The crack on the left side of the spring clamp PROBABLY isn’t a problem. But you don’t have to guess. With the car outside, start the engine, let it idle to warm up. Pop the hood. Spray brake cleaner or carb cleaner on the suspected area. If the sound and RPM of the engine changes, you have found the leak. You can also do the same test with an (unlit) propane torch. Repeat test at all vacuum connections, hoses, intake manifold, throttle body gaskets, etc.

Remember, all the materials listed above are flammable. That's why you do it outside. I would also recommend having a fire extinguisher of the correct type handy. Fires are rare, but you don’t want to be the one case. Eye protection is also a good idea.

A vacuum leak causes the engine to run lean, and the O2 sensor feedback causes the PCM to increase fuel flow to compensate for the lean condition. That isn't likely to cause the engine to run rich and foul the plugs. The problem generally occurs when the is a “false” indication the engine is running lean, and the PCM adds extra fuel the engine doesn’t need. That is discussed in the earlier posts in this thread.

 

Okay thanks injuneer for finding this thread. I have yet to get a laptop.

I was about to get one off a guy locally but he ended up selling it to someone else.

I think I'm gonna buy another tect 2 scanner since that did give me some good feedback.

Today I will be fixing the oil leak on the timing cover.

And replacing my not so old optispark with a msd.

You think oil getting all over the optispark will mess it up but still enough for it to still run the car?

Along with that I'm replace the fuel filter as well.

I'm having symptoms similar to a guy on a thread that had a clogged fuel filter.

Low/rough idle at cold start. Rpm bouncing around when slowed down

I'm just surprised I haven't got a code or anything cause once it gets to the right temp it runs good.











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I personally do NOT recommend MSD. They have had way too many problems over the years - they fix one problem and another pops up. A few years back they produced a batch that cause huge idle problems, surging, etc. After I sent them data logs showing he symptoms of the problem, they eventually figured it out. They were rebuilding units for free, and two of the people I helped received rebuilt units that failed out of the box. I'll never understand how they can build the best magnetos for top fuel dragsters, but can't produce a reliable Opti.

Go here:- this is the only supplier I have seen with no negative feedback. There is a reason he is often out of stock.

https://petrisenterprises.com/

 

As far as the fuel filter is concerned, if it was dirty and causing flow problems, it would create issues at HIGH engine loads, where fuel flow is max. Not at idle there there is very little flow required.

Seems like there are a lot of people with problems from your tuner.

You need to do diagnostics and stop replacing parts at random, hoping you'll get lucky.

 

That's funny that you brought this up, I'm thinking maybe I should return it.

I seen on other forums you and shoebox mentioning about how the msd optispark have problems.

I didn't even install it yet cause me and a buddy of mine wasn't sure if it would start due to the timing feature on the unit. Is that optional? Or do you have to set the timing on it in order to start the car?


I wished I would of known about this site before I purchased this msd unit.

 

As I understand it, there is a screw that is set to allow you to advance or retard the timing relative to the cam. It's a small adjustment. I can’t see any use for it, unless you have advanced or retarded the cam relative to the crank/TDC. I also believe there are no markings on the adjustment screw, but they tell you how many turns from the end point will get you to “stock” timing. Shouldn’t be a problem.

 

I actually felt some differences after changing the fuel filter.
Low/rough idle is still present when cold, but not so much like before. It recovers after a couple of sec.

​​​​​​I blew through the old one and air didn't come out the other side. Assuming clodded?

Also Which bring to mind, I notice that my evap duty be cycling through 55-77

I don't know if it was you who said this on a different thread. But I read that the evap duty on the scanner should only show 0-100 (Open and closed) nothing else. Correct me if I'm wrong.

I just like replacing parts, especially while building a car.

​​​​​​I don't feel comfortable adding power adder without replacing anything.

I've done this on all my cars that saved a lot of headaches and money on the long run.

As far as my tuner, I've been hearing bad things about him lately..

I told him about the code 51.

​​​​​​He said that maybe my pcm is bad, but he wasn't sure.

 

If the fuel filter is BADLY plugged, it will affect both idle and normal driving. Does the engine run OK under heavy load?

I never said "the evap duty on the scanner should only show 0-100 (Open and closed) nothing else" because that is totally incorrect.

EVAP purge is pulse width modulated (vacuum to purge solenoid rapidly turned on and off). That means the scanner shows the "duty cycle", which is the percent of the time the flow channel is open. It is variable over the full range of 0-100%.

Since you feel playing "parts replacement roulette" is the way to go, good luck.

 

It's runs better then it did before I change it. It still does have a little low rough idle at cold start.

I seafoam my car last month, is it possible dirt from the lines or pump broke off and clodded it?

Cause even that fuel filter wasn't that old, I put that on like a couple of months ago.

I'm starting to think this is a fuel issue, cause why when I replace the fuel filter, things are running way better then it did?

And why did that one go bad so quickly?

Could a bad injectors cause these symptoms? What would a scanner show if a injector or injectors was functioning wrong?

Maybe I read wrong, but a lot ppl be have issues from that evap system right? Can I cap it off? Even tho it's not disable.

And also what does it mean when theirs oil in the throttle body?

Sorry if I'm asking a lot of questions.