Wish I could get 10mpg. I get about 4 to 4.5 on good days.

 

Well i seperated the wires a couple days ago and it *seems* like it helped, but i'm going to drive it a week before come to any conclusions. I don't hear any pinging either. Before I would hear an occasional ping. I just filled up, so i'll see if it helped with the mpg at all.

Thanks guys,
scott

 

Today I finally was able to bump the timing from 8 BTDC, to 12ish(a smidgin over 12 BTDC).

No ping on regular gas, I'm able to pass cars again. No ping going up hills in OD when load is at its greatest and RPMs are down.

Next, I'm gonna try 14 degrees BTDC on regular. I think it'll work now that the intake and combustion chambers are clean due to the Wynn's treatment.

If this thing wasn't Speed Desity I'd throw a cam in today!

 

when i got this posted mpg it was on reg and i was pinging badly at times..i've got my wires seperated so no crossfire . i need to do something about the ping .

 

Sometimes ping is caused by carbon build up on the piston tops. When I tore aprt my mustang it had alot of carbon and slight pre-ignition. Saturns SOHC engine carbons up in about 45k by drivers who caost everywhere. We've had good success de-carboning useing Wynn's 3 part Fuel System clean. Similar to Top Engine clean from what I've heard.

As the carbon warms and gets saturated w/ fuel it starts to fire early, causing pre-ignition. The carbon acts like a sponge. I knew this wasn't the case w/ mine because mine would ping when cold...hence wire seperation

 

mine doesn't ping cold and not at WOT just part throttle situations and this was after driving 100 miles .

 

Ray-

Did it do this before your airbox mod? I'm just asking because the two times when it doesn't do it are the two times the ECM automatically richens the mix. Have you checked your fuel pressure? I'm curious to know how much it changes with the vacuum hose disconnected. Just thinking out loud (and typing it).

Take care,
-Chris

 

My truck has the same symptoms as Ray's....Doesn't ping when its cold, or at WOT. Just at part throttle cruise. It used to be alot worse when I had the vacuum leak. I have to timing down, so it doesn't do it very often now, but occasionally it will ping. I'm going to put a 180* thermostat in to see if that helps any...

 

Chris
ya it has always done it . and no i haven't checked the fuel pressure . the posted MPG on this thread also is off my front tank . i normally don't use my front tank because the sending unit doesn't work on it . i am running another tank full on it now just to see if the MPG stays around abouts the same .then i'll go back to usin the rear tank to see if my MPG drops back to 13.5, if it does i got a fuel pump/line problem ?

 

Old catalitic converters will decrease MPG also.

Shannon

 

if i had one ...........lol

 

this thread i started i posted 15.69 mpg when i drove 100 miles and 100 miles back . that was on my front tank . i filled it again . and drove back and forth to work . 13.33 mpg . well then i filled the rear tank and drove the same distance again 100 miles there and back . 15.70 mpg . so it seems my truck likes to streach it's legs out . not go for short runs . i drive 15 miles to work and home . gonna try another tank to work and try (yes i said try) to keep my foot out of it some as i do when i am driving long distances . will post results .

 

well i did keep mt foot out of it some . well a little maybe . lol enough to bump it up to 14.56 back and forth to work .

 

Well finally have some results with the MAF. It is a 88 F150 4x4 with a 5.8, C6, 3.08 gears, and 31" tires. I converted it to MAF and SEFI with a 91 T-Bird EEC and now have a 93 Mustang Auto EEC. With a 15 mile drive to work, 10 miles hwy, 2 miles country, and 3 miles city it has averaged 12.5mpg. That is also getting WOT a few times a day.
The best I ever seen with the speed density was 11.2, but that was in warm weather and lightly driving it. I hope to get about 14 on a long run, and once I find a E4OD I would like to see 16-17 highway. But I will have to see first.

 

That sounds very promising! I'm in the process of soldering my wiring harness for the conversion at the moment and hope to post the results here some time during the summer.