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Love the f1. Went to the British gp this year. I’ve been a few times now and it’s mind boggling how they can take corners flat out. Hope u enjoyed the day out
Thanks Rattman.
The transmission appears to shift ok and there’s no odd clunks or noises. in fact I’d say it’s smooth changes.
Is there a way to test to see if it’s slipping?
Anyone? 🙂
ps, can a worn/wearing auto transmission cause acceleration loss? if so how come? as I have a healthy engine (very healthy in fact) and haveevidence to support that, I’ve got to conclude this is a transmission issue? its a15 year old box and its never had an oil change. will the oil definitely be burned causing slight slip and thus power loss?
Hi guys, hope you’re well.
So, a quick recap in that car is slightly down on power. I’ve done compression tests on all 6 cylinders and they’re bang on spec.
it was quiet at work today so pulled car in and plummed in the vacuum gauge straight from the brake servo (and tee’d it in so it was all still plumbed up)……. got car up to temp and at idle it was holding a ROCK STEADY vacuum of 20inHG. Perfect!!!
I then brought the rpm’s up to 3k and held it there…..again, rock steady vacuum of 23inHG. PERFECT! This confirms there’s zero exhaust restrictions, zero vacuum leaks and the engine is very healthy. really really pleased actually.
I blipped the throttle a few times and all vacuum dropped to 0 and came back to a steady 20inHG at idle. i believe this to also be completely normal?
while car was in and up to temperature i got my infrared thermometer out and got one of the mechanics to jump in and hold it at 2000-2500k rpm. i checked the inlet and outlet temp. of both cats. Now, my understanding is that the outlet should be 100oF hotter than the inlet. however, i got similarly odd readings on both cats….
drivers side cat:
inlet 180oF
outlet 135oFpass. cat:
inlet 230oF
outlet 180(ish)oFWould this have any bearing on performance?
Thank you 🙂
Thanks for that. As I mentioned there is soot in thee that I’ve seen but I couldn’t tell you how thick the layer is. I’ve no idea if this would restrict anything.
I’ll borrow my head mechanics vacuum gauge and I’ll post up the results as soon as I can.
Thanks for all your replies 🙂
Thanks guys, I’ll look further in to it. I’ll redo the compression tests also just to be sure.
I had the heads off and manifolds off a little while back. Could all the soot in the exhaust manifold be the actual restriction after 15 years of running? There was definitely no fun blockage but thing perhaps the soot in there could restrict the flow?
Thank you
Yeah I assumed if compression was bang on spec then everything would be good.
Just to add though we are talking about a 15 year old car with 112k miles on.
guysthanks so much for all the positive comments. 🙂
ill look in to that snap on rep for my area! thanj you 🙂
Thanks cap.
its not a vacuum operated one but it’s something to check. can I spray carb cleaner around it and the exh. manifold in search for the leak? like looking for a vac leak?
…I believe this was sold in the states as a ”Catera” but don’t quote me on that lol
Just to recap…
Definitely got no air leaks as I’ve tested for them and nothing leaking.
ICV replaced (I had a spare so thought I’d put it on)I looked at the fuel trims yesterday… car goes in to closed loop as it gets up to temp (as expected) and o2 sensor switching nicely between 0.12v and 0.82v.
[quote=”cap269″ post=139396][quote=”Webby the Bear” post=139381]… and that leak is causing the O2 sensors some fuel ratio problems hence causing the lumpy idle. After a few minutes the heating up closes the leak and that’s why my idle returns to normal. [/quote]
The only problem is, the O2 sensor data is ignored by the computer until the engine is warm and goes into closed loop operation. Your issue occurs at cold start, so O2 sensor data wouldn’t factor in.[/quote]
That is an excellent point!!!
Thanks for that.
As I’ve got no vac leaks and I’ve cleaned my ICV I’m wondering where to go now :unsure: