Bilster

iTrader: (21)

Bought a new harness and tuned ECM from a manufacturer and it appears the ECM is either dead or the VATS is not removed because I have no functions. I pulled the two ECM plug-ins and checked power to the power pins. They all show 12 volts. So I know there is power to the ECM. But I don't have spark or even a signal from the computer to operate the fuel pump relay. I jumped the relay power main circuit and the pump functioned so I know the relay is not the problem. Got to be the ECM...right?

psiconversion

iTrader: (5)

There should be a switched power source you had to hook up when installing the harness. Did you do that? Make sure it has power with key on as well as crank. Not sure who you bought harness from, but if it is ours you call us for support.

Jon
PSI

BP Automotive

iTrader: (3)

As stated above, you should check the ignition power. Also check that the crank sensor pins didnt get bent when you were installing that connector, this is also a common mistake because in some situations it is very hard to reach.

Also as stated above, you should call the manufacturer as some companies drastically make harnesses differently than others.

btlegacy

iTrader: (1)

I concur with the others above. Also of note is to check all of your grounds.

Bilster

iTrader: (21)

Triple checked all power connections...both switched and constant. They all show over 12 volts.
Now how would the crank sensor affect the fuel pump not activating?

psiconversion

iTrader: (5)

What year is the engine/trans? Is this DBC or DBW?

Jon
PSI

Bilster

iTrader: (21)

The motor is a 5.3 backed by a T56 in a 1998 Ford F150. It is a drive by cable. Just one more thing...I did check for continuity at the pins of the ECM plug-in. In other words, i disconnected the plug in and all of my power leads showed over 12 volts. I pulled the fuel pump relay and jumped the main power with a jumper cable. The fuel pump operated with 67 lbs as read at the Shrader valve. Tried to fire it but didn't start. That's when I pulled a plug wire, turned it again but no spark. With the fuel pump relay back in, I get no fuel pressure. I pulled another fuel pump relay from my running truck and no difference so I know the relay is not the culprit.

Is there a way to check continuity at the crank sensor? I did have to splice in 4" of wire on both leads to reach the sensor. But still not sure why that would affect fuel pressure. An incorrect splicing should only affect spark...right?

I do have an LS1 ECM with VATS removed that I could try but will it recognize the sensor inputs. In other words, are LS1 sensors the same as 5.3? I'm guessing the crank and cam sensors are the same but not sure about the MAF sensors.

Thanks for the help......

psiconversion

iTrader: (5)

For all intents and purposes here the sensors between the ls1 and 5.3 are the same. If you have power and ground in correct places fuel pump should go on. If crank sensor, cam sensor signals have issues you won't be getting spark or injector pulse.

Really would like to know year of engine and pcm. Your not using a 98 pcm with 99 harness pinout or vice versa are you? Is this a green/blue pcm or red/blue? Need some details.

Jon
PSI

btlegacy

iTrader: (1)

Also, if you have jumpered the fuel pump and see pressure at the rail and it is still not starting then it most likely is not a fueling issue.

Like Jon Said above write down where your items came from

ECU Model and Year?
ECU Service/Part No?
Harness Model and Year?

Did the crank sensor come with the motor or did you purchase one separately? Is it black or white?

BP Automotive

iTrader: (3)

Your not getting any spark, injector pulse, or fuel pump. There are one of two things wrong.

PCM is not powering up, wrong pcm, improper pinout.

The PCM is not receiving the proper rotating assembly position signal.

Why you will not get fuel if there is a crank position signal problem is when the pcm first sees ignition, it primes the pump. Then when it receives the proper rotating signal it initiates Spark, Pulse, and Pump.

Bilster

iTrader: (21)

Thank you for that explanation!! So it's the crank position signal and the cam sensor that provides the "rotating assembly position signal". I have a spare crank sensor to install (both the spare and the original are black),as well as a spare cam sensor. The crank and cam sensors were part of the engine package I purchased. The ECM came from the harness manufacturer. It is supposed to be matched to the harness and engine year and model. I really didn't want to divulge the manufacturer because I purchased it before I knew that LS1tech had harness sponsors. It wasn't until after I purchased the harness/ECU that I did an LS1tech search and found this company has a poor reputation. The company is S&S. But it is what it is. So I'm interested in getting my truck going. Not hearing about the less than stellar purchase I made. I already know that.

Anyway, when I purchased the motor, a crate rebuild from WES Engines out of the Dallas area. When it arrived, the cam sensor wasn't bolted down securely. It was just kind of swinging around on it's mounting bolt. I oriented the plug-in to a position I thought was the proper position by viewing Google Images. Is there an exact position that I'm not knowing about?

I will read the ECU part number and post it lateer

psiconversion

iTrader: (5)

Blister, I thought you said the fuel pump would not prime at all when the key was turned on?

Jon
Psi

Bilster

iTrader: (21)

That is correct....sort of. Let me explain. When I remove the fuel pump relay and use a jumper cable to initiate the primary (F150) circuitry, the fuel pump will operate. When I put the relay back in and rely on the ECU secondary signal to initiate the relay, the fuel pump will not operate. Does that clear things up?

BP Automotive

iTrader: (3)

If it is not priming at all you should check to make sure the fuel pump signal wire is pinned correctly are red/green 9.

If that is fine you should check to make sure that the pcm is getting power. One thing that might be of issue is if your using a truck pcm and they did put the two ignition sources in.

Let us know the pcm and what vehicle the pcm is flashed for and we can let you know what to check for power and ground.

Bilster

iTrader: (21)

I am using the RED/BLUE harness pin-out. I will get details tonight on the PCM Service Part Number. Checking that fuel pump signal pin location, as well.

Bilster

iTrader: (21)

The PCM Service Part Number is 09354896. My two power leads that feed the PCM are in the Blue plug-in at the 57 and 20 locations. That appears to be correct. My fuel pump signal location is at the red plug-in at the number 9 location...also appearing to be the correct location.

I talked to an automotive electrician about my problem and he said the best way to check power leads at the plug in is with a test lamp. That way you can see if possibly resistance is the culprit. If the light is weak but I have 12 volts, then look for resistance issues. HUH????? So I could have a resistance problem?????

BP Automotive

iTrader: (3)

When you first turn the key on does the fuel pump prime for 2-3 seconds?

Do you know how to check for continuity?

psiconversion

iTrader: (5)

Per post 13, it appears it does not prime unless he jumps the relay.

Blister,

Per your previous post, constant power and fuel pump are pinned out correctly.

Do you have Key On power at Blue PCM connector, Position 19?
Do you have ground at Blue PCM connector, Position 1 and 40?
Do you have ground at Red PCM connector, Position 1 and 40?

Jon
PSI

Bilster

iTrader: (21)

Hmmm....I will double check but I only remember soldering in a connection for one ground. I'll tell you what pin position that is in.

Bilster

iTrader: (21)

Sorry for the late update but "life" got in the way. If you would allow me to revisit this, here is what has transpired. I did mix up my constant hot and switch only hot connections. I repaired that. I also replaced my crank sensor. I am in the process of connecting my wire to the fuel pump relay closer to the relay. Originally, I tied into the original engine harness for the F150. I've now run a wire from the 5.3 ECU directly it to the the fuel pump relay at the junction as per the photos. There is one of the schematic and one of the area in a photo though not the actual connection. Both areas are highlighted in yellow. Does anyone see anything wrong with making my relay connection here?