Crappy MPG

slydog113 · 06-12-2009, 11:33 PM

Just got my 89 S/C back on the road after replacing Clutch, P/Plate Timing belt,water pump,exhaust, and a complete tune up. The only problem is my mileage has now dropped by aprox. a third. This thing got better mileage with the original plug wires and plugs that looked as though they may have been OE also.
I have noticed on start up the engine stumbles a little but the idle picks up almost immediately and idles normally. As usual any help would be greatly appreciated.

nikn · 06-13-2009, 12:48 AM

sounds like a vacuum/boost leak of some sort.

slydog113 · 06-16-2009, 09:37 PM

All vacuum lines look good. S/C sounds normal(although I probably wouldn't know abnormal if I heard it).

Jackstand Queen · 06-17-2009, 12:23 AM

Welcome to the Time of Troubles. The age and mileage of yours car's parts will begin to create many new and interesting problems for you.

Your problem is most likely due to the unfamiliarity (with the SC MR2) of the mechanic who worked on your car. Mechanics in garages are under immense pressure to Get r' Done REALLY, REALLY fast. Yours probably glossed over a few critical details in his haste.

Your only way out of the box you are in, is to gather the tools and expertise . . . and become your own mechanic, or find someone who knows Mk I SC's really well. The SC is full of peculiar devices, odd parts that are so rare, most mechanics have never seen or heard of them. And if you read the Forced Induction Forum, even experienced and good mechanics like myself have a tough time keeping them running to full potential, . .. . er make that even running at all.

Your mechanic screwed up. Get another, or become your own.

There is also a regional forum here for the Pacific Northwest. You might post there and find an SC owner with some skills and spare time, or they might could refer you to a damn good mechanic for SC's near where you live.

Good Luck!

slydog113 · 06-18-2009, 06:25 PM

If the repairs were done incorrectly I have no one to blame but myself as I performed the repairs myself. In the beginning I assumed the car wouldn't be much different than my 89 N/A. Needless to say I was in for a rude awakening right off the bat.
The car has great acceleration it just gets lousy mileage and doesn't sound right on start up (rpm's are low initially but pick up quickly).
Thanks again for the reply. Any further suggestions would be greatly appreciated.

palos · 06-18-2009, 07:26 PM

Considering that you changed the timing belt and did a tune up, I'd double check that the timing belt was installed properly and the timing set properly (after shorting the E1 & T connectors). Are all of the spark plug wires secure at both ends? Any chance they became slightly wet before installing, if so spray with WD40?

Also, check that the AFM connector and water temperature connector are securely fastened.

Did you disconnect the oxygen sensor when removing the transmission?

If there are any questions in your mind that the connectors are properly connected, I could take photos of my engine compartment or compare photos of your engine to mine.

slydog113 · 06-18-2009, 07:38 PM

Pics would be great, I will pm you with my email address. As for the timing issue, all marks line up but the previous owner must have pulled the lower pulley with a pry bar because it is badly chipped making the timing marks difficult to impossible to make out. And finding an affordable replacement has proven to be next to impossible.
Thanks again for your assistance.

Luni · 06-18-2009, 07:46 PM

Really? You cant find a 4AGZE pulley? All sorts of guys on here have those things laying around.

You should post a want to buy thread for the pulley. Replace that, then double check your timing.

Really, the only logical thing that could have been done on a timing belt that would affect your gas mileage is the belt. How is your performance? If your belt was off by a tooth or 2, youd really feel it.

Jackstand Queen · 06-18-2009, 08:53 PM

Slydog I gotta a couple helpfuls for you:

1. The toothed timing belt cog has a timing mark on it. It lines up with a adjacent at 2:00 Oclock mark on the Timing cover. It difficult to see, but I've always used it.

2. Similar to Palo's suggestion, start smacking down the corrosion and rust off your electrical connectors, on all the critical sensors and devices having to do with the engine. This is a big job, so start with the AFM coolant temperature sensor, ignitor, coil, etc. and move on down to the lesser devices. If you read the Forced Induction forum's posts, you'll see that this solves a lot of running problems.

And yes, Brother, keeping these SC engines going smoothly is a whole nother ball game. Hell, I'm at War with my engine's difficulties.

slydog113 · 06-21-2009, 08:05 PM

Thanks,
Posting a wtb never even crossed my mind. BTW I think I have the problem solved, number 4 plug wire wasn't making good contact with the plug. I could swear I double checked the wires but apparently I was mistaken. I am however going to track down a pulley and check the timing.
Thanks again for all the help. You people are irreplaceable

06-12-2009, 11:33 PM	#1 (permalink)
slydog113 SLYDOG Join Date: May 2007 Location: Vancouver,WA Posts: 42 Thanks: 12 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (2/100% )	Crappy MPG Just got my 89 S/C back on the road after replacing Clutch, P/Plate Timing belt,water pump,exhaust, and a complete tune up. The only problem is my mileage has now dropped by aprox. a third. This thing got better mileage with the original plug wires and plugs that looked as though they may have been OE also. I have noticed on start up the engine stumbles a little but the idle picks up almost immediately and idles normally. As usual any help would be greatly appreciated.

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06-13-2009, 12:48 AM	#2 (permalink)
nikn Cage Fighter Join Date: Jan 2007 Location: dirty jerzey Posts: 144 Thanks: 11 Thanked 3 Times in 3 Posts iTrader Rating: (5/100% )	sounds like a vacuum/boost leak of some sort.

06-16-2009, 09:37 PM	#3 (permalink)
slydog113 SLYDOG Join Date: May 2007 Location: Vancouver,WA Posts: 42 Thanks: 12 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (2/100% )	All vacuum lines look good. S/C sounds normal(although I probably wouldn't know abnormal if I heard it).

06-17-2009, 12:23 AM	#4 (permalink)
Jackstand Queen Cage Fighter Join Date: May 2008 Posts: 677 Thanks: 52 Thanked 56 Times in 53 Posts iTrader Rating: (1/100% )	Welcome to the Time of Troubles. The age and mileage of yours car's parts will begin to create many new and interesting problems for you. Your problem is most likely due to the unfamiliarity (with the SC MR2) of the mechanic who worked on your car. Mechanics in garages are under immense pressure to Get r' Done REALLY, REALLY fast. Yours probably glossed over a few critical details in his haste. Your only way out of the box you are in, is to gather the tools and expertise . . . and become your own mechanic, or find someone who knows Mk I SC's really well. The SC is full of peculiar devices, odd parts that are so rare, most mechanics have never seen or heard of them. And if you read the Forced Induction Forum, even experienced and good mechanics like myself have a tough time keeping them running to full potential, . .. . er make that even running at all. Your mechanic screwed up. Get another, or become your own. There is also a regional forum here for the Pacific Northwest. You might post there and find an SC owner with some skills and spare time, or they might could refer you to a damn good mechanic for SC's near where you live. Good Luck!

06-18-2009, 06:25 PM	#5 (permalink)
slydog113 SLYDOG Join Date: May 2007 Location: Vancouver,WA Posts: 42 Thanks: 12 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (2/100% )	If the repairs were done incorrectly I have no one to blame but myself as I performed the repairs myself. In the beginning I assumed the car wouldn't be much different than my 89 N/A. Needless to say I was in for a rude awakening right off the bat. The car has great acceleration it just gets lousy mileage and doesn't sound right on start up (rpm's are low initially but pick up quickly). Thanks again for the reply. Any further suggestions would be greatly appreciated.

06-18-2009, 07:26 PM	#6 (permalink)
palos … Join Date: Apr 2009 Posts: 170 Thanks: 0 Thanked 20 Times in 18 Posts iTrader Rating: (0/0% )	Considering that you changed the timing belt and did a tune up, I'd double check that the timing belt was installed properly and the timing set properly (after shorting the E1 & T connectors). Are all of the spark plug wires secure at both ends? Any chance they became slightly wet before installing, if so spray with WD40? Also, check that the AFM connector and water temperature connector are securely fastened. Did you disconnect the oxygen sensor when removing the transmission? If there are any questions in your mind that the connectors are properly connected, I could take photos of my engine compartment or compare photos of your engine to mine.

06-18-2009, 07:38 PM	#7 (permalink)
slydog113 SLYDOG Join Date: May 2007 Location: Vancouver,WA Posts: 42 Thanks: 12 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (2/100% )	Pics would be great, I will pm you with my email address. As for the timing issue, all marks line up but the previous owner must have pulled the lower pulley with a pry bar because it is badly chipped making the timing marks difficult to impossible to make out. And finding an affordable replacement has proven to be next to impossible. Thanks again for your assistance.

06-18-2009, 07:46 PM	#8 (permalink)
Luni ST185 Powered SW20 Join Date: Oct 2005 Location: Salt Lake City Utah Posts: 2,959 Thanks: 9 Thanked 106 Times in 92 Posts My Google Map iTrader Rating: (8/100% )	Really? You cant find a 4AGZE pulley? All sorts of guys on here have those things laying around. You should post a want to buy thread for the pulley. Replace that, then double check your timing. Really, the only logical thing that could have been done on a timing belt that would affect your gas mileage is the belt. How is your performance? If your belt was off by a tooth or 2, youd really feel it.

06-18-2009, 08:53 PM	#9 (permalink)
Jackstand Queen Cage Fighter Join Date: May 2008 Posts: 677 Thanks: 52 Thanked 56 Times in 53 Posts iTrader Rating: (1/100% )	Slydog I gotta a couple helpfuls for you: 1. The toothed timing belt cog has a timing mark on it. It lines up with a adjacent at 2:00 Oclock mark on the Timing cover. It difficult to see, but I've always used it. 2. Similar to Palo's suggestion, start smacking down the corrosion and rust off your electrical connectors, on all the critical sensors and devices having to do with the engine. This is a big job, so start with the AFM coolant temperature sensor, ignitor, coil, etc. and move on down to the lesser devices. If you read the Forced Induction forum's posts, you'll see that this solves a lot of running problems. And yes, Brother, keeping these SC engines going smoothly is a whole nother ball game. Hell, I'm at War with my engine's difficulties.

06-21-2009, 08:05 PM	#10 (permalink)
slydog113 SLYDOG Join Date: May 2007 Location: Vancouver,WA Posts: 42 Thanks: 12 Thanked 1 Time in 1 Post My Google Map iTrader Rating: (2/100% )	Thanks, Posting a wtb never even crossed my mind. BTW I think I have the problem solved, number 4 plug wire wasn't making good contact with the plug. I could swear I double checked the wires but apparently I was mistaken. I am however going to track down a pulley and check the timing. Thanks again for all the help. You people are irreplaceable