98 XC occasional hiccup/light stutter

jsrnsis · Post by **jsrnsis** » 26 Sep 2024, 18:16

My 98 XC with 187k miles has an occasional stutter/hiccup that ranges from slight to feeling like the car is about to stall. Usually when driving in the highway it's slight, and it's more noticable at idle. It lasts for only a second.

Today I got around to getting a fuel pressure gauge on it, and the needle was moving around wildly. I thought I remembered seeing a steady needle when testing the 97 GLT, so I also hooked the gauge up to a 98 NA V70. The needle on the NA was smooth.
Videos are below:

XC

NA

Any reason for this? I didn't experience any hiccups or stutters while I had the gauge on.
Also jumpered the fuel pump relay and got the same jumpy needle.

Post by **scot850** » 26 Sep 2024, 19:37

The V70 has the fuel pressure in the right range of 43psi for that car. The XC is running low. Probably ok to run but marginal if under load.

Fuel pump swap is a big job. Only aftermarket pumps available now. Look up a thread from Abscate on the pump he used on his S70 AWD.

Neil.

jsrnsis · Post by **jsrnsis** » 26 Sep 2024, 21:19

scot850 wrote: ↑26 Sep 2024, 19:37 The V70 has the fuel pressure in the right range of 43psi for that car. The XC is running low. Probably ok to run but marginal if under load.

Fuel pump swap is a big job. Only aftermarket pumps available now. Look up a thread from Abscate on the pump he used on his S70 AWD.

Neil.

That's what I feared. I tried to always fill up before I reached a quarter tank, but I have to admit I hit the low fuel warning a few times. It's been doing this little hiccup since I acquired it though. Any chance this is just the fuel pressure regulator on the fritz? I don't think I've ever changed the fuel filter on this car. I was under the assumption that 35psi was good for the LPT 97 and 98 cars. I find the bouncing pressure strange.

Edit: is this possibly a bad fuel damper?

Post by **scot850** » 26 Sep 2024, 23:27

There is a pressure regulator that is NLA and has been for years and was built into one of the fuel lines (also NLA).

Even if your regulator was bad, I'd expect to see higher pressure output. If you have not changed the fuel filter, go for the small wins and try that first.

Neil.