7mge running poorly...suggestions?

2genfun · 03-10-2011, 03:23 AM

so here the story...i blew a head gasket, sent the head out and got it resurfaced and checked for cracks. the heads good. put it all back together and i guess the distributor was off a tooth. although it ran very strong at idle it had a funny prrrrrr...blip, blip, prrrr. and it was running at 25 degrees advance timing. so i rechecked the timing found out the cams were both off a tooth. now timing is perfect no bliping from the distributor and car runs at 10 degrees as indicated by the hood diagram (and timing light). when cranked up it would run at 1400 rpm. so i checked the idle screw and got the idle back down to about 750. So heres the problem. When cold the car bogs down under throttle with no misfire basically just making no power. when hot it runs better but u can still feel as though its lacking power. what puzzles me is that if i advance the distributor a tooth it runs very stong again but then has the bliping and wont idle. its mind baffling so any suggestion ill see if they work. thanks

cre · 03-10-2011, 05:43 AM

First off, the idle screw is a legacy component and not to be used on any of the 7M vehicles. If you have to adjust it to get a consistent idle then you haven't yet found the problem.

Second, have you checked for any diagnostic codes?

Third, when setting the mechanical timing did you check to make sure that the #1 piston is at TDC when the indicator on the balancer says 0?? The rubber in the balancer can twist as it ages putting the 0? mark off more than 10?.

Fourth, when setting the ignition timing, did you have the diagnostic jumper in place?

Fifth, have you tested the ISC valve (electrical and mechanical) and it's plumbing?

Sixth, I dunno what's with the counting.... Started with one and just had to go as high as I could (pathetic, I know).

2genfun · 03-10-2011, 03:24 PM

lol all good. had the jumper in. #1 was at tdc. havent checked for codes yet. And no i havent tested the isc valve because i dont know what that is.

cre · 03-10-2011, 06:27 PM

Quote:

Originally Posted by 2genfun

havent checked for codes yet.

Always start with checking codes. Most of the diagnostic errors which set codes in the memory don't cause the check engine light to some on... your entire issue could be detailed and waiting for you to stop wasting time and just read.

http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

Quote:

Originally Posted by 2genfun

And no i havent tested the isc valve because i dont know what that is.

Idle Speed Control Valve (ISCV or ISC valve).

More reading:
http://www.cygnusx1.net/Supra/Librar...ction=FI&P=106

Did you calibrate the TPS when you put everything back together?

Is the A/C system intact?

Sonyps307 · 03-10-2011, 06:51 PM

Sound like the TPS needs to be calibrated. Check codes if u have code 51 the tps needs calibration.

2genfun · 03-10-2011, 11:49 PM

so finally got a second to check the codes....and i got none. it blinks quickly non stop. but still runs like its lacking power. now what smart people??? oh and yes the idle valve makes ticka ticka ticka when i shut it off.

cre · 03-11-2011, 02:47 AM

Well, the idle adjustment (quite obviously) has just masked one of the symptoms of a greater problem. Don't know why you'd feel it was the problem as (I assume) you didn't touch it prior to now.

Time to start with the usual things. First, reset whichever screw you adjusted as per the TSRM... if it's not shown in the TSRM (which is because not even Toyota certified techs are supposed to dick with it) then set it back how you found it; where it was back when everything was running fine.

Then, physically inspect the ISCV, just because the stepper motor is trying to move doesn't mean there isn't debris in there keeping it open. Check the cam and crank timing and make sure the timing belt tension is equal on both sides... See the FAQ for a LOT of info on adjusting and setting both mechanical and electronic timing, I'm not going to recap all of it.

Have you inspected all of the intake and PCV piping for cracks? Have you verified all of the vacuum hoses are correct? I don't suppose you marked the CPS before you pulled it so you could at least reinstall it where it was previously (should put it at 10?)?

This sounds most like an air problem; One tooth on the CPS will cause a minor bog but won't cause the idle jump a mile. You didn't try to clean the KVAFM (that's the air flow meter), did you?

When after having the head tested and reinstalling the cams did you verify the cam/shim clearances? This would cause bogging but not a high idle.

When you reinstalled the cam gears did you use the center holes on both cam and gear for the dowel pins?

03-10-2011, 05:43 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	First off, the idle screw is a legacy component and not to be used on any of the 7M vehicles. If you have to adjust it to get a consistent idle then you haven't yet found the problem. Second, have you checked for any diagnostic codes? Third, when setting the mechanical timing did you check to make sure that the #1 piston is at TDC when the indicator on the balancer says 0?? The rubber in the balancer can twist as it ages putting the 0? mark off more than 10?. Fourth, when setting the ignition timing, did you have the diagnostic jumper in place? Fifth, have you tested the ISC valve (electrical and mechanical) and it's plumbing? Sixth, I dunno what's with the counting.... Started with one and just had to go as high as I could (pathetic, I know). __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

03-10-2011, 03:24 PM	#3
2genfun 3" Exhaust Join Date: Feb 2010 Location: Orlando, FL Posts: 65	lol all good. had the jumper in. #1 was at tdc. havent checked for codes yet. And no i havent tested the isc valve because i dont know what that is. __________________ 88 targa. H&R springs, koni adustable shocks, 18" wheels, d&s rotors, goodrich brake lines, 7mgte in progress...

03-10-2011, 11:49 PM	#6
2genfun 3" Exhaust Join Date: Feb 2010 Location: Orlando, FL Posts: 65	so finally got a second to check the codes....and i got none. it blinks quickly non stop. but still runs like its lacking power. now what smart people??? oh and yes the idle valve makes ticka ticka ticka when i shut it off. __________________ 88 targa. H&R springs, koni adustable shocks, 18" wheels, d&s rotors, goodrich brake lines, 7mgte in progress...

03-11-2011, 02:47 AM	#7
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Well, the idle adjustment (quite obviously) has just masked one of the symptoms of a greater problem. Don't know why you'd feel it was the problem as (I assume) you didn't touch it prior to now. Time to start with the usual things. First, reset whichever screw you adjusted as per the TSRM... if it's not shown in the TSRM (which is because not even Toyota certified techs are supposed to dick with it) then set it back how you found it; where it was back when everything was running fine. Then, physically inspect the ISCV, just because the stepper motor is trying to move doesn't mean there isn't debris in there keeping it open. Check the cam and crank timing and make sure the timing belt tension is equal on both sides... See the FAQ for a LOT of info on adjusting and setting both mechanical and electronic timing, I'm not going to recap all of it. Have you inspected all of the intake and PCV piping for cracks? Have you verified all of the vacuum hoses are correct? I don't suppose you marked the CPS before you pulled it so you could at least reinstall it where it was previously (should put it at 10?)? This sounds most like an air problem; One tooth on the CPS will cause a minor bog but won't cause the idle jump a mile. You didn't try to clean the KVAFM (that's the air flow meter), did you? When after having the head tested and reinstalling the cams did you verify the cam/shim clearances? This would cause bogging but not a high idle. When you reinstalled the cam gears did you use the center holes on both cam and gear for the dowel pins? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

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03-10-2011, 03:23 AM	#1
2genfun 3" Exhaust Join Date: Feb 2010 Location: Orlando, FL Posts: 65	7mge running poorly...suggestions? so here the story...i blew a head gasket, sent the head out and got it resurfaced and checked for cracks. the heads good. put it all back together and i guess the distributor was off a tooth. although it ran very strong at idle it had a funny prrrrrr...blip, blip, prrrr. and it was running at 25 degrees advance timing. so i rechecked the timing found out the cams were both off a tooth. now timing is perfect no bliping from the distributor and car runs at 10 degrees as indicated by the hood diagram (and timing light). when cranked up it would run at 1400 rpm. so i checked the idle screw and got the idle back down to about 750. So heres the problem. When cold the car bogs down under throttle with no misfire basically just making no power. when hot it runs better but u can still feel as though its lacking power. what puzzles me is that if i advance the distributor a tooth it runs very stong again but then has the bliping and wont idle. its mind baffling so any suggestion ill see if they work. thanks __________________ 88 targa. H&R springs, koni adustable shocks, 18" wheels, d&s rotors, goodrich brake lines, 7mgte in progress...

03-10-2011, 06:51 PM	#5
Sonyps307 Lexus & 550's Join Date: May 2010 Location: Baltimore Posts: 526	Sound like the TPS needs to be calibrated. Check codes if u have code 51 the tps needs calibration.