Dean Tanner

I think my car is running a little rich and I'm not sure how to tell for sure, or what to do about it. Here is what it's doing: The idle speed is a little low. Seems a little sluggish from a standing start. On decelleration it sounds like I get some real minor popping through the exhaust. I think the exhaust smells a little gassy. Once I get off the line, it runs real smoothly and has good acceleration.
Any thoughts?

Jim @ EuroWerks

Do you have emmision state inspections where you live? If so get a reading and that should tell you everything.

Dean Tanner

No we don't. Good idea though.

g-50cab

O2 Sensor? Should be replaced every 60 k miles

Dean Tanner

I just replaced it about 1000 miles ago.

Jim @ EuroWerks

Dean, how much difference did it make in you car?

Dean Tanner

None, I only did it because I had no idea how long since the last replacement.

Jim @ EuroWerks

I've always advised customers to replace it only when having problems. Makes me feel like I'm helping spend their money for more informed and useful services.

Slow Guy

I just went through a rough idle/surging and severe exhaust popping problem that ended up being 2 problems. (1) my 9 mo O2 sensor was bad and (2) the nuts on the intake manifold were very loose. The intake problem caused a lean situation, no telling what the O2 caused.

I'm far from an expert but I think you can unplug the O2 and take it for a drive, if it runs better then replace the sensor. Am I correct in thinking if the oil filler cap is removed it has the affect of leaning out the mixture? Drive it w/ the cap off to see if it runs better, if it does it's running rich.

My .02...
Bill W.
'88 Cab.

Dean Tanner

I worked on it again tonight and found a injector connector that is suspect. It doesn't click like the others when plugged in. I messed with that a bit and tightened the v-belt slightly. Somewhere between these two things, it seems to be running better. Bill, good suggestion with the oil cap, but my car runs like crap when I open it.
Thanks for the input.

Slow Guy

If the car runs like crap w/ the oil filler cap off I would think it was running lean and not rich, again, I'm no expert. But since it sounds like it's running lean I would check the intake manifold nuts. Checking vacuum lines is advisable too.
As I found out w/ my problem the nuts loosen up over time and I was told they should be checked on a reg. maint. schedule. On my '88 the torque is supposed to be 25Nm, I had the wrench set at 15Nm and all 12 nuts turned from 1/4 to 3/4 turn just to get to 15Nm! I then re-torqued all to 25Nm. I was also told the gaskets (2 on each cyl's intake) can get sucked into the cyl. Use a can of starter fluid and spray around the intakes (w/ O2 & Idle Air Cont Valve unplugged and car running) to see if the idle runs faster. If it does there is your leak.

I put in .03 this time...
Bill W.
'88 Cab