Low rpm chug

[upnorthMike]

Good morning! New to your forum as of today and also new to the "99" Honda Passport I purchased about two weeks ago.
The problem I've run into is at low rpm while accelerating I'm getting a chugging/bucking thing going on until I feather the throttle up to around 40-45 mph and things seem to smooth out.If I kick the throttle down into passing gear it sputters again.
Changed plugs to factory recommended specs and gap,car starts instantly,has a high rpm idle but settles down to around 900-1000 rpm after a few seconds.Don't no if timing belt/waterpump was ever changed out and car has 122000 miles on it as of today.Check engine light just came on yesterday and I've not had that checked yet.
To me it feels like cat convertors plugged,but is their a certain path I should be following to a simple check/fix? Really like the way this SUV handles and rides.Rust free,nice body style(4 dr,4WD,EX),great forum,glad to have found it!
upnorthMike

[Cat Fuzz]

Have the codes read and report back with them. I'm thinking you might have a vacuum leak caused by cracked intake gaskets. Pretty common. The trouble codes will help.

[upnorthMike]

Thanks for your input.Heading out of town for a couple days of work but have a mechanic coming to my house to scan the vehicle.Will post results and outcome.

[upnorthMike]

Back in town from truck run,called my mechanic(son-in-law) who scanned motor on monday afternoon to ask what code(s) he came up with and he said he could'nt remember....dang.....said it was to do with maf,oxygen sensors,something like that.
I dug around the engine with the plastic intake cover off so I could see all vacume connections.What I discovered was a vacume line cracked and worn where it attaches to a port on the back drivers side off the fuel rail. I shortened it up with a quick cut,reattached it and I was off to the races with full power,no chugging at all!
I still have the dreaded ticking of a timing belt tensioner so thats now on my list of things to tackle.I'm a old school chevy 327/350 tinkering type of guy but feel up to the challange of the timing belt/waterpump/tensioner replacement.My older age(57) keeps me from tossing tools through the air and approach new tasks with more of a sence of accomplisment.Even my wife of 39 1/2 years has noticed!
My upper and lower radiator hoses feel a little bulged and hard while the motor is running but it doesn't seem to overheat and the temp gauge doesn't travel past the halfway mark? Seems to pressurize very quickly? Any thoughts on this? Cap stays fairly cool to the touch also. I reset the c.e.l and will take it for a test run tonight. Any inexpensive tools out there for checking fault codes? Also the idle stays at 600-650 at startup! upnorthMike

[amigo-2k]

If it takes more then 3 miles for it to reach normal running temp your thermostat maybe stuck open. I had mine replaced at 107k. I knew something was up when it look 7-8 miles to get up to temp during winter (and I had a CEL come on that tossed a code for a possible bad thermostat)

I had mine replaced at about 107k along with the t-belt, water pump, tensor and upper and lower rad hoses.

code readers, harbor freight sells them for pretty cheap. They are a great tool to have and to help out others too.

[amigo-2k]

Thanks for the tip on your vacuum line that was split. I checked the 3 that go into the fuel pressure regulator and one was split open on mine... I did as you did and cut back a 1/2 inch and stuck it back on.

I've been having starting issues for about 6 months now. Cold start it is fine, but run it til it is up to temp and then turn off and then try to start 10-45 minutes later it would start, run for 3-10 seconds and then die. Turn the key a second time and then there were no issues.

I hope this simple fix does the trick!

[upnorthMike]

Have a new issue....little surge in between a couple shift points yesterday.Had my son-in-law scan engine (no cel on) and it shows P1640 quad driver module malfuntion?What am I looking for here? upnorthMike

[fourwd1]

Originally Posted by Cat Fuzz

Have the codes read and report back with them. I'm thinking you might have a vacuum leak caused by cracked intake gaskets. Pretty common. The trouble codes will help.

That is common with this engine, had it on my 2000 Trooper.
Codes will usually show bank 1 lean, bank 1 rich, bank 2 lean, bank 2 rich (very confusing). Will also die at idle.