Hey all,

This may be better in the V-10 forum, feel free to move.

We are on a road trip and while working through Arizona going up a pass with cruise control set to 70, all of the a sudden it couldn't keep up. It downshifted but no power. On level ground I can get up to speed if I take my time, but if give too much input in the accelerator, the power isn't there, it'll down shift on not acclerate. We found a shop that didn't have their mechanic in today but a person looked at it, and didn't seem to think it was the transmission slipping (he put it drive, held the brake and tried to see if it'd slip out of the first gear at least but it held), fluid was full, looks good and doesn't smell burnt. No other shop that was open. So we have been limping along up grades and doing find if flat or downhill.

No check engine light is on. Within. The last 2 years I've had the heads rebuilt (had a stuck intake valve), new coil packs, plugs, replaced injectors with rebuilt injectors, cleaned throttle body, replaced fuel pump, fuel filter, air filter, and other stuff that shouldn't be related. I had a new muffler put on and had the shop test the cat and he said it appeared it only had 1 of the honey comb pieces remaining, so maybe that that piece broke off? I don't notice a rattle in the exhaust, and no smoke or smell that I am aware of.

The only thing I did out of the norm for this rig is I put 85 octane in it, but I want to think that is coincidence and not causation.

We will make it to our destination tonight and get it to a shop Monday probably. Just wanting to get some insight from you guys in case I am missing something obvious...

Update: Made it to our destination. Rig seems to not want to go above 2800rpms or so. Even if I put it in 2nd, it won't go past that. In park it will. I also looked at the cat in the dark at a rest stop after some time on the road and it wasn't glowing red or anything.
Thanks all,

Grady

 

I would rule out spark unless the truck is misfiring.

Fuel, could be a fuel filter restricted or weak pump, need a reading of fuel pressure while driving. Fuel filter is easy to replace, pump not so much.

Exhaust restriction, cat could be plugged, will cause a loss of power. Early V-1os have OBD1 so you will not get as much info on code readouts, a lot of old school diag.

Good Luck!

 

My first thoughts were fuel filter and / or clogged cat. For the cat you could separate the down pipe or pre-cat flange and test the performance, if it then runs like it should (but loudly…) the cat would appear to be clogged.

 

Clogged cat it was. Thanks all.

Update 12/28 - Just went to leave for church this morning and no power again. No check engine light still, acting pretty much the same. Probably y going to take to a shop in the morning. Debating on disconnecting the y-pipe to see if that confirms car again. I'm just curious the likelihood of getting a bad car instead of some other cause. Engine is running well as far as I can tell so I don't think it's dumping unburnt fuel or anything in the exhaust, but I am confused, and pretty bummed, but things happen.

Thanks all,

Grady

 

Here is a photo of the cat that went bad between AZ and in CA... What is the likelyhood it is just a defective cat that had underlying issues vs some mechanical problem that I am unaware of? Planning to head back home to Montana in the morning.

 

IF Montana don't care, I would leave it out, and straight pipe it to the muffler.

that is what I did up in Montana, as I was heading for Oklahoma, where those laws don't exist.

 

I thought about it if I could find a shop to do it in CA, but read a couple of threads on the topic and it seemed the general consensus was that the V-10 didn't benefit from it and that it didn't sound great either. And I don't mind the helping keep the air a little cleaner having a cat on my gas hog 😂

 

true they don't like not having a cat, tried and proved on a dyno back in 2006 on my 05 250