question about clearing codes

Hey there, havnt posted in a long time, the van has been running well till lately...
86 5 speed, was running normal, shut it off for 45 min. and then upon start up an instant change. shuddering and loss of power. as I drove it home @10 minutes, it got worse, till I had to tow it. codes were 5 and 11. replaced the o2 sensor. got rid of 5, found the plugs extremely leaned out and the coil burnt up (coincidence with the coil ?) replaced, no change.
I am still getting a code 11, TPS, It starts up and runs great for @ 15 seconds but then really bogs down and I can barely keep It running. I left the neg battery terminal off for a minute, and before starting checked to see if code was clear, but it was still there, left the neg terminal off all night and this morning without turning it over checked and it is still there? is that normal, I thought the codes would clear untill the van was run again?
thanks
josh

When codes don't clear it typically means you have a bad ECU. Get the number off your old one then use it to search eBay. I've got good spares off there for as little as $10 (average is around $50). I'm guessing your TPS is probably bad too, but that won't make it run as bad as you describe. I've had ECU problems that created issues similar to what you describe. Tim

Van gods must be very angry with me, replaced the ecu (I went ahead and bought a Cardone remanned unit) and it acts the same. since then ive gone through a lot of other things to try and solve. I don't have a fuel tester but there sure seems to be a lot of pressure. the weird part is it seems to get progressively worse.it now wont start all the time and when it does it runs smooth for a shorter period of time. I have checked and replaced vacuum lines, and fooled with so many other parts I cant keep track anymore. Guess I need to track down a fuel pressure tester.
TPS is on the way, old one was crumbled plastic on the inside......Has a TPS ever caused such grief? is it possible at all?

Sorry to hear that. FYI, I have never purchased a new or rebuilt ECU as I couldn't imagine spending that much (I hope they didn't rape you too bad). You're saying that both ECU's will flash the TPS code & neither will reset? Very odd. I've had my TPS disconnected before and ECU would still reset. It usually takes around 5 minutes of running before the TPS code would come back (and that's with it completely disconnected). If you're wondering if the TPS could make it run that bad, in my experience, no. I've had customers run with TPS disconnected for years and they still ran decent. TPS mainly effects timing advance and fuel mix. If there's no signal the ECU will go into a "limp" mode. Limp mode tends to resemble the performance of a carburetor (approximate fuel mix). The result is slight power reduction and poor fuel efficiency. Loss of electronic advance can lead to exhaust overtemps (glowing exhaust manifold). Over a long period of time this can lead a prematurely cracked manifold and/or a failed (plugged) catalytic converter. It's been my experience that TPS units typically fail every 100k - 150k miles. Tim

PS: Speaking of cat failure, you might want to search the forum for "catalytic converter" and read up on the symptoms/testing of that. Tim

Got the van running!!!

after start up it would run fine with carb cleaner injected through a vacuum port in the manifold (wish I had done that 1st) so it would seem fuel delivery or pressure and since the pump is the start of all that I dropped the tank and replaced it. I jumped the pump to prime the lines and etc and instantly noticed the difference, the WOOSH sound of fuel was loud, I had no idea! Maybe a short video or sound clip to demonstrate just how noticeable this is would be cool!

The ECU was 300 with shipping and everything and the core is worth 40 but I may keep it as a back up. its a lot of $ but I really wanted a known good unit. plus ive spent so little on this van in the 5 years ive owned it it didn't bother me too much.

about the tps code, the old ECU wouldn't clear, the new one was clear but threw the code when I ran the van for the brief moments it would run. now that the TPS is replaced ill clear it again and check on it. I think the new ECU will clear the code fine.

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Originally Posted by bald josh

about the tps code, the old ECU wouldn't clear, the new one was clear but threw the code when I ran the van for the brief moments it would run. now that the TPS is replaced ill clear it again and check on it. I think the new ECU will clear the code fine.

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Sounds like there was a fault with the old ECU, so at least you needed that...........although I would have had a very hard time paying $300 (so far the most I've spent was ~$50). Still, I can understand wanting something verified good. I'm glad the pump fixed it, but didn't you replace that in THIS POST?. If so, that Napa pump sure didn't last very long. Tim

Wow, good memory Tim, im glad you remembered that. reading back through that really makes me wonder. I did the fuel pump test on the side of the road and heard nothing. the coil was burnt up as well. makes me wonder if the pump was bad and the coil burnt up at the same time then as it was this time. this whole deal seems like a repeat of the previous and makes me wonder what the underlying cause could be! seems way to weird to be coincidence. changing the pump on the side of the road didn't give me a lot of chance to have a clean work environment and I was thinking maybe a lot of dirt got in the tank fouling the fuel strainer and burning up the motor but now I wonder if there isn't some other underlying problem. I wish I had kept the first pump I pulled back then to test and see if it really was bad...