Tess has been a bit grumpy recently, and it was probably my own silly fault, but now I have to fix it.
I took Tess for a WOF inspection the other day, which she passed, of course. I did need to clean the reflector on one of the tail lights as it was completely obscured by dust, but that was as easy as blasting the inside of the light out with compressed air through the bulb holes.
Moving along; I was a bit silly with the WOF. I didn’t have the money for a tank of gas (not 60L of 98oct at these prices), so I chose to take it for the WOF with somewhere in the vicinity of 1/8 of a tank. Maybe 1/4 at the most. The fuel gauge is a bit of a joke, it consistently reads about 1/4 low so on the lower end of the dial it’s anyone’s guess what’s in the tank.
The WOF was fine, but driving the car shortly after that (a celebratory WOF passed hoon) it developed an annoying stutter/hesitation when quickly pressing the throttle. If you rolled the throttle on it would rev out and drive fine, but if you jabbed the throttle too quick, like when rev matching or changing gear spiritedly, it would fall flat on its face for a bit, possibly pop out the exhaust and then come back to life and rev fine.
I tried adding some more gas to the tank, but obviously I had made her mad. This gave me a huge sinking feeling…. the car had been sitting for years before I got her, was the tank full of rust? Had rust blocked the filter?
The first step for me was to see if the fuel pump might have been mad. Its been making weird noises since I got the car. When you first turn the key and the pump primes, 1/4 of the time it would make a normal buzzing sound, but often it would just make a series of clicking noises. It still seemed to work, but you had to prime the system twice when cold or the car was hard to start. One prime, lots of cranking. Two primes, instant start.
The Rover SD1 EFI system runs a big resistor on the power feed for the fuel pump, which drops the voltage so the pump runs quieter with less output. These pumps are basically the same as the infamous Bosch “070” pump as used on fabulous machines such as the V12 Jaaag XJS, and the VL Commodore “tsutsutsu” turbo. Good for something like 300-400hp apparently, so obviously not stressed on the old 190hp RV8.
Because my car is running an aftermarket LinkECU, but has the standard loom adapted, I had no idea if it was still running the resistor or not. In Effie I bypassed it when the Speeduino was fitted.
The good news was that the fuel pump made lovely buzzing noises all every time now, and you only needed the prime the system once and the car would fire into life without issue. The bad news, was that the hesitation was still there.
The next step here was to check the fuel filter. The SD1 has a particulate filter in the fuel tank, on the outlet pipe (more on that later), and a fine EFI filter in the engine bay. I replaced the EFI filter when I got Tess, so anything in it would have been since then. I removed the filter and drained it backwards, from the inlet, into a clean jar.
It looks like someone poured fine glitter in my fuel. It wasn’t rusty, it was silver, and ferrous. I swirled a magnet around in the jar and this is what came out (looks kinda brown here, but in person it was shiny silver)
Well that’s good and bad I guess. No rust means the it may not have sucked up rust, but metal filings mean the fuel pump is probably poked.
The clicking noise made me wonder, and the glitter confirmed it, the fuel pump wasn’t a happy chappy.
Thankfully I have a spare, original fuel pump. I wasn’t sure how good it was, but it did come alive when 12v was shoved into it.
Before replacing the pump there was one other quick check to do, remove the fuel level sender and check the inside of the tank.
Mine was covered in crud, but that soon loosened when I got the hammer out to remove the retaining ring. The retaining ring has three tabs sticking up from it. I used a screwdriver and hammer to tap it around anti-clockwise with the tabs. There are three cutouts in the retainer, that will line up with three bumps on the tank housing, and when lined up you can remove the retainer
I gave the area a quick vacuum so that crud didn’t end up in the tank.
So, with bated breath I shone a light into the tank and had a look. Well I’ll be. Nothing but clean metal, even on the sides of the tank that I could see. There was some sediment at the bottom of the tank, but nothing major. Unfortunately the particulate filter was in the tank…. but no longer attached to the outlet, so useless. This is a common occurrence with SD1s.
Due to the design of the tank, the only access hole is the sender hole which is too small for an adult hand, and the tank is very deep in this area, so there is no way to reach the filter and reattach it.
Stoked, the tank is all good. I wasnt looking forward to paying the $600+freight+GST for one from Rimmers, which would still need to be cleaned and internally coated.
The terminals on the sender were all badly corroded, so they got a quick clean up, but I also found the reason for the sender reading 1/4 low…. the float had fuel in it! Not much, but enough it wouldn’t be floating on the top anymore. Strangely, there are no signs of any holes or gaps in the seams, so no idea how it got in there.
I did test the sender when it was out, and it seemed to read accurately based on where I positioned the arm, except no matter what, it wouldn’t go over 3/4. I suspect an issue with the fuel gauge or maybe the sender itself, but as long as the rest of the scale is accurate now, I’m not bothered.
With the terminals cleaned, and the float emptied and sealed, I refit the sender with a new gasket ring. I used copious amounts of red rubber grease to lubricate the seal, so the retaining ring wouldn’t catch it. Screwdriver and hammer once again employed to knock the retaining ring clockwise to lock it in place.
Back to the fuel pump, which is the main course in this buffet of goodness.
Replacing the fuel pump is a pretty straightforward process, I just wish I didn’t add another 20L or so to the tank, as the fuel pump is inline under the car and gravity fed from the tank. It lives tucked up in front of the tank, covered by steel plates and in a little rubber/foam housing. It should be bolted to a crossmember that goes across the trans tunnel, but my crossmember was cut off so the stupid exhaust would fit.
I had previously noted that the high pressure hose on the outlet of the pump was looking a bit worse for wear, so wanted to do this job anyway, this just sped it up. I purchased some spare 8mm hose for the pressure side, and some new hose for the inlet side, which is low pressure, so doesn’t need to be special EFI hose.
Since the in tank filter was no good, I wanted to fit an inline filter before the pump. This is also a common mod with SD1s, to try to trap rust before it kills the pump. It may not have been rust that went into my pump, but something chewed it up. This filter may have saved the pump, but oh well.
The standard hose from the tank to pump is 12mm ID. Finding a filter on the shelf with an inlet/outlet of 12mm or 1/2″ is damn near impossible here (You can order them online, such as the WIX 33299, but I needed it quicker than that), so I had to look for an alternative. I ended up buying 7/16″/11.1mm fuel hose from Repco and picking up a Ryco Z153K filter. It has a 10mm inlet/outlet.
To remove the pump I found it easiest to remove the whole crossmember and bracket assembly first, and leave the pump hanging by the hoses. I don’t have any photos of this because it’s a pain taking photos under the car, and the next step got pretty messy.
Being gravity fed, as soon as you remove the feed to the pump the fuel tank is going to drain, quickly. I removed the hose from the pump and directed the end into an empty fuel can. I drained the tank until the fuel started to sputter from the hose, as the little baffle sump in the tank filled and drained. This allowed me to remove the hose from tank and fit a piece of new hose that I had plugged with a wheel stud
Moving to the bench it was time to replace the pump and hoses. The outlet hose was worse than expected. It’s a miracle it wasn’t obviously leaking (although there has always been a strong fuel smell in the vicinity of the fuel pump, but no obvious wetness). Sorry for the average photos.
Pinched the connections from the old pump and swapped to replacement, with some modification as old pump wasnt original (it’s actually a proper Bosch 070, or maybe a “copy”) and uses screw terminals not spade terminals the standard one does. Nice new hose (and not the shitty fake R9 hose)
I pre-assembled it on the brackets to see how it all fit, but you can’t actually fit it to the car like this, you need to do the reverse of removal; hang the pump from its hoses and then fit the brackets
Then it was just a case of refitting it all. Once the pump was back in place, I directed the hose in the engine bay (inlet for EFI filter) into a bottle, reconnected the fuel pump connector and turned the key. It took a couple of primes to get all the air out, and fill the pre-filter, but then it shot a nice stream of fuel into the bottle. I did this twice to make sure there was no more glitter or dirt in the lines, and fit the new fuel filter.
A quick test to fill and prime the filter, and then proceed to spray pressurised fuel all over the engine….. oops. I replaced all the hose clamps on the fuel filter with proper EFI clamps, as the hoses were still good, but I hadn’t got a good seal on one of the clamps. Repositioned and tightened, and she was all sealed up.
The replacement pump is nice and quiet, and makes a smoother whirring sound than the old 070, even with the resistor bypass in place.
I took Tess for a quick drive to see how she was. I was a little peeved off, the hesitation was still there.
I returned home, swapped back to the fuel pump relay, which quieted the pump down further, but it still makes a nice soft whirring sound, but the issue remained, even to the point where stabbing the throttle at idle caused the engine to stall. I tried to restart but it wouldn’t immediately start, so I decided to have a quick look at the spark plugs.
I whipped out all 8 of the plugs, and they were all the same. I cleaned then all with a wire brush and brake clean, and regapped them from the 0.9 they were (I lowered the gap when fitted at recommendation of others), to 1.1. I figure a bigger gap might help have a bigger spark to blast through the carbon on the plugs.
I had to shoot out and pick the wife up from the train, so took Tess to see if tweaking the plugs had changed anything. The car started fine with the clean plugs, but still hesitated. I picked her up and just as we got home she asked if I had given it a good blow out. No, not really, so we went the really long way home… with a decent italian tuneup. The car now revs happily and freely, no matter how quick you jab the throttle. Despite taking care in the wet conditions, because traction, I still put the hammer down and blew them cobwebs out.
I can’t be sure what fixed it exactly, but the fuel pump was not in a happy place, and the spark gap may have been too small. I also suspect one or more injector is weeping/leaking, so that wont be helping. The fuel gauge reads much more accurate now, which is awesome.
The lesson here? If you don’t have a pre-pump filter, and your fuel pump is already sad, don’t run your 30+ year old car low on fuel. It might just be the straw that breaks everything.
As a side note, don’t worry, Le Mini Snicket is still here. I moved it outside the other day and then it proceeded to rain. This was a good test of the new window seals i fitted, as the interior was dry, with no signs of leaks. Success. I’m just getting the money together to take it for the registration inspection, and then we will see where we are.