16V GTi - Cough / Wobbly around 5k rpm July 24, 2022, 09:47:53 AM Hi. My 1991 16V GTi has recently had service, timing, new plugs, HT leads, and a good check over, and I was hoping it would cure a problem - but hasn't. It drives through the range rev pretty solid but when I hit around 5000 rpm it really has a fit. At best its a hiccup, at worst it almost starts bouncing.Any ideas what I should be looking at next?PS it also sometimes almost stalls when the revs drop when coming to a stop. ie braking at a roundabout, sometimes revs will just drop too low and it will stall.
Re: 16V GTi - Cough / Wobbly around 5k rpm Reply #1 – July 24, 2022, 04:01:46 PM Sounds like a rev limiter, has the rotor arm got a spring on it?
Re: 16V GTi - Cough / Wobbly around 5k rpm Reply #2 – July 28, 2022, 08:40:13 AM Quote from: t2000 on July 24, 2022, 04:01:46 PMSounds like a rev limiter, has the rotor arm got a spring on it?I’m not sure about the spring. To be honest it doesn’t feel like a rev limiter, more like a real problem. Sometimes it doesn’t happen quite the same way; and if I’m brave I can get past the first cough at least!
Re: 16V GTi - Cough / Wobbly around 5k rpm Reply #3 – July 28, 2022, 11:41:22 AM AS 16v is k-jet it could be fuel related, so if you compare the 5000 rpm issue with the low idle there's a couple of scenarios that would contribute to both.Look at Irregular idle with warm engine and Engine will not accelerate. Check for air leaks in the system, splits in the rubber boot, or iffy vac pipes.Lift the big rubber boot on the air box and check the state of the plunger, blow a can of carb cleaner all over if you need to.Also, don't overlook the tiny details, it could be as simple as the o-ring on the idle adjuster screw.Other than that I'd be looking to get the fuel pressure tested at the WUR.More detail here: https://www.vwgolfmk2.co.uk/clubforum/index.php?topic=114.0