Misfire
- Thread starter Kristian_Wraae
- Start date
The guy who installed the rebuilt engine into my car was supposed to set the timing. He did but the engine didn't run that well. He told me it was because of the cams so I didn't think much about it.
When I later (after driving 1200 kms) had the timing checked again it was set to 25. Setting it to 12 made the car run much better but we noticed the small misfire. I don't know if it has been present all the time or it developed during those 1200 kms.
Could driving with the ignition timing set to 25 destroy the valves?
I have been very gentle with the car during those 1200 km and I don't think I have been above 3000 rpm.
When I later (after driving 1200 kms) had the timing checked again it was set to 25. Setting it to 12 made the car run much better but we noticed the small misfire. I don't know if it has been present all the time or it developed during those 1200 kms.
Could driving with the ignition timing set to 25 destroy the valves?
I have been very gentle with the car during those 1200 km and I don't think I have been above 3000 rpm.
I had the car checked at Toyota today.
They didn't have equipment to do a leak down test. They did a compressiontest which was like the one we did ourselves. A little high on 1 + 2 cylinder compared to the rest.
The valves checked out fine except for three of them. They were too tight and were adjusted (the were on the intake side og cylinder 1 and 2)
The TPS was not adjusted correct either. So it was fixed.
Timing was set to 12. The cams are set to +4 on the exhaust and 12 was as low as it would go at that setting without filing anything. So if I dial the cam back to +3 it should be 10 on the timing.
No effect on the misfire.
We also did an exhaust gas test and it turned out perfect. Lambda was 1.00
Abosolutely no unburned gas in the exhaust.
Since the exhaust gas test was so good they didn't recommend getting the injectors testet.
So I'm thinking that the engine might be running a bit lean?
Could that be the problem? Should I get a fuel pressure regulator? Or would a set of 550 injectors and a Lex AFM do the trick? (I seem to remember someone saying that this combo runs a bit richer than stock)
Because of the good exhaust gas test have I ruled out valves and injectors?
Any suggestions?
They didn't have equipment to do a leak down test. They did a compressiontest which was like the one we did ourselves. A little high on 1 + 2 cylinder compared to the rest.
The valves checked out fine except for three of them. They were too tight and were adjusted (the were on the intake side og cylinder 1 and 2)
The TPS was not adjusted correct either. So it was fixed.
Timing was set to 12. The cams are set to +4 on the exhaust and 12 was as low as it would go at that setting without filing anything. So if I dial the cam back to +3 it should be 10 on the timing.
No effect on the misfire.
We also did an exhaust gas test and it turned out perfect. Lambda was 1.00
Abosolutely no unburned gas in the exhaust.
Since the exhaust gas test was so good they didn't recommend getting the injectors testet.
So I'm thinking that the engine might be running a bit lean?
Could that be the problem? Should I get a fuel pressure regulator? Or would a set of 550 injectors and a Lex AFM do the trick? (I seem to remember someone saying that this combo runs a bit richer than stock)
Because of the good exhaust gas test have I ruled out valves and injectors?
Any suggestions?
It could be a lean misfire...I would check the FP relay per this:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=114
Also make sure you don't get a voltage drop across terminals +B and FP (bad contact).
Might want to consider running the FP on a constant 12 volts...just make a jumper across the harness side connector to the resistor:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=115
Check your fuel pressure here:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=71
Reading through this thread, a couple things:
- If you go with a Lex AFM, you will need 550 injectors...those should be plenty big enough unless you're going for huge HP numbers
- Upgrading the FP to a Walbro is not required, but a very good idea...especially if the FP in the car is original
- An AFPR is a very good idea running a Lex AFM/550 combo...allows a "global" setting for fuel
- I would get a wideband O2...this will give you a good idea of what effect fuel changes have. It would also help in a situation like this
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=FI&P=114
Also make sure you don't get a voltage drop across terminals +B and FP (bad contact).
Might want to consider running the FP on a constant 12 volts...just make a jumper across the harness side connector to the resistor:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=115
Check your fuel pressure here:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=71
Reading through this thread, a couple things:
- If you go with a Lex AFM, you will need 550 injectors...those should be plenty big enough unless you're going for huge HP numbers
- Upgrading the FP to a Walbro is not required, but a very good idea...especially if the FP in the car is original
- An AFPR is a very good idea running a Lex AFM/550 combo...allows a "global" setting for fuel
- I would get a wideband O2...this will give you a good idea of what effect fuel changes have. It would also help in a situation like this
Ok, thanks
I have a (probably) stupid question.
If I get a wideband O2 sensor would I need to run both the original O2 sensor and the wideband or could the wideband be hooked up to the ECU instead of the old sensor?
The reason I ask is that I have stock turbo knee and it only one sensor port.
Any suggestions to which brand wideband I should get?
On ebay there are lots of AEM Uego.
This one: http://cgi.ebay.com/ebaymotors/PLX-...005QQitemZ150220277466QQrdZ1QQsspagenameZWDVW
seems to have output for both wideband and narrow band. So could it be hooked up instead of the stock sensor?
I have a (probably) stupid question.
If I get a wideband O2 sensor would I need to run both the original O2 sensor and the wideband or could the wideband be hooked up to the ECU instead of the old sensor?
The reason I ask is that I have stock turbo knee and it only one sensor port.
Any suggestions to which brand wideband I should get?
On ebay there are lots of AEM Uego.
This one: http://cgi.ebay.com/ebaymotors/PLX-...005QQitemZ150220277466QQrdZ1QQsspagenameZWDVW
seems to have output for both wideband and narrow band. So could it be hooked up instead of the stock sensor?
I've decided to get a MAFT Pro setup. It comes with the wideband and has data logging capability. Should make it easier to understand what is going on and correct it if indeed it's just running a little lean.
My power goals are 400 hp so it should be adequate with some bigger injectors later. Also my car is an automatic so it would be nice to keep the original ecu.
My power goals are 400 hp so it should be adequate with some bigger injectors later. Also my car is an automatic so it would be nice to keep the original ecu.
I was going to change the PS pump today and when I had most of it taken apart I noticed the IC hose going from the turbo to the intercooler.
Firstly the clamp wasn't tightend at all. Completely loose.
Secondly it looked like this:
I don't have a replacement but I'll be ordering one.
Could this be the problem?
Firstly the clamp wasn't tightend at all. Completely loose.
Secondly it looked like this:
I don't have a replacement but I'll be ordering one.
Could this be the problem?
it would make it run rich that's for sure... so you figure out the rest
edit. Multi tabs ftl here.
edit. Multi tabs ftl here.
I had noticed that the car had been a bit sluggish since the engine had been out but I was told that it was because I had put a 2mm HG instead of a 1.2 mm.
BTW: there is a equally sized crack on the back side too.
BTW: there is a equally sized crack on the back side too.
PROBLEM SOLVED !!!!!!!!!!!!!!!
:evil2::biglaugh::biglaugh::evil2:
:biggrinki:thumbup::biggrinbo:rofl::burnout::thefinger:eek3dance:x::bigthumb:
:evil2::biglaugh::biglaugh::evil2:
:biggrinki:thumbup::biggrinbo:rofl::burnout::thefinger:eek3dance:x::bigthumb:
Belive it or not but it was that hose in the picture above.
It had two big cracks and further more it wasn't clamped down at all.
The car drives very well now and pulls very strongly.
I don't understand how anyone can put a hose looking like that back on the car.
It had two big cracks and further more it wasn't clamped down at all.
The car drives very well now and pulls very strongly.
I don't understand how anyone can put a hose looking like that back on the car.
Time for a hard pipe replacement
At least you got quite a few other things fixed during the search. It's amazing the short-cuts "professional mechanics" will take to get the car out in the interest of making $$$. I guess it's job security...they hope you'll come back and drop more cash on what should have been done right the 1st time.
At least you got quite a few other things fixed during the search. It's amazing the short-cuts "professional mechanics" will take to get the car out in the interest of making $$$. I guess it's job security...they hope you'll come back and drop more cash on what should have been done right the 1st time.
Yeah, hardpipes will be done when I find a FFIM. But that will have to wait until next year. Now I want an entire summer of driving and no down time due to mechanical problems.
My story:
1. Bought the car in april 2007. I paid a Supra specialist go check it out before buying.
2. May: Found out car had been in accident. Front end not straight.
3. BHG in june.
4. Sent car to another proffesional Supra specialist for a HKS MHG.
5. BHG in Juli.
6. Found out the specialist didn't resurface the head prio to installing the MHG in contrast to what was agreed upon and what he told me he had done. Also turbo leaking oil from oil delivery tube. It was bent out of shape because the entire head had been lying one week on a bench with the manifold and turbo still attached until they decided not to resurface the head and just clamp it down again reusing all the 15 year old gaskets.
7. Got him on tape making so many selfcontraditions that he finally admitted to his short cut.
8. Got refunded by threatning to go public with the story.
9. Had engine pulled in September. Started full rebuild.
10. Found out that the HKS MHG I bought from #4 was infact a Cometic. Also found out that the head was destroyed (severely warped because of #4 - 1mm on the narrow side) and that #4 had clamped the head down over that rivet that needed to be removed.
11. Got car's front straightend at Toyota - first job well done.
12. Received car back with ignition set at 25, engine harness not grounded, EGR cooler plate leaking and turbo pressure hose not clamped down and with two big cracks in it.
Now everything has been fixed apart from the EGR. Still contemplating how to do that with the engine in the car.
My story:
1. Bought the car in april 2007. I paid a Supra specialist go check it out before buying.
2. May: Found out car had been in accident. Front end not straight.
3. BHG in june.
4. Sent car to another proffesional Supra specialist for a HKS MHG.
5. BHG in Juli.
6. Found out the specialist didn't resurface the head prio to installing the MHG in contrast to what was agreed upon and what he told me he had done. Also turbo leaking oil from oil delivery tube. It was bent out of shape because the entire head had been lying one week on a bench with the manifold and turbo still attached until they decided not to resurface the head and just clamp it down again reusing all the 15 year old gaskets.
7. Got him on tape making so many selfcontraditions that he finally admitted to his short cut.
8. Got refunded by threatning to go public with the story.
9. Had engine pulled in September. Started full rebuild.
10. Found out that the HKS MHG I bought from #4 was infact a Cometic. Also found out that the head was destroyed (severely warped because of #4 - 1mm on the narrow side) and that #4 had clamped the head down over that rivet that needed to be removed.
11. Got car's front straightend at Toyota - first job well done.
12. Received car back with ignition set at 25, engine harness not grounded, EGR cooler plate leaking and turbo pressure hose not clamped down and with two big cracks in it.
Now everything has been fixed apart from the EGR. Still contemplating how to do that with the engine in the car.
Geez! :3d_frown:
You can install the EGR valve with the motor in the car...hopefully you have small, nimble hands
I did it, but it's not fun...if the EGR cooler is missing, it becomes a real PITA. Putting one in is going to depend whether a plug or a block-off plate was used on the exhaust gas feed port. If a plate was used, you can do it in the car...a plug will be a different story...it will be tough to get to it with the limited space behind the motor. The good news is a plate is used most of the time. In any case, tightening the 8 bolts down for the cooler is going to be frustrating...you need a low profile socket (10mm I think) and a lot of patience. Laying an old matress across the top of the motor and laying on it will save your back
You can install the EGR valve with the motor in the car...hopefully you have small, nimble hands
I did it, but it's not fun...if the EGR cooler is missing, it becomes a real PITA. Putting one in is going to depend whether a plug or a block-off plate was used on the exhaust gas feed port. If a plate was used, you can do it in the car...a plug will be a different story...it will be tough to get to it with the limited space behind the motor. The good news is a plate is used most of the time. In any case, tightening the 8 bolts down for the cooler is going to be frustrating...you need a low profile socket (10mm I think) and a lot of patience. Laying an old matress across the top of the motor and laying on it will save your back
Yes, a horror story.
The only good thing is that the engine has been built by a very good mechanic.
He is an ex-toyota mechanic and he also has a 7mgte Supra himself - going for 800 hp.
He knows his stuff. He won the European Championships in Lexus some years ago.
So that part should be ok. He just didn't have the proper gasket for the EGR cooler plate so I had the guy who installed the engine into the car put the EGR cooler plate on with a new gasket. I shouldn't have done that.
I'll see if I can remove the cooler plate and block the exhaust gas feed port.
The only good thing is that the engine has been built by a very good mechanic.
He is an ex-toyota mechanic and he also has a 7mgte Supra himself - going for 800 hp.
He knows his stuff. He won the European Championships in Lexus some years ago.
So that part should be ok. He just didn't have the proper gasket for the EGR cooler plate so I had the guy who installed the engine into the car put the EGR cooler plate on with a new gasket. I shouldn't have done that.
I'll see if I can remove the cooler plate and block the exhaust gas feed port.