View Full Version : Poorly D90.

04-03-2009, 05:10 PM
OK gents,
This is a posting for a friend who has a 95 D90 with a manual tranny. It’s got one of them new fangled EFI V8s and it is giving him problems. Truck has about 135K on it.

The symptoms are it starts fine, idles fine and takes off OK. As soon as he tries to accelerate she bogs horribly and will only reach about 45 mph. After running for a bit the driver’s side, and only that side CAT is glowing red. There is no check engine light and no smoke at idle or revving it in the driveway.

The plugs are a bit sooty but I put that down to the truck only doing short test runs and not being driven long enough to burn it off. This is the same on both banks.

So far he has:
- Swapped out the O2 sensors for the common Nissan swap and spliced the Rover connectors back in place. I pulled both sides and neither is sooty so I assume the heaters are working.
- Replaced the injectors. He once had one disintegrate and only that one was replaced at that time. He just replaced all 8. Before replacement he turned on the ignition and without turning the engine over we pulled the plugs. One was wet with fuel.
- He replaced the Y pipe and CATS as his first fix. There is a leak on the passenger side manifold to down pipe joint.
- He has replaced the MAF, the stepper valve on the back of the plenum and the coolant temp sensor.

I assume that if this was a timing issue that it would affect both banks and both cats would glow red. I checked the dizzy cap for tracking but could not get the rotor off to inspect the weights or the vacuum advance.

I could also do with being told where the timing marks are on this engine. I looked in the same places as my 101 carb fed V8 and there is nothing there

Any suggestions? My answer was to swap it for a series but that didn’t seem to fly.

Les Parker
04-07-2009, 12:59 PM
Have you checked the operation of the vac. unit on the dist.?
Is there movement on the centre of the dist. shaft (indicating a worn dist. shaft/bearings).
What sort of "Y" pipe is now fitted?
Have you checked the PCV system, breather filter, hoses good and clean?

All these can contribute to fouling the plugs/ poor running, though 45 flat out would indicate a restriction of some kind.

04-07-2009, 04:07 PM
Thanks Les,
The one thing that throws me is that only one cat is glowing. The Y-pipe was replaced because the old cat was glowing too. I won't discount that the new cat is bad or has been destroyed in the <100 miles it has been driven. The fact that both cats in the same position have done the same thing indicates to me that, although it may now be contributing to hte poor running I don't think it is the root cause.

I left the gent to do his on dizzy as the rotor was stuck on pretty tight. I din't want to break so left him to do it.

By the way I've left several messages with your man with A34 but he never gets back to me. If you want the photos through the fence to match my verbal description then fair enough but I can't get into the compound.

04-13-2009, 02:14 PM
Just for a little closure on this.

It seems to have been a dizzy problem. He is not sure exactly what was wrong but a general tinker and something started working again so problem solved.

The cats on these are deceptive as they must have different construction so only one glows. From other comments I expect that the passenger cat has an extra heat shielding skin to protect the prop shaft. It would be interesting to cut them open and see what's inside.

05-31-2009, 08:45 PM
I would personally ditch the cats and tune the MAF