Just about finished with my tuck I decided to plug in my cluster to make sure that I didnt have any CEL's before I reinstall my dash. The motor will turn over, but doesn't start. I also noticed the fuel pump doesn't prime so it isn't getting any fuel. My CEL is solid and will not blink when I jump the connector. I have reason to believe that the ECU is not getting power or ground. Does this sound right? Any thoughts?

 

could be grounds

did you arc any wires that you remember?

i hda this problem with a imobilizer issue. had to use a different ecu.

 

I didnt throw a solid cell with my wire tuck,but my car wouldnt crank untill I added more grounds.

 

make sure u jumped it correctly. then check your main relay

 

where do I add more grounds? I checked the fuse box with a mulitmeter and I have power all throughout. Car Turns over, CEL is on from the beggining.

 

also, I know i didnt arc any wires what so ever. IS the only ECU ground the ecu bolted to the car?

 

I was gonna say Bad Ecu or Main Relay.

 

Atach a grond to the valve cover and add another too the block.

 

If the ECU was good before, then it's probably not bad now. Much more likely you F'd something up in the wiring and need to go back and check your work.

 

^^^ That is what I was thinking. I ran flawless before I decided to take on this task... so i wasnt sure if the ecu could just go bad all of a sudden. It has to be in the wiring. Thanks for the input guys, any more is appreciated as well.

 

dude add grounds that was my probelm, a ground from your valve cover to the chasis and another ground from the transmission to the chassis and you should be ready to go

 

sounds lie grounds. do you have the ground on the thermostat on? thats the ground for the ecu

 

I had this problem too when i did my first tuck and it was something somewhere in the wiring. Needless to say i had to redo the whole wiring and make sure everything was connected securely. Its a live and learn type deal.

 

Do you have your main harness grounded? Its a eyelid connection with like 4 or so fully black wires on it that are normally screwed on to the therm housing. Scratch the surface on both the eyelid and the housing where they will make contact with each other. I had a similar problem and thought it was the main relay but it was the ground. If you dont know what I am talking about Im sure that someone will post pics soon, if not Ill grad some this weekend.

 

I have a similar problem. Earlier today I had no and the car would crank but not start. Turns out my ecu wasn't grounded at the thermostat so I was getting no cel when the key was turned to ign. So I grounded my ecu etc at the thermo. Now the car starts and idles, but I have a solid cel which signifies code 0 aka dead ecu.... but the car runs. It doesn't make sense. Can anyone help? Btw this was after installing a built Z6 in place of a B7. vtec has not been wired yet, and the ecu is a p06 modded to p28 by one of the bigger ecu guys on HMT (i forget who exactly, I got it a year or two ago from a friend that needed my chipped p28 immediately and gave this to me as a replacement). Any help is appreciated.

edit: I also plugged in my virgin p06 that was in the car a week ago with the running B7 and I had the solid cel then too. This **** is bogus.

 

Sorry to kick this up again... but Exact same as the Original post going on with mine. Was this ever resolved? If so what fixed it?

 

Check whether any of the three main relay fuses are blown and whether the ground on the thermostat housing is clean and tight.

 

-All fuses check fine and the ground is clean and connected.
-Ive pulled the harness out 3 times now to confirm all wires aren't broke open or corrosion on any ends.
-Triple checked all wires i have shortened/lengthened. (No shielded wires were touched shortened or lengthened. Shielding remains as OEM)
-All cuts were Soldered/Heat shrink.
-It ran great before, but to be sure I swapped with working known ECUs to get the same result.
-While following Helms Troubleshooting to help track the problem down... I noticed that probing the Green/white wire at the TPS, when probed by the test light, would kick on the Radiator fan. Found this out right as i came in for the night so haven't looked further into wether that's normal or not yet.
-I'm 99% sure no wires were mixed up due to the fact that i only cut/repaired one wire at a time to avoid this.
-Yellow/White wire at D20 on the ECU shows continuity to a ground (as following procedure in the helms) but traced it from end to end with no visible damage. Not sure if something else might cause this.
-Probably normal with this problem happening... the main relay doesn't click and Fuel pump doesn't prime when ignition is on. Assuming ECU not working to control them is the only reason for that at the moment though.

Sorry for a lot of reading but just trying to get as much of the info across to make the problem a little more clear i hope.
Thanks in advance to any helpful info.

 

The main relay should click three times. First when you put the key in the one position. Second when the cel light goes off. Third when the key goes to the start position. If they all happen, the relay is fine, if they don't try swapping the relay out with a known working one and see if it fixes the problem.

Dealt with this today and last night (just swapping the motor not a tuck) and mine just turned to be the ground, but I did hear all three clicks as they were supposed to occur.

 

I have a similar problem with my B18c5 not starting. It ran perfect in my other EK before the sawp and wire tuck. I thought it might be the fuel pump before since I left both stock pupms in their respective cars and the current one had less mileage. I was thinking it was the fuel pump but now I am gonna check all of my grounds. I will report back my findings as well.

 

A simple way to rule out the fuel pump being bad is to gain access to the pump under the rear seat bottom. Remove the cover. Looke down and you'll see two circles bolted down with lines attached and wiring attached. The one with the high pressure fuel line is your pump (this is the one with the plastic clip built on to the end). Remove the cover over the harness plug and take a simple 12v test light and hold it on one contact while someone turns the key in the start position. Does it light up? If no, switch to the other pin. Does it light up? If not, then you are not getting power to the pump and your problem is before the pump.

 

A bad fuel pump won't throw a solid code. Neither will just the bad relay.

 

Incorrect.

 

just basing it from i had the problem before when the relay went bad. It didn't have the solid Code. So you're saying when the Main fuel relay goes out it will throw a solid CEL Code?
It didn't throw it for me when the main relay went bad a couple years back that i remember at all.

 

Not all main relay failures will throw CEL code 0. The main relay supplies power to multiple components, including the ECU. If the latter main relay function fails, CEL code 0 will result.

In this regard, did you check the main relay fuses with a voltmeter as described here?