybody ever has this issue. I really don't wanna call them tomorrow if it is something simple that my dumb ass is overlooking.
5.7L engine problems
1 - 13 of 13 Posts
Joined
·
1,557 Posts
Most of us use the PCM/harness that came with the engine.
Trying to give you specific advice is difficult, unless we/me has specific experience with the"Howell" system, which I don't.
So, in general, with a flashing SES, key on, engine off (of course it's off, hehe) I'd suspect ECM or wiring errors.
You say you have fuel. With a bad ECM/PCM, I wouldn't expect the injectors to operate at all.
If your Howell ECM is old school, meaning it has a removable EPROM, I'd insure it's installed properly, with no bent pins.
I'm helping Andy out with this install. he got the harness and computer both from howell. they did the PCM, so VATS shouldn't be an issue. didn't check the eprom. (andy, you might pull that little cover on the PCM and check the eprom)
no codes showing when checked with a scantool. BUT, when you check the readiness data with the scantool, it does show O2 sensor data incomplete (I don't know if that really means anything or not)
definitely getting voltage to the PCM. both dedicated power and switched power. definitely getting voltage to the Crankshaft position sensor and the camshaft position sensor. defnitely getting voltage to the coil.
no spark at the plugs. new coil, plugs, wires, cap and rotor.
don't know if the injectors are firing, but the fuel pump is putting fuel to the motor. (I didn't think to check the injectors).
harness and pcm are new from howell. new long block. everything else is off of another motor, that we are unsure of the condition of the sensors, or even the distributer.
no codes showing when checked with a scantool. BUT, when you check the readiness data with the scantool, it does show O2 sensor data incomplete (I don't know if that really means anything or not)
definitely getting voltage to the PCM. both dedicated power and switched power. definitely getting voltage to the Crankshaft position sensor and the camshaft position sensor. defnitely getting voltage to the coil.
no spark at the plugs. new coil, plugs, wires, cap and rotor.
don't know if the injectors are firing, but the fuel pump is putting fuel to the motor. (I didn't think to check the injectors).
harness and pcm are new from howell. new long block. everything else is off of another motor, that we are unsure of the condition of the sensors, or even the distributer.
Joined
·
1,557 Posts
Well, assuming the Howell ECM is based on a GM unit (one should never assume
), when you turn on the ign, but before you go to start, two things happen: One, the fuel pump will run for approximately 3 sec, then shut off (this primes the fuel system), and two, the SES light will come on and stay lite until you start the engine. These are the first indicators that all is well with the ECM and wiring. The flashing SES tells me you either have a wiring problem, or a bad ECM, or the EPROM has a bent, or missing connection--they are very fragile, and it's easy to bend a contact while inserting them. Also, improper handling will kill them (static electricity).Are the flashes constant, IE flash, flash, flash, etc, etc, about 2xsec? Or are they varying, like flash, flash, pause flash, with this, or similar pattern repeated? If you short the ALDL pins A to B, the ECM will go into diagnostic mode, and the SES will flash stored codes. Since pin A is ground, grounding pin B will do the same thing as connecting A to B; however, the engine will start in diagnostic mode. Under this circumstance, the SES now becomes a "rich/Lean" indicator (once in closed loop).
In order for the injectors to fire, the ECM must recieve a signal from the Ign module, telling the ECM that the engine is turning over; this also causes the fuel pump to start running again.
Wow...that is a lot of good info. I have checked or tried some of your suggestions. The EPROM look to be undamaged, the pulses on the check engine light are constant. The fuel pump does come on and prime the system. The ECM is a reflashed GM model. My coil is brand new and I put a new crank sensor in today without any change. I spoke with Rob at Howell earlier and once I explained to him what was going on he almost without hesitation told me to send the ECM back and they would get me another one out immediatly. So I already have it here in a box and we will see.
It is OBD-II. Yeah that is what I thought also so I went and picked up a brand new sensor and installed it with it giving me no results.
Did you check all the fuses? I had a no-start condition on my Camaro one time and none of the injector fuses were installed. My fault, of course...
checked all the fuses.
think he's looking at the ignition module tonight. one of the howell guys says its the computer (another bad one?) and another guy is tellng him its definitely something in the ignition system.
I think he's swapping in an ignition module right now actually.
IT's Alive!!!!!
Turns out the Crate engine that I picked up.....had no reluctor ring for for the Crank sensor to read off of.:mad3:
I ran over to the local salvage yard and the guy actually gave me one. Tore it all down...put the ring in there, put it all back together, set the time and bang...the bitch fired up.
Turns out the Crate engine that I picked up.....had no reluctor ring for for the Crank sensor to read off of.:mad3:
I ran over to the local salvage yard and the guy actually gave me one. Tore it all down...put the ring in there, put it all back together, set the time and bang...the bitch fired up.
1 - 13 of 13 Posts
Join the discussion
Join now to ask and comment!