8.1 MPG stumble at idle???

[cobra0478]

I have been the weekend screwing with my 85 trying to decide why I am getting crappy milage and having a bad stumble at idle.
Also when the car is cold in the mornings and you go wot it seems to crossfire or maby flood,if you back out of the throttle for a few ceconds it clears up and runs OK.Ease into the throttle and it goes fine.
I did a full tuneup again with the correct parts,set base idle,timing, tps,replaced the injectors(had one that was kinda week)compression is good,20" vacuume at idle, flutters only when engine stumbles,otherwise steady.
The only thing I found,last thing before I quit for the day was a sloppy loose dist.shaft,I will change that later.
What do you think?Could the worn dist. be the cause of all my problems?
I have all the usual bolt ons.
Don

[SVOeric]

what did you replace the injectors with ??

Someone didn't slip you some 35's or even some 42's did they??

[cobra0478]

Yes they are 35# injectors,I have did the La3 computer,ported intakes,gillis valve,bailey valve,2 1/2 exhaust,hi flo cat no muffler,
adjustable FPR,the car has the t3-04 turbo.
It was suggested before that the problems with the car falling down at WOT when cold could be valve springs,I replaced thoes and still had the problem,found that I was leaking under boost around the IC hoses,repaired that and haven't had a chance to see if that problem was solved,the car does run better,but still not right.
I am concerned about the distrobuter,and plain on changing it tomorrow evening.I know it can cause rough idle,and maby some of the problems I am having at WOT,but the fuel usage is unreal.
I haven't pulled the codes yet,just working around suspected problems.I guess I should do that after I change the dist.and get everything reset as it should be.
I cleaned the IAC even tho it apeared to be clean and working properly,I have a new TPS I could swap on,but the one on the car is checking within the specified ranges.
I am also running without the EGR valve.
I am just looking to you guys now for ideas.
Don

[GAboySVO]

Don,

What is your fuel pressure set at? Excessive fuel pressure could cause the poor mileage. You might want to pull the AFPR vacuum line and see if the FPR is leaking. This will also make the car run rich. Are you smelling gas under the hood? Are any injectors leaking?

I know the EGR is supposed to help with fuel mileage buy getting a second chance to burn some of the exhaust gases, but nothing like your problem indicates. Do you have the EGR setup that you could through back on the car to see if that makes a difference?

A wobbley ditributor could be a factor because of its relationship to the PIP.

[Eyelawdoc]

Don,

Sorry to hear your mileage is so bad. By all means pull the codes, they can help point you in the right direction.

Other things to check that may be responsible for your symptoms are the VAF, O2 sensor and the ECT. I have had a couple cars with a bad ECT run poorly and start very hard of late. Mileage was poor also, but not as bad as yours.

[gbeaird]

Don,

Also, verify that the cam timing is correct. This sounds like the timing could have jumped a tooth. You can tune out a tooth off, but the car will perform poorly. Verify that.

Gene Beaird
86 SVO, running again,
Pearland, Texas

[cobra0478]

Guys sorry I haven't gotten back,I have been waiting for the weekend to replace the Dist.and see what that does for the car.should know by Sunday.
Hopeing for some good weather,been kinda cold here.We had light drizzel with temps in the low 50's today,in this part of the country that is kind cool.Expect mid 60's tomorrow.

[cobra0478]

OK guy's,
Changed the dist.today,car runs much better,does not pop through exhaust on decel,now just a nice rumble.
drove a 93 mile round trip today only used 1/4 tank of fuel,much better there.
Still has a hesitation sometimes on light excel in first gear,and does not idle as smooth as I had expected.
Got a good kill on an 98 GT on the way home,that made the trip worth while.
Car runs extremly strong,I just wish I could get the idle smooth and get rid of the occasional hesitation.
Thanks,
Don

[Eyelawdoc]

Good to hear it's running better, Don! Keep after it and I'm sure you will isolate the cause of your remaining gremlins! Here's some ideas:

Try installing your new TPS. Also try swapping in a new set of Motorcraft plug wires. (Pat Pearson and myself were going nuts trying to diagnose an ignition breakdown on a local 84. It turned out that even though the owner said he'd replaced the plug wires, he hadn't!) Also, how fresh is your O2 sensor? Have you pulled codes since the dizzy swap?

[cobra0478]

Gremlins sometimes bite

Well car was running so well today that I decided on takeing it on a little trip.(2000 silverado down with ign problems)
Well all goes well untill on the return trip,about 60 miles from home,cruising at hwy speeds,the car misses just one beat, I get the smell of antifreeze,check the rearview to pull over,see nothing behind me but smoke.
When I get stopped and check,the radiator is mostly empty,no oil mixing at this time,engine running with a slight miss.
I am hopeing to find a blown head gasket,also hope that the repairs will solve the problems I have been having.
What do you guys think,could the gasket have beeen weak all along,maby leaking a little causing some of the problems I have been fighting?
Oh well now to tear it down and decide if I can save it or if I need to install the new engine I have built for the Gazelle.
Do these things ever run trouble free??
I guess I will be driving a Hertz car of A different color for a few days now.Hello rental.
Maby I need another SVO so I can work on one and drive the other,or would I need more than two??LOL
The wife bout craped her draws when I road in on the roll back and had her write a check for the tow.
Don

[Eyelawdoc]

Sorry to hear about your bad luck, Don. It's a tough situation when you HOPE it's a head gasket! A bad HG could well account for some of the problems you've been having.

Let us know what you find on teardown.

Your "car poor" situation reminds me of my reply to a young lady who asked me why I had 5 cars (that was a while ago when I only had 5! ), "Well, there's one for me to drive and the other four to work on!"

As a fellow SVO owner, may I suggest you look into the AAA extended towing option.

[gbeaird]

Usually, with a bad head gasket, the car will run so bad you will KNOW something is wrong. IIRC, you said the car ran okay, it just didn't perform well. I guess if it is partially blown, you could have partial sealing and partial power from that cyllinder, but usually, that cyllinder is dead, resulting in a loss of more than 25% of power.

Of course, no matter what the other problem may have been, you now have to replace the head gasket. At least it will give you the opportunity to get in there and check to make sure the cam timing is correct.

Good luck! It sux having to work on a car in this weather.

Gene Beaird
86 SVO,
Pearland, Texas

[Pro-Hawk]

Your "car poor" situation reminds me of my reply to a young lady who asked me why I had 5 cars (that was a while ago when I only had 5! ), "Well, there's one for me to drive and the other four to work on!"

As a fellow SVO owner, may I suggest you look into the AAA extended towing option. [/B]

You really know how to make a new SVO owner relaxed and excited to drive one

Now I know why I still have my ole 93' N/A, just in case

[Pro-Hawk]

Originally posted by Eyelawdoc
I have actually been very lucky with my 84 SVO. In almost 20 years of ownership and 222,000 miles, it has only left me stranded once where I had to be towed. It was a broken timing belt and it was MY fault, not the car's. We've had a couple of other close calls, but it has always brought me home!

20 Years, now that is something to brag about So fair mine has only gave me a scare when drove it home ( 330 miles) the first time. The radiator spung a leak, come to find out it was a known leak that they put stop leak in it. Luckly it didn't even get close to getting hot, I guess because it was at night and pretty cold out side that it held to gether that last 100 miles

My biggest problem with my SVO so fair, is my Foot

[gbeaird]

Yep, with the exception of the popped TFI that happened at our 'Houston meet', and a couple of failed items at autocrosses, our SVO has been THE car we use as our spare, when our daily-drivers won't start.

Heck, it is a 20-year-old car fer Crissakes!! You gotta expect some stuff to wear out. Still, our 86 2R can sit in the driveway for months at a time, and we EXPECT it to start when we get in it with the key.

Even after this little episode with the failed TFI module, I still rely on it to start and go when I need it.

Fun to drive, and dependable, too.

Gene Beaird
86 2R SVO
Pearland, Texas