Unusual power loss
 

Okay, something strange has happened to my 1998 3.3 V6 Grand Voyager.

The engine just refuses to pull beyond 3500 rpm under load, though it revs freely when sitting. It doesn't hesitate or or anything just refuses to pull as if it only was seeing partial throttle.

It starts and idles without issue, there are no error codes showing, fuel pressure and compression are okay. I’m seeing 19 to 21 mpg so no decline in economy. It had new plugs and wires about 6 weeks ago after which it ran okay. It does have a cold air intake but this is also okay. Now, the only thing that has been done to the van in the past month or so was, I had the cruise control checked out and the garage said they had to remove something from the intake manifold to gain access. However since then I haven’t been using it for anything more than local journey’s so I'm hoping its something they have done..

Now the only thing I can see that looks like it been removed sits down behind the throttle body; it has several vacuum lines, one of which is a triangular shaped piece of rubber, and an electrical connection. However, it just doesn't look right. The pipes are awkwardly connected and I’m wondering if this could have something to do with the problem? I’ve checked around online and in the Haynes manual but I cannot find a diagram or explanation as to what this is or the correct way in which this should be hooked up.

So does anybody have any thoughts?

Find someone with an identical engine and ask him if you can look at his throttle-body area? For comparison purposes of course...

Leedsman.

Unfortunately the only one I've found so far was in the junk yard with a missing engine, I've been phoning around a few just on the off chance there was one. I just haven't seen another 98 era GV around in my area for a long time. Lots of the later, post 2000 models but no pre 99's

HIYa Vonhofinvule - I thought you were propane not petrol ! Select from here and get the proper diagram, if you are 2.5L/2.8 TURBO DIESEL diesel get this and go to section 9a. The 98 diesel is here, look at 14 & 14a.

Best of luck

Thanks I'll check it out. Its actually dual fuel, it can run on either. However, at the moment there an issue with the a pressure switch in the propane system. It should switch over automatically when the propane levels drop below a certain point but its stuck in the off position so right now it only runs on petrol. Although I'm heading to the US at the end of the month so that can wait until I return in November.

Again, thak's, I'll dig through see what I can find.

Well I decided to just switch around the pipes noting where they were just to see if it would make a difference and unfortunately it didn't. So my guess is the issue lies elsewhere.

This really had me beat; its as if the ECU is limiting top end power, but nothing is showing up anywhere. I even removed the air cleaner thinking maybe there's a restriction there somewhere but nothing. Damn I miss carbs. LOL!

I had a Jag that ran on propane or petrol. Funny thing was, when the injectors gor a little clogged, the engine ran badly with low power and misfires on petrol, but the LPG propane was perfect. It was my own fault because I got in the habit of starting the engine on propane, therefore after a while, the injectors got clogged. as they never had any petrol going through.
Maybe your remark about carburetors was strangely prophetic -- are the petrol injectors slightly clogged?

Leedsman

Hi Leedsman, my system won't let me start the engine on the gas, it has to be on petrol. If you press the button it just flashes the LEDS and the petrol light comes back on. However, I have solved the problem and it was a strange one.

I decided to do a vacuum test on the engine today. I'd replaced the intake and valley gaskets a few months back because of a vacuum leak so knew from the before and after tests that the engine should be drawing around 19 inches of vacuum. However, it was showing only 17.5 inches so I knew something was amiss. So again checked the vacuum lines and nothing. Did the usual tests but nothing indicated a vacuum leak. So once again I went back to the air cleaner, it had a cold air system which went down and under the front bumper but I only checked the actual filer.which I had previously removed for a quick test to see if it was the issue.

However, I hadn't removed the pipework, so I figured, it was worth a closer look and found the problem straight away. Simply put, a mouse. hahahaha

A mouse had decided to build a nest in the inlet pipe beneath the air cleaner. It had chewed away all the plastic around the inlet and had twigs and stuff I really have no desire to understand rammed in there. Now, the only place I can think of that this little guy, or gal came from was Devon. I was down there the week prior to the van going into the garage to have the cruise control checked. It the actual return journey that the problem with it arose. The van had had been parked for a few days in a field with the nose up to some bushes so is the only place I can think of he might have come from.

So, the lower airbox is at this point trash so for now I've adapted an old cold air intake I'd removed from a Charger a while back and that's it fixed, I have my old van back again!

- winters's just a short while away, getting colder each night
- hang on that looks a lot like a burrow. How convenient for little me
- it can supply one of my four basic survival needs: air, water, food and living space
- that nice human provided a prefab tunnel just waiting for me to move in and fill the pantry with groceries!

http://media.salon.com/2012/11/shutt...k_57341071.jpg

We all learn each day - that 'Vonhofinvule' is brilliant ! - it certainly lightened my day !

A mouse? Gotta admit -- I never would have thought of that...Must have been a pretty draughty home for him.
Worry not, I'm not going to do any mouse gags.

Leedsman.