No start - Injectors won't fire

[sdw]

My '91 5-speed died when going over a speed bump.

I have looked for a connector that came apart but have found nothing. I have spark, and fuel but the noid light did not flash when I checked the injectors.

I changed the crank sensor to one of my spares but no change. Changed the IRCM to a known good one, no change.

The car is modified and has a BHJ balancer and a QH chip, etc, etc.

I am not sure where to look now.

My grounds are good including the the one at the back of the drivers side head.

Is there a way to test the EEC?

There is one connector under the car attached to the transmission support that is melted from where it must have hit the exhaust. But the EVTM and wiring diagram has no info on it. My EVTM is at my garage so I can't give the page number but if you find where the two connectors go into the transmission you will see it pictured attached to the tranny support bracket. The connector has an end plug on it, but I have no idea what it is for.

Any suggestions would be appreciated.

Sean

 

[sam jones]

Good afternoon

Try this. Open the trunk. On the driver side check for the (red button) inertia switch in the open position. If it is reset (push down).

 

[sdw]

Thank for your reply.

Inertia switch is closed. Fuel pump comes on and delivers 40lbs to the rail.

I had installed a remote cutoff switch at the inertia switch as my car had been stolen but that has been removed for now and the wiring is returned to stock.

Sean

 

[sam jones]

Good evening

Inertia switch good- check.

With the key on is the fuel pump constantly running (priming) with engine check and upshift arrow lights on?

Check the ignition switch for separation and the connector pins for security.

Check the DIS harness. Visual inspection will be twisted, frayed and exposed wiring. Remove from car. With the EVTM ohms checks the following connectors potentially causing intermittent electrical outputs.

CAM connector to DIS gray/black connectors.

CRANK connector to DIS gray/black connectors.

.

 

[MadMikeyL]

Do you have a chip, or the actual quarter horse in the computer? If it is the quarter horse, I have had the battery go bad before and prevent the car from starting, so you might want to try removing that from the ECM and seeing if it will start without it.

 

[Tim Groth]

Expanding on bad QH battery. Usually with key in the forward position the fans will run on high which is also a tell.

-Tim

 

[sdw]

I had the QH swapped over to the replaceable battery one.

I will pop it off the EEC and see what happens.

I hadn't thought it would have thought it would have lost it's charge already but I have spares so will replace it nonetheless. The car was running when it died so I am pretty sure it isn't a QH battery issue, but better to change it and be sure.

tks

Sean

 

[sdw]

Went through the evtm and wiring diagram to track down all the connectors.

The PIP is working and there is no resistance on pins 56 and 16 to pins 1 and 3 respectively.

I cut out my melted connector from beside the transmission to clean that up but I can't imagine it has anything to do with the no start issue.

Here is a picture of the connector, sorry for the quality. if anyone knows what it is for that would be great.

Is there a way to test the EEC?

Regards

Sean

 

[sam jones]

Good morning

You can do a Key On Engine Off scan quick test. If you get 11/111 the EEC should be good. Correct any other fault codes. You could remove the EEC and do a physical inspection. Disassemble and look for corrosion, bad solder or overheated capacitors. Does your tuning chip cause a leg of the capacitor to be compromised? Inclosed is a short subject and although it is mustang directed it (EEC IV capacitors inspection) applies to the super coupe.

 

[sdw]

Thanks for the reply.

I did a KOEO test and got 111. There were no other fault codes but as the battery got discharged any stored codes are gone.

I will have a look at the circuit board and see what it looks like.

Sean

 

[sdw]

Still no luck.

The circuit board looks fine. I removed the QH and tried to start without it, but nothing. I checked the impedance on all the injectors, all of them between 11.5 and 12 ohms.

The only thing left that I can see is the EEC itself.

Will check with Ludorf and hope he has one to send me.

Am very close to parting it out. : (

 

[sdw]

Still can't get it to start.

I have spark and I have a flashing noid light at the injectors.

I I have 40lbs fuel pressure when the key is turned on. To ensure that the ecu powers the pump I relieved the pressure and then cranked and the pressure came back up.

Is it possible that all the injectors are clogged?

Sean

 

[sam jones]

Good afternoon


Is the ignition switch serviceable (not separated)?

Attempt engine start with starting fluid. If successful suspect/inspect engine fuel system.


May have to have the rear of the car elevated and supported for the next step.


Have someone take a mallet and continually strike the bottom of the fuel tank (passenger side) and while trying a start.



If it now starts replace the fuel pump. Check the fuel pump harness connector for damage (corrosion/overheating).


Check out this supercoupe non start troubleshooting video starting at the 30:47 mark.

 

[DOUG H]

He has spark & 40lbs of pressure at fuel rail.

Rules out ignition switch & fuel pump issue's

 

[DOUG H]

I've never heard of all inj's plugging at the same time, but ?

Unless a big chunk of something broke loose after the fuel filter when you
went over the bump? Never heard of it, but doesn't mean its not possible. See
what others on here think. The inj's have a screen where the fuel rail connects
to them, so thats where it would be if there is something.

 

[KMT]

I cut out my melted connector from beside the transmission to clean that up but I can't imagine it has anything to do with the no start issue.

The connector has an end plug on it, but I have no idea what it is for.

I think the P/N is for the transmission harness, and that connector is for a neutral safety switch on a manual trans. Assuming your SC is an automatic without that switch on the trans, the connector uses a bridging plug to keep that circuit closed.

I'd do what I could to put things back like they were from the factory, as that circuit might well be an on/off fuel defeat scheme.

 

[DOUG H]

My 5 speeds all will start in any gear, I wasn't aware there was supposed to be a neutral switch on tranny too.
They only have a clutch safety switch for the starter circuit & a reverse switch on transmission.

Maybe mine have all been bypassed, but seeing there is 4, not likely, possibly it's just because they are Canadian & they delete it for our
cars-maybe its used for the auto seat belts on U.S. vehicles?

 

[KMT]

My 5 speeds all will start in any gear

Ah, good info, thanks. Clutch safety or reverse then. If the OPs car tries to start, but just won't fire... Dunno. Sounds like when an aftermarket alarm goes into prohibit mode.

 

[sdw]

Thanks for all the replies!

I did re-wire that melted plug even though I did not know what it was for.

I have pulled the injectors and am going to take them in to get tested.

There was a short in the cam sensor / crank sensor wiring so perhaps that fubar'd my injectors.

I will post the results once I get the injectors back.

Sean

 

[David Neibert]

Thanks for all the replies!

I did re-wire that melted plug even though I did not know what it was for.

I have pulled the injectors and am going to take them in to get tested.

There was a short in the cam sensor / crank sensor wiring so perhaps that fubar'd my injectors.

I will post the results once I get the injectors back.

Sean

Sounds like the problem was crank/cam sensor wiring. Injectors are likely fine.