JOMJ87 Posted November 7, 2006 Share Posted November 7, 2006 First I have an 1987 2.5 manual sportruck with 206000 or more miles on it I have finnaly decided that I need to fix a problem with my motor instead of doing some other projects. I have been running semi rich since i got the truck 6 years or longer ago but havent tracked down the problem. I have a bad IAC motor (the thing on the front of the TB at the linkage that adjust your Idle I think) but that shouldnt cause me problems driving down the road. I am thinking CPS but i don't know for sure, or what about the O2 sensor which was changed when i first got the truck, I have checked all vaccum lines and cleaned the entire TB and injector (TBI Motor if you didnt know). I have seen a post on this but never caught what motor and when I searched for it today 50 pages came up of posts and I didnt want to look through them. I have no clue other than what was mentioned as to what it might be OR i am looking over something simple it could be. let me know what you guys think Thanks Cole Link to comment Share on other sites More sharing options...
Pete M Posted November 7, 2006 Share Posted November 7, 2006 Check that the fuel injectors aren't leaking or stuck open. Link to comment Share on other sites More sharing options...
JOMJ87 Posted November 7, 2006 Author Share Posted November 7, 2006 OK after an hour of searching I have found the post. It was the one aemsee was talking about the MAP sensor and I think thats the problem. Pete I have cleaned every peice of the TB including the injector and check it and it sprayed a fine mist cone so its good. Now one more question.. I know some of you 2.5 guys and 4.0 guys have done some vaccum line work so here's my question. My 2.5 has a stupid block that the lines pass thru next to the TB. Can this block be eliminated or does it do something special???? I broke a line on it while checking lines today and now I want to remove it so I can fix all the lines properly. Cole Link to comment Share on other sites More sharing options...
Oizarod115 Posted November 7, 2006 Share Posted November 7, 2006 have you had the fuel pressure regulator tested? i seem to remember that being bad in my brothers and causing it to run rich. Link to comment Share on other sites More sharing options...
JOMJ87 Posted November 7, 2006 Author Share Posted November 7, 2006 Ill look into that if it stops raining today. Is there a voltage reading that should be good or how should I test it. Cole Link to comment Share on other sites More sharing options...
87manche Posted November 7, 2006 Share Posted November 7, 2006 Ill look into that if it stops raining today. Is there a voltage reading that should be good or how should I test it. Cole you'll need a fuel presure guage that goes up to 50 psi at least. I'm not sure what your 2.5 is supposed to have, but on the 4.0 of the renix flavor it should read 31 PSI with the vacuum line connected and 39 PSI without. Link to comment Share on other sites More sharing options...
mjeff87 Posted November 7, 2006 Share Posted November 7, 2006 Fuel pressure should be 14.5 psi. The FSM claims the regulator is adjustable via a torx screw on the underside, but I could find no such thing on my TB :nuts: in the past when I was trying to diagnose an intermittent stumbling problem (turned out to be the O2 sensor anyways). Lemme see if I can figure out how to post the pic from the FSM that shows the "adjustmet" thingy..... Jeff Link to comment Share on other sites More sharing options...
87manche Posted November 7, 2006 Share Posted November 7, 2006 Fuel pressure should be 14.5 psi. The FSM claims the regulator is adjustable via a torx screw on the underside, but I could find no such thing on my TB :nuts: in the past when I was trying to diagnose an intermittent stumbling problem (turned out to be the O2 sensor anyways). Lemme see if I can figure out how to post the pic from the FSM that shows the "adjustmet" thingy..... Jeff well, that's good to know. Must be lower because it's only got to feed one injector. Link to comment Share on other sites More sharing options...
Pete M Posted November 7, 2006 Share Posted November 7, 2006 While we're on the subject, is there 2 injectors in the throttle body, or only one? Link to comment Share on other sites More sharing options...
mjeff87 Posted November 7, 2006 Share Posted November 7, 2006 just one injector. Here's the pic from the FSM: Image Not Found Remove air filter elbow and hose. Connect tachometer leads to diagnostic connector D1, attaching negative lead to terminal D1-3 and positive lead to terminal D1-1. See Fig. 4. Remove screw plug and install fuel pressure test fitting. NOTE: Fuel pressure test fitting is not included with throttle body. Fitting (8983 501 572) must be obtained separately. 2) Connect fuel pressure gauge to test fitting. Start engine and increase speed to approximately 2000 RPM. Turn Torx head screw at bottom of regulator to set correct pressure. Turning screw inward increases pressure and turning screw outward decreases pressure. See Fig. 3. 3) All models require fuel pressure of 14.5 psi (1.0 kg/cm Like I said, I didn't find any type of adjustment screw on mine. YMMV :D Jeff Link to comment Share on other sites More sharing options...
JOMJ87 Posted November 8, 2006 Author Share Posted November 8, 2006 NE one know if I can eliminate that junction block that the vac lines go through see my above post for exact location and stuff. I don't think it does anything extra??? Cole Link to comment Share on other sites More sharing options...
aemsee Posted November 8, 2006 Share Posted November 8, 2006 I don't see any reason for not bypassing it. It is a silly design anyhow. Link to comment Share on other sites More sharing options...
JOMJ87 Posted November 8, 2006 Author Share Posted November 8, 2006 Ok I think aemsee is right but has anyone done it. And if not does anyone want to confirm the lines just pass straight through without doing anything spectacular.....I am planning to work on the truck in the morning since i got off work to do it. :brows: so let me know what you guys think about removal of this item plus i discovered 2 lines are cracked on it anyways. :roll: Cole Link to comment Share on other sites More sharing options...
JOMJ87 Posted November 8, 2006 Author Share Posted November 8, 2006 OK the MAP sensor seems to be working when i unplug the vac line and stop the leak the motor dies ???immediatly??? but I could get my volt meter to work I think I have a bad lead. Anyways I removed the block for the vac lines that i was asking about earlier and bam it cleared alot of the Rich idle up but not all of it. I think the Vac lines for the EGR and a couple others were cracked?? I also looked at my injector And it was spraying jjust as pretty as before BUT is it suposed to coat the butterfly in fuel or should it not spray so much at idle cause it seemed like alot. I have to get a fuel pressure tester and see if thats right and BTW I found that adjustment screw thing on the regulator. If anyone has anymore ideas I would greatly appreciate them Cole Link to comment Share on other sites More sharing options...
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