Plenty Fuel, No Spark. Car will not start

01Stang65 · Apr 25, 2020

I am completely at loss right now on my current engine swap project. I got the motor in finally and just ready to hear the dang thing run lol. I will try to thoroughly explain everything I know.

Late 2001 GT. After previous motor blew up, car sat for 1 month with battery disconnected. Motor was then removed and car sat for 4 months. Last night I finally got to turn the key and try to fire it up for the first time.

Motor is getting plenty of fuel. Can hear the pump kicking on, and shrader valve was full of pressure. I can't get any spark. Car turns over fine but will not fire. I checked crank position sensor and codes. The only code I am getting is p0193 for fuel pressure sensor. This is the little module on the drivers side fuel rail. I did an egr delete on new motor, so the vacuum line associated with that fuel sensor is probably whats causing that code. Not sure about that one just my speculations... Some reading showed that code can cause crank with no start.

Tried testing spark next. Wasn't getting any spark with plug contact on alternator. Was getting spark once or twice on battery terminal. Don't know what the deal is there.

Other things are grounds. In the below picture I circled 2 grounds I dealt with when putting the new engine in. In the left circle you can see a bracket that broke off for the body to engine ground. The bracket broke off so I rerouted and used my own ground cable to a different bolt on that pump. The circle on the right is a ground from the starter and just seemed like the most natural spot.

Can the antitheft system cause cranking but no start? What would be the light signal for that on the dash? I got the normal steady flash when car is off, completely off when on acc.

Such a weird issue and I am sure its something obvious. Appreciate any help I can get I know this is a tough one lol.

wmburns · Apr 25, 2020

01Stang65 said:
The only code I am getting is p0193 for fuel pressure sensor.

True. For the 1999-2004 MY a faulty FRPS value would cause a crank with no start. IMO you should FOCUS here. IMO your problem is NOT a missing vacuum line to the FRPS. Why? Because every motor before it starts has zero vacuum. The intake vacuum reference line comes into play once the motor has actually started.

As a side note, EXPECT the motor will run rich at idle without the intake vacuum reference line connected to the FRPS.

01Stang65 said:
Other things are grounds. In the below picture I circled 2 grounds I dealt with when putting the new engine in. In the left circle you can see a bracket that broke off for the body to engine ground. The bracket broke off so I rerouted and used my own ground cable to a different bolt on that pump. The circle on the right is a ground from the starter and just seemed like the most natural spot.

On my Mustang the two spots for the motor grounds are on the front timing cover bolt and one of the dual headed bolts of the left hand motor mount

01Stang65 said:
Can the antitheft system cause cranking but no start? What would be the light signal for that on the dash? I got the normal steady flash when car is off, completely off when on acc

Yes PATS if tripped could be one of the causes of a crank with no start. Want to know for certain? Turn the key on but do NOT crank. Does the theft light go out after a 3 second "prove out"? If true it means that the key has been read and accepted. Therefore PATS is not the reason for the crank with no start. The other reason why I don't think your issue is PATS related is because there is a PATS specific DTC code that is set. In your case it's not present.

When the motor is cranked, does the check engine light go out? IF it does this means that the PCM is "seeing"a valid CKP sensor signal. Want more proof? Use a mechanics stethoscope on an injector to listen for the sound of the injector pulse. Even better is to use a "noid" style test light to see the electrical signal pulse.

Do you have an ODB2 scanner (more than a code reader)? If you did this might make very short work of this problem. As previously mentioned I believe that your first focus should be on the basic tests given above and assuming they pass, focus on the FRPS. Focus should be on the electrical connections to/from the FRPS.

>>Form Ford manual
P0193 - Fuel Rail Pressure Sensor Circuit High Input (FRPS)

FRP signal shorted to VREF or VPWR.
FRP signal open (gasoline only)
Low fuel pressure (NG only)
Damaged FRP sensor.
Damaged PCM.

A FRP PID value during KOER or KOEO less than 0.3 volts for gasoline or 0.5 volts for natural gas vehicles (NG) would indicate a hard fault.

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...

www.stangnet.com

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...

www.stangnet.com

If you suspect a poor motor ground a low-tech (red neck) test method is to use a jumper cable between battery negative and the alternator case (or any other solid metal ground location).

01Stang65 · Apr 25, 2020

wmburns said:
True. For the 1999-2004 MY a faulty FRPS value would cause a crank with no start. IMO you should FOCUS here. IMO your problem is NOT a missing vacuum line to the FRPS. Why? Because every motor before it starts has zero vacuum. The intake vacuum reference line comes into play once the motor has actually started.

As a side note, EXPECT the motor will run rich at idle without the intake vacuum reference line connected to the FRPS.

On my Mustang the two spots for the motor grounds are on the front timing cover bolt and one of the dual headed bolts of the left hand motor mount
Yes PATS if tripped could be one of the causes of a crank with no start. Want to know for certain? Turn the key on but do NOT crank. Does the theft light go out after a 3 second "prove out"? If true it means that the key has been read and accepted. Therefore PATS is not the reason for the crank with no start. The other reason why I don't think your issue is PATS related is because there is a PATS specific DTC code that is set. In your case it's not present.

When the motor is cranked, does the check engine light go out? IF it does this means that the PCM is "seeing"a valid CKP sensor signal. Want more proof? Use a mechanics stethoscope on an injector to listen for the sound of the injector pulse. Even better is to use a "noid" style test light to see the electrical signal pulse.

Do you have an ODB2 scanner (more than a code reader)? If you did this might make very short work of this problem. As previously mentioned I believe that your first focus should be on the basic tests given above and assuming they pass, focus on the FRPS. Focus should be on the electrical connections to/from the FRPS.

>>Form Ford manual
P0193 - Fuel Rail Pressure Sensor Circuit High Input (FRPS)

FRP signal shorted to VREF or VPWR.
FRP signal open (gasoline only)
Low fuel pressure (NG only)
Damaged FRP sensor.
Damaged PCM.

A FRP PID value during KOER or KOEO less than 0.3 volts for gasoline or 0.5 volts for natural gas vehicles (NG) would indicate a hard fault.

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...

www.stangnet.com

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...

www.stangnet.com

If you suspect a poor motor ground a low-tech (red neck) test method is to use a jumper cable between battery negative and the alternator case (or any other solid metal ground location).

This is by far the most thorough answer I have received yet. I appreciate that.

I am using a old Diablosport Predator. Its aged, but it does what I assume is a full scan. It gave me the high circuit explanation you provided. I just figured that was directly related to the EGR, makes sense that it doesn't kick on till after car is running. On a adjacent subject, I do have a vac line still going to the frps from the plenum. I just got rid of all the other hoses. It looks like this now, just to make sure we are on the same page. I can deal with any idle issues once we get to that bridge.

Moving forward, How should I check for a faulty FRPS? I can check the voltage with a multimeter on the connector when I get home. Then what?

wmburns · Apr 25, 2020

01Stang65 said:
It looks like this now, just to make sure we are on the same page

From the diagram posted this should give a valid intake vaccuum reference.

01Stang65 said:
Moving forward, How should I check for a faulty FRPS? I can check the voltage with a multimeter on the connector when I get home. Then what?

Hands down the best and easiest way is to "ask" the PCM what it "thinks" the Fuel pressure is. This then takes the total sensor and wiring into account.

Many generic ODB2 scanners will have fuel pressure as an available PID.

The next best method is to measure voltage at the FRPS. Confirm that the +5 volt VREF is present between the BN/WH and GY/RD wires. Next measure the signal return voltage between the RD/PK and GY/RD wires. You should be able to see this voltage change in response to changes in fuel pressure.

If this were my car, I would pull the fuel pump fuse so that the fuel pump doesn't run at key on. Set the VOM up and then turn the key on. What is that voltage? While watching the FRPS voltage put the fuel pump fuse back in. Does the value change?

01Stang65 · Apr 25, 2020

wmburns said:
From the diagram posted this should give a valid intake vaccuum reference.

Hands down the best and easiest way is to "ask" the PCM what it "thinks" the Fuel pressure is. This then takes the total sensor and wiring into account.

Many generic ODB2 scanners will have fuel pressure as an available PID.

The next best method is to measure voltage at the FRPS. Confirm that the +5 volt VREF is present between the BN/WH and GY/RD wires. Next measure the signal return voltage between the RD/PK and GY/RD wires. You should be able to see this voltage change in response to changes in fuel pressure.

If this were my car, I would pull the fuel pump fuse so that the fuel pump doesn't run at key on. Set the VOM up and then turn the key on. What is that voltage? While watching the FRPS voltage put the fuel pump fuse back in. Does the value change?

I will report back tomorrow, thanks again

01Stang65 · Apr 29, 2020

Well, I'm gonna let my mistake be a lesson for everyone else. Its always the small things. I didn't screw down the main wiring harness PCM? connector all the way, was probably sending inconsistent signals. When I plugged my reader in my FRPS was reading 90psi right after I bled the system.

When I was installing the wiring harness I must have left the screw barely threaded just to give my some wiggle room, probably planned to come back later and tighten id all the way down. I never went back to it, totally escaped my mind. I tightened that sucker down, and the FRPS adjusted to 1 psi. Car fired right up immediately.

Oh well, you live and learn. Thanks WMBurns for the help. Definitely was insightful and learned some things.

Plenty Fuel, No Spark. Car will not start

01Stang65

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wmburns

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01Stang65

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wmburns

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