Intermittent Start/Shut Off Issues

[EddieC]

Hello All,

I'm back on the forum for some advice!

As the title says I've been having intermittent starting and also shutting off mid drive issues. I have been troubleshooting and struggling, so I thought I would post on here to see if anyone has had a similar issue. It's not the most fun to go out for a drive with an intermittent issue that I can't pinpoint, that's for sure! I'll put some info below to hopefully paint a picture.

I have a Blueprint 427 with Holley Sniper, and also the Digital Guard Dawg keyless ignition system. The Digital Guard Dawg system seems to be functioning as it should.

I have never had a failed start when the engine is cold. It has only failed to re-start after I shut it down after driving, or failed to re-start if it has died mid drive. If it fails to re-start, it will either start after I wait an hour or so, or occasionally it will just immediately fire up after a bunch of attempts. In these cases, it hardly even has time for the starter to turn over before the car fires up, even if it has failed for 10 tries right before. At this point I really haven't changed anything, and the car will always start eventually.

I installed an Aeromotive in tank fuel pump. When I turn on the accessories, I don't think the fuel pump ever fails to do its 3 second run before shutting off again, even when the car fails to start afterwards. Unfortunately I haven't been able to watch the fuel pressure when it's failing to start, and since it's intermittent I can't seem to recreate it when a buddy is nearby to watch it! I have the RF harness, and the blue Sniper fuel pump wire is spliced into the orange RF wire going to the fuel pump relay on the fuse board. This seemed to be the simplest way to wire it, but maybe this is causing an issue?

I have also read some issues with RF interference with the Sniper, any thoughts if this could be a problem?

Another thing on my mind is the inertia switch, but I have actually already replaced it once because the one from FFR was actually broken on the inside and failed. So this inertia switch is new and the same as the one FFR supplied, and seems to be functioning properly. Also the fuel pump runs when I turn on accessories, which I imagine it shouldn't if the inertia switch is tripped or malfunctioning.

I have been thinking about an issue with a ground somewhere, but before I start digging into that I thought I would ask for some advice on here.

There has never been any coolant temp issues, and plenty of fuel...just to throw that in there. RPM and other info on the Sniper screen seems to be reading correctly, but I haven't monitored this too much to be honest.

It's definitely been a challenge to trouble shoot, because the car starts and runs perfectly most of the time...until it doesn't. Please let me know if anybody has any thoughts, and thank you all very much in advance. I'm not sure if I have given enough info to help find the problem but if I can give more let me know.

Merry Christmas!

[Flip Smiley]

Not to familiar with the Blue Print ignition set up but I would check the TFI module located on the distributor first if you have one. Then look at the PIP located inside the base of the distributor. My 302 was exhibiting some similar problems and it was a bad stator.
Good luck and I’m sure others will chime in here soon with other recommendations.
Flip

[Flip Smiley]

Just a recommendation. If you find you have an issue with the TFI or PIP Stator replace with OEM Motorcraft or known good quality parts. The less expensive ignition components have high failure rate and don’t last.
Flip

[Papa]

Eddie,

I fought with a similar issue for a couple of years on my MK4, so I feel your frustration. My issue turned out to be a faulty Weatherpak connector where a ground pin slid over the barrel instead of in to it on my fuel pump connection. This created a high-resistance connection that heated up enough to melt the plastic inside the connector. It eventually got bad enough that I was able to see it when I started tracing wires.

Some things to check:

1. Battery condition - Sniper is very sensitive to voltage drops.
2. Check the plug on the fuel pump. The old Ford connectors are known to be problematic.
3. Try to capture a stall event in a data log.

Dave

[Papa]

Not to familiar with the Blue Print ignition set up but I would check the TFI module located on the distributor first if you have one. Then look at the PIP located inside the base of the distributor. My 302 was exhibiting some similar problems and it was a bad stator.
Good luck and I’m sure others will chime in here soon with other recommendations.
Flip


Just a recommendation. If you find you have an issue with the TFI or PIP Stator replace with OEM Motorcraft or known good quality parts. The less expensive ignition components have high failure rate and don’t last.
Flip

BluePrint doesn't use TFI ignition systems.

[Papa]

Here is the thread I created on my issue:

https://thefactoryfiveforum.com/showthread.php?51662-Papa-s-Random-Stall-Issue-Data-Log-Captured!

[Norm B]

I had a similar issue after I installed the Sniper. I had two different problems. The fuel pump connector, as already mentioned, and a RF issue. The fuel pump would cause the fail to restart issue and the RF was causing the Sniper to randomly reboot while driving.
The Holley tech helped me diagnose the RF issue. Had me wrap the distributor with aluminum foil and do a test drive. I would suggest you try that after checking the fuel pump circuit.

Norm

[PMD24]

I had a similar issue after I installed the Sniper. I had two different problems. The fuel pump connector, as already mentioned, and a RF issue. The fuel pump would cause the fail to restart issue and the RF was causing the Sniper to randomly reboot while driving.
The Holley tech helped me diagnose the RF issue. Had me wrap the distributor with aluminum foil and do a test drive. I would suggest you try that after checking the fuel pump circuit.

Norm

Norm, can you share what you did long term to resolve the RF issue? Thanks,

Pat

[PMD24]

Reading here about fuel pump connector issues... take a look at post 151 in my build thread. Both fuel tank connectors in my harness were assembled poorly. The fuel pump one would have likely overheated or not worked at all due to the terminals being out of position.

Pat

[weendoggy]

After doing the obvious, checking all connections etc., without knowing if it's ignition, spark or fuel is guess work. If you have a Sniper2, you can install a transducer and get actual fuel pressure readings. You also need to datalog sessions, maybe everyone and hope you capture the problem. Guessing is just guessing. If you have a Sniper1, you can still get fuel pressure, but it will have to be a stand alone install and not be seen on the datalog, so you'd have to view it when it happens.

[Norm B]

Norm, can you share what you did long term to resolve the RF issue? Thanks,

Pat
Pat, I made a shield out of aluminum sheet by forming it over a block of wood the same diameter as my distributor. In the attached picture you can see the inside of it. I covered the outside with black hockey tape, truly Canadian eh, until the Cobra distributor cover from EBay arrived. The shield is grounded to the frame. Don’t know if that is necessary.
At the suggestion of the Holley tech, I routed all ignition wires as far from the Sniper as possible and moved the coil to the F panel.

HTH

Norm

[Presdough]

I had the same issue, it would quit while driving and not restart. No spark. I replaced the coil, module, pickup and ecm. no love. Did it all again, still no love. The only part I hadn't replaced was the shutter wheel in the distributor. I bought a cheap aftermarket distributor as a diagnostic tool and the car runs perfectly. I dont know how a piece od aluminum can fail, but apparently it has...

[phileas_fogg]

The data log is key; until you can catch the stall in the log, you're just guessing. You can set the log to start at an event, such as engine RPM above 300. That will start a log every time you start the car. Download a log from time to time to set a baseline, and then when you catch the stall you can compare the data.

I had a similar issue & thanks to some over-and-above help from Weendoggy, finally determined my distributor was failing. The tipoff was in the commanded timing; at the time the car would buck/stall, the commanded timing dropped from nominal to 15*, which is what the ECU was set to command at start. So basically, the ECU thought the car was off & then would try to start. Fuel pressure was rock steady, leading us to conclude the problem was with spark.



John

P.S. You don't have to spend $150 for the Holley fuel pressure transducer; this one works just fine https://www.amazon.com/dp/B00NIK9E10?ref_=ppx_hzsearch_conn_dt_b_fed_asin_ti tle_2.

P.P.S. You might also check the temperature of your fuel pump relay. If it overheats, you can get some weird behavior.