Running problems, at a wits end please help.

[Mav122]

..damn. I am slowly getting rev3 bits, I have injectors and knock sensor I just need the rest. 90% solved problem as well now. I started checking for vacuum leaks again and took my manual boost controller off in the process to return boost to stock and hey presto car ran good as gold at idle cold and hot . I drove the car and it hits a brick wall at 5psi boost. Second gear with foot down at 4000rpm and you can hear the turbo spooling but it will only goto 5psi and the car won't pick up. any suggestions...

Im frankly over the moon that the car is now driveable at all. weird that a small spring and ball type boost controller gave me so much of a headache. I remember on the way home (After I bought it) that my boost gauge was showing 20psi. My cylinders were slightly purple when I changed HG so im guessing it had been running lean at that amount of boost and burning cylinders a bit. dont know if that was faulty valve or controller knob wound too tight.

[stuMR2lee]

Sounds like you are getting somewhere. I know my way around most of the MK2 (suspension, brakes, etc.) but Engine's, especially the Turbo (only had it 6 weeks, NA's before that), are a bit of a magic art at the moment! You should come along to the Essex meets. Have you reset the ECU after your tinkering?

[Mav122]

ok just found an article that says the MR2's wastegate is set to 7psi and if boost cut is needed the VSV closes controlling the wastegate so the car only makes 7 psi. I have the VSV side of the wastegate blocked off as I had a MBC so I am assuming this is why I am seeing 5psi of boost (looks like cheap boost gauge, is probably 7 psi ish). Can anyone confirm my theory? If this is correct I assume the VSV side of the wastgate normally bleeds air off to the inlet manifold or somewhere until 14psi is reached thus acting as a boost controller itself bypassing the wastgate until a problem occurs where it needs to shut the vsv so the car will only make 7psi, is this correct?

[Mav122]

I used to go to the essex meets with Mark and lynn all the time in my Mk1 Mr2. I put a supercharged lump in it and kept up with the turbo guys on the meets . 180bhp in a mk1 = lotta go with no weight. I was trying to get the car ready to go to this months one but failed. I believe it is hatfield peveral they meet now.

[stuMR2lee]

I used to go to the essex meets with Mark and lynn all the time in my Mk1 Mr2. I put a supercharged lump in it and kept up with the turbo guys on the meets . 180bhp in a mk1 = lotta go with no weight. I was trying to get the car ready to go to this months one but failed. I believe it is hatfield peveral they meet now.

Yes that's right 2nd Thursday every month. Mark & Lyn are still running them. There's a couple of us go from this way. Hopefully yours will be sorted soon. The MK1 sounded good I bet. Don't see many around. We've got a MK3 as well, very good handling but not the power in straight line.

[stuMR2lee]

http://www.sopertek.co.uk/mr2/mods/engine/index.htm

This info on the vsv looks interesting. You probably already know this stuff though.

[Mav122]

I considered getting a mk3 and putting the 190 bhp celica version of the 1.8vvt in it but thought why bother when for the same money I can get close to 300 bhp in a mk2.

[Mav122]

Ok I checked the two hoses to and from mbc and they were a-ok, no leaks. I re-installed mbc and the car ran badly again. Without the mbc I only make 5psi boost and the car still mis-fires. Its like it hits a brickwall acceleration wise. Im confused as hell. Maybe I should keep going down igniter or distributer faulty route? There are still no DTC's and I have checked all sensors with multimeter and all are a ok. Ive calibrated AFM and TPS. Ive checked all hoses are tight and there are no leaks. I have 150psi accross all cylinders still... WHAT CAN BE WRONG!!!!!! .

[toxo]

You could pop the coil off and see how rusty the bracket is (it grounds through it), or if the plastic housing is cracked allowing water ingress. It doesn't normally suddenly go wrong or create the problems you're describing, though!

Could look like this:



Should look like this:

[Mav122]

I replaced the coil last week as it had a crack down both sides. I thought that'd be the answer to my problem but no sadly not. didn't know it earthed through bracket. might copper grease the threads up to all coil and bracket bolts to aid earthing in a vauge hope it helps.

[bobhatton]

I replaced the coil last week as it had a crack down both sides. I thought that'd be the answer to my problem but no sadly not. didn't know it earthed through bracket. might copper grease the threads up to all coil and bracket bolts to aid earthing in a vauge hope it helps.

And it was a Toyota coil not an aftermarket one I hope for what ever Rev your car is

[Mav122]

ignitor on rev 3 is different... not sure bout distributor.

[Mav122]

Ok I cleaned the bracket up that the coil sits on as sure enough it was rusty as hell ,I also made a wire up and clamped it between the coil and the clean bracket. The other end of the wire I put under a bolt on the inlet manifold. This has made a HUGE difference! The car drives like crap still but with or without the mbc on it idles properly now. still sounds like it misses a bit not as bad as before by a long shot.

Right problem now is that when driven the car has no boost until 3500 - 4000 rpm when it all comes at once. With or without mbc my gauge swung up to 20psi boost. The car wasnt boosting smoothly either it was juddery like it was boosting then not then a little more etc. I got the car home and turned it off after a 1.5 ish mile drive and the engine light was on. I opened the engine bay bonnet and could hear coolant bubbling but temp gauge was ok. Put my hand round rad rad cap pipe and it coolant was bubbling in it. I also had code numbers 52 (Knock sensor signal), 24 (Intake air temp sensor) and 31 (Air flow meter signal).

code 52 - I have spare knock sensor (not sure of condition) will install tomorrow.

code 24 - hmm dont think I tested it. I'm assuming it is in the manifold somewhere. I dont have one in any pipe work, will look tomorrow. What ohm readings should i see from it at what temps?

code 31 - apparently this means there is an open circuit in the VC signal or short circuit between VS and E2 when idle contacts closed. I tested AFM and it checked out ok... could it be faulty. how would I check VC signal? I'm assuming the VS and E2 I just need the ECU pinouts for and check voltage across the two terminals? If there is no voltage at idle I just work back through the loom and check loom right out of AFM as well at VS and E2. is this assumption correct?

Boiling coolant - coolant is fresh longlife halfords stuff (pink one) mixed in 50/50. Could it be getting hot due to misfire and rough running. It has just been re-built with addition of metal HG. head was re-surfaced as well.

[toxo]

Air intake temp sensor is in the AFM so those 2 will be linked.

Coolant might still just be bleeding air out after the rebuild? I always used to get a bit of a bubbling noise when I turned the car off.

The knock could be caused by it running like xxxx due to the other faults... or the sensor might have blown, or it might not be plugged in?

[Mav122]

I replaced the coil last week as it had a crack down both sides. I thought that'd be the answer to my problem but no sadly not. didn't know it earthed through bracket. might copper grease the threads up to all coil and bracket bolts to aid earthing in a vauge hope it helps.

And it was a Toyota coil not an aftermarket one I hope for what ever Rev your car is

Sorry a Lucas one . I am running on a very tight budget at the moment. If I could have afforded a toyota one I would have.

[Mav122]

Air intake temp sensor is in the AFM so those 2 will be linked.

Coolant might still just be bleeding air out after the rebuild? I always used to get a bit of a bubbling noise when I turned the car off.

The knock could be caused by it running like xxxx due to the other faults... or the sensor might have blown, or it might not be plugged in?

Ahh temp sensor part of AFM. I tested it as per BGB and it was ok (afm that is), If I unplug AFM the the car dies so ecu must be sensing it in some way. When I calibrated AFM as per instruction on mr2oc in Mk2 MR2 general info I found that the screw was 3 turns round from where it should be. I will invest in an Air/fuel ratio gauge when I can to make sure all is hunky dorey.

Glad bubbling is normal, Ill take rad cap off in morning and add coolant then.

[toxo]

Normally when you get those 2 codes it's because it's unplugged, or it has been unplugged. Are those new codes, did you clear them before you took it out for a drive?

[Mav122]

Why would the car boost at 20psi with the pipe straight from turbo outlet to wastegate with the VSV pipe blocked off? Thought the wastegate opened at 7psi? Could my wastegate be stuck open and then when turbo spools it shuts it creating high boost? Could the wastegate be damaged or working in reverse? rod on wastegate on pivot arm wrong way perhaps? would that make sense?

[toxo]

What downpipe have you got? Some of the crapper ones can foul the wastegate.

[Mav122]

There were no codes set before test drive (I didn't however clear any either), I will clear codes and drive it again later. I have a toyosport 3inch system. I unbolted wastegate with rod still attached and if you push then pull on the rod you can hear the valve moving (open or close im not sure though). I have pics of wastegate and rod on valve end of it on my phone, If I get pics on my laptop how do I get them on here? The arm sits at the bottom of the hole on the wastegate side and the arm the rod sits on is almost in line with the rod but slightly facing the rear of the car. 20 degrees backwards as a guestimate. does this sound correct?