Rough running after freeway miles--checklist

[raygreenwood]

The maddening thing about the idle on this system is that it FOOLS you.

Technically.....as it warms up.....it will not get richer. As the CHT temp rises and resistance falls.....that makes it leaner.
But if you are already too rich, once the engine is warmed up....the need for that excessively rich background setting....decreases .....so it ACTS like its getting richer.

The increasing idle is part of ths "I fooled you " pattern. Whats causing it is the fact that at idle and virtually any rpm below 1500.....because this is paired injection and two injectors are out of time (injecting while the intake valve is closed).....you run very wet ports on two valves. The slow creep up of idle is due to the scavenging of excessive fuel in the ports. Rev it up hard a couple of times.....and it usually goes back to normal idle for a while.

Also....another check.....that is a common problem.....is that when the idle creeps up again after warm up.....reach over and push the throttle, closed hard with your thumb. If that changes the idle....install a stiffer spring. Also check the o ring between the TB and plenum. Also if you switched to the 2.0 bus TB....highly recommended mod......it has a circular positive return spring that really helps this problem. The problem is a combination of the TB heating up and the accel cable getting tighter.

If you get a bus 2.0 TB....borrow or buy a cheap 2" tailpipe expander from harbor freight and cleanly widen the intake on the plenum to match the 5mm bugger TB....and dont forget to replace the shaft seal on the bottom of this TB.
Ray

[bradself]

I haven't been able to find the shaft seals yet. I doubled up the plenum seals, the 1.7 rtv'd to the 2.0, that rtv'd to the TB then all of the rtv'd to the plenum.

I use the old 1.7 TB return spring as well, from one if the arms on the vertical spring cluster headed straight across towards the air cleaner side; had to experiment with the tension. Will make a decent bracket for the upright tin/firewall--helps a bit with the tight accelerator cable problem.

Your explanation of idle creep makes perfect sense, esp. in stop and go traffic.

[raygreenwood]

[bradself]

I also have the square LJet air filter housing as a spare here, it doesn't look like it will be to hard to adapt it to the DJet intake snorkel. This way I can get the K&N flat filter in and increase huge potèntial for air flow, along with the 2.0L TB. I honestly don't know which stock muffler I have now but I've heard the Ernst is the best of the stock variety. I also have a Thunderbird tho I got it long ago with the intention of using it for the AFR guage--it's hella noisy.

All these small moves are really adding up to good running and improved drivability. Once I deal with that dodgy intake rocker on #1 and get the injection harness redone the too of the motor will be complete and I cam move on to the MPS. I'll have to post some pics of the beast soon.

[bradself]

Here 'tis, on a moist Xmas eve. Painted at least once, drivers door is yellow under that Marathon blue, front strut inserts are shot for sure, quite bouncy. 393k miles, mine is the 4th motor, rebuild of a replacement engine from PO, EB004644. Interior is just hammered, but the passenger seat is still quite nice so I'm not worried.

I like it!

Happy Xmas all, enjoy the day! --Brad

[raygreenwood]

Nice car! Mine was originally Marathon, blue as well and will be again. Its a, nice color on this carw shape.
Have merry Christmas!
Ray

[bradself]

About 40 miles city, 80 miles unobstructed highway @ 60-65 mph (according to GPS) and I got 15 mpg. With bypassed cold start injector,( suspected a leak). Quizzed. Unless the MPS is that out of whack.

Once the harness is done I think I need to get the spare trans rebuilt, as quickly as possible. I'll check the wheel bearing adjustments, but what else could be tearing down the MPG? Torque convertor? There are 165s on the car, so perhaps the mushy tall sidewall is contributing to this too. Found a set of chrome 15/5.5 4X130 for the price of one new wheel, so fresh short meats could be on the horizon too.

[raygreenwood]

Yes....its very very common that the MPS is that out of whack. You also have a slightly different than stock cam correct? That will also change the response of the MPS, requiring a readjustment.

You are doing it right though.....patiently driving and testing to make sure all is correct before adjusting the MPS.

I have chrome type stock 5.5" x 15" , 4 × 130 wheels on my car.

I ran with 205-60/15s for ages. They are very close to stock diameter....so the speedo r3ads correctly....but much reduced sidewall and wider tread.

This wheel and tire combination is a major handling upgrade. I ran one set of 205/55-15s....and the handling was slightly better but not enough to offset the extra wear and tear to the suspension it caused before I upgraded to the bronze idler bushkng and delrin control arm bushings. I should probably try them again once I put everything together.

My chrome rims were Eagle brand. They are not as good as some that may be out there now. They were only chrome on the outer lip. The chrome started rusting after 5 years. Also they were a little soft. I know Dallas streets sucked but I had to replace one and have another straightened in a three year period.
But...they run well and at about $60 a wheel....and they actually look good and fit the stock hubcap.

There are some listings now for these same basic wheels that list them as available full chrome or unchromed/painted. I will probably replace mine with painted and have them painted black.

Im also picky about my tires. Having the right tire in the 5.5" with 60 profile is a MAJOR handling upgrade.

Up until about 2002...continental sold a conti-contact all season radial with deep aggressive tread a traction and temp rating of AA....and a treadwear of B....which was good because these tires were so grippy that you could almost leave your fingernail marks in them....just awesome. I didnt mind replacing them every 40k miles.....at $70 a tire. ..because they stick like glue. They dont make that tire anymore but there are some as good or better.

But....im having a hard time finding quality tires in this size in 15" now.

BUT......last year I bought a hybrid snow tire for my golf. Its designed to run and handle like a dry pavement/wet weather tire but is a high speed assymetrical snow tire.

Its stunning! These tires handle better on dry pavement by far....than my brand new factory conti-pro touring tires...and better by far than my Michellins did on my Jetta. I pu them on at first snow and take them off in late spring. Awesome 85 mph cruise and handling.....no discernable effect on gas mileage.....superb on ice and snow.

Just an awesome, awesome, awesome tire....with a Wild tread pattern that really works.....and you can get them at Pep boys and Sears in 205/ 60-15(the tire rack does not list them in our size but you may be able to order them)......for about $80 each.

And....its odd and cool.....the visible tread edge pattern is almost a dead knock off of the original 1970s Michelein XZX tires that were common on these cars back when they were new.

They are Continental extreme winter contact. Look them up on line and you will see whats unique with the tread pattern. These are listed right up there with the Bridgestone blizzak as the two best high speed winter tires made.

I am almost certain I will be buying a set for my 412. Just a perfect year round tire with huge grip.....and we need all the improvements we can get to drive these cars safely at modern highway speeds.
Ray

[bradself]

Oh, 60s, I was shopping 205/50-15. I can run a summer tire, I never go to the snow. And I don't see the Conti Pro-Contacts, no Contis at all actually, at TireRack. Yokohama AVids, Pirelli P4s. But there's nice BFGoodrich gForce summer tires in 205/50-15.

The wheels I found are Mangels.

The WebCam stock DJet grind cam, 33/39s, stock exhaust, stock stock stock stock, except 1.8L.

[raygreenwood]

[bradself]

Nope, not 73, this:

http://webcamshafts.com/mobile/automobile/porsche/install_data/tc_001691_002437.html

[bradself]

That is a crazy tread pattern:

http://www.tirerack.com/tires/tires.jsp?tireMake=Continental&tireModel=ExtremeWinterContact

Only 205/65-15, kinda tall

195/60-15, 24.2" high 3/8" narrower than the 205.

[bradself]

[raygreenwood]

[raygreenwood]

[raygreenwood]

[raygreenwood]

[bradself]

[bradself]

[bradself]

Okay, back to the Ranger fuel pump plumbing (if that was discussed here, erm.)

The return loop is plumbed in after the pressure regulator and before the filter, after the filter, or before the dampner?

Before filter pictured: