mattaway

my truck was running rough and i got a code 13. so i put a new distributor in it, it still ran rough, but got better. the tps was showing low ohms, so i replaced that too. it ran fine for 2 weeks. now it's running rough again. i checked the codes today and the 13 is back along with a code 41. i don't see how both the new parts would go bad??? does it sound like i have a wire gremlin, or does this point to the ecu?

Dirt Driver

I think you probably need to check grounds, contacts, and continuity to know whether it's the wiring or the ECU.

abecedarian

have you checked the ECU connectors for any loose connections or corrosion?

Flash319

If it runs the ECU is fine. I would check that your intake tube is in good condition with no leaks.

mattaway

abe, i checked the ECU a couple weeks ago when i put in the new circuit opening relay. there's no corrosion and everything's connected properly. and it was running rough before replacing the COR, so i'm 99.99999% sure i connected everything correctly

Flash, glad to know that the ECU is fine if the truck runs .... it's a very expensive part!

the intake tubing is a little dry rotted, but i've checked it for leaks with brake cleaner, couldn't find anything. i got the day off tomorrow so i'll poke around under the hood and see what i can find.

thanks guys

iamsuperbleeder

good luck!

yeah definately check your grounds


excuse the dirty motor, but...


you have one at the rear of the head:




one on the lower passenger side of the block:




and one connected right to the intake manifold:

abecedarian

Too bad you're in FL... I'm bored.

On the intake, you can't just check for leaks with brake cleaner since it's not under any significant vacuum. You'll need to be a bit more vigilant and thorough in checking for cracks in the boots... for instance by shining a flashlight on the inside and flexing the boot with your hands, looking for cracks evident by light shining through.

BUT... that won't solve your 13 and 41. 13 (as you know) is no NE signal to ECU and 41 is open/short in TPS VTA circuit.
If you've replaced the distributor (and thus have a new pick-up in the distributor) the igniter is the next device in line to check. The NE signal is relayed by the igniter from the pick-up in the distributor to the ECU. The engine will run if the ECU doesn't get the NE signal from the igniter (the igniter starts the engine with the signal from the distributor then takes direction from the ECU to change the advance or retard accordingly). If the connection between the igniter and ECU is intermittent, or the igniter itself is malfunctioning, the igniter will randomly advance the timing then drop to baseline timing and that could cause a rough running engine that sometimes is fine and othertimes isn't.
The 41... well that's another issue... could be an issue with the plug to the TPS, or in the wiring from the TPS to the ECU... or the ECU too.

mattaway

i need to clarify what i meant by "running rough"

the truck will crank up and idle fine anytime, everytime. you can rev it to the max or hold it at any rpm in neutral, without any problems. now before i replaced the distrib. and the tps, it would misfire and sometime stall out when you take off from a red light/stop sign, but only after it warmed up. i put the distrib. and tps in and it was fine for 2 weeks....

this past weekend i went out to the woods saturday, it ran fine the whole time no problems. sunday morning when i got up it started acting up again, but wasn't nearly as bad as before. we went out to the woods again on sunday and it started acting up after being out there a couple hours. on the way home, it was ok until i stopped at the first redlight, it's been bad ever since.

something weird i noticed is that it never misses in reverse. if i pull into a mudhole and it starts missin and losing power in first, i'll put it in reverse and pull right out with no problem.

i checked all the ground bleeder showed me, they're all good. abe, i pulled the intake tubing off and did what you said. i couldn't see any leaks.

the igniter looks factory, and the wires are kinda brittle. the clip on the tps is broke, but i "rigged" it so it stays tight and can't wiggle itself lose.