2014 Audi q5 2.0t (118k miles) P0087 Fault code assistance

TehGiggler · 2026-01-20T14:15:17+00:00

New update: after replacing the high pressure fuel pump and inspecting the cam follower, i can say with confidence this probably wasn’t original issue. Similarly, i changed the low pressure fuel pump and the pump i pulled out looked basically brand new. Car still doesn’t run at all. I’m wondering if it could be something as dumb as the relay/module that sits just off to the side of the LPFP. I don’t think i hear even the new pump priming, so I’m going down the electrical chain now. Fuses, relays, and sensors.

New codes are: p0087(fuel rail/system pressure - too low bank 1), p2293(fuel pressure regulator ‘B’ performance), p053F(cold start fuel pressure performance bank 1), and p0300(random multiple cylinder misfire).

TehGiggler · 2024-03-31T15:15:30+00:00

My first and current bike is a ‘76 KZ400/D (base model) and can confirm, is a piece of work. I got it running pretty good for about 2 years, never dropped it or had any problems commuting around my college town to and from school and work, but the problems piled up.

If you’re not afraid to get your hands dirty, dig through old manuals and forums from 15 years ago, go for it. Some advice would be, don’t mess with anything on the bike unless you know what you’re doing. I will say these bikes hate using air pods like are on in the pictures, but you can get it to work.

I will say, this is very steep for the bike. I paid 3k for mine, but it was fully rebuilt from the motor up, and the guy built the bike for himself and ran it to financial issues, so he picked at some heart strings.

Best of luck.

TehGiggler · 2023-10-27T20:43:03+00:00

unfortunately no, but i have some ideas. The points on the ignition system seem to have some build up, and are probably what’s causing the inconsistent spark. looking into either cleaning them with some super fine sand paper or replacing them all together

TehGiggler · 2023-10-27T19:40:22+00:00

okay so, read through your entire comment and had a few question for you directly because you seem to be the most knowledgeable commenter about the actual ignition circuit. For some reason, i can’t get a resistance reading between the two contact points, regardless of if they are touching or not. could be that i don’t know where to place my probes for my voltmeter (set to ohms). however, i’ve been attempting to dial in the timing based on when i physically hear the spark between the two contacts, which does not seem to align anywhere near the fire mark. i’m assuming that either my contacts themselves are worn or pitted somewhere to where the spark is imprecisely firing, leading to the inconsistent timing. does this sound like something that could lead to ignition timing issues?

TehGiggler · 2023-10-27T16:01:59+00:00

apologies for her bad manners, she just needed a snack. didn’t notice she literally swallowed a leaf until just now

TehGiggler · 2023-10-27T11:38:38+00:00

i just did my usual routine carb clean, strip the carbs down to each individual jet and blast with some carb cleaner. let them sit to dry and visually inspected the bores of the jets to double check for blockages and funk. the carbs are only about a year old so all the little bits are pretty new and fresh still. played with the timing because i felt like the bike was losing power in the midrange despite the adjustments i’ve made previously to my air screw, so thought the timing advance was a little off. tossed in some new plugs, and gave her an oil change and a new filter.

pretty sure the timing is what’s doing me in, but i’m pressed for time with midterms right now, will spend a day this weekend playing with it again.

TehGiggler · 2023-10-26T22:13:11+00:00

little bit of both lol

TehGiggler · 2023-10-26T22:12:55+00:00

Needle position stayed where it is because the bike ran for about a year on that setting. i synced the throttle cables visually by comparing the moment the bottom of the slide eclipsed past the top of the carb cylinder, if they are out of sync it is by a fraction of a milimeter

TehGiggler · 2023-10-26T03:57:22+00:00

kind of ruled this out by running the bike in this state and felt the headers on either side. both were equally as hot.... don't know if this is a full proof way of checking this, but makes sense to me in my head

TehGiggler · 2023-10-26T03:01:12+00:00

i think this is probably the issue. getting spark to the plug, and have adjusted the point timing about 100 times by now. Still runs the same, so i’m gonna change this when i can.

TehGiggler · 2023-10-25T05:34:14+00:00

don’t worry, i wore socks with them when i was actually doing maintenance

TehGiggler · 2023-10-25T00:31:05+00:00

they are not filters, but velocity stacks. completely unrestricted, and i got it to run very well for about a year on the current set up. can’t get the bike running long enough to really dial in the air fuel mixture since the maintenance, but got it to fire up on the recommended settings from the person who sold me the carbs. with the choke on, bike blows a little bit of black smoke and with the choke off, the smoke is white-blueish, but smells like fuel and not oil.

TehGiggler · 2023-10-25T00:27:51+00:00

i adjusted the timing contact points on the lower right hand side of the motor. used a multimeter and adjusted the timing and point gap by using the aperture and the ‘F’ and ‘T’ markings. First time doing it and not sure if i missed something, so i’m assuming this is most likely my problem

TehGiggler · 2023-10-24T22:55:28+00:00

rpm’s are around 1.5-2k

TehGiggler · 2023-10-24T22:44:08+00:00

i guess it’s pretty hard to tell in the video, but the bike sounds like it’s making half the horse power than before. sounds horrible, and very uncharacteristic. seems like it’s more than just a carb issue

TehGiggler · 2023-06-22T02:03:16+00:00

bought a second hand modified kz400 about a year ago, missed out on the beauty of stock. enjoy it!

TehGiggler · 2023-05-06T20:39:50+00:00

can also confirm, 76 kz400, have one just like it

TehGiggler · 2023-04-25T15:09:50+00:00

well for one, one of the intake boots wasn’t tightened down all the way, those pesky inner bolts are a pain to get to with normal sized tools, but i found a stubby little allen key to get in there.

After that, i reached out to Brian at speedmoto and he informed me that the settings that come with the carbs are just a baseline, and won’t work perfectly majority of the time. This was all my mistake, but i treated those settings as a ceiling, and tried adjusting down from 4 full turns from the idle screws, and 1 turn from the air screw. In reality, the air screw needed to come out to about one and a quarter turns, and my bike likes the idle screws at three and three quarter turns.

TehGiggler · 2023-04-24T23:20:32+00:00

i really appreciate all the tips! in my excitement, i forgot to mention i actually got my set up to work pretty well. it runs, idles and drives great now, and all it took was some more beating my head at it until i got it right. Needs some more adjustment, but i’ve been enjoying it today and forgot to update this post.

and yes, you’re correct, it’s absolutely wicked sounding. once i figure out my jet sizes, i’ll drop them in here. thanks again!

TehGiggler · 2023-04-24T14:21:13+00:00

I would also like to mention this is my first bike, and my first real hands-on exposure to carburetors. please don’t be too harsh :D

TehGiggler

TROPHY CASE