grantf

Hi, me again. So after removing my clogged catalytic converter my car now runs considerably better, but not like it did before my trouble started about a month ago. I am thinking that I have blown the exhaust manifold again. the car sounds a lot like it did before I replaced it a year ago. First question: could a clogged exhaust cause my new manifold gasket to leak? Also I have spotted oil seeping from the head gasket. So my second question is should I replace the head gasket. It seems that half of the work to replace the head gasket would already be done because of the work required to replace the manifold gasket. here is a little more info: compression test results starting with cylinder one are:143,140,145,146,140,139 hot with all plugs removed and WOT. I also replaced my plugs to NGK and did a cold valve adjust. The valve adjust was after the compression test was made so I do not know if it would effect the results. car ran a little better also but it is still noisy. Grant P.S. I plan to check the valves hot soon, I did the cold adjust just because I have not acheved valve adjustment zenn yet.

perhaps someone would take the whole remainder of your car for a restoration and they would cut out what they need.

cover is held on by silicone. Just jently pry it off. start the engine you can see it move on its own when you revv it. At idle just jently move it to the left and right. If idle increases when you move it counter clockwise, you are lean.

I cut out the cat and put in a straight pipe today. The core was completely crumbled away and the screen at the back was totally clogged up. I took the car on a little test drive and the lost power is back, also took a new vacuum reading and it increased by 2 hg. I am not out of the woods yet, I think my manifold gasket is leaking and I am almost sure that I have a small head gasket leak, I saw a little oil bubbling out at the rear near cylinder six. Tomorrow is a compression test and further planing but that is a different story and perhaps a new thread. Thanks for all the help tracking this down I always learn a little more when ever my car gets sick.

If you try the above start with using a left hand bit it may just back out.

I second that! Stuck and broken bolt are a pain in the butt. Still do not give up hope. they are a pain but not impossible to remove. Just do not cause more harm than good. I would stay away from "easy outs". If you you break one it become a "difficult out". I have never had a fastener I could not get out eventually. But if you are really that stuck take it to a machine shop instead of a mechanic. A good machinist will have it out in less time and will probably cost less.

Cool beans! And yes the new 350 and 370z's can't compare to you're 240 when it comes to class.

Sorry just trying to be funny as I do not have a real answer. I wonder if anyone on the hybridz site has done a modification.

Take things one step at a time. The Fuel injection system looks sort of confusing at first but as you start testing each component one at a time it becomes really quite simple. Do you have the EFI bible and the FSM downloaded yet? Some things that can cause an incorrect mixture are: Bad temp sensor, poor vacuum, AFM out of wack (in my case it was due to someone adjusting it incorrectly), poor fuel pressure, leaky vacuum hoses, torn boot between the AFM and throttle and bad or corroded electrical conections. I would encourage testing components before replacing them, You may end up throwing money at a problem and not solving it. One simple test is the Water temp sensor all you really need is a multi meter and take readings at the ECU connector or if you want to be really accurate take out the sensor and suspend it in water on the stove using a thermometer you can see if the ohm readings are correct. Then you can move on to the next component. Testing tools neaded: multimeter (If you own a Z you need one anyhow) vacuum gauge fuel pressure gauge timing light In regards to the fumes try this: when you drive the car with the window rolled down and you start to smell the fumes :sick: roll up the window and see if they go away. If they do then it is exahst that is coming out of the tail pipe (normal) and entering into body leaks around the hatch tail light gaskets ect. If you are planing on painting youre car soon this would be the best time to remove the seals and gaskets and put new ones on.

I am not an expert on the SU carbs (my car has FI) but I do see two fram g3 fuel filters that look like they need replacing.

Do you mean he did not extract the bolt? can you post a picture?

Why replace the TPS? if it is out of adjustment you can easly fix it. have you looked at the atlantic Z tech page? it helped out alot. http://atlanticz.ca/zclub/techtips/EFI&fuel.htm If you are running rich and have some specific questions Fastwoman may drop a hint or two on this thread she helped out alot with my EFI issues. Adjusting the AFM is tricky. If you are thinking about the idle inrichment screw, that will adjust the air fuel mostly at idle and not reallyu cause a rich condition. Again even when you do have youre mixture about right, you may still get fumes in the cabin. Try sealling up anything that would allow this. Also check the conditon of youre fuel hoses including the ones that go to the expantion tank in the rear of the car. Hope this helps. Grant

Paint them hot pink. Everyone will think you are super cool.

You know it's funny you mention the fuel filters and the TPS. The first thing I did after noticing that my car was running poorly was first to replace the after tank filter then the under hood filter. Then I looked at the thermostat because my engine was running a little hot. Behold! the P.O. (idiot) had installed the old one in upside down! never ceases to amaze me what the last owner could screw up on the car. Oh and I did take a look see at the TPS it has not changed since I last adjusted it a year ago. I have suspected the exhaust to be the culprit from the start, but I have not been sure. I still have not ruled out something else yet, but I am getting a pretty closer to actually thinking that it is the catalytic converter. before putting my EFI back in normal running order last year it was running very rich. So much that I had black soot building up on the rear bumper and left tail lens. I have heard that a rich condition is bad for catalytic converters. So if it ends up being the exhaust I am thinking of buying an exhaust kit from ether MSA or BD. any thoughts on there exhaust products?

I like to call youre car a 240 Zett. But it's youre car not mine.

Did mine one year ago, no broken studs. I soaked all of them with BP blaster for 24 hours and took my time. One thing that was scary was that after firing up the engine after the job was done, light blue smoke pored out of the engine bay. Not to worry though it was just the bp blaster burning off of the exhaust and it stopped after about 5 minutes. I second the new stud kit, peice of mind to have them if you do brake any. don't forget to get a new manifold to exhaust gasket. Edit: I see you already remembered the smaller gasket.

Ok, so I did some more testing, this is what I found. The timing at idle, engine up to temp and everything connected is 13 deg advanced The timing with the vacuum advance routed straight to manifold vacuum at idle resulted in an increase of about 5 deg, total about 18 deg advance. The timing with vacuum advance disconnected completely and revving the engine to 2000 RPMs resulted in an increase of over 20 deg. Hard to tell really like you said off the scale. I understand that these numbers are not precise and I did not set my static timing to 0 before timing, but I am getting the idea that even though my vacuum advance seems low perhaps due to low vacuum that my distribution system may not be the culprit. I hate to focus on one idea, but I keep returning to the idea that this may be a clogged exhaust.

I am not an expert on the BCDD. If you're plugs are black you are running rich. My car was running way rich in the past. It was so bad my rear bumper had black soot building up on it http://www.classiczcars.com/forums/thread42574.html. Again it is common to smell exhaust in the cabin of S30s. If the window is rolled down at least part way the air flow actually causes exhaust to be drawn from the rear of the car into the cabin. I know this sounds counter intuitive. best course on that issue so far I have learned is to try to seal up any holes or caps in the body of the car including replacing worn weather stripping, tail light caskets and drain plug holes.

I just replaced one about a month ago, not easy but not impossible I got a length that was as close as possible but on the long side. Put a little extra bend here and there. It worked out good. And remember use double flare not bubble flare fittings.

It could be both exhuast and fuel. Look at you're plugs. Are the black? As I am sure you know by now most S30s have the problem of exhaust leaking into the cabin. Do you find that there are more fumes when you drive with the window down?

Zed head, perhaps "bogging down" is vague at best. What I am experiencing is a lack of HP but in a big way. When I drive it I can push the accelerator all the way to the floor and the car will barely reach 3000 RPMs. uphill is even worse. I would say that it does not hesitate, stumble or stall. Idle is steady. Vacuum though low is steady and reads predictably when revving (does not flutter and drops a little with increased rpm then climbs to around 20 hg when throttle is released). It's like I am trying to tow a mac truck. With the car parked, if I rev the engine it revs fine up to about 4000 RPMs then the engine will start to run rough and not climb higher. Before anyone jumps on the clutch or brakes I am sure it is not ether (car coasts just fine and no burning clutch). I still need to perform the tests you mentioned above later this evening and I will report on the results. Madkaw, You are correct in regards to the AFM, but I am not considering it to be in any way the culprit. The symptom I have existed before I "messed" with the AFM and no change has occurred with performance since then. I calibrated the AFM last year after finding out that the P.O. had adjusted it way rich. I increased my mpg from about 9 to 19 mpg and the fuel cut off restored to normal. I was very gentile with it and it no longer has the sticky spot. I may revisit the AFM at a later date just to fine tune it (I suspect I am running a little lean). As stated above I have disconected the booster and heater control vacuum hose as well as the EGR system hoses and they have not caused a change in vacuum readings. I am considering cutting out the catalytic converter, but I will not do that until I have ruled out other possibilities. Thanks again and I will give a little more info this evening.

My help me thread: http://www.classiczcars.com/forums/thread46498.html

Understood, terminology: is centrifugal advance the same as mechanical advance? Understood I will perform this test tomorrow and report back I had to reread this twice but I understand. I may dive into testing the distributor more, but could this be barking up the wrong tree or a likely cause of the symptoms?

Good to know you fixed it now fix my car.

http://www.classiczcars.com/forums/thread46526.html Perhaps the moderator will combine or delete some of his threads. He may not quite understand how the forum works. But yes He should give up a little more info if he wants help, But I do understand what it is like to be in a pickle. Check for spark.