I just bought an 89 F150. It has a straight 6, C6 auto tranny (I believe- "K" tranny code)
Guy I bought it from put in the straight 6 crate motor 6 months ago and it runs like a champ.
Couple issues, it starts fine cold, but has a hard time turning over when hot. It has a strong battery, new terminals, new grounds, and I cleaned all connections + & -. But still goes grrrr, grrr, grrr then starts 50/50 when hot. Could the starting issue be the starter itself? It seems to start fine when cold though. BTW when it's hot it doesn't want to crank over, but sometimes does. I thought maybe coil is getting hot, but I believe it would crank at normal speed, but not fire if that was the case.

Check engine light came on, so I pulled the codes via the instructions on this site. This is what I got:
33 throttle position sensor noisy/harsh on line
41 o2 sensor indicates system always running lean
81 MAP has not changed normally
84 EGR vacuum regulator circuit failure
87 fuel pump circuit failure

The running engine codes were:
33, 41, and 52 power steering pressure switch open

On the code 33, what does TPS noisy/harsh on line mean?

I'm going to clean the EGR, and check MAP hoses and look for any vacuum leaks. I'm guesing that's why it's running lean.

I'm not sure why I have the fuel pump circuit failure, it seems to run really well, it does not feel like there is a fuel problem. Is there a fuel pressure sensor that reads this code, or is it just a voltage reading at the PCM? Maybe I could just clean connections. All the other battery connections I cleaned were pretty dirty...

Thanks in advance for any suggestions, and glad to be a Ford owner again. I've had an LTD, town car, aerostar, and a mustang, (with a few dodges and chevy's inbetween) but this is my first truck.

Rob

 

I don't have time to jump into this too far at the moment as I was just getting ready to go, but I'd check the base time to start with. It should be at 10BTDC (w/ the SPOUT plug removed) And it sounds like the P/S pressure switch was disconnected during the engine swap & not reconnected.

 

Your 33 code is saying that the PCM is reading a noisy signal. I would suggest cleaning the TPS connector with alcohol. That might fix the issue. Your other codes sounds like you have a vacuum leak. But don't be surprised if you start getting random repeat codes. If you do, expect to replace the PCM. Frankly, it sounds like it's dying. Does the truck by any chance have an alarm system on it with a start disable feature?

 

I found a vacuum leak on one of the elbow connectors to one of the small hard vac lines, and a cpl hoses that were dryrotting, didn't feel/hear any leaks in them, but replaced them anyway. I'm thinking that leak might fix the EGR and MAP codes, if not a good cleaning or replacing for those parts is probably next. I have a vacuum guage, what should it be reading on a properly running engine?
Thanks for the tip on the TPS, wasn't sure what "noisy" meant. I'll clean the connections and see if that clears it up. I'll check voltage at idle and WOT to see if the TPS is functioning right, but it might just be the wire connections as mentioned above.
The fuel pump code, and hot start issue may be related, I'll have to get into that tomorrow.
Thanks again!

 

I don't know where you got your code definitions from, but most are wrong.
33=EGR valve opening not detected
41=no oxygen sensor switching detected OR oxygen sensor indicates lean
52=power steering pressure switch always open or closed
81=air management 2 circuit failure
84=EGR vacuum solenoid circuit failure
87=fuel pump primary circuit failure

Most of the trouble is coming from the EGR which may have been fixed when you found the vacuum leak, and some of the others may have been from the leak. Clear the codes, drive the truck some and check the codes again.

 

I got the codes from an online obd1 list, I have since got a haynes manual, and see what you mean.
I replaced the lines, fixed the vacuum leak, and disconnected the battery. Will drive in the morning, and recheck. I'll post results and/or questions.
Still need to resolve the hot start issue though. Haynes says, air filter, electrical or fuel related...
Thanks!

 

Or timing.

 

Can anyone post a link with the right codes?

 

I had a lot of hot start issues with mine. Went through several starters, solenoids, terminal ends and finally changed all 3 cables. Never really solved the problem totally but the cables helped most. Probably need a REALLY good battery, I hadn't tried getting a good one.

 

Well I got all the mushy vacuum lines replaced, the auto parts store didn't sell the elbow boot that was leaking, so I electrical taped it (no more hissing) replaced the fuel filter, air filter, plugs wires, cap, rotor, and PCV. I pulled the EGR out and it was surprisingly fairly clean, and applied vacuum, and diaghram opened and closed smoothly, so I put it back on. Reconnected the battery and took it for a drive. Check engine light came on after 5 miles so I went home and rechecked codes. They flashed in this order:
87, 84, 87, 84 long pause, 41, 33, 41, 33 The 81 air managment 2 code didn't show up this time. Running codes were 41, 33, 52, 41, 33, 52.

The truck idles smooth, throttles nice, drives fine, shifts fine, doesn't stall or hesitate, if it wasn't for the check engine light, I'd think nothing was wrong except for the fact it barely wants to crank over when hot still. (earlier question-no I don't have an alarm) When hot it starts like an almost dead battery, grrr, grrr, grrr, then fires right up sometimes, sometimes it doesn't and I have to wait for it to cool off. Battery voltage is 12.74 off and 14.47 when running. Battery seems fime, and alt is working. New battery terminals, new bat ground to frame, new ground engine to frame, new ground frame to hood, cleaned all terminals ends at the starter solnoid and at the starter. Starter cranks right over when cold, and after a cpl slow grr's it cranks right over sometimes too.

Next step, I'm testing the EGR solnoid and wiring.
If there was a fuel pump circuit failure (code 87), wouldn't I have drivability issues? I can hear the pump engage when key is turned. And when it doesn't want to start, primimg the fuel pump a few times doesn't help.
And with no HEGO switching detected (code 41), does that automatically mean the o2 sensor is bad? wiring looks good, or is there something else that could be going on to cause it?
I have a 5 hour trip, and have to haul a trailer on the way back in the next couple days. I really need to fix these issues, so any input is appreciated, thanks everyone.