GTI - Yep bolts arrived and the car is back together and running, thanks very much! Still takes 4 or 5 goes to cold start though as usual before it'll idle and not stall! Pigbladder - yeah, a while ago I checked the head sensors with my multimeter and all three gave the same readings as the engine warmed up. I assume that means they are all ok as it's unlikely they'd all fail, plus the temp gauge works from one and that's fine. I also cleaned up the wiring and fitted new spades to them all. I'm convinced now my problem is a fuel related one as the car started and ran so well after I'd cleaned that fuel line out. Perhaps the fuel pump is a bit weak or the accumulator knackered? I had a look under the car while running and there are no leaks or dampness in the fuel pump area (whole thing is very dry and rusty looking!) but the fuel pump is quite noisy, not excessively so though really. Any more ideas of things to check before I try and get hold of a second hand pump and accumulator from a breakers yard?
someone mentioned try checking the fuel pump wiring for dirty contacts..thats something i will look at on mine asap have you had the c/o checked after youve fiddled with it? mine shot up to 10% last year after id been tinkering
Fuel pump wiring - do you mean where the wiring feed actually joins the pump under the car? No haven't looked there, will check it out when the rain goes off. Co - no, not had that checked. I haven't altered the mixture screw or anything though, will messing with the fuel lines, idle screw, blowing out that return line etc have affected it?
with my car , doing almost anything to it will through the mixture out...maybe worth trying to get freindly with somewhere with a gastester did you try a spare wur then? when its doing its stalling stuff..will it run if you re start with lots of throttle? any black smoke??
No, didn't try swapping the WUR in the end as it ran so well after I blew that line out so I assume the WUR is ok. When starting there is nothing you can do to prevent stalling for the firs few goes, any attempt to rev the car just results in a misfire then it stalls anyway. Pressing the throttle during the 'chugging' phase after it actually starts just causes the revs to plummet as if it's choking somehow, then it'll stall - you have to let it chug away trying to find a decent idle for about a minute then it's alright. No black smoke that I'm aware of, smells a bit of petrol but that may be 'cos it's always in my (small) garage when I start it up so not that much space for air flow?
stu, as with pig, i'd seriously recommend checking your fuel pressures before anything else. just a small tweak to the wur, or fpr can make a big difference. just as does a small tweak to the co screw.
Pigbladder - yep, tried unplugging csv a while back and it made starting even worse, might be worth trying again now though since my recent tinkering. GTI - good info, looks like I'll have to get myself a gauge and suitable fittings and get the pressures checked out. Where's the cheapest/best place to get a suitable gauge?
Ok thanks, will have a look on there. I jacked the car up and had a look at the pump, filter and accumulator. The filter is nearly new, had that done a while back, the accumulator looks rusty as do the fuel lines but they are leak free from what I can see. I tested the fuel pump electrical connections and when you turn the ignition on (when the pump would prime if connected) the connections get 11.6v maximum - is that correct? On that thread on Vortex the guy with the 'tip of the day' regarding blowing out the fuel lines seems to think there is more chance of the FPR will have failed than the accumulator? What could 'fail' on the FPR, it looks ok, clean, not blocked and with a new o-ring. Edited by: Stu
that voltage sounds fine. i.e. battery voltage minus some small loss from the wiring resitance. the fpr spring could have gone 'saggy' with age. only real way to tell is with a gauge though! well worth the money if you ask me!
Yeah, think you are right on the gauges, I will have to get one. I'm sure my Dad has one actually but I don't know if it'll have the right fittings or be suitable for my car, will check and see From reading up a bit on K-Jet last night and looking on Vortex it seems a dodgy FPR could cause the car to temporarily cheer up when the return line was cleared out the other day and then revert back to being a pain in the @rse again afterwards! Will get hold of a gauge and then find out what's actually going on with it! I bet it's something simple I've overlooked in the end though!
Right, I tried swapping out the fuel pump & accumulator assembley yesterday (got a secondhand known good one). Unfortunately the problem with cold starting still exists, the car acts exactly the same which I suppose means my original pump & accumulator was fine! What next? Best get a fuel pressure guage and check the system out that way - I'm determined to sort it! I did get the fuel lines from metering head and back too in with the pump but haven't swapped them yet - do you think it'd be worth swapping them? Cleaning my return line the other week with an airline did seem to have a temporary but positive effect on the cars starting. Help!
Very interesting topic, so I thought I'd make it a 'sticky' for a while. I personally had a cold start issue with my first 16V when I first got it. The problem was due to a faulty wiring connection to one of the three temperature senders on the side of the head. Trev
About this temp senders... I test mine the other day, and I got something like 300 of resistence in the ones on the right side of the head, and 260 on the back(I don't know what temp the car was at). The difference between them can make something wrong with the ISV, cold starts?
hidro...the 3 on the end of the head should all read approx the same ohms for any given temp, if one is way differant replace it
Yep - regarding the temp senders, as Pigbladder says the three on the side of the head are identical so should read the same, the one on the back of the head (green wire) is a different type so different reading.
Sounds like this is the way to go, certainly need to get a gauge on there and check the readings out. The fuel pressure gauge needs to be the type that you plumb 'inline' rather than one with just an input feed doesn't it? Will probably get the one that GTI recommended earlier in the thread
