Help! Post-rebuild engine problems!

Tony · 10-23-2009, 09:24 AM

Hey everyone,

I bought my 88 Supra Turbo with a BHG a while back, and have since done the following to it:

New HG and upper gasket set
ARP Bolts (70ft/lb)
Different turbo head purchased (old was warped .020")
Head machined flat, checked, and valves reseated
Set of completely refurbished fuel injectors (ultrasonically cleaned and flow tested)
Vacuum systed completely gone through and everything is properly connected.
Also tested every coil pack for spark (looked for spark in a removed plug attached to each coil pack)

Feels like a cylinder or two isn't firing.
Here's a video (don't mind the squeak, alternator belt is not tensioned all the way)

http://www.youtube.com/watch?v=1BudtjtPh70

The car starts but runs terribly, once the RPMs go past 2500, all power is lost until it drops below that.
If you keep the accelerator floored, it will go up past 2500 RPMS, then fall back to it over and over.

Can someone help me?
I want to get this thing on the road!

cre · 10-24-2009, 12:09 AM

Double check the mechanical timing (crank, cams and CPS), if that's all square, check the ignition timing.

Any error codes?

CanadianBak'inSupra · 10-24-2009, 01:46 AM

i agree chek the error codes...
simple and a start...

86.5supra · 10-24-2009, 03:05 PM

your getting a fuel cut out my 7mgte did it after we had it rebuilt. after they tore the motor back apart we found out that it was a O2 sensor that was fucking up the computer.

CanadianBak'inSupra · 10-24-2009, 03:53 PM

Quote:

Originally Posted by 86.5supra

your getting a fuel cut out my 7mgte did it after we had it rebuilt. after they tore the motor back apart we found out that it was a O2 sensor that was fucking up the computer.

not tryin to topic steal, but how many sensors does the engine have (for a non turbo)
i wouldnt mind getting all mine checked

ricerbaby · 10-24-2009, 06:24 PM

having the same problem at the moment.. my 88 is doing the same thing. it sounds just like a computer problem, i had a broken coolant hose and it threw coolant and water all over the engine and it got in my cpu which made my car do the same thing. a new cpu unit is pretty expensive... but you can look for one on ebay too...

cre · 10-24-2009, 11:08 PM

What the OP is referring to is generally known as "limp mode". It's a base setting which is used in the event that a critical problem is detected. Often it's not really something big, an unplugged sensor, a leak,

Check for error codes, check the TPS' alignment, inspect all of the intake plumbing for holes/cracks/or other leaks, make sure the AFM harness plug is connected firmly to the AFM, check the knock sensors and their wiring.

A bad O2 sensor may cause you to run a bit rich or a bit lean but anything too far out of range and the ECU stops reading the O2 sensor altogether and reverts to the stock fueling maps... Also, at WOT, the ECU doesn't even read the O2 sensor; so, if you've got problems at WOT it is definitely something else.

One other possibility is that the timing belt skipped a tooth or wasn't properly installed causing uneven tension which when the motor is finally turned over puts the pulleys out of sync.

cre · 10-24-2009, 11:11 PM

Quote:

Originally Posted by ricerbaby

having the same problem at the moment.. my 88 is doing the same thing. it sounds just like a computer problem, i had a broken coolant hose and it threw coolant and water all over the engine and it got in my cpu which made my car do the same thing. a new cpu unit is pretty expensive... but you can look for one on ebay too...

In your case it very well may be the ECU. Try cleaning out ALL of the harness connectors behind the dash with electrical contact cleaner (Radio Shack carries it as well as most electronic supply shops). If the problem remains another ECU may indeed be in order. What are you driving? N/A or Turbo, Manual or Auto? I have another GE ECU which I know is good.

CanadianBak'inSupra · 10-25-2009, 03:57 PM

i just did my ecu
guy crashed his 89 7mge and i got his ecu for the lowball price of 40 dollers
if you need help on getting it in its still fresh in my mind...

Tony · 10-26-2009, 04:46 AM

It's a turbo manual.

Crank and cams are timed right, popped off the timing cover and looked (cover off in the vid)
Cam position sensor adjusted... there is separate ignition timing? I'll have to look that up in the TSRM, I thought it was just the CPS.

I think it didn't fire on all cylinders with the BHG, so i'll have to have the ECU checked... the check engine light has never been on... but who knows.

The knock sensors... I didn't know what those were until I looked them up... they are at the bottom of the upper intake manifold, with vacuum lines running through them... so they're all squared away right.

Ugh after dropping 2k AFTER purchase of the car into this thing, I need to be slapped for not getting a 1jz... but I was a noob then.

Haha one of you should just drive here and plug in the thing I missed so it'll run lol.

10-23-2009, 09:24 AM	#1
Tony Stock Join Date: Aug 2009 Location: Indiana Posts: 15	Help! Post-rebuild engine problems! Hey everyone, I bought my 88 Supra Turbo with a BHG a while back, and have since done the following to it: New HG and upper gasket set ARP Bolts (70ft/lb) Different turbo head purchased (old was warped .020") Head machined flat, checked, and valves reseated Set of completely refurbished fuel injectors (ultrasonically cleaned and flow tested) Vacuum systed completely gone through and everything is properly connected. Also tested every coil pack for spark (looked for spark in a removed plug attached to each coil pack) Feels like a cylinder or two isn't firing. Here's a video (don't mind the squeak, alternator belt is not tensioned all the way) http://www.youtube.com/watch?v=1BudtjtPh70 The car starts but runs terribly, once the RPMs go past 2500, all power is lost until it drops below that. If you keep the accelerator floored, it will go up past 2500 RPMS, then fall back to it over and over. Can someone help me? I want to get this thing on the road!

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10-24-2009, 12:09 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Double check the mechanical timing (crank, cams and CPS), if that's all square, check the ignition timing. Any error codes?

10-24-2009, 01:46 AM	#3
CanadianBak'inSupra Official hall monitor / search nazi - NO SOUP FOR YOU! Join Date: Oct 2009 Location: Canada, BC Posts: 837	i agree chek the error codes... simple and a start...

10-24-2009, 03:05 PM	#4
86.5supra 3" Exhaust Join Date: Jun 2009 Location: ny Posts: 83	your getting a fuel cut out my 7mgte did it after we had it rebuilt. after they tore the motor back apart we found out that it was a O2 sensor that was fucking up the computer.

10-24-2009, 06:24 PM	#6
ricerbaby Stock Join Date: Oct 2009 Location: flower mound texas Posts: 7	having the same problem at the moment.. my 88 is doing the same thing. it sounds just like a computer problem, i had a broken coolant hose and it threw coolant and water all over the engine and it got in my cpu which made my car do the same thing. a new cpu unit is pretty expensive... but you can look for one on ebay too...

10-24-2009, 11:08 PM	#7
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	What the OP is referring to is generally known as "limp mode". It's a base setting which is used in the event that a critical problem is detected. Often it's not really something big, an unplugged sensor, a leak, Check for error codes, check the TPS' alignment, inspect all of the intake plumbing for holes/cracks/or other leaks, make sure the AFM harness plug is connected firmly to the AFM, check the knock sensors and their wiring. A bad O2 sensor may cause you to run a bit rich or a bit lean but anything too far out of range and the ECU stops reading the O2 sensor altogether and reverts to the stock fueling maps... Also, at WOT, the ECU doesn't even read the O2 sensor; so, if you've got problems at WOT it is definitely something else. One other possibility is that the timing belt skipped a tooth or wasn't properly installed causing uneven tension which when the motor is finally turned over puts the pulleys out of sync.

10-25-2009, 03:57 PM	#9
CanadianBak'inSupra Official hall monitor / search nazi - NO SOUP FOR YOU! Join Date: Oct 2009 Location: Canada, BC Posts: 837	i just did my ecu guy crashed his 89 7mge and i got his ecu for the lowball price of 40 dollers if you need help on getting it in its still fresh in my mind...

10-26-2009, 04:46 AM	#10
Tony Stock Join Date: Aug 2009 Location: Indiana Posts: 15	It's a turbo manual. Crank and cams are timed right, popped off the timing cover and looked (cover off in the vid) Cam position sensor adjusted... there is separate ignition timing? I'll have to look that up in the TSRM, I thought it was just the CPS. I think it didn't fire on all cylinders with the BHG, so i'll have to have the ECU checked... the check engine light has never been on... but who knows. The knock sensors... I didn't know what those were until I looked them up... they are at the bottom of the upper intake manifold, with vacuum lines running through them... so they're all squared away right. Ugh after dropping 2k AFTER purchase of the car into this thing, I need to be slapped for not getting a 1jz... but I was a noob then. Haha one of you should just drive here and plug in the thing I missed so it'll run lol.