Running Rich? Cat Clogged? Maf?

[someguy]

I recently purchased a 92 sc300 for cheap to fix it.

I think it's been running rich. When cold, I start it up and doesnt stay on for more than a split second. I have to give it some gas so it can stay on. When it's running at normal operating temperature, it will idle decently, unless I start jerking the steering wheel, then it gets rough again

The fumes from the exhaust smell like gas. I also pulled the spark plugs and they were all black/smoked

I replaced the o2 sensors and gave it a tuneup. I ran a compression test and its showing 150 psi on all cylinders and my timing is perfect.

Has anyone else had this problem? input will be appreciated.

[jamesbondsc300]

I recently purchased a 92 sc300 for cheap to fix it.

I think it's been running rich. When cold, I start it up and doesnt stay on for more than a split second. I have to give it some gas so it can stay on. When it's running at normal operating temperature, it will idle decently, unless I start jerking the steering wheel, then it gets rough again

The fumes from the exhaust smell like gas. I also pulled the spark plugs and they were all black/smoked

I replaced the o2 sensors and gave it a tuneup. I ran a compression test and its showing 150 psi on all cylinders and my timing is perfect.

Has anyone else had this problem? input will be appreciated.

is the CEL (check engine light) on? MAF is a good start, but if its not throwing a code then hold off on just spending money and changing parts. Get a scanner and pull the codes. Just because the light isn't constantly on does not mean it doesn't have any stored codes. Anyways, this is a good place to start. Let me know what you find out.

[lexdud]

I recently purchased a 92 sc300 for cheap to fix it.

I think it's been running rich. When cold, I start it up and doesnt stay on for more than a split second. I have to give it some gas so it can stay on. When it's running at normal operating temperature, it will idle decently, unless I start jerking the steering wheel, then it gets rough again

The fumes from the exhaust smell like gas. I also pulled the spark plugs and they were all black/smoked

I replaced the o2 sensors and gave it a tuneup. I ran a compression test and its showing 150 psi on all cylinders and my timing is perfect.

Has anyone else had this problem? input will be appreciated.

is the CEL (check engine light) on? MAF is a good start, but if its not throwing a code then hold off on just spending money and changing parts. Get a scanner and pull the codes. Just because the light isn't constantly on does not mean it doesn't have any stored codes. Anyways, this is a good place to start. Let me know what you find out.

I have a 93 SC4 with only 52,000 miles and I am having problems as well. Unless I am mistaken (I've bee know to) both of our cars are OBD I and NOT OBD II. I have an OBD II scanner but it would be worthless on pretty much any car manufactured prior to 1996.

[jamesbondsc300]

I recently purchased a 92 sc300 for cheap to fix it.

I think it's been running rich. When cold, I start it up and doesnt stay on for more than a split second. I have to give it some gas so it can stay on. When it's running at normal operating temperature, it will idle decently, unless I start jerking the steering wheel, then it gets rough again

The fumes from the exhaust smell like gas. I also pulled the spark plugs and they were all black/smoked

I replaced the o2 sensors and gave it a tuneup. I ran a compression test and its showing 150 psi on all cylinders and my timing is perfect.

Has anyone else had this problem? input will be appreciated.

is the CEL (check engine light) on? MAF is a good start, but if its not throwing a code then hold off on just spending money and changing parts. Get a scanner and pull the codes. Just because the light isn't constantly on does not mean it doesn't have any stored codes. Anyways, this is a good place to start. Let me know what you find out.

you are correct, it is obd1. sorry must have been on the crack pipe hahaha! anyways just pull the codes with a paper clip. count the flashes of the check engine light and look up the code(if one is stored)

I have a 93 SC4 with only 52,000 miles and I am having problems as well. Unless I am mistaken (I've bee know to) both of our cars are OBD I and NOT OBD II. I have an OBD II scanner but it would be worthless on pretty much any car manufactured prior to 1996.

[someguy]

Thanks for the response. No check engine is not on, and I ran an OBDI diagnostic and no codes are being shown.

However, I do think it is the Idle speed control valve (ISC) I took it out and saw that it was stuck in the "closed" position so there was little air coming in. I took apart my ISC and manually adjusted it so I can get the right mix. I'll post more updates

[lexdud]

I recently purchased a 92 sc300 for cheap to fix it.

I think it's been running rich. When cold, I start it up and doesnt stay on for more than a split second. I have to give it some gas so it can stay on. When it's running at normal operating temperature, it will idle decently, unless I start jerking the steering wheel, then it gets rough again

The fumes from the exhaust smell like gas. I also pulled the spark plugs and they were all black/smoked

I replaced the o2 sensors and gave it a tuneup. I ran a compression test and its showing 150 psi on all cylinders and my timing is perfect.

Has anyone else had this problem? input will be appreciated.

is the CEL (check engine light) on? MAF is a good start, but if its not throwing a code then hold off on just spending money and changing parts. Get a scanner and pull the codes. Just because the light isn't constantly on does not mean it doesn't have any stored codes. Anyways, this is a good place to start. Let me know what you find out.

you are correct, it is obd1. sorry must have been on the crack pipe hahaha! anyways just pull the codes with a paper clip. count the flashes of the check engine light and look up the code(if one is stored)

Tried this last night to no avail. The CEL blinks at 0.5 sec intervals forever. I was told that either there are no stored codes and/or the ECU is fried.

Any other suggestions ... short of seeing a mechanic?

I have a 93 SC4 with only 52,000 miles and I am having problems as well. Unless I am mistaken (I've bee know to) both of our cars are OBD I and NOT OBD II. I have an OBD II scanner but it would be worthless on pretty much any car manufactured prior to 1996.

[jamesbondsc300]

I recently purchased a 92 sc300 for cheap to fix it.

I think it's been running rich. When cold, I start it up and doesnt stay on for more than a split second. I have to give it some gas so it can stay on. When it's running at normal operating temperature, it will idle decently, unless I start jerking the steering wheel, then it gets rough again

The fumes from the exhaust smell like gas. I also pulled the spark plugs and they were all black/smoked

I replaced the o2 sensors and gave it a tuneup. I ran a compression test and its showing 150 psi on all cylinders and my timing is perfect.

Has anyone else had this problem? input will be appreciated.

is the CEL (check engine light) on? MAF is a good start, but if its not throwing a code then hold off on just spending money and changing parts. Get a scanner and pull the codes. Just because the light isn't constantly on does not mean it doesn't have any stored codes. Anyways, this is a good place to start. Let me know what you find out.

you are correct, it is obd1. sorry must have been on the crack pipe hahaha! anyways just pull the codes with a paper clip. count the flashes of the check engine light and look up the code(if one is stored)

Tried this last night to no avail. The CEL blinks at 0.5 sec intervals forever. I was told that either there are no stored codes and/or the ECU is fried.

Any other suggestions ... short of seeing a mechanic?

I have a 93 SC4 with only 52,000 miles and I am having problems as well. Unless I am mistaken (I've bee know to) both of our cars are OBD I and NOT OBD II. I have an OBD II scanner but it would be worthless on pretty much any car manufactured prior to 1996.

Check my response to the rescent post "93 sc300 easy start but won't idle" I think its the third one down on the list. another member picked up on my train of thought and posted some interesting points as well.