flat spot/rev limiter when accelerating hard round a left hand turn.
Any one ? Fuel pump?
Thanks in advance.
Lance
Soggy engine mounts and a split in inlet hose opens up on left handers?
Wow..
I love this forum, where else can you get that kind of insight!
Thanks, I have a look tomorrow.
L
So I'm still confused as to where this leak/split could be..it seems to have got worse..started rough idling..pops..
power loss usually around 4.5k but can be higher intermittent ..also now started to hear a bit of a low end knocking when warm. Although I hear that more in the cab than in the engine bay?
I'm thinking of changing all the pipes, does anyone one have a break down of all the sizes? and maybe the main culprits? Also what about the carbon canister, or PCV..
OK thanks for the help in advance,
Lance ;)
I was suggesting (and still think) there might be a split or leak in the air inlet ducting somewhere after the MAF.
So I'd suggest perhaps taking it all off between the throttle body and the airbox and inspect.
If not there then the inlet manifold which is much harder to inspect but I guess you could check the nuts and bolts securing it aren't lose.
As for the knock, wouldn't be an air leak. Can you identify where it's coming from?
There is a plastic baffle in the inlet manifold, which has been known to come adrift. It can cause the symptoms you describe. If it's floating around in there, the effects will be inconsistent and it would rattle.
This is not common but it does happen and you can find examples on the web.
I'd follow Jonbill's advice first.
EDIT: A loose lump of plastic in the inlet manifold would also explain why you hear the rattle more from in the cab. (Considering that the manifold is very close to the firewall.)
You mentioned pops. This still indicates a bit lean running (I.e unmetered air entering the system). So that would be post-MAF.
Hopefully Jon's advice flushes it out
Thanks everyone, I'll have a look Sunday and get back. I have a short home made intake, 45* silicone and the maf housing from the oem with a Ramair filter behind the battery. So now I'm thinking manifold unless I've not put it back on properly..
Also when I changed the alternator a couple of months ago I discovered that the long bolt was missing?? As I'd been driving around a while with just the short one holding in the alternator before I'd changed it, I thought it would be OK until I sourced one, but I'm having difficulty finding one..Anyone know where I can get one?
Thanks.
Lance
Quote from: tommytoneism on November 9, 2018, 23:38
Thanks everyone, I'll have a look Sunday and get back. I have a short home made intake, 45* silicone and the maf housing from the oem with a Ramair filter behind the battery. So now I'm thinking manifold unless I've not put it back on properly..
Also when I changed the alternator a couple of months ago I discovered that the long bolt was missing?? As I'd been driving around a while with just the short one holding in the alternator before I'd changed it, I thought it would be OK until I sourced one, but I'm having difficulty finding one..Anyone know where I can get one?
Thanks.
Lance
Rutland MR2 or D. Sloan,
Your fuel trims, maf values and vacuum can help you figure out where the leak is. If you have Torque Pro (heavily recommended bit of kit for the money).
Graphs for the win.
Could be coil pack issues. You can check for misfires in Torque Pro as well.
Could be a fuel pump/injectors.
Basically, there's a number of possibilities. Some metrics will help flush it out. Saving that, trial and error.
Your intake is suspect being DIY. Incorrect MAF readings can easily cause these symptoms.
Quote from: shnazzle on November 10, 2018, 09:12
Your fuel trims, maf values and vacuum can help you figure out where the leak is. If you have Torque Pro (heavily recommended bit of kit for the money).
Graphs for the win.
Could be coil pack issues. You can check for misfires in Torque Pro as well.
Could be a fuel pump/injectors.
Basically, there's a number of possibilities. Some metrics will help flush it out. Saving that, trial and error.
Your intake is suspect being DIY. Incorrect MAF readings can easily cause these symptoms.
Yes but none of the above explains why the problem is sensitive to lateral G and why there's a rattle. By all means do a diagnostic but......
So I took all the intake of today and made sure it has no leaks, also cleaned the MAF. Went for a blast with the roof down and it still feels starved at 4.5k-5.5k in 1st and 2nd..3rd is fine. Sometimes left handers sometimes straight ahead. Then in the last few miles to a sharp left hander floored it and it was OK??
Also the rattle wasn't there when I pulled up but started as I lifted the roof?? Only on idle and goes away when revved.
Is the alternator bolt missing anything to do with this?
If it worse case scenario and it's the baffle in the manifold, is it an engine out job?
Thanks again.
Lance :)
I'd get bolt and put it in. Not the most likely culprit, but the alternator does earth though the engine??? May not cure the issue, but it should be done.
you could lash up something to use as a stethoscope and listen to the inlet manifold when it#s rattling. Or buy a stethoscope (very handy and cheap!) and have a good listen around.
The inlet manifold can be changed with the engine in. It's a pita (I've done it) but it can be done.
With luck, your ECU has relearned after the MAF clean and you've cured it!!
Thanks Carolyn, you're a star. It'll be next Sunday now before I get a look.
Thanks again,
Lance
The saga continues!! So it has been driveable even with this problem, as I've needed to go out a couple of times this week.
Yesterday however just as I was driving into the village with some hard acceleration, it really started to play up and kept stalling. I managed to park it up, just!!. I came to it this morning to move it round the back so I could work on it and it starts but then immediately stalls. I'm going to try a diagnostic with TORQUE in a bit when my phone is charged,
but anyone got any ideas before I do? Is there any way it's a fueling thing , filter/pump ? Thursday I had to nip out and it ran fine till I got to the petrol station, put about 3 gallons in and almost as soon as I pulled out of the station it started playing up at 1k-2k revs and then it stalled. I managed to get to where I was going and back again but it wasn't quite right. I've got no CELs or battery light, I might just try switching off my DASTEK and see if it runs ok on stock ECU..maybe?
Thanks Lance
Ah - running a piggy back!
Yep, I'd take it off and see how she does. Could be a failing connection.
Ah you didn't manage the Dastek!
Yes definitely worth unplugging. Don't talk to me about Dasteks... :)
Hi all,
OK...so I pulled the dastek out of the equation and it made no difference, car would start and rev to 2k and then stall. I did loose my plastic cover about 6 months ago and I was wondering if that may affect anything..? injectors? So I waddle the electric connectors to the injectors and whether it was just because I revved it a little harder I managed to keep it up above 4K. I couldn't keep it steady though I managed to keep it going above 2.5k as it got warmer. I noticed a burning smell and could see the neighbours were getting annoyed by my antics, so I let the pedal go to see if it would idle ..but it didn't. went to check out the burning smell and the back-box was really really hot... the rest of the exhaust apart from the main cat is heat wrapped, and I have a toyosport manifold.
So what do think? I'm lost.. :-\
Thanks again
Lance
Hard to know if it was hotter than it should be, but if it was, it might indicate lean running. Which is consistent with the air leak theory and I think not consistent with baffles blocking the induction.
Really I think you need to capture and analyse the data from the engine to see what MAF, fuel trim, lambda etc values are.
If you don't fancy that, you could pull the spark plugs out and have a look. If it was running lean during that session they'll be bone white.
Yes, running lean on sensors 1 and 2.
So if air is getting in and it's not at the intake.. where are the likely culprits? If I need to change any or all of the vacuum hoses, has anyone got a breakdown of the sizes?
Thanks again,
Lance
There are 3 hoses going to the intake, Worth examining them for leaks/cracks two large ones from the cam cover and one small one from the little solenoid valve that connects to the canister (clipped to the side of the big rubber main inlet tub). You can measure their ID while you're checking them.
Doh!! What device could be sensitive to lateral G and cause excess air in the intake??
PCV valve!!!
A truly duff PCV could cause your symptoms, though. I know Dean at Rutland MR2 has some new ones. They need to be replaced every 30,000 miles or so....
It's on the left hand end of the cam cover, closest to you as you look at the engine. Examining it to see if it's working doesn't work. It relies on very specific spring tension, once that's lost, it's buggered.
Could be a hose, though, so examine them first.
I just put the PCV in and no difference, should I have reset the ECU?
Ta lance
No don't think so. Did you say it had a new MAF? What kind is that? Can you share the values its outputting? Wouldn't be the first new MAF to tell lies.
no , no new MAF. I think it has to be hose? :-\
If it's not a hose!! what are the other possibilities? I know the previous owner put a resistor in place of the back box sensor, and looks like a crap job? but surely if that was becoming disconnected I'd be getting a CEL wouldn't I?
I'm personally a great hater of the resistor "mod". But it shouldn't (!) cause these symptoms.
Boy, this one is being stubborn isn't it?
If the car was in my workshop, I'd start with an thorough electronic diagnosis, then (if nothing shows up) I'd be systematically unbolting/ removing bits until I found something that wasn't as it should be...
The answer is in there somewhere.
I suspect a failing fuel pump, seem similar symptom's on other vehicles. The rubber diaphragm inside the pump is failing causing lack of fuel pressure.
Loss of power/cutting out when accelerating. Cutting out while under high revs, will eventually fail completely.
just my thoughts ... <- :withstupid:
Quote from: moredun on December 2, 2018, 21:07
I suspect a failing fuel pump, seem similar symptom's on other vehicles. The rubber diaphragm inside the pump is failing causing lack of fuel pressure.
Loss of power/cutting out when accelerating. Cutting out while under high revs, will eventually fail completely.
just my thoughts ... <- :withstupid:
Tempted to agree if leaks are not being found. It also explains the lean conditions
Never heard of a fuel pump failure on our cars but it sounds logical to my uneducated ears.
Quote from: tommytoneism on November 11, 2018, 17:12
Also the rattle wasn't there when I pulled up but started as I lifted the roof?? Only on idle and goes away when revved.
Is the alternator bolt missing anything to do with this?
Thanks again.
Lance :)
The alternator will be flexing on the remaining mount and possibly hitting something to give you the knocking noise when accelerating.
This needs replaced ASAP before the remaining mount breaks
<- :withstupid:
Thanks for this all,
So I took the vacuum pipes off and found a few little cracks at the end of the PCV one. I cut it clean and replaced all and tightened well. No difference.. The car starts, revs to 2K and then just dies, if I apply the pedal it dies quicker. I've ordered a new Pump/Filter kit etc, so I'll swap that out next week. I did find a similar thread about the arch bishops car : https://www.mr2roc.org/forum/index.php?topic=65086.0 that turned out to be a dodgy MAF.
So once I've done the pump, I'll take my intake off again make doubly sure there's no leaks clean the MAF and the fingers crossed. If no joy, then new MAF. Are there any other possibilities?
OK thanks again everyone for your help.
Lance.
Could you share what your MAF values are at different throttle positions?
It really sounds like it's not getting either any fuel or any air.
It fires up, burns through the air in the manifold and dies.
You press the throttle, it adds more fuel, run out of air quicker and dies.
All very odd.
Is it possible to give you the MAF readings if I can't start it? I'll have a look tomorrow.
Yes all very odd, got to keep on keeping on!
L
Quote from: tommytoneism on December 8, 2018, 16:05
Is it possible to give you the MAF readings if I can't start it? I'll have a look tomorrow.
Yes all very odd, got to keep on keeping on!
L
No, rather think it needs to be running one way or another.
I'd there any way you can record or broadcast Torque or the likes while (try to) run it?
OK! Had a bit of a breakthrough today, got a new can of carb cleaner. Took all the intake off again, cleaned the MAF cleaned the TB, had the battery off for approx 30 mins. All back together fired up and ran. Went out for a drive and no problem until it warmed up then still had the flat spot from 4.5k upwards but it didn't seem as aggressive. Kept driven about, quite hard and then it cleared. It didn't come back on that trip. So came home to have a look at my Torque data, but realised I'd not been recording it all!! dooh! So went out again, all fine for a couple of miles and then started flat spotting again around 4.5k upwards when I changed up say from 2nd-3rd the flat spot would be there almost straight away at 4k.. Then after only a mile of that, I revved the engine out of gear to see if it would do the same ..and it didn't, and then from there on in it had cleared and didn't do it again for 10 miles or so.
So this time I've recorded some data, but to be honest I don't know what I'm looking at, and it seems incomplete. Also this is without my Dastek back on..but I'm pretty sure that's not what was causing the issue. So if anybody would be up for having a look at the csv file and seeing if there is anything obvious? That would be cool.
Also I now have a walbro 255 and new filter. Question is it worth fitting? will it help or is it possibly overkill?
Thanks again
L :)
OH.. forgot to mention the knocking has gone? which I'm putting down to my makeshift heat-shield round my air filter :-[
Good to hear of the progress!
I think the big new clue is that the carb cleaner made a difference.
I've re-read the entire thread to see if you removed the throttle body and cleaned it on the bench. It would appear not.
You can't properly clean the bugger on the car. If you haven't removed it, I suggest that you do.
If you have, the only remaining item is a new decent quality Maf??
Perhaps another factor is that the inlet hose has been off and on again, so possible leaks at the clamps have been fixed/changed.
I'd like to take a look at the csv file. Can you put it in a Google sheet maybe?
I'd love a neb at those csv files as well
A neb?
here you go : https://docs.google.com/spreadsheets/d/1o3QgLFKRQkzHgR7ub2uFiHhqxfQ3JkjJjbV8d0Ji6Fs/edit?usp=sharing
I deleted the columns that just didn't record anything, which I was confused by, because I thought there should have been more. I'll probably try another tomorrow.
Also what do you think about the fuel pump upgrade? worth doing or will I not notice any different?
Thanks again everyone, and yes Carolyn I'll have a better go at the TB now you think that may have made the difference.
Thanks L
Few observations at first glance.
1) MAF values seem a bit erratic at best
2) you definitely had knock at 4194ish rpm once as it pulled 4deg timing. That's a fail-safe in action.
3) MAF flow of 110? That's rather high. Impressive if real!
4) at one point it suddenly pulls a lot of fuel. A lot. And the intake temperature is 36deg. That's awful high for these ambient temps.
All in all... A bit suspicious on the MAF
That's great thanks for that.
Yes I have a new MAF on the way.
Thanks again everyone, invaluable resource! :notworthy:
Another hint at that is that your timing figures just aren't right. It's advancing too much at idle. If it was caused by fueling then it would be due to overfueling, not underfueling like we suspected earlier.
And this can in turn be traced back to your throttle body or IAC valve.
Maybe see if you can source another one from a breaker? Then you can quickly replace it and see what happens. Then you can service yours properly and swap it back when it suits
Good fun this!
Ok so I tried a new MAF, mad no difference, possibly slightly worse? So cleaned the other one again, took off all the intake again, gave the TB a good soak with carb cleaner. Cleaned the evap. Also put back dastek. So here is a link to the new torque data. It did it once maybe twice on this trip and seemed to sort itself out.. So I don't know..
Question, if the IAC valve is dirty/gummed up because it rocks/pivots could it be this that is causing it when taking a left hander? That said the last left hander of that trip..no problem.. so don't know..intermittent?
Thanks again for taking a neb! :
https://docs.google.com/spreadsheets/d/1VLEeFqelbb8-bmM7kqes7-Oi5avx6JPoXM4aSWq5RS0/edit?usp=sharing
Lance
Hard to see anything wrong in those logs.
So, some more observations;
1) IAC seems to not be stuck as when cold you're idling at 1400ish which then drops to 750ish when at operating temp. Timing is also correct so it's using the IAC to achieve that, not compensating with timing. This also suggests the TB isn't stuck open. It's a pretty strong magnet so cornering really wouldn't affect it.
2) it warms up correctly
3) MAF values seem to match load
4) still some odd excessive fuel trims but no maf values to associate them with.
I'm at a loss. Fuel pump swap would be my next trial (easy to do). Then injectors.
If you've got torque, download the torque knock detector extension. Do a few runs with that with a warm engine. It monitors OBD2 knock parameters.
Also, log misfires. You'll find them in the parameters to choose.
Have you undone, cleaned. and re-connected the various earths? Two on the left-hand end of the head, the crankshaft sensor (common cause of mysterious faults, down behind the crank pulley), the main earth on the gearbox?
Have you put the missing bolt into the alternator (it has to earth too!)?
If it were my car, I'd stop throwing money/parts at it for now and do the basics (Including throttle body off and properly cleaned).
Will do Carolyn, I think you're feeling my frustration. (:< >:) Today though I did a trip of about 25mile, bit of traffic and bit of motorway, didn't real drive it hard, and all felt very normal and smooth. Then just as I was coming into the village to park up, gave it a blast to 6K and seemed fine until I pulled up and the idling was a bit odd like it was breathing in gulps of fueling sporadically.
Anyway I will probably change the pump/filter and have a look at the float, a it seems to stick now again.
Ok thanks again. I would have had this all done a little sooner Carolyn, only I have no parking till the weekend when I can pull it round the back of the shop next door.. My next house will have a garage, promise. ;D
Some more data I have taken whilst at idle. :
https://docs.google.com/spreadsheets/d/1CzGCD9uUSXYf9pWr9_lr1_5P01Qhh__UqeQ7AIYgUJ0/edit?usp=sharing
I went out earlier and it was still running a bit rough and gulping when idling, then it threw an engine fault, running too lean, and when I got back, that's when I took this idling data.
So come Sunday I'm going to :
1 . take off the TB, clean properly including the Idle valve,
2. Check all hoses again,
3. Check and clean all earths,
4. Put new bolt in for alternator mounting,
5. Change fuel pump and filter.
Can you think of anything else I should check/clean?
OK thanks again, everyone. It's good to not feel alone with this! ;)
Sounds like a good plan.
I might be wrong but my recollection is that MAF value should be just over 2 at idle.
If right and your MAF is good then I think it still indicates you've got an air leak after it.
I'll check mine later and see what it runs at...
Maf values look OK to me. Everything checks out for idle.
Just the top end (wide open throttle) look a bit high.
Cold idle has a higher rpm and more advance with a bit richer mix, which is spot on. Then when warm timing reduces to 14.5-15 and rpms to 750-850 with what seems like stoich. fueling. So that's good.
I had one more thought; it seems that when you let off throttle suddenly is goes into a sudden rich condition and inversely when you floor it, it goes lean (which is when you had your knock). This is as expected but the ecu compensates. Well... It SHOULD. But on yours it seems to struggle.
The only way the ecu can compensate for that is by reading the TPS (it's really the only time it uses the TPS signal much). So... What I would try, to isolate the TPS, is do a full run in 3rd on the motorway from as slow as you can (pulling onto motorway) all the way to 6k rpm or so. But do it very progressively. That way it won't use the tip-in map for sudden throttle.
If it pulls fine, the TPS would be my next bet before all else.
PS if it is the TPS then I've got a working one for you. For free
That's brilliant thanks, I'll keep you posted. :D
:-[
Ok so seems to be sorted, but I'll explain how I got there. Little bit embarrassing :-[ because after my frequent removals of the air intake (DIY job having used the original MAF housing) and saying that I couldn't find the leak...Well, :o I found one. As most of you will know, where the fins are, and where in the OEM set-up meets the filter box, there is a sliding movement across the pipe just before the box where the two meet. This had play on mine as I'd left this section in when I cut it up. So with certain lateral g, it would let air in. Admittedly this is before the MAF but obviously enough to confuse it. This is why on a couple of occasions where I had floored it coming in to my village , it had moved a lot more, and suddenly started coughing and stalling, and then I couldn't start it!
So I re-cut the mounting and made sure there was no leaks.. put it all back together and it ran great, but 15 miles or so and it just did it once again..not as bad and only once.. I then read another forum feed about a similar issue where he believed it to be the fuel pump, I was going to change my pump but when I took it all apart I realised you had to do bit of modification of the housing to get the pump in. So I just settled with changing the filter and left the original pump in. The other thread had mentioned that he also threw in some redex and v-power. So I did the same and changed my map on my Dastek for the v-power...and hey presto..it's going like a rocket and no bogging down.
So here are my conclusions...
1. the worst of it was coming from changes of air into the intake because of movement from lateral g.
2. Possibly some crap through the fuel system and injectors
3. and, but not sure, possibly a fault in the normal unleaded map caused by running it with the first fault..?
The knocking noise, which came and went, I pinpointed to the charcoal canister..
Thanks again to everyone that has helped me through this :notworthy:, and I hope this helps someone else. ;)
As a suggestion, it might be an idea for those who can run off spreadsheets of data of their cars running well, to start a new thread and post, so that it can be a source of comparison..what do you think?
Thanks again,
Lance
Woohoo! Good news. Glad it's sorted.
If the mr2 had a proper refresh rate on the obd2 readings we would have noticed the MAF readings being erratic. Unfortunately, the granularity is piss poor and you have to be lucky to catch something.
A leak that close to back of the maf might as well be a leak in front of it. It disturbs the airflow massively. That mixed with some bad fuel and there's your misfire.
Onwards and upwards!
Glad it's sorted. I knew it was an air leak :-)
:'(
I pulled into the garage the other day to fill up...no high octane.. so normal in, switched map back to normal fuel..problem started again!! just craps out at 5k..but it's intermittent! doesn't do it when it's cold! So when I could I put v-power back in,, switched map to high octane..still did it!! :'(... intermittent.
What's going on..! :-\