Electrical 95 Gt 347 - No Cranking Possible Tps, Maybe??

[dwbro1]

1995 Mustang GTS - 347 Stroked, Stage 3 Canfield heads, Kenne Bell TS-1000 (Yes that is next upgrade was fine on 302 but not 347). Plethora of other upgrades not relevant here. . My poor girl has sat under the carport fending off wanna be buyers for about 10 years now (long story).

Anyway to my problem. She will fire over if I use starting fluid but never on her own nor will she stay after starting fuel is gone. Have new pump working fine, 50lbs at rails (aeromotive throughout). Checked for vapor lock and nope she's good. Good spark MSD 6AL. Now down to possibly the TPS sensor, see video and I welcome any advice. If I remember correctly from checklist if one of these probes was over 3.7 volts then the ECC shuts off the injectors. If that is the case I'm not sure where exactly the problem is or how to narrow it down. Hope I did the test correctly, see video.



By the way I have come this far by running the not start checklist for fuel injected mustangs at the link below. GREAT checklist!
Cranks OK, but No Start Checklist for Fuel Injected Mustangs | Mustang Forums at StangNet

 

[Noobz347]

First thing is first.

The car is "cranking" but not "firing"/"starting".

I saw no mention whatsoever about the 10 year old gas being purged from the fuel lines and tank. I also saw no mention of fuel injectors removed and either cleaned of 10 year old gas or replaced.

Where exactly did you start and stop on the checklist?

The TPS will not prevent the vehicle from starting.

I notice from your video that the fuel pump just runs continuously or for really long periods? You have a return style fuel system. That symptom would have me looking at either a bad fuel pump (internally bypassing = replace) or that the fuel regulator is bad and not allowing pressure to build in the rails.

[USERGROUP=77]@SN Certified Technician[/USERGROUP]

 

[dwbro1]

Correct she will "crank over" not "fire/start" on her own.

The gas has been purged from the lines. I removed the end caps from the rails and pumped the gas out. Installed a brand new tank with new gas.

Well like most check list I started at the beginning and ended when I hit the problem.

If I remember correctly the TPS will not allow the injectors to fire if one of those leads from the TPS sensor is reading over 3.7 volts.

Believe me there is pressure in the rails (50lbs at pressure gauge) and I've removed the end cpas to purge old gas. There is tons of pressure. I replaced the gas tank and put in a band new aeromotive stealth in-tank pump.

I have not removed the injectors, yet. Was hoping to find a problem somewhere else first. That requires me removing the kenne Belle which that one damn bolt makes it a horrible proposition.

 

[dwbro1]

Ok just said forget it and removed kenne bell and pulled injectors. Ordering new set since I don't want to have to pull it again and motor only has 100 miles on it so playing it safe.

 

[toyman]

The TPS signal to sensor ground in the closed position should be about 1v. WOT about 4.7v with a smooth transition between the two readings. Yes, the ecu will shut off the injectors at WOT. (Flood clear mode) Not certain but I think it's at about 75% which is 3.75v. The voltage reference reading should be 5v.

 

[dwbro1]

Thanks for the reply. Appears I'm still hunting my problems, plus creating a few more to boot. .. As for the ECU I'm replacing it with a Megasquirt, their third generation pro (forgot exact name). I currently have on my stock ECU and EECTuner. Literally, I still have the old IBM Thinkpad (brick) with Windows 95 on it running the software. Have not booted it in years though. LOL.. Now let me go post my next oops in another thread so I don't get in trouble.

Thanks again for the reply will updated this post at my next milestone.