I have more questions

The place to discuss problems and routine maintenance questions and tips that are NOT specifically diesel-related.
Regular Member
Posts: 19
Joined: Sat Aug 25, 2018 11:38 pm
Location: Yelm WA.
Isuzu vehicle(s): 2002 Trooper TOD/4WD 1991 Space cab LS 4wd

I have more questions

Postby lucas » Thu Sep 06, 2018 11:28 pm

After doing a pretty decent tune up on my 2.6 space cab I still have some erratic idle issues.
The list of parts I replaces are as follows
2. Plug wires
3.Cap and rotor/ sprayed a ton of cleaner into the distributor to wash out the oil
4. new valve cover gasket
5. Air filter
6. Radiator cap/ coolant temp sensor.
7. new walker muffler (old exhaust had more holes then swiss cheese

I have a new fuel filter that I can't seem to find out where it goes yet but I haven't investigated enough to find it.
So before the new muffler I was having an erratic idle issue when pushing in the clutch would idle from 500 to 1500 over and over sometimes it would stop sometimes id tap the throttle and it would even out. Ive associated the erratic idle to two possible issues, the IACV, or the TPS.. I still don't know enough about these trucks to make an educated guess. Having owned 5 other vehicles from the early 90's I know they all have IACV problems in one way or another. I also have noticed after driving it the last few days after the idle stabilizes it will sometimes begin to creep up slowly another light tap would correct this also.

Although I noticed this evening that after I installed the new muffler the truck had the opposite problem, started fine and idled normally around 900rpms after running for a few mins either my RPM gauge stopped working or it was idling lower then 500rpm or below. I also noticed a slight miss, either the distributor is still goo'd up or I still have aforementioned problems.

While changing the coolant temp sensor I saw near the bottom of the engine there was a sensor with two wires come off of it that weren't connected to anything. I have consulted my factory manual and haven't found what its for yet, but I doubt its related to my idle problems.
If anyone can shed some insight on my idle problems id greatly appreciate it, there are a few vacuum concerns and while I had the valve cover off I completely forgot to check the head bolts but did wiggle the valves and non were loose.


Red Truck
Regular Member
Posts: 81
Joined: Wed Sep 18, 2013 7:10 pm
Location: Vader, WA

Re: I have more questions

Postby Red Truck » Mon Sep 10, 2018 3:24 pm

I don't have your engine type, but maybe I can offer a hand: All I see are two plug/pin connectors coming out of a cable-wire bundle. Partially hidden under the cable bundle appears to be the oil pressure sender. Mine has a single wire, tho later models have two wires. Does your oil pressure light work? Otherwise, 'what is this sensor with two wires of which you speak?' Can you tell what colors are the wires?

I had to look up what an IACV was, and from the description of what happens when they go bad, it appears to fit your symptoms perfectly. Kinda sucks they're about $200 a pop, maybe they come apart somehow......
'87 Isuzu pickup 2.3 gas, 5spd, 4WD