Crank No Start

[Jardon]

Alright yall im back already haha. My 94 mustang 5.0 just up and died on me at a red light. Its got open headers and one O2 sensor for some reason. It surges real bad when idling and now it'd cranking and smelling like fuel. Battery tested fine last I checked it. What happened was it died while surging (normal for it), cranked it back up, it fired on maybe one or two cylinders and just died out again and now won't even fire on any cylinders. I need help trying to figure out how to diagnose this and what direction to go in

 

[weendoggy]

Spark and fuel. That's where to start. Get someone to help you, or use a remote starter button to test while under the hood. Key on/engine off, you should hear fuel pump for a few seconds. Easy way to see IF you have fuel is to press the schrader valve in the fuel rail and see if it shoots fuel (use a rag).

To test injectors for firing, you will need a NOID light. DO NOT USE A TESTLIGHT to test them. Pull an injector plug off and put the NOID light in place, crank engine and it should flash. Each one should flash, testing each independently. If not, you have issues.

Next is to pull the coil wire off the distributor cap and have someone crank the engine, while holding the wire about 1/2" from the block/manifold (ground). It should spark.

If so, next is to test a plug wire. Put the coil wire back in the cap, pull a plug wire off (any one of them), put a phillips head screwdriver #2 in the wire boot and hold about 1/2" off block/head/manifold (ground) and crank the engine. It should spark and if so, may start so be ready to shut off the engine.

So many things to test, but those are basic starters. Of course, this is assuming you still have the stock ECU/TFI setup. Sometimes (mostly) it's a bad TFI unit, but not always.

 

[Jardon]

Spark and fuel. That's where to start. Get someone to help you, or use a remote starter button to test while under the hood. Key on/engine off, you should hear fuel pump for a few seconds. Easy way to see IF you have fuel is to press the schrader valve in the fuel rail and see if it shoots fuel (use a rag).

To test injectors for firing, you will need a NOID light. DO NOT USE A TESTLIGHT to test them. Pull an injector plug off and put the NOID light in place, crank engine and it should flash. Each one should flash, testing each independently. If not, you have issues.

Next is to pull the coil wire off the distributor cap and have someone crank the engine, while holding the wire about 1/2" from the block/manifold (ground). It should spark.

If so, next is to test a plug wire. Put the coil wire back in the cap, pull a plug wire off (any one of them), put a phillips head screwdriver #2 in the wire boot and hold about 1/2" off block/head/manifold (ground) and crank the engine. It should spark and if so, may start so be ready to shut off the engine.

So many things to test, but those are basic starters. Of course, this is assuming you still have the stock ECU/TFI setup. Sometimes (mostly) it's a bad TFI unit, but not always.

It basically is all stock. Only thing though is that with how its running open headers, its just dumping fuel in. So something I want to try out is removing the injector relay and cranking for a few seconds to see if that'll remove any excess fuel from the cylinders. I unfortunately don't really have the time to dive into a full diag seeing as its wicked cold and I work at a shop where im busy all day. Thank you for the help though! If my idea doesn't work I'll go with your suggestion

 

[ttocs]

open headers? Wouldn't that allow oxygen to get up to the o2 sensor and throw the reading off?

 

[Jardon]

open headers? Wouldn't that allow oxygen to get up to the o2 sensor and throw the reading off?

Its only running one O2 sensor on a loose pipe. Funny thing is, my stang started and drove maybe 10 feet, the just cut off while moving. So its definitely getting fuel spark and air. Now idk what to think

 

[weendoggy]

Its only running one O2 sensor on a loose pipe. Funny thing is, my stang started and drove maybe 10 feet, the just cut off while moving. So its definitely getting fuel spark and air. Now idk what to think

Loose or open headers can cause a misreading O2 sensor, and will effect performance. If it's running, but only for a few seconds, you have issues. My understanding is it isn't running now.

 

[Jardon]

Loose or open headers can cause a misreading O2 sensor, and will effect performance. If it's running, but only for a few seconds, you have issues. My understanding is it isn't running now.

Correct. It did die on me a few days ago at around 45mph in gear cruising. Didn't stay dead since it forced a bump start. As of now, im looking for get a ford obd1 scanner for it since id dont understand the paperclip readings. It is fully immobile and not starting

 

[weendoggy]

Correct. It did die on me a few days ago at around 45mph in gear cruising. Didn't stay dead since it forced a bump start. As of now, im looking for get a ford obd1 scanner for it since id dont understand the paperclip readings. It is fully immobile and not starting

You don't need a scanner to do the tests I suggest. Do those first. Especially fuel/spark. From my previous experience, I bet you have fuel pressure and no spark, but I'm not there checking. If so, I'd be the TFI if you have all stock.

 

[Jardon]

You don't need a scanner to do the tests I suggest. Do those first. Especially fuel/spark. From my previous experience, I bet you have fuel pressure and no spark, but I'm not there checking. If so, I'd be the TFI if you have all stock.

Its all stock. Brand new plugs, wires, and distributor before I got it. Was running basically as fine as it could for the last 3 weeks since I got it. Was surging really bad from what I understand is lack of exhaust and O2 sensor. I tried pulling codes with a paperclip and none of it made sense ngl

 

[ttocs]

I thought that when it first started up it isn't monitoring the o2 sensors for the first few seconds? If this is the case it sounds like it is probably confused by the extra oxygen making it to the sensor making the motor think it is not running right and causing it to make changes.

 

[Jardon]

I thought that when it first started up it isn't monitoring the o2 sensors for the first few seconds? If this is the case it sounds like it is probably confused by the extra oxygen making it to the sensor making the motor think it is not running right and causing it to make changes.

Makes sense. Now im thinking I could just up and unplug the second O2 sensor so it at least just runs on essentially the oem base map

 

[95opal]

o2 has zero effect on start up.
if it dont start you have spark or fuel issues. Test accordingly.
If you had it running and it died check your plugs see if they are fouled out.
Until you fix your exhaust and have a proper o2 set up it will run like crap.

 

[Jardon]

o2 has zero effect on start up.
if it dont start you have spark or fuel issues. Test accordingly.
If you had it running and it died check your plugs see if they are fouled out.
Until you fix your exhaust and have a proper o2 set up it will run like crap.

I know it'll keep running like crap until I get the exhaust stuff figured out. Previous owner told me to drive it above 2k rpm and I haven't been able to since I live in a densely packed area. Ive considered the fact the plugs could be fuel fouled. I also have a new TFI module, MAF sensor, and coil pack on order to see if it'll help since they all look original. Seeing as it doesn't start, I can't get it into my shop to take a peek at a plug. As for fuel, its definitely getting it as I can smell it out of the exhaust when I crank it over.

 

[I_LIKE_TURTLEZ]

Why would someone run open pipes on a 190hp stock car? It actually loses power from that.

Anyway it's most likely a fuel delivery issue based on the symptoms given, the o2 sensor does nothing until closed loop is achieved later on.

Assuming it has spark, since you've been cranking on it you should pull the spark plugs and let them dry off, then disconnect the negative battery cable and run a wire from the cable-end to the positive cable that's still attached. For about 30 seconds.

This will reset the adaptive fuel strategy back to it's programmed baseline, running the vehicle with open headers will have the PCM thinking it's running lean and therefore command fuel to start dumping in until fuel trims are pegged. Eventually the car will just flood itself out.