Yesterday, we started sputtering going uphill and not getting enough power. Seemed to be at both high and low speeds. Got to top of hill, added some Lucas Fuel Stabilizer and it then ran normal at lower and higher speeds on straightaway and downhill. Struggling still uphill, and after climbing long hill again, problem is now at all speeds.

History: Replaced fuel filter and pump last year, spark plugs about six months ago and subsequently fuel injectors after it was doing similar power loss, also had compression test which was good all around, had another issue- stalling and not starting for 20 minutes- which was fuel pressure regulator, which got replaced. Fuel pump relay has been checked and rechecked throughout these previous issues. Starter motor/solenoid replaced a couple months ago.

So, waiting for engine to cool and I'll check plugs and plug wires (which were also replaced 6 months ago). Going to check distributor cap. Maybe that or ignition coil? Any takers?

Mahalo

 

could be your in-tank fuel pump, as opposed to the main pump. when the tank pump is dead, the main pump has to work harder, and has trouble delivering enough fuel for heavy throttle pulling, especially up hill.

 

Gotcha. I just was looking at that in the Chilton book (which is way more detailed than the Haynes manual I got on Amazon which turned out to be from the UK and harder to understand with terms like "bonnet"). I'll go back and reread and see how to test it (how do I test it, listen with fuel cap off?). I saw it was easier than I suspected to get to- under and behind one of the back seats, so I'm encouraged by that.

When I replaced the spark plugs several months ago, it was due to oil on a couple of them. This made me think that it was why it was having the loss of power that time, yet, it turned out that two of the injectors were not spraying correctly. One mechanic told me to try Engine Repair in the cylinders, turn it over with plugs out for 30-45 seconds (that was before the injectors were fixed).

 

re that tank pump, see Volvo Fuel Tank Pump/Sender Replacement

having done mine (1992 740 turbo wagon), its actually a major pain to get out and back in. one thing I learned, after you remove the band and the ring, tighten the band back up on the ring, otherwise it likely will warp, and not stay back on when you reassemble.

and a bunch of the cheaper aftermarket pump & senders have the wires colors reversed. people install these, and the pump is running BACKWARDS, so its SUCKING rather than PUSHING. eeek. check the color codes, maybe even jumper-wire the pump across 12V to make sure its going the right way while its out of the car, save a lot of grief later. I used a real Volvo pump and didn't have this problem.

 

Before I do that, the Chilton book says (under Pressure Testing) that I can listen with the fuel cap off while Fuel Pump Relay is off and jumper lead between terminals 30 and 87/2.

 

Yep, the front most plug had solid build up of corrosion- no gap! Always start at the simplest solution and move on from there!

I decided to listen for clicking in the fuel pump anyway, so I took apart the back plywood wheel cover just for fun. No clicking, but maybe I wasn't supposed to hear it? Oh well, it was fun to find where and how to get to that fuel tank pump in any case.

Put some NGK plugs in and now it's running smooth. Besides the corroded front plug, one of the middle ones (all Champions) had a loose outside stump- the part that the plug wire slips over- it was loose and would not thread back tight. Not sure if that was a part of the issue, so I just replaced all four and kept the other two good ones for backup.

 

the tank pump makes a soft flutter sound, from the gas filler tube (gas cap off) and probably only audible if the tank is less than 1/4 full. the main fuel pump makes a soft whirring sound, unless the tank pump is dead, then it gets kinda whiney.

 

The plugs were likely your problem then... Champions?

Often it is the simple things.

 

yeah, they were Champions.
guy at Napa said NGK were better or Bosch, since it's European, but I thought I read a few comments about how Bosch weren't so good. And, no Volvo dealer here for me to go get reamed by for Volvo spark plugs.

It's definitely purring better and has more power. Knock on wood. Wondering what could have caused that corrosion build up in six months. Or, is it just that the Champions were not a good match? At least I wasn't seeing more oil on the spark ends!!

Now, if I could figure out how to disconnect the damn useless alarm system that keeps killing the battery on my Subaru!

Thanks again, guys.

 

actually, the 4-pack of volvo plugs really aren't that expensive. but I'd DEFINTELY take NGK over Champion, hands down, for any import. you just have to make sure you're getting the right plug, they make a bajillion.

bosch W7DC for non turbos (or old 240 b21 turbos)
volvo 270746 for all newer (89+?) ($12 for a set of 4 at IPDusa)
volvo 271409 for older (up to 88?)
ngk BP6ES for non-turbos
ngk BP7ES for turbos


these are all more or less interchangable, but they will work best when matched accordingly.

I've had issues with Bosch aftermarket plugs in the last few years, so I'm using Volvo OE or NGK. for my mercedes 300E, you can't even get the correct Bosch copper core non-resistor plugs any more, so you HAVE to use NGK (or $$$ Mercedes OE).

 

Yeah, I knew the Champions were probably crappy, cheap from WalMart.
Thanks, Pierce. You rock.