Well I''ll start by saying I''m not only a new Isuzu Forum member but a new Isuzu owner. I''ve never driven, ridden in, or owned an Isuzu up until about a 2 months ago. I purchased one with abit of hesitation simply because I knew nothing about the vehicles as in reliability, driveability etc. But once I read some reviews on kelly blue book and saw many people giving praise to the vehicles even up around 300,000 miles I decided to take a chance. Please don''t mind my long post I just like to get the facts/details out in the open rather than spend days answering individual questions.

I bought an ''89 Isuzu LS Spacecab pickup. Which I''m starting to find out was kinda rare. It has the 2.6L FI engine, manual 5speed, and 4 wheel drive with manual hubs. Upon lookin around for body parts is where I started to realize these pickups weren''t nearly as popular as the other 4x4 Isuzu''s. I''ve called a dozen junk yards in Boise, Id. and everything is fine until I say "extended cab pickup" and suddenly the people say "We don''t have any". The odometer says that the truck has 240,000 miles. But the title says EXEMPT. I have no idea if this engine was changed or what. I do know the speedometer does not work BUT the odometer still does.

So as a quick side question, whats up with the speedo? The needle never comes back to rest as 0. It usually sits around 25-35mph but I''ve also noticed when I pick up speed quickly, it will start to rise normally but when I start to de-accelerate it stays where it is and over time slowly drops. I''ve even noticed if I smack the top of the dashboard it will drop in 3mph increments. Probably need to replace the guage?

Ok my main question. The truck seems to run pretty nice to me for being 240,000miles if, in fact, thats accurate. It gets good mileage, it picks up speed quickly, especially after 3,000rpm. It seems to really boost after that. But I experience hesitation sometimes. When I first start the truck at the start of the day, it won''t stay running. The Tach rises up to warm up level (1800rpm) and sometimes it stays, sometimes it doesn''t. Most times it will sit for a few seconds and drop to idle level (around 900rpm) but quickly after it will start to flucuate. The needle starts to bounce between 400rpm and 800rpm. I can give it gas and will rev right up smooth and without problems but as soon as I stop, it will try to rest at 900 but drops again. If I don''t keep it running with the gas pedal, it will start hitting low rpms, the truck starts to shake alittle and it usually dies. But it always starts right back up, but usually does the exact same thing again. Now here''s where it gets confusing...I can start it, and it will act that way, but if I throw it into gear and drive for even a block, once I stop again, the truck idles fine. I mean, seconds later it acts completely ok. As if it ran great the whole time. If I park it and come back when it''s still warm, it will fire right up and idle normally. If I let it get cold, it starts acting up again. My brother is a mechanic and we''ve both talked about the choke or throttle positioning sensor being bad. But the only thing stopping me from replacing those is the fact that it also hesitates sometimes on the road.

If I drive down the road and switch gears around 3,000rpm, by the time I hit 4th the truck starts to stutter. It lasts for a few seconds during the low rpms and then goes away. I''ve also experienced this stutter when I''ve been playing off-road. I was in the middle of a pretty steep hill climb and it started to stutter at the top. Luckily I made it but, it could''ve been bad. I discussed this with my brother and we went for a ride. He told me to wait til around 4,000rpm to switch gear instead of 3,000. It did seem to help alot. He then started to say it was acting as though it was "loading up" but then quickly said, "This is fuel injected, it should not be loading up".

The guy I bought it from was aware of the hesitation and told me about it before purchase. I did a thorough tune-up and nothing changed. I do know that some of my vaccum lines are bad but a few mechanics have told me it would not cause the truck to hesitate in the way I''m explaining. Also could use a new muffler but again, wouldn''t cause this problem. The man I bought the truck from stated that his father in law was a mechanic and he thought one of the injectors was going bad. My brother said it was possible, but normally an injector either runs good, or bad. not both. Which led him to think it''s a sensor/electrical problem. But my Check Engine light isn''t on. I see it light up right before starting the truck, as do all the small dash lights, but it has never come on while its running.

As I said before, sometimes it runs fine all day without a problem. Sometimes it hesitates alittle and nothing more the rest of the day. But every time it hesitates it''s only for a few seconds. And changing gears at higher rpms seems to keep it from hesitating, which points back to a gas related issue, not sensor/electrical. And I''ve further been convinced it''s gas related when I was on the highway climbing over a rather large hill, as the truck couldn''t maintain speed, the rpms starts to drop below 3,000. When this happened, it began stuttering alot. I went into third and pushed it up until almost 5,000rpm (start of redline is 6,000) then hit 4th and it did not stutter. But if I let it fall below 3000 while it''s under load, it will start doing it again which comes right back to my brother suggesting it''s "loading-up".

So, I''m just hoping someone out there who has had the same engine in their vehicle do this same thing and can point me in the right direction before I start playing "parts chaser". I hate spending money and replacing part after part just to find that the previous 5 things I changed were perfectly fine. As far as the starting issue, it''s not a big deal right now, but as my brother pointed out, the 2 problems could be linked to the same thing. So perhaps if you''ve experienced the starting issues you can give me a hint there too. Any help would be greatly appreciated and again I apologize for the long post. But I can say this...for being an old truck with lots of miles that I paid $500 for...it has blown me away. It has small issues but always starts, always drives and has proven to be reliable. I absolutely love the little truck, it''s one of the best I''ve owned, and has given me faith in a company I otherwise knew nothing about. As far as I''m concerned, Isuzu = Good

 

i have had some of the same issues with my 93'' space cab. mine isn''t 4WD but it does have the 2.6..... Now that being said these engines are very sensitive to vaccum line issues due to all of the smog "california friendly" items that come on the truck. I had many of the same issues when i first bought mine and too like yours a very fine toothed tune up really didn''t do much to help it. Now i have gone through and COMPLETLY replaced all of the vaccum lines and a few of the emmissions components and if you never looked at the odometer you would never guess my truck has 207,678 miles on it. So i would try the vaccum lines and then move to the emmissions components from there. also i noticed when i was going through mine when i first got it (i''ve only had it about 7 or 8 months now) that all of the main power and ground wires are a pretty small gauge 8 ga. if i remember correctly. i have gone through and jumped all of these to at least a 4 ga. and it has not only helped my fuel economy and general smoothness of the engine but it also resolved an issue of "dim lights" anyway i''ve digressed i would try the vaccum lines then emissions components.