Timing off - can't pass smog test


Asked by Mar 09, 2015 at 05:01 PM about the 1988 Toyota MR2 Supercharged Coupe

Question type: Maintenance & Repair

I have a problem with my 1988 Toyota MR2 Supercharged. The timing is way off and won’t pass smog. Although the timing is off, the car runs fine. But it won’t pass smog.
Several years back I had a mechanic rebuild the engine. When this mechanic put the engine back together, he must have discovered a problem with a part and chose to eliminate this part from his reassembly – which I believe was a part of the emissions system. I don’t know for sure if the missing part is the reason for the timing being so far out, but I thought it would be a good place to start.
The problem is I can’t figure out what part is missing. This part has several vacuum type hoses that run to it. The vacuum hoses are pretty long(about 24”) and they feed from the intake manifold. Please see the image and notice the circle – this is where one of the two vacuum hoses come from. The other vacuum hose comes from the lower part of the intake manifold, about eight inches below the other vacuum hose connection. The two hoses had been “clamped off” on the other end - where the missing part is supposed to be.
So two questions: One is, can you tell me what is the missing part? And two is, do you think this part would dramatically effect timing?

2 Answers


Whew...I have really been looking and this is the best I can come up with. I drew blue lines on the vacuum hoses, and where they cross and are connected. One is EGR and the other is EVAP. Both emissions, but will not affect timing, the one on top is PCV and is on properly click image


The Evap vac-hoses "off" are not effecting timing in anyway this is a basic 4A-GE forget the electrical engaging supercharger attached. maybe the catalytic converter being removed is the cause of emission woes! There is no internal part that's effecting emission (had to many of these down). Why not dial the timing back?

Your Answer

Add photo

Related Questions


Looking for a Used MR2 in your area?

CarGurus has 15 nationwide MR2 listings and the tools to find you a great deal.


Search Toyota MR2 Questions

Toyota MR2 Experts

#1 Nick Eidemiller
Nick Eidemiller
Reputation 190
#2 Francis Lapointe
Francis Lapointe
Reputation 130
#3 carGrrl
Reputation 120
View All

Related Models For Sale

Used Toyota Supra"
54 listings starting at $36,995
Used Toyota Celica"
6 Great Deals out of 424 listings starting at $1,195
Used Chevrolet Corvette"
434 Great Deals out of 20,224 listings starting at $3,688
Used BMW 3 Series"
1,607 Great Deals out of 39,619 listings starting at $888
Used Ford Mustang"
733 Great Deals out of 41,077 listings starting at $900
Used Honda Civic"
1,143 Great Deals out of 59,092 listings starting at $995
Used Nissan 300ZX"
165 listings
Used Acura Integra"
158 listings starting at $2,150
Used BMW M3"
87 Great Deals out of 1,918 listings starting at $5,495

Used Cars For Sale