Question-------------------------
Followup to...Hi again and thank you for helping me..I ran the codes last night and here's what I got in this order.. 21, 44, 33, 77, 74, 65,.I have a new EGR valve and sensor, new ECT sensor I have taken off the smog pump hoses and valves O.K. but my EGR valve is getting no vaccum. traced the line and seem like I am getting no vaccum from the black tube at the passenger side vaccum canister which feeds the two selinoids mounted on the bracket on the top of the motor. It ran perfect this morning, till it warmed up about a mile and a half then it all started happening, stopped for coffee and ran good for about 1 minute and stared happening. Is there a thermatic valve or somthing I need to replace and cant find making this diffacult but easy to find. I even put a new IAC vavle on and nothing, If one of these connector wires were shorted would the check engine light flicker during the the irractic idle
also to mention that I get a continuance flow of air out of this little canister mounted on the pass fender well and I get a stronger than normal
exhaust smell from the smog pump area. I will clear the codes cause I think that some of them are stored codes from before and I will pull new ones during my lunch break 12:00 EST. I will let you know them as soon as I get them. could you explain to me the vaccum process of that vac canister on the pass fender well, it has a red tube and black tube hooked up to it which runs over to the diverter valves ect. I'm going crazy..I dont believe there is any question on the gaskets I have sprayed carb cleaner all aroud the areas and no change in RPM accured
Dan
Question -
I have a 1990 bronco 5.8l. when I turn it on for the first less than 1 minute its at normal high idle, it comes down and drives fine, after about
three miles or so the irratic idle begin's, almost like dropping to 200 and back up, it also pings at this point but nothing drastic only going up hills ect.it does this randomly after it warmed up. Now if I unplug the spout connector and leave it off it will drive fine with no idle problem but it lacks the pull the 5.8 has. The motor is rebuilt by my race car mechanic and was fine for about two years unitl one day coming home from work the bronco began to idle real bad and I had to keep my foot on the gas and brake to get home during this ride home the fumes it was giving off was enought to almost kill me. At home I turned it off and it never restarted, come to find out after replacing... fuel pump, fuel pressure regulator, fuel pump relays, then it still never started so I replace the computer and sure as hell it was the eec IV. now I have this problem with the idle. Is it possible that there is a thermatic valve/senser some where I cant find. since the new computer I have replace or checked out all the emmisions stuff, replaced MAP, EGR, DIST, EGR SELENOID, vac lines but not the 02 sensor and so on...I need HELP PLEASE..
Dan
Answer -
You need to check for codes on this Bronco.If you have you didn't mention it. Throwing parts at it will just cost money until you stumble onto something. This engine had problems with the intake gaskets, EGR valves, IAC valves, throttle body gaskets. I wouldn't replace anything without doing some diagnosis, starting with a code test.
AnswerCode 21 is related to a sensor, either the ECT or IAT.
Code 44 is smog pump related.
Code 33 is EGR
Code 77, 74, 65 indicate you didn't do the KOER test correctly. During that test you are supposed to step on the brake pedal, turn the OD switch on/off, and goose the throttle. You can repeat the test and do these or ignore them.
The canister you mentioned, does it look like a tin can? If so that is a vacuum storage reservoir that maintains vacuum in the systems during periods of full throttle or heavy loads. There should be engine vacuum on the red line, and with it connected there should be a weaker vacuum on the black line. If not then you have a leak, possibly from the can itself.
Smelling exhaust fumes at the smog pump anywhere means a leak of some kind, either from the EGR tube from the valve to the exhaust(prone to crakcking)or one the check valves after the smog pump has ruptured and sending exhaust backwards thru the system. The check valves are supposed be a one way valve.
Breakage of the small plastic vacuum lines is very common on these older vehicles.
