[jdmcentral71]

Hey Everyone,

I'm happy to be the new owner of an 88 Trooper LS. It's a 4ze1 backed with an automatic transmission.

I purchased the rig for a reasonable price due to it being in none running condition. And I've already searched the forum for help and hope to dive into the repairs soon. There is a ton of good info to be had on this site And I'm glad to have found Planet Isuzoo.

What I have solved so far a fueling issue (new pump/filter and tank clean). And now I'm sorting out what I believe is a timing issue. When attempting to start it will only backfire through the intake, which I believe is a timing issue, but we shall see. I'll post up some pictures once I figure out where to have them hosted.

Thanks,
Royce

 

[Guitarbuilder]

Welcome to the show. You don't need to have your photos hosted, you can upload them right to the post.
Mike

 

[turnerd]

Sweet-- one of the reliable automatics. I'd start by adjusting the valves and timing it. Note that the 4ZE1 is timed off the number 4 cylinder

 

[jdmcentral71]

Soild suggestions. I picked up plugs, wires, cap, and rotor today. Definitely needs to be timed. There so many vacuum leaks on this poor thing. It appears to be missing the EGR back pressure transducer off the valve cover. This may lead me down the path of a full EGR system delete unless I can locate one of those.

I ran codes using the ecm diagnostic mode and got 61 and 21. We'll see where that leads...but first the basics.

 

[turnerd]

the back pressure transducer isn't too hard to find used -- I suggest asking in the classifieds

 

[jdmcentral71]

I'll give the classifieds a go on the BPT. Worth a look at least.

 

[NCEvets]

Welcome to the Planet! I, too, am in NC, near Hillsborough.

 

[jdmcentral71]

Awesome! I'm in Winston Salem, close to Midway.

 

[NCEvets]

Being in NC, I'd consider eliminating ALL of the outdated smog equipment. I did, and I definitely feel it helped make my 1990 and 1987 Troopers run better. It depends on your county/municipality, though, as I don't have an emissions test where I reside so I can do whatever I want; I don't even have to have a catalytic converter. It used to be that I had to have one for the physical inspection, but it didn't have to be operable! Now it doesn't matter at all, just as long as the horn and turn signals work

 

[gruff54]

Inspection no longer required on these older trucks in NC
From NCDMV website:

Vehicle Emissions Inspections
This inspection uses the computerized equipment installed on vehicles.
Exempt vehicles include:

• Diesel-operated vehicles.
• Vehicles model year 20 years old and older.
• Select vehicles that are 3 years old or under and with less than 70,000 miles.
• 
  
  
• Farmer-rate licensed vehicles.

Vehicle Safety Inspections
Most vehicles in North Carolina are required to undergo a safety inspection on their vehicle— only vehicles 30 years old or older are exempt from getting a safety check.


Mike

 

[itsmehb]

Welcome. Great forum here. Quick check of the ignition timing. The nut on the front of the crank is 24 mm or 15/16th. Remove the top timing cover and turn engine clockwise till the upper mark on cam sprocket is aligned with the mark. Now look down and see if the lower mark on the damper is close to the zero mark on the timing scale. If it's nowhere in sight your on No. 1 TDC. Rotate till you can see both marks. The lower mark may be off some as these 2.6 dampers can slip with age. When both marks are lined up your on no. 4 TDC. At this point the distributor rotor should be pointing to the no. one plug wire or better explanation would be the contact on the rotor where the no. one wire goes. With the cap off the distributor the rotor should be pointing to the hold down bolt. That should get you close enough to start and fine tune it. I'll post a pic. of my lower damper so you can see how the slip can alter the timing mark. The white is correct. The painted black is the original mark.

 

[jdmcentral71]

I will definitely be checking out the balancer when the time comes. I have yet to drop a timing light onto it because there were some many things a miss with it. But I did read a member post about how the balancers are bonded and with age they start to "slip". Purchasing a new one might be worth avoiding that aggravation, for sure.

I've started the process of an emissions delete. I have watched the ******* video about routing coolant hoses and what not. It all seems pretty straight forward, a little tedious, but worth it in the long run. There are also a number of awesome picture filled threads to guide me through this as well. I'm impressed by the goodness found within this forum. I was considering replacing the BPT but so many pieces to the emissions puzzle are missing from the engine it would be more trouble than its worth to track it all down. So, after pulling the intake I have capped the egr tube input on the plenum side and on the exhaust manifold too. Now to re-route a little of this and that!

The previous owner said that he had someone clean his injectors. I do not know who they were but I would not let them near any vehicle, ever. There were so many loose hose clamps and missing vacuum lines on the poor engine I'm amazed I was able to get it started at all. Between all the unmetered, escaping and miss directed air getting into and escaping from the intake, I can only think that the old fella was just happy to get some decent attention and wanted to prove itself worthy of the time spend.

Oil pressure is excellent and no odd noises from the valve train. I've discovered multiple leaks in a very punky radiator and the coolant temp gauge just sits flat even after 5 mins of attempted idle in the garage. All this is an early assessment of course, but I'm optimistic of the final outcome.

 

[itsmehb]

One thing that's easy to check is the hard section of the air intake tube where it runs over the valve cover. We've seen several of these where they Rub against the valve cover till a hole is rubbed through. This lets air in that's not measured by the MAF sensor. this doesn't have a MAP sensor so if there is air entering the intake that's not measured the ECM will end up sending the wrong pulses to the fuel injectors and it will not run correctly. Also as you mentioned missing vacuum lines. This engine will not run correctly with a vacuum leak, so getting the diagram under the hood and following it, replace all those missing lines.

 

[jdmcentral71]

And example of what I've encountered through the disassembly process is the two vacuum ports under the throttle plate of the throttle body were just looped together with a small section of vacuum hose. Another one was the coolant hoses running through the throttle body were just barely attached to the ports, leaking coolant, and the hose clamps (spring type) were not slid in place to secure them over the port. Its bad enough the position those connectors are located in, but not connecting them properly or bypassing them correctly is an accident waiting to happen.

That color coded vacuum diagram under the hood is a god send!! Which my sons '89 300zx had once of those too!! LOL
The poor ECM has been opening the injector flood gates to keep pace with all the miss guided air. Thankfully the intake tube is complete and without holes.

 

[jdmcentral71]

Here are some over due shots of my rig....
These were snapped before I dollied it home with me.

[

 

[gruff54]

Nice looking truck!

Mike

 

[NCEvets]

Inspection no longer required on these older trucks in NC
From NCDMV website:

Vehicle Emissions Inspections
This inspection uses the computerized equipment installed on vehicles.
Exempt vehicles include:

• Diesel-operated vehicles.
• Vehicles model year 20 years old and older.
• Select vehicles that are 3 years old or under and with less than 70,000 miles.
• Farmer-rate licensed vehicles.

Vehicle Safety Inspections
Most vehicles in North Carolina are required to undergo a safety inspection on their vehicle— only vehicles 30 years old or older are exempt from getting a safety check.

Mike

Ha...I have to snicker at myself, as I've been getting safety inspections for the past several years, even though I didn't need to! They are only $13, but still. Thanks for the heads up!

 

[NCEvets]

BTW, jdmcentral71, regarding removing the outdated smog equipment, if you remove the exhaust/air injectors/smog rail (or whatever it's called), the best thing I've found is to just cut the little metal lines to the nozzle things (the air injectors) instead of having to remove it all and using hex plugs or whatever. Then, either weld up the now open holes on the air injectors or use JB weld to close up the ends. Some people apparently just crimp them over, but I haven't tried that myself.

On one of my Troopers, I tried using hex plugs but they whistled, quite annoyingly; one needs to use something that reaches into the cavity like the air injectors did originally to keep it from whistling.

People have to do the same thing to 1980s Lamborghinis even! I just found that out while watching this video (@ around 12:13):

 

[jdmcentral71]

LOL... Lamborghini in an Trooper thread! That's awesome though. I did go the route of the 1/4"threaded inserts. I have not noticed a whistle as of yet, but I'll keep an ear out.

The biggest reason I did the delete was because some of the equipment for the EGR system was missing (transducer) or broken (EGR tube). Plus the air pump was damaged. Couple that with ALL the vacuum business going on with it, I figured simplifying would be the best route to go.

I think the Thermal Valve on the thermostat housing is bad, as it never seems to shut down high idle. I do have a new temp sender and sensor to install to see if that's the problem and not the valve. Currently I have a reducer in the hose for the thermal valve to keep the idle around 950rpm.

I recently put 60+ miles on a small run around town and it handle the journey very well. Looking forward to more!!😄

 

[NCEvets]

Eliminating or replacing the vacuum lines and rebuilding my distributor (since oil was getting into my distributor cap) were probably the best things I did to make my 1990 Trooper run its best. It was running strong until I blew my head gasket!