ozzy

Coming home from work and decided to give the car a nice blast, but within a couple of miles from home the car stopped boosting over 8psi (reads 9psi on my Autometer gauge).

Car was nice and warm as I did a 15-mile cruise along the motorway, followed by another 10-miles of a fast'ish A-road with little corners (so not a lot of gear changes). Get close to home and gave it some stick along a B-road. Blast would only have been 4-5 miles tops before the problem started.

Car felt as if it was hesitating through the gears and then going from 3rd -> 4th after a fast'ish corner, on a short straight I get a couple of big flashes on Knocklink. I back off accelerating (well the corners appraoching anyway) and when I try to accelerate through the left/right bends, the car's lost all it's punch. Tried accelerating again and noticed not boosting over 10psi. Drove home slowly and stuck my head under the bonnet to see if I could spot anything. All the hoses look intact, there's no dodgy fluids anywhere and the engine sounds like it normally does.

Car is a MY99 RB5 (AE801 ECU) with about 70K on the clock. Engine standard running stock boost. Has a TSL de-cat DP, de-cat centre and an STI backbox fitted and air filter/dump valve are standard. All other mods are suspension, wheels & brakes.

Only other thing worth mentioning is the car's running on a new full tank of Optimax. Filled up this morning and the cars down about 42 miles on the new tank (including my blast). I did have a fast run along an A-road into work and I did get a few flashes on Knocklink high in 5th gear. It was on bumpy ground, so I wasn't sure if it was just excess noise or actual knock.

The car hasn't really felt right for a month or so. I've had a few flashes on Knocklink when hitting around 5,000 rpm, so since then I've not been accelerating hard and short-shifting to avoid any knocklink activity.

Other than this mornings run and the problems tonight, the cars been treated easily.

Any ideas on what to check first??

Stefan

drb5

iTrader: (4)

MAF's gone















































sorry, couldn't resist do you have any oc to stick in the tank to make sure it's not just a bad tank full? after that, then the fun begins

john banks

Even with crap petrol it shouldn't do that on your spec.

It probably is the MAF.

drb5

iTrader: (4)

DOH!




ozzy
i have to ask what "sort" of driving you were doing just to see if it relates to when my MAF went? i found that it happened just after consistently on and off the accelerator pedal quite a lot. almost like sort of making the car/engine judder(was waiting for a passing place to emerge), doing this the maf obviously didn't like/didn't know what to do, except break down

ozzy

Cheers Dave, ya smart @rse

Would a ECU reset do anything to help diagnose the MAF? I mean will it run on low boost until the MAF's changed or the ECU reset.

Is it safe to drive it like this (obviously not hard) to get me to/from work?

Stefan

drb5

iTrader: (4)

is the engine light on? i figured if it was the maf, it would be on?

if it is indeed in limp mode, it'll get you somewhere, but it won't be happy and i don't think the ecu reset will help.

ozzy

Haven't noticed the CEL, but I'll pop out and check.

Driving was accelerating through 2nd, 3rd, 4th and then into 5th on a long straight. Not fully foot to the floor, but almost. Would cruise up to the back of a car, then drop the car to 4th and overtake. Although it was hard, I didn't get the revs high when dropping gear and booting it again.

Slightly different on the B-road. Quick change from 2nd to 3rd and then held in 3rd through a few corners. Met some traffic, so kept in 3rd with trailing throttle. Got a gap and only changed up to 4th after a corner - that's when the flashes appeared whilst accelerating towards the next left hander in 4th. Went through the bent, down a right/left in a dip and lost power going up the other side of the dip. Tried to pass another car and it felt like I had got out and started running past him.

Average speeds were high, but I wasn't hammering it all that hard to be honest

drb5

iTrader: (4)

bum deal dood. i have to say when u were in 2nd or 3rd, did you notice yourself just staying in gear, but on-off the accelerator, even just a wee bit? or were you keeping the revs even when not booting it?

ozzy

No CEL and car starts fine.

Over the past week I've noticed the Oil Temp has been higher than normal on cruises. I'm lucky if I see 90+ getting to work on the motorway, but occasionally it's jumped up to around 105. Then in the same breath it's jump back down to around 85/90. My SPA gauge is going back to get the backlight fixed, so I was a bit dubious as to whether it was reading properly. I couldn't see why the oil temp would jump around so much in only a few minutes, before it settled back down again to the norm.

Tonight it did rise when driving fast along the straight road (say 102/104 max), but I noticed it jumped to around 120 just around the time it lost boost.

Coincidence or another sign of trouble?

ozzy

Yeah, I was definetely riding the throttle in gear. Certainly wasn't just change gear, foot to floor until next gear change.

Stefan

drb5

iTrader: (4)

the oil thing doesn't sound too good m8 and as for the last post, it won't help the maf anyway's, i don't think

ozzy

Hmm, not sure if the Oil Temp can be relied on though.

What would cause the Oil Temp to rise for short periods of time? I mean, it was fine this morning and over the weekend

Stefan

drb5

iTrader: (4)

tbh, i ain't got a clue


sorry i don't/can't help any more bud

ozzy

OK, thanks anyway. Hopefully I'll get some more comments.

Cheers,
Stefan

ozzy

OK, just been out in the car. Turned it on and the Oil Temp hit 100+. Jumped around for a few seconds (i.e. 100, 104, 102, 104, 101, etc..) and then settled at 60 - WTF Took the car for a drive and the first 200-400 yrds, it rose to around 100 again, before going back down to around 60.

Checked the boost and it's back to 15psi on my Autometer gauge (over-reads by around 1psi), so it was back to normal

Next 4-miles, it just steadily climbed up to it's normal 85 deg. Stopped at a garage and when I got back in and turned it on, it went back up to around 100 again. I pulled away and within 200 yards it was back to around 85 as I would have expected.

All the way home the Oil Temp was fine, so I can only assume the readings aren't correct - unless someone can explain otherwise.

Stefan

ozzy

ne1 else have any ideas???

drb5

iTrader: (4)

get another oil temp sender and give it a bash m8. first things first really

ozzy

I've spoken to Tony Taylor at SPA. He's asked me to double-check the conections before getting a new sender, cable and gauge.

I'm off to Oz for a month a week on Sunday, so if it can't get replaced before then I'll wait 'til I'm back.

Stefan

john banks

My SPA oil temp gauge flits up far quicker than oil could heat up when the connector is a bit loose. Mine is also going back to Tony to sort the backlight.