PAHonda

Stuttering issue has not changed in anyway since it started despite all I've done. Tach is fine. When I change out the TPS I'll let you know what happens.

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test the tps before replacing it ...use a voltmeter ,throttle close should read around .5 volts, open throttle around 4.5 volts

 

Nomad2020... as mentioned in the orginal post that was done and it worked fine.... I'm trying PAHonda's theory... that it can still be bad even if it tests ok

 

sounds like you are pretty knowledgeable and done a lot of testing and work for this issue..
Have you also tried an injector cleaner ?? chk for a vacuum leak?
Also if you have a fuel pressure gauge , hook it up and monitor fuel pressure
when issue is present , pressure should be around 40-50 psi,,,,,
Since you have done so much, best way to find the issue is to do the eliminating process,

 

I've changed out the tps and no difference. Still no codes. Haven't fiddled with the MAP sensor yet... that was suggested by a smog guy who's excellent, been diagnosing for 30 years. He was stumped though as he's never seen this.

Let me review the symptoms. Perhaps something will shake loose in someones memory:

It starts up fine. runs well until it's warmed up. When at idle it sometime skips cylinders and sometimes run smooth. if you attempt to raise the RPMs it stutters as it increases until about 2500 rpms. It rarely stutters over 3000 unless it's under a load like going up a hill. Slow acceleration will keep it from stuttering. I must manually use the automatic gearshift to control the balance between load and rpms.

I'm duplicating the things I mentioned having been done from my first post and adding other experiments.

Valve cover gasket (There was oil in the plug holes)
Distributor cap and rotor
Fuel filter
Did the jumper on the computer to check for codes... nothing.
ICM
Throttle position sensor tested good
Plugs and wires a year old.
EGR checked
Fuel pressure in spec.
Pulled 7amp fuse for computer (had to reset the clock and stations on my radio).
Replaced computer
Replaced and adjusted TPS

Whats maddening about this is that absolutely nothing I've done has even made a slight change.

Any other ideas? Would Honda be able to diagnose.it?

 

Was the computer used or new?

 

Seanjordan20

Used... but it behaved the same as the old one.

 

Have you tested fuel pressure once the car has warmed up and displaying the issue. Could it be an injector. I just don't see how nothing has gotten better after everything that's been done

 

PAHonda Turns out the timing belt skipped two teeth.... amazing that the computer could adjust for that...