Nytrosfinder Posted March 12, 2009 Share Posted March 12, 2009 (edited) So my 88 quit on me, definably fuel related, cause it would crank but not turn over, pumps good, filter is new, lines are clean. I pulled my throttle body Tuesday, found a whole bunch of carbon build up on it. So i am gonna get that cleaned up, and get my throttle body cleaned up a bit. I got Certified friends to help me out with this, and people for supplies. Getting the rebuild kit from NAPA tomorrow (3/12/09). Now my main concern is, are there any dangers with rebuilding a throttle body? My other question is, besides port and polishing, are there any other ways to get more performance from the throttle body? I know they sell spacer kits for them but haven't found one for my '88..... Do they sell jetting kits for throttle bodies? I know that upgrading my injectors COULD help but im not so sure. Got anything? Help me out... Edited March 12, 2009 by Nytrosfinder Link to comment Share on other sites More sharing options...
88pathoffroad Posted March 12, 2009 Share Posted March 12, 2009 As long as the injectors seat properly and you use new o-rings and gaskets it should be fine. No dangers I can think of. There's nothing you can really do to the stock TBI for more power except smooth/port it slightly and polish it. The stock injectors will support a supercharger running 12-15 PSI of boost, so that should tell you something about those...um...one other thing you can do is eliminate the mixture heater or break out the honeycomb...that helps airflow. I made a couple of 3/8" thick spacers (3/4" total) out of UHMWPE plastic but it didn't seem to make any difference. I didn't expect it would, but I had to try. No such thing as a jetting kit for fuel injection, man. That's only on carburetors. Link to comment Share on other sites More sharing options...
MY1PATH Posted March 12, 2009 Share Posted March 12, 2009 (edited) Leave your injectors allone. The nissan TBI injector is best left stock. I had some python performance injectors and they both failed @ the same time after 4 months, this led to several other problems. there are not spacers available for the tbi but I saw somone who 88pathoffroad made a spacers for his and said he noticied no differance in power or gas. I good polish should yeild some results as well as porting and getting an enlarged your butterfly may improve throttle response. dangers; after your TB is removed (mixture heater too) look @ your manifold, the passageway to the egr may have allot of buidup inside it. Do not let any of this hardened buildup fall into your manifold. I just p&p my manifold and knocked 20 yrs of crap outa that passage it is big enough and hard enough to do some damage. Edited March 12, 2009 by MY1PATH Link to comment Share on other sites More sharing options...
MY1PATH Posted March 12, 2009 Share Posted March 12, 2009 one other thing you can do is eliminate the mixture heater or break out the honeycomb...that helps airflow I never thought of that... I assume doing so might offer better mpg too... will removing the mixture heater throw any codes? will doing so give me problems in cold weather?(running closed loop longer) anthing else I should know about this? Link to comment Share on other sites More sharing options...
Kingman Posted March 12, 2009 Share Posted March 12, 2009 X2 I'm all for anything to get me some better mileage Link to comment Share on other sites More sharing options...
88pathoffroad Posted March 12, 2009 Share Posted March 12, 2009 You can unplug the mixture heater and just tape it up. It won't throw any codes. Here's what my setup looks like. It did seem to give me more juice, but not a lot. There's the mixture heater on the bench inthe background with the center removed. I also trimmed the base flange and belled it outward like a rocket nozzle for better airflow. Link to comment Share on other sites More sharing options...
MY1PATH Posted March 12, 2009 Share Posted March 12, 2009 yes but the guys that did your TB are out of buisness and all the local guys are afraid to touch mine... thanks for the info on the mixture heater. U have any issues running in the cold there in OR. If it doesn't really effect anythign exept airflow I just might gut when it get warm enough to work outside. Link to comment Share on other sites More sharing options...
Nytrosfinder Posted March 12, 2009 Author Share Posted March 12, 2009 yeah when i pulled my Tb off i found alot of build up. I am gonna get a vacuum with a long hose and at the same time vacuum all of it up and scrape it clean so it wont fall in... did that on a friends maxima and his runs strong.... Now the whole thing about the mixture heater, isn't it better for combustion to have a cooler mixture? If I remember right I think thats why they make COLD air intakes, for colder air to get to the engine... Doesn't make much sense.... Now when it comes to port and polishing, is there some way I could do it in my own garage? I know its expensive (above $150) to get that done cause its around $200 per Head on my friends 1969 El Camino and he could afford it... I am gonna rebuild my TB and clean it up a bit, my rebuild kit should be at napa later today. If anyone has got some advice about this that would be awesome.... And does anyone have an "exploded view picture" of the throttle body? like a diagram of all the parts and what not? Link to comment Share on other sites More sharing options...
88pathoffroad Posted March 12, 2009 Share Posted March 12, 2009 My intake was all carboned up too. Take a look. Zero EGR function, the EGR passage was completely blocked. TBI, split into main components... FSM page with exploded view. Link to comment Share on other sites More sharing options...
MY1PATH Posted March 12, 2009 Share Posted March 12, 2009 Now when it comes to port and polishing, is there some way I could do it in my own garage? I know its expensive (above $150) to get that done cause its around $200 per Head on my friends 1969 El Camino and he could afford it... you can polish your TB with demel and some 400 grit attachments working up to soft buffers. To port it you would need to have a larger buterfly made and a way of enlarging the opening so that it stays perfectly round. Link to comment Share on other sites More sharing options...
88pathoffroad Posted March 12, 2009 Share Posted March 12, 2009 yes but the guys that did your TB are out of buisness and all the local guys are afraid to touch mine... thanks for the info on the mixture heater. U have any issues running in the cold there in OR. If it doesn't really effect anythign exept airflow I just might gut when it get warm enough to work outside. The mixture heater only runs on a cold start, to aid in warm-up and emissions. Yeah, mine runs worse in cold weather. After it warms up, no problem. One thing I regret doing was tossing my AB valve. Anti-backfire valve. Keep yours. Link to comment Share on other sites More sharing options...
Nytrosfinder Posted March 12, 2009 Author Share Posted March 12, 2009 My intake was all carboned up too. Take a look. Zero EGR function, the EGR passage was completely blocked. Looks like alot was needed to get that cleaned... lame Here is mine: got some build up.... not too much though I was thinking about the 400grit, but i dont wanna ruin this throttle body if i accidentally hit something wrong.... Where did you get that diagram picture from? Link to comment Share on other sites More sharing options...
88pathoffroad Posted March 12, 2009 Share Posted March 12, 2009 It came from my factory service manual. It was a present from a friend who found it on Ebay. Airflow through the throttlebody is essential to MAF operation, you definitely don't want to randomly grind stuff off on the inside. I would say that smoothing out any casting flash and making it shiny wouldn't hurt though. Link to comment Share on other sites More sharing options...
Nytrosfinder Posted March 13, 2009 Author Share Posted March 13, 2009 It came from my factory service manual. It was a present from a friend who found it on Ebay. Airflow through the throttlebody is essential to MAF operation, you definitely don't want to randomly grind stuff off on the inside. I would say that smoothing out any casting flash and making it shiny wouldn't hurt though. thats what i ment..... just to clean it up.... and get rid of it to a clean surface.... grinding is overdoing it..... Link to comment Share on other sites More sharing options...
MY1PATH Posted March 13, 2009 Share Posted March 13, 2009 It came from my factory service manual. It was a present from a friend who found it on Ebay. there happens to be one for an 89 on ebay rt now Link to comment Share on other sites More sharing options...
Nytrosfinder Posted March 15, 2009 Author Share Posted March 15, 2009 So get this I get my throttle body rebuild kit from Napa auto parts, and none of the parts in there will fit with my throttle body! I am so mad about it... I spent $23 bucks on a kit that i got nothing out of it.... (and no i cant return it cause its opened). Makes me so mad...... So i gotta spend 3x as much at the dealer to order new gaskets.... Link to comment Share on other sites More sharing options...
Kingman Posted March 15, 2009 Share Posted March 15, 2009 So get this I get my throttle body rebuild kit from Napa auto parts, and none of the parts in there will fit with my throttle body! I am so mad about it... I spent $23 bucks on a kit that i got nothing out of it.... (and no i cant return it cause its opened). Makes me so mad...... So i gotta spend 3x as much at the dealer to order new gaskets.... ...did you order the correct one for your truck? Link to comment Share on other sites More sharing options...
MY1PATH Posted March 15, 2009 Share Posted March 15, 2009 So get this I get my throttle body rebuild kit from Napa auto parts, and none of the parts in there will fit with my throttle body! I am so mad about it... I spent $23 bucks on a kit that i got nothing out of it.... (and no i cant return it cause its opened). if its wrong and unused they should take it back. they should just inventory it, tape it up if its all there and put it on the shelf. Link to comment Share on other sites More sharing options...
GrimGreg Posted March 15, 2009 Share Posted March 15, 2009 I take oepned stuff back to NAPA all the time, they just check all the parts are there and send you on your way with your money back. Link to comment Share on other sites More sharing options...
Nytrosfinder Posted March 16, 2009 Author Share Posted March 16, 2009 Thats what happened when i returned it( yes i ordered the right one, made sure of that when i handed the money over) and it turned out to be wrong. The guy there was odd though.... he started questioning me as to why i had to return it.... as in "was i able to afford it?" <-dumb question....would i have gotten it if i wasnt? lol Link to comment Share on other sites More sharing options...
Kingman Posted March 16, 2009 Share Posted March 16, 2009 (edited) The mixture heater only runs on a cold start, to aid in warm-up and emissions. Yeah, mine runs worse in cold weather. After it warms up, no problem. One thing I regret doing was tossing my AB valve. Anti-backfire valve. Keep yours. X2. Keep that... What kind of improvement does polishing the TB give? Edited March 16, 2009 by Kingman Link to comment Share on other sites More sharing options...
Nytrosfinder Posted March 16, 2009 Author Share Posted March 16, 2009 It allows for a better airflow - you know how on a dirt road that hasnt been smoothed up... cant go so fast on it, where as on a paved road you can fly- same principle, smoother way for air to move directly to the engine... and its also basically a cleaning too... restoring it to brand new is the goal, as well as removing all the gas build up, dirt and grime build up thats gotten past the air filter.... Link to comment Share on other sites More sharing options...
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