I just bought a 90 MM. It has 104K miles on it and a few issues to resolve.
I need to find exactly which engine I have because to register I just chose the first option until I check.
I have some mechanical knowledge but it is limited and I am new to this truck and motor so please go easy on me! haha
Anyways the problems I am having and what I have already fixed.
Average about 23-24 mpg on 93 octane.
First off ... I had the CEL for coolant temp sensor- replaced.
replaced top and bottom coolant hoses.
replaced most of the vacuum lines that I can find.
Air filter looks perfect.
MAF looks new
the other sensors around the intake look a little grimey though.
Some of this is just preventative maintenance and old parts off new parts on swap.
I need to soon install a tach because I don't like that I can't tell the RPMs.
I have started to notice an oil leak near the top half of the timing belt cover ... it is leaking where the bottom half and top half meet. I have not found the courage to pull this off yet to see exactly what might be leaking the oil.
The valve cover seems to have slowed down on the leaks ... it must have sat a little while with minimal driving. Older man owned and rarely driven in the past 2-3 years.
The oil is best I can tell (jug behind the seat) castrol dino oil 10w-30. I am thinking of going to MaxLife because everyone told me not to put Mobil 1 full syn in it. (don't know why though)
So my biggest issues ...
the idle is not what I am used to. I burn 93 in it so that it is clean and I know the possible old gas in the tank will burn out smoother. I crank it and I get the valve rattle (imports!) and it lags then fast idles then back to slower idle then back ... it smooths out but it is a noticeable fast and slow idle pattern. I am thinking my IAC and TPS might need to be pulled and cleaned ... carb cleaner??? Can where throttle attaches to the intake (top say EFI) and clean it then replace ... I think it has a gasket there as well - or is it better left in place?
Now I have noticed that when I am slowing down on the highway and I put it in neutral to idle while coming to a stop or a turning lane it will almost bottom out on the idle and the oil light will flicker. I am probably going to go ahead and replace the oil sensor b/c it is a 8.00 part and looks to be easy to replace.
How hard is the dash to remove if I need to replace my Speedo cable? I had a morning of bouncing speeds and I will probably need to replace or grease sometime soon.
Hopefully last issue for tonight ... when I start the truck either in the mornings or for the first time in hours it sometimes seems to "backfire" under the hood ... that's the sound it makes anyways. If I start it up and take off first gear will hop and bounce and a muffled "poof" noise can often be heard ... same way for 2nd and 3rd until it winds up or if it warms up first it is smooth as butter.
This truck seems fairly simple and straight forward but I hate to get in over my head.
I just parked my 97 Nissan Hardbody for some work when I found this ... I love smaller import trucks!
Many of these issues are probably simple to many people ... please any help at all is greatly appreciated. This is my main ride right now and I need to get her into a bit better shape. I drive about 60 miles round trip and then to night college after work weekly. It feels pretty reliable but I really want to make it better all around ... THANK YOU!!! I appreciate any and all help.
BTW I have searched for some of these issues but I have never found true answers for my issues!