88 7mge issues HELP!!!!!

[Bigin1987]

I just got a 1988 Toyota supra like a month ago. The guy who had it before me didn't take care of it at all. I changed the oil, put in ngk iridium ix plugs, new wires, distributor cap and rotor button and fuel filter. I also added an aftermarket fuel pressure regulator cause the other one went out. I have also gutted the cat and put all new 2.5 inch piping back. But the car still continues to run pig rich even after I adjust it to the right settings and it idles erratically and when I go WOT it stutters from 4 to 4500 rpm then quits and starts again at 5500 but won't go past the 5500. The guy who owned it before me took out the egr. It also has some noise in the head at lower Rpm that isn't valve tick. I have also checked all vacuums and they are all good. Someone please help me on this cause I can't figure it out. Any insight wouldn't appreciated.

 

[AJ'S 88NA]

Could be a few things, timing, ISC, TPS, any codes?

 

[Bigin1987]

No codes and I checked the resistance with an ohm meter on the tps and it's within spec. What exactly is an isc? And I've looked at the timing but it seems to check out. I need a timing light to be sure. So what else could it be if it's not the timing? I also checked the and and the distributor with the ohm meter.

---------- Post added at 06:31 PM ---------- Previous post was at 06:31 PM ----------

Would the ignitor and coil cause all this?

 

[AJ'S 88NA]

TPS has to be set, may check out OK but still has to be calibrated. Timing should also be set with a timing light.

ISC is Idle speed control, don't think that's your problem.

 

[Bigin1987]

Well tps is set to specs. What else could it be if it ain't the timing?

 

[Bigin1987]

I noticed the vsv for (FPU) is unhooked. The wires broke so now just vacuum lines are hooked up. Can I bypass this without problems?

 

[hvyman]

You need it.

Also you could have just used this thread instead of starting another one.

 

[Bigin1987]

Sorry about that. What exactly is that vsv for? I looked at it just a minute ago and seen that the wires ripped out of the the plug that plugs into the vsv!!! What do I do now????? And someone please tell me what that vsv does and what it's for?!?!?

 

[Devin LeBlanc]

The ECU sends a signal to the valve to send vacuum to the fuel pressure regulator. First thing is get rid of the "aftermarket" fuel pressure regulator. Get a stock replacement.

The wiring harness can easily be repaired. Just solder on a new connector.

 

[Bigin1987]

But why is it the hose has vacuum st all times?

---------- Post added at 07:49 AM ---------- Previous post was at 07:46 AM ----------

And would that be what's causing my car to miss and stutter????

 

[Devin LeBlanc]

Well there could be a number of things.. Have you done a compression check? What about check the valve lash? Cam timing? Checked the injectors? Spark plug wires? Wiring harness continuity test?

Not trying to be an ass, but you can't just show up and say I have a 88 supra 7mge its missfiring and sputtering and running rich what is wrong. You have to back it up. How do you know its running rich? Are you using a wideband to measure the air fuel ratio?

 

[AJ'S 88NA]

Fix the obvious first, may take care of it may not. Like everybody is saying fix the VSV you do need it.

 

[Bigin1987]

Well I've checked the wires plugs distributor cap rotor button plug wires amf tps coil etc.... Now how would I go about checking the cam timing and how would I check the injectors?

And I'm not trying to be a pain in the ass, It's just been bothering.

And the reason I know it's running rich is because it's blows black smoke and you can smell the gas in the exhaust.

 

[AJ'S 88NA]

Pull the upper timing cover, line up the marks on the cam gears, verify #1 piston is at TDC, take distributor cap off and check that rotor is pointing at #1 wire, and the mark on the crank pulley is at the "0" on the cover.

Buy the way did you make sure that your plug wires are in the right order?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=29

 

[jetjock]

The ECU sends a signal to the valve to send vacuum to the fuel pressure regulator.

You have it backwards. When active the valve vents (sends atmospheric pressure to) the regulator. When inactive the valve is open to the manifold. Put simply the valve is a normally open three-way that's plumbed to be fail safe for the normal (hot) operating condition of the engine. That's why he has vacuum all the time.

 

[Devin LeBlanc]

My bad, I was thinking of the two port VSV. Now I remember the FPU VSV has the vent on the other side. Sorry for the mis information

Thanks,
Devin LeBlanc

 

[jetjock]

It happens Dev. I wouldn't be picky if you hadn't come such a long way. After all you're right most of the time and that needs to continue.

You still have some pretty weird ideas about oil though :icon_razz

 

[Bigin1987]

The plug wires are all right and the timing is good. So would this vsv be causing this along with the aftermarket fuel pressure regulator? I figure it just getting to much fuel and that the vsv isn't working so the it's not letting enough vacuum travel so it's causing the stutter. Or do you think it's something else?

 

[Devin LeBlanc]

The VSV is not causing it the "stutter" The aftermarket FPR could be though.. Search around in the for sale section.. You can find stock Fuel pressure regulators for 5-10.00

 

[bioskyline]

noise in the head at low rpm.... i think all 7ms have noisy heads, atleast in my experiance. could be alot of things, but could be a slight exaust leak casued by a 20 year old exaust gasket and exuast manifold bolts/studs backing out. also if you have an exaust leak at the manifold, it could alllow fresh air in, and thus the o2 sensor is getting a lean signal and adding more fuel to compensate, which would explain it running rich.

could also be a bad o2 sensor

but very carefully try to tighten the manifold bolts. if they are loose, then this could solve it. but if you strip one....then its helicoil time....