Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

Christ · 04-20-2010, 10:46 PM

For some reason, I feel like I had other vehicles that used them, too. Either way, it's a nice surprise when you think your fuel pump is dead, and you do your own service work. (I couldn't imagine paying a garage to do the work, only to find out they pushed a button and it fixed your car... magic buttons, eh?)

Regardless -

I got my truck's engine running correctly again! Final culprit - bad spark plug.

For some reason, I got a spark plug with an internal short to ground. Trusting my tools, I never even thought to swap the plugs between cylinders and see if the misfire moved to another cylinder, because my spark checker told me I was getting spark to all 6 cylinders. Stupid me - I didn't stop and think that just because there's current flow doesn't mean you're getting a spark inside the combustion chamber.

So - 6 hours in the garage and a 6 pack ingested, I changed the injectors. Have to tear the whole top end of the intake manifold off to do this, by the way. However, it was worth it. Now that I've done that, the truck feels like it's got a new engine. I mean new. I can bark the tires in 3rd gear if I play the clutch properly, and they're 30" tires. It really comes to life when I give it some throttle, too, even at the higher RPM's, where 300's usually fall on their faces. Running to 4k is not a problem anymore, and getting on the highway, which was comfortable before, is just dandy now. I do believe now that I have a full engine under the hood, I may have to quit using 1st gear most of the time. I feel like it's just wasting energy to shift between 1st and 2nd at ~10-13 MPH.

For anyone with a EFI 300, though, I HIGHLY recommend getting a cheap set of balanced injectors. It's a world of difference. I got mine for under $100 shipped from eBay - "precisionautoinjectors". I negotiated with the seller and got a set for $75 shipped, and they came with a flow sheet showing that all the injectors were perfectly matched within 1cc of flow. Nice, eh?

Now, I have to patch the floors, (I'll get pics), install some bucket seats, and finish my exhaust (air injection tube just sits in the pipe, threads have been stripped since I got it.). The exhaust is 2.5" into a Cherry Bomb Turbo, 2.5" out to a 2.75" turn out in front of the pass-side spring front spring shackle.

04-20-2010, 10:46 PM	#110 (permalink)
Christ Moderate your Moderation. Join Date: Nov 2008 Location: Troy, Pa. Posts: 8,919 Pasta - '96 Volkswagen Passat TDi 90 day: 45.22 mpg (US) Thanks: 1,369 Thanked 430 Times in 353 Posts	For some reason, I feel like I had other vehicles that used them, too. Either way, it's a nice surprise when you think your fuel pump is dead, and you do your own service work. (I couldn't imagine paying a garage to do the work, only to find out they pushed a button and it fixed your car... magic buttons, eh?) Regardless - I got my truck's engine running correctly again! Final culprit - bad spark plug. For some reason, I got a spark plug with an internal short to ground. Trusting my tools, I never even thought to swap the plugs between cylinders and see if the misfire moved to another cylinder, because my spark checker told me I was getting spark to all 6 cylinders. Stupid me - I didn't stop and think that just because there's current flow doesn't mean you're getting a spark inside the combustion chamber. So - 6 hours in the garage and a 6 pack ingested, I changed the injectors. Have to tear the whole top end of the intake manifold off to do this, by the way. However, it was worth it. Now that I've done that, the truck feels like it's got a new engine. I mean new. I can bark the tires in 3rd gear if I play the clutch properly, and they're 30" tires. It really comes to life when I give it some throttle, too, even at the higher RPM's, where 300's usually fall on their faces. Running to 4k is not a problem anymore, and getting on the highway, which was comfortable before, is just dandy now. I do believe now that I have a full engine under the hood, I may have to quit using 1st gear most of the time. I feel like it's just wasting energy to shift between 1st and 2nd at ~10-13 MPH. For anyone with a EFI 300, though, I HIGHLY recommend getting a cheap set of balanced injectors. It's a world of difference. I got mine for under $100 shipped from eBay - "precisionautoinjectors". I negotiated with the seller and got a set for $75 shipped, and they came with a flow sheet showing that all the injectors were perfectly matched within 1cc of flow. Nice, eh? Now, I have to patch the floors, (I'll get pics), install some bucket seats, and finish my exhaust (air injection tube just sits in the pipe, threads have been stripped since I got it.). The exhaust is 2.5" into a Cherry Bomb Turbo, 2.5" out to a 2.75" turn out in front of the pass-side spring front spring shackle. __________________ "¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"