My 91 Navajo has a rough idle. | Ford Explorer - Ford Ranger Forums - Serious Explorations
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My 91 Navajo has a rough idle.

megadeth

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91 navajo
i have a 91 navajo with idle prob i can not find. 4.0 5 speed...i have replaced the following...maf,iac,ect,o2,coil,plugs,wires,crankshaft posision sensor,tps,aircharge sensor,fpr....still the rough idle continues next plan involves a can of gas and a book of matches can anyone save the navajo...thanks
 



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BrooklynBay

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megadeth

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I have good compresion and have found no vacume leaks. the check engine light is not on. it runs great when driving but rough idle is making me crazy.i have put alot into it. just put 1300.00 in clutch and trans rebuild. just one of those things that eats at ya......
 






MrShorty

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I would probably start with some basic diagnostics:

Pull codes, even if the CEL isn't on. Some faults will trigger codes without the CEL, and it only takes 5 minutes (10 if unfamiliar with the procedure) to get codes.

Check fuel pressure and check for gas in the vacuum line to the FPR.

Where it seems to be most problematic at idle, check/clean the passages to the IAC.
 






megadeth

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i have cleaned the iac passage when installed new aic,also replace fpr and checked fuel presure and all was good. as far as fuel in vac line to fpr i will have to check if there is what does this mean?...also i have gone everywhere to get it hooked up to scanner and they could not do it due to being a 91. went to buy scanner and no one had it either???? driving me nuts
 






fixxxer

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megadeth

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I know you could test alot of older cars with paper clip but i really dont know how to do it..
 






Spdrcer34

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I had the EXACT same problem with my motor, that coincedentally I got from a Navajo..

After checking the firing order for the 10th time, and I knew it was right...I changed the plugs. I checked each and every wire. I checked the EDIS module, and I checked the Coil...all tested good. I knew it wasn't a spark problem. Only other thing left was fuel.

Start with a new Fuel Filter, then move to the Injectors. Replace them.

With 95% assurity, that will fix your issues.

Ryan
 






tgreene92

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rough idle

i had a rough and high idle in my explorer i replaced the iac and oxygen sensor and it eliminated both problems. you said you replaced the iac you should try replacing the oxygen sensor
 






MrShorty

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I know you could test alot of older cars with paper clip but i really dont know how to do it..
Browse around this site a little more. We have at least three sticky threads that describe how to pull codes on these: One in the Under the hood forum and two in the EEC-IV forum. After reading those, if you still have specific questions about the procedure, ask away and we'll help you get through it.
 






megadeth

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thanks going to try pulling codes.
 






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