The truck is a 1995 f150 4x4 speed density originally a 351, with a 1996 f150 302. I have known the last 4 owners up to the one that blew up the 351, he bought a cheap 302 and had a shop put it in. The shop couldn't get it running and the next 3 owners couldn't, they all swore it was the computer. They used the 1996 harness on the engine, I restabbed the distributor, set it to the HO firing order and got an engine harness from a 1995 speed density pickup and bam she ran! I buttoned up some things and decided to take it around the block then I wasn't quite as happy. It's like it's taking off in 3rd or 4th gear, OD off light flashing and a solid check engine light. It does better when manually shifting on the column but seems weird still. I've dug and dug and cleaned the vss on the rear diff, checked the tps, cleaned the 2 connections on the trans, and checked wires and fuses. I don't really have the money to throw at it nor do I want to throw parts and $$$ at it aimlessly. I had to swap harness plugs on a couple of things between harnesses, one being the tps plug. I just made sure I put the wires into the engine wiring harness plug correctly hoping maybe I put them in wrong but they're correct. My thought I just had that made me make this post, will a 1996 tps work on a 1995? They have different part #'s but I thought maybe it's because of the different plugs/connectors. The owner that burned up the 351 says the trans was fine when his ordeal happened and I had rode with him in it when the cylinder dropped and the trans was indeed good. I have codes 113 327 637 552 553 558 565 621 in that order. The 637 and 621 for trans temp and solenoid #1 are in question with me. I still need to sort out the other codes and they're probably the reason it idles a little rough but that's a later project. It has a new distributor, msd cap/rotor, wires, coil, plugs, fuel pump with 46lbs of pressure, new injectors, new fuel lines, headman headers (no egr hookup on intake or exhaust), new ignition module on the fender, timing is set spot on (with timing light), all new seals in the engine and some other stuff I can't remember that I have receipts for at the previous 4 owners expense trying to get it running. Anywho, I would be more detailed on the trans and how it shifts but with no exhaust/open headers I can't feel or hear a whole lot. Any thoughts on that 1996 tps or anything else? I tried clearing the codes just to see what happened and they don't go away, the problem is consistent and never goes away like it does in most post I've read.

 

Biggest problem you have is starting out in 3rd gear.

KOEO self test codes can not be "cleared", the problem must be corrected or they will cause problems when driven/they will remain until corrected.

You have codes for tab tad and EGR, not a huge problem at this point and I wouldn't worry to much about trans temp code either, get it to shift right that one will probably be corrected at the same time along with 621.

Figure out why the computer has no connection with shift solenoid 1, 621 is a KOEO code showing it is either dead or it has no connection with it. My bet would be no connection with it over a dead solenoid. Solenoids can and do die yea but far more likely to be a bad connection and or busted wire in the harness instead.

Without shift solenoid 1 it can't get any gear lower than 3rd.

You state "cleaned the 2 connections on the trans, and checked wires and fuses" but its not clear exactly what wires you've checked or what you've done to check them.

Shift solenoid 1 should be an orange-yellow wire, test it for continuity from the PCM main harness connector (pin 52) at the computer, to the connector down to the other end of the circuit on the solenoid pack (pin 3), on the right hand side of the transmission. Disconnect the harness at both ends, test that circuit.

If you haven't already.

If passes that test then test the solenoid itself, should test between 20 to 30ohms and show no continuity to ground, should "click" when 12v is applied to it and should sound just like the other 3 in the pack.

 

In addition, 46 PSI of fuel pressure is way too high. It should be 40 PSI at the absolute most. Make sure your fuel return line from the regulator is not kinked, crushed, or pinched.

The reason why quite a few of your plugs are different, is because the 1996 5.0 uses a different emissions system. The 1996 model year actually required verification that things like the EGR valve and smog system were functioning. The '96 uses differential pressure sensors among other things to determine that.

To make the codes go away, you'll have to swap in the EGR valve, EGR position sensor and their associated control solenoids from a '95 or earlier engine.

dan1r has you covered on the transmission.

 

How exactly do I go about applying 12v to them? I've never tested the solenoids in any vehicle. I have them pulled out, also which pins to I test for ohms?

 

You need to figure out what PCM is in truck, if it's the original OK but anything else could be a big part of your problem.

You need some kind of exhaust on the truck, if the O2 sensor is just hanging in the air fueling will go wacked as soon as the engine reaches operating temp, and you need to get the motor up to operating temp to be able to tell what codes are real and what are red herrings.

 

It's the 1995 PCM that is original to the truck, I'm just trying to get the shifting figured out at the moment, the harness I got from the junk yard doesn't even have plugs for o2 sensors which confused me.

 

1995 and earlier trucks only have 1 O2 sensor.

 

Here is the pins to use.





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