Topic: Loping- What makes this happen?

[bajamil]

OK here is the issue I am having:
After putting a new wiring harness on the 22-re as the old one was pretty beat up. I used the same wire harness for the rest of the truck as it was in pretty good shape. I cleaned the throttle body and removed tons of crap from the lines that were attached to the intake, made sure they are all in the proper location and clean. Started it up with the wiring harness just hanging inside and she fired first try!
then it happened-----LOPING-- after she warmed up loping from 1500 to 3000 RPMs..... then it starts sounding worse. Any ideas- I could sure use some help on this one... already read the lnfo on this on the other threads as well tested the TPS with another used one, switched the computer from the old one along with the open circuit relay and fuel relay, all fuses, all vacuum lines, new gapped plugs, wires, cap and rotor, timed it, no vacuum leaks, swithced EGR, compression fine, its got spark, good grounds, switched out pick up coil, solonoid resister, adjusted valves hot, switched thermostatic air cleaner, injectors seem fine as it runs till it gets warm, new cam and timing chain from a few thousand miles ago-did not change anything in this swap. New PVC valve. it ran fine before and all i did is switch it into new rig....

also posted in my build thread

[Duffil]

check the codes

BTW--its a Positive Crankcase Ventilation Valve, not a PolyVinylChloride Valve.

[bajamil [OP]]

opps ya the valve is what I meant -- OK I will check the codes.. the check engine light does not come on and several have said this condition does not throw codes?

[bajamil [OP]]

go code 6 and code 7
one is ignitor or curcuit
other is TPS must be a 2nd bad TPS i will get another one and try it.
I switched Ignitors already and same deal but both trucks ran fine before the swap.

[bajamil [OP]]

just pulled the 30 Amp EFI fuse under the hood out - retested the codes and only got code 7 TPS.....
part should be here next week.

[MiniSimp]

only got code 7 TPS.....

any money that the next code will be 11?

[THK Matt]

your tps was in the wrong position? you make sure it was on there right after you cleaned the TB?
i just cleaned my stuff last week and mine did the same.
the TPS was on wrong...

idk if thats what u said your problem was... i got lost.

[bajamil [OP]]

no code 11 yet..... i tried previous 2 TPS switches using an OHM meter and following: http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

I would say it they were both on correct. it just seems unlikely that both switches are bad??? But this thread showed the same thing:

http://board.marlincrawler.com/index.php?topic=6559.0;highlight=loping

Just for giggles I moved the TPS to its farthest position Clockwise and then counter clockwise and adjusted the Stop screw accordingly and it seemed to make the loping either speed up or slow down but still loping.

 

[THK Matt]

take pipe cleaners and make sure your vacuum passages arent clogged

[93tonkatoy]

try blocking off the egr system(the tube bolted to the very back of the upper intake). I had the same problem and the compression nut in the egr line (just below the connection to the intake) would not tighten enough to seal. this caused a major vacuum leak, and the computer was trying to slow the engine down to idle. another thing to check is the idle set screw on the throttle body. try screwing it ALL the way in. Don't overtighten it, just run it down until it's snug. If the engine is warm and still running, you have a vacuum leak, and I would suspect the egr tube.

[bajamil [OP]]

OK i cleaned out all of the vacuum ports of the intake manifold and triple checked the lines and they all look good. I took a piece of .5 in tubing and listened for leaks or a hissing sound and nothing. I switched the EGR with another one and same deal. I will try to do as 93tonkatoy says and block off the EGR system and see what happens do you have a picture that shows the nut you are talking about just to make sure? I screwed the idle set screw all the way in and its still runs so = vacuum leak. what about the TPS code this thing is throwing?

[THK Matt]

OK i cleaned out all of the vacuum ports of the intake manifold and triple checked the lines and they all look good. I took a piece of .5 in tubing and listened for leaks or a hissing sound and nothing. I switched the EGR with another one and same deal. I will try to do as 93tonkatoy says and block off the EGR system and see what happens do you have a picture that shows the nut you are talking about just to make sure? I screwed the idle set screw all the way in and its still runs so = vacuum leak. what about the TPS code this thing is throwing?

I learned from my dad... t hat a peice of wood works WAY better then a piece of metal to find sounds...
the wood isolates the sound.... metal on metal.... sound travels and vibrates. just a tip

its how i find which valves need adjustment.

[93tonkatoy]

I don't have a pic right now, but I can take one tomorrow and post it up for ya.

[bajamil [OP]]

thanks man that woild be great and I am sure someone else has this issue out there.....

[85-4roller]

You need to try a different TPS. I had the same problem, after cleaning my intake. I replaced the TPS with a good used one. Problem solved.

[bajamil [OP]]

that was it! Both of the TPS switches that I tried did not work and 3rd one was the lucky break. The 3rd one did not have proper readings on the OHM meter like it says in the manual but I decided that I would just start it and see and she runs like a top! I have not even adjusted the TPS, i just bolted it in the middle of path and it seems to run fine. I am glad it was it and not something I had to keep working on.
Thanks again guys for the help on this one!!!!!!!!!!!

[kneedownnate]

Sweet