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Hey all..
I've been putting a new motor into a 94 f150 for the past few months and I've ran into the issue of the truck not starting. It cranks over, starts for maybe a second, putters out, backfires and dies. It ran fine when I swapped everything on, but randomly it just wont start anymore. There is a strong smell of gas when I try to start it. No leaks as far as I can see.. there's gas all over the spark plugs when I pull them.
New parts that I have installed: Distributor & cap, ignition coil, coil plugs, spark plugs, ICM, IAC, MAF, Fuel pump, Fuel filter, air filter, Coolant temperature sensor, radiator, starter, ETC...
I've replaced the vacuum lines in the engine bay, tested the tps, I have spark, & I have 30 psi at the rail after prime. The only code I get off the reader is 212: Loss of IDM input to EEC or SPOUT circuit grounded.
Any help would be appreciated! I'm at a total loss here..
Check your fuel pressure while you're cranking. It may have 30psi (already on the low end of the spectrum) and it may not be able to provide enough fuel to keep it running.
Check your fuel pressure while you're cranking. It may have 30psi (already on the low end of the spectrum) and it may not be able to provide enough fuel to keep it running.
figured it out. I was running a black icm but it wasn't a CCD style one. Autozone's reversed engineered ones was a bust.. I got that code cleared but It still wont start. I also have code 121 popping up now for throttle position sensor voltage being too low. I checked signal voltage and it read .86 v and rose steadily to 4.7 v. The orange wire on the tps has 5.1 volts. I was inspecting the harness trying to see if there's any breaks and found this.. it's by the brake fluid cylinder right off the main harness plug. I found it looking for the 22k ohm resistor that everyone has issues with but my truck doesn't have one. Instead it has this mess.
It doesn't look like that's from factory. It's 3 black wires that are soldered into a diode labeled in4003, and the 3 other soldered wires on the other end are red/grey, green/orange, & grey/white. I can't find any information on what this was supposed to look like before, how to fix it, or what these wires even do.
figured it out. I was running a black icm but it wasn't a CCD style one. Autozone's reversed engineered ones was a bust.. I got that code cleared but It still wont start. I also have code 121 popping up now for throttle position sensor voltage being too low. I checked signal voltage and it read .86 v and rose steadily to 4.7 v. The orange wire on the tps has 5.1 volts. I was inspecting the harness trying to see if there's any breaks and found this.. it's by the brake fluid cylinder right off the main harness plug. I found it looking for the 22k ohm resistor that everyone has issues with but my truck doesn't have one. Instead it has this mess.
It doesn't look like that's from factory. It's 3 black wires that are soldered into a diode labeled in4003, and the 3 other soldered wires on the other end are red/grey, green/orange, & grey/white. I can't find any information on what this was supposed to look like before, how to fix it, or what these wires even do.
I dont know what engine you have... but if you have any other sensors which use the 5v reference, you should check the reference at the various sensors, or even disconnect each of them. your 5v reference isnt a big deal being 5.1 but to me that sounds like its getting power shorted onto it somewhere
Make sure the connector to the ignition coil is well seated. Did you install the distributor at TDC (0*) on the number one cylinder? It seems like its real easy to mess the distributor timing up. When the dampener lines up with TDC on number one cylinder, take the distributor off, is it pointing at the number 1 cylinder?
Make sure the connector to the ignition coil is well seated. Did you install the distributor at TDC (0*) on the number one cylinder? It seems like its real easy to mess the distributor timing up. When the dampener lines up with TDC on number one cylinder, take the distributor off, is it pointing at the number 1 cylinder?
Make sure the connector to the ignition coil is well seated. Did you install the distributor at TDC (0*) on the number one cylinder? It seems like its real easy to mess the distributor timing up. When the dampener lines up with TDC on number one cylinder, take the distributor off, is it pointing at the number 1 cylinder?
Does the rotor and #1 plug have to point at #1 cylinder? Information on where the distributor needs to point is a bit skewed.. I put my distributor in at 0 TDC ON THE COMPRESSION STROKE (; with #1 pointed at cyl 6 due to reference photos that I could find. Thing about the truck is that it fires up and runs perfectly sometimes for like 3 seconds then just poops out. I just ordered fittings for a fuel gauge so I can double check the fuel pressure and point a camera at it when I crank it. The spark plugs are coated in fuel from cranking so fuel pressure hasn't been something I've been to concerned with because I've just been assuming its an ignition or air problem but maybe that's where I am wrong.
I dont know what engine you have... but if you have any other sensors which use the 5v reference, you should check the reference at the various sensors, or even disconnect each of them. your 5v reference isnt a big deal being 5.1 but to me that sounds like its getting power shorted onto it somewhere
It probably would've been wise of me to say what engine I have... Its a 5.0 with an auto
I have gotten a cap with the one in the wrong place, pic of your cap so everyone with a 5.0 can rationality check it visually
I'll go pull it today after work. Anything else other than fuel pressure that i should check when i get to the truck after work today? I found a spare pcm for cheap, figured id swap it in and see if that's the problem because I know it's a common problem with these trucks.
Stolen from @torq'ta 5 8
Your harness should look something like this. There's only a minor risk of cross firing if it's in any other orientation.
Computers rarely go bad. It's usually the last thing to inspect in my opinion. It's much more common for a sensor to be telling the ECU to mis behave. But it doesn't hurt to have one on standby.
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