1987 Isuzu Pup

[Roastchestnuts]

Hey everone cruising in from the fj40 side of the Forum. I just bought a 1987 isuzu pup 2wd 4speed with the 1.9 gas 4 cylinder I am not starting a build thread here but maybe a questions thread for repairs/parts acquisition . I know I would love to find a new dash for mine as its toast and a few other odds and ends.

a few things that have already been recently done prior to purchase: it has a new transmission, clutch, starter, weber carb, waterpump, coil, and plugs and wires.

Some things I will need and would like to find are the under the hood cowel gasket, Radio, PCV valve, Dash, and seat or seat upholstery.

 

[Roastchestnuts]

I completley forgot I made this thread. Not really a build thread. I guess I should update it here! SO back on june 18th I think I started to notice overheating. I decided to check the head gasket with one of those testers and it slowly failed. Then some time in late june I decided to pull the head off. and found the place that it had blown. I decided to take the head to a machine shop. By august it was ready to put back together. well my dang slippery hands dropped the timing chain down in the front cover. Unfortunulty I could not get the front cover off without pulling the Pan off. and even more unfortunutly it was easer to pull the engine and pull the pan than it was to do it under the truck. I didnt really look like there was enough room under the truck. So long story short the engine came out.

After the engine came out I got the head back on and the timing chain all figured out. then the annoying part... I could not get the engine back in with the trans in the truck. SO i pulled the rear drive shaft and the transmission. Then I put the engine back togeither with the trans then with the help of my father stabbed it back in.

So seems like alot... the pup had one more fit to throw! SO I needed to cut the exaust mnifold down pipe studs off to get the manifold out and a new donut gasket in. I was fine with drilling and tapping new studs. so I preceded to do that. Well one I was almost done tapping the last threads for the stud the tap preceded to break off in the manifold causing me another two days of work. this leads to where I am at now.

I have most of the assesories back on the engine. I need to attached the ground strap to the engine, get the starter wiring back together, donut gasket on the exhaust, and install the radiator and radiator hoses. I need to also put new gear oil in the transmission (found water in it when I pulled the trans) and bolt up the drive shaft. Hopfully after all that this weekend I can get the old pup started and driving again! Hell I gotta get it going I just paid my yearly registration.

It took me so long to get the truck back working because I was distracted by this project:

You can see where the gasket failed inbetween the two cylenders.

There it is on the head gasket too

Cylenders still have alot of good cross hatching. the odometer says about 170k I am happy to see this at least.

The head after the machine shop! I only paid 155$ for this. The guy was super nice and super old school. He said the valve guides looked good and no cracks.

The engine when I pulled it. Yes I am in dirt... I had to move the truck out of the way not the hoist.

That transmission had to come out too....

Head installed. at this point it had been down so long that I had alread painted and did body work on my samurai project. that paint on the valve cover was from a mixing paint spill in my shed. the paint is for the samurai.

 

[Roastchestnuts]

Getting ready to stab it back in. you will notice the truck is in a different position. I had to move everything because of a storm and we were worried about flooding.

Engine back in and accesories are starting to go back on.

Exhaust manifold repaired and back on.

Today.... we have a noreaster that flooded alot of the east cost. of course this is a low spot in the yard... the drive shaft will have to wait. I have been buttoning stuff back up in the engine bay.

This is where I am at today. Ill post more as I get it going again! I do love this little pup. its just been hard on me latley haha.

 

[Roastchestnuts]

The water has gone down of latley and I think I am going to try and get the drive shaft and the transmission all buttoned up. I had not realized that the truck uses 5w30 engine oil in the transmission. I am glad I looked in my service manual. I will post pictures when I can!

 

[theglobb]

The water has gone down of latley and I think I am going to try and get the drive shaft and the transmission all buttoned up. I had not realized that the truck uses 5w30 engine oil in the transmission. I am glad I looked in my service manual. I will post pictures when I can!

That's why the first transmission failed that I swapped out. PO had put gear oil in the transmission. I checked it and changed it to motor oil when I first bought it, but I think the damage was already done. 15,000 miles later and the input shaft bearing failed, hence the new trans haha.

 

[Roastchestnuts]

copying the updates from my fj55 build Builds - Salted Pork fj55 family wagon build - https://forum.ih8mud.com/threads/salted-pork-fj55-family-wagon-build.1364847/page-13

Sidequest update: The isuzu truck - where I have the isuzu truck is parked in a level spot so I could get the engine back in. Unfortunately there is about 3-4 inches of standing water right now. I really need to install the drive shaft and bolt down the transmission at the mounts and bolt the down pipe onto the exhaust manifold... Once I do that I feel comfortable getting the whole thing running again. unfortunately I cant do that because I don't really want to be laying in water installing that stuff. I was itching to do somthing yesterday so I installed the carb throttle cable bracket, throttle cable, I bolted down more stuff and Looked at wiring. Tried to decipher some vacuum stuff But I might just cap some of that stuff off and keep the vacuum going to the brake booster and the distributor vacuum advance. I am a fan of simplicity. I dont have any of the smog stuff still. I lso found a rust hole in the roof that I will weld up too. Cant stand rust! I have been thinking about doing a respray on the truck too. I think that would make me happy haha.

 

[Roastchestnuts]

Hey everyone I need some input/help on my isuzu pup. This page gets more traction than the little repair thread I have going on it. My isuzu pup has had more hurdles on repairing it than any other vehicle I have ever had. So my issue now is yes I can get it started and running but its running really really poorly. I dont want to run it much in fear something is going to break.

here are my symptoms 1. seems to have an intake valve or two that is pushing compresson out the carb. 2. it seems to have a tight spot when I crank the engine over. I think its cam shaft related because it seems to go away when I loosen the rocker assembly. 3. I did a compression test and the numbers were all over the place. I think the first time I did it it was 125psi, 75psi, 130, 160. I re adjusted the valves 2 times the first time I got 150, 160, 155, 170. but the second time got 100, 165, 170, 165 but I could not get Number 1 to come up. (this is where I gave up in frustration yesterday because with the valves adjusted on the first time I adjusted them it still ran like s***. I think the 4th thing I figured out was at tdc on the crank I had it TDC on #4. Because when adjusting the valves I hard a hard time because I kept doing it backwards till I figured this out. (meaning I was adjusting cilynder 1 first when I should have been adjusting #4 intake and exhaust.

I think the cam shaft does line up at tdc with the cam and crank (but TDC on #4) at least it does according to my haynes manual.

I think its a timing issue for sure. just not sure what could be the fix.

I think I want to fix symptom #4. Not sure how to do it though. what are your thoughts?? Rotate the cam assembly 180 degrees. or Undo the timing chain and rotate the engine assembly 180 and hook it back up? Just DONT DROP IT. do you all think this would cause my problems being 180 out?

I also want to check the rotor on the dizzy when I am at tdc on Number 4 and number one. (Note to my self)


Or do you all have any thoughts? Ill post some pictures this evening when I get done with work.


Other news the fj55 is running great with the Holley. Those who dont like holleys on land cruisers dont know what they are missing. I think I will get the baffle kit from Downy eventually just for better off road characteristics and piece of mind.

 

[Roastchestnuts]

Ran great before all this. I had the head gasket go. and had the head skimmed flat. but thats pretty much it. I know its not a lifter as the rockers ride on the cam. Yeah maybe number 1. I was also thinking it could be off a tooth on the timing possibly.

 

[Roastchestnuts]

here is a video of the poor running. of course youtube does not really tell you much. the combustion coming through the carb popped the air cleaner tang things off. also I did run it with the valve cover off to see if I could see something obvious. it did sling oil everywhere. you can see that in the video too.

 

[Roastchestnuts]

I went down the rabbit hole of reading all of this.... man makes you appriciate the simplicity of the 2f motors and timing gears. https://www.isuzupup.com/viewtopic.php?t=16133

One tooth will make it run poor.

I am going to check this when I get off work. Its what makes most sense to me as to the issues. it just does not look like it is off. but maybe 1 tooth would not look that out of tolerance on the alignment marks on the cam and crank.

 

[Roastchestnuts]

I think this afternoon I am going to check all of this that was said in the Isuzu forum I posted above by a person called oldestisuzuist. https://www.isuzupup.com/viewtopic.php?t=16133. Some of the things I did not know where the timing chain and timing sprocket marks. I thought they were degrees before tdc or somthing. I did know the TDC on the cam shaft marks he talks about.The only thing I dont think he is right on is the valve interference. Every thing I have read about the G200 isuzu 1.9l engine says its a Non interference motor. My haynes manual Sucks I am learning haha. But I am posting this as a bookmark to myself. I hope it helps.

Here is the quote below:

"This is what I would do given the info that I have- and please take pictures of every step in case we need to tweak it:
- do what you have to do to allow the crank to be rotated without the pistons hitting the valves. If you loosen the rocker shafts make sure the shaft marks are straight up when you reinstall & you hold the shaft springs while you tighten the nuts in the proper sequence.
- hold snug up pressure on the chain while you rotate the crank until the notch on the crank pulley aligns with the zero degrees TDC timing mark on the front cover. The chain can be on the cam gear at this time but the gear should not be attached to the cam. The distributor rotor should be pointing to #4 post, if it's pointing to #1 rotate the crank another full revolution. The pressure on the chain is to keep the chain engaged with the crank pulley teeth in the proper place. The crank should now be at #4 TDC.
- there is a scribe line on the cam collar a short distance behind the cam gear mounting flange, turn the cam as neccessary until this line aligns with a similar line on the front rocker shaft bracket. When both these marks align the cam gear dowel should also be pointing straight up. This should put the cam at #4TDC. Re-tighten the rockers if they were loosened.
- look at the chain & cam gear, there are two marks on the gear. The triangular mark aligns with the chain mark. This chain mark can actually be a mark on a chain link or most probably the link side plates are a different color and/or shape than the rest- think a master link in a bicycle chain. When the cam gear in installed this chain mark is a couple of links to the passenger side of straight up. Put the chain onto the cam gear keeping the driver's side of the chain tight, align the cam gear & chain marks. The gear dowel hole should be straight up & hopefully the cam gear & chain will slide onto the cam without moving anything. Snug the gear to the cam.
- right now you should have the crank pulley at zero degrees, the rotor at #4, the cam mark and the cam dowel straight up and the cam gear mark pointing to the chain mark. If all this is present you now need to test it: if you're not sure about the chain mark identify the link the cam mark is pointing to. Engage the chain tensioner. Now rotate the engine exactly two full revolutions until the timing mark is again at zero degrees & the rotor pointing to #4. The cam mark & dowel should also return to straight up and the cam gear mark should point to the same chain mark. Everything re-aligns, the chain is installed correctly. If not- maybe needs some tweaking.
Anyone who wants please comment on my proposed method, maybe I'm wrong & it won't work at all."

The other person he was talking to said he fixed it with the info.

 

[Roastchestnuts]

Looking at your video and your description, I would guess a bent valve, or timing related. Whenever I replace a cam or timing set in any engine I always rotate the crank 2 full revolutions(2 revolutions=4 strokes) to insure the valvetrain doesn't interfere with the pistons. Once you recheck everything and make sure the the cam is in time with the crank, rotate the crank 2 revolutions. If that's OK, then do a compression test. If there's a weak cylinder do a quick cylinder leak down on the cylinder. You don't need a fancy leak tester. My compression gauge is 2 piece, a hose with the threaded end and a fitting and the gauge which can be separated from the hose. Remove the shrader/valvecore on the threaded end of the hose, so air moves freely in and out. The fitting end of the hose can attach to an air hose fitting. Put the cylinder on TDC on the compression stroke and apply compressed air. Listen for an air leak thru the carb, the oil fill, and exhaust. This will help ID where the problem is.

I sure hope its not a bent valve. But I will go down that rabbit hole when I check everything else. Leak down test will be a good next if the timing chain timing is all good. Compression actually seems good on all the cylenders. I am not sure why I could not get #1 back up to good psi because the test before I adjusted a second time was 150 and then I readjusted it and it would not come above 100. The others came up 10psi on the readjustment haha. If it is a bent valve I am going to be super annoyed and might actually give up on this truck for the time being. Its been beating me up since June. The Baby is coming and the land cruiser (we want to drive the baby home in this), the house and life have priority over the Pup. I feel like we all have one of these projects in life where it just fights you every step. I just gotta be aware of how much time I am going to spend on this. so I can spend time on other projects that need to get done.

 

[Roastchestnuts]

It could be a number of things, miss adjusted valve or cam timing etc. I only messed with a couple of overhead cam set ups in the past. Crank and cam orientation is important along with the chain. The chains sometimes have markings on them to keep the crank and cam timed correctly.

This one has markings on the cam shaft and the sproket has a dowel that it lines up with on the cam. TDC on the crank has a mark on the crank pulley and the pulley has a key way that makes it only go in one way. But what I am hoping is that I didn't have the crank all the way at tdc when I lined up the cam with the crank. maybe it moved or something when I installed it. and maybe I didn't notice. It looks lined up though. or I have the wrong timing marks lined up or something. I keep seeing timing stuff to #4 and not to #1 so I am going to look into that too. The other thing is apparently the chain has a link that you line up on a mark on the cam shaft sproket as well and I did not know that. So I will fix that. However I dont see how that would make a difference. maybe the links are not equal distance. Either way I am going to need to adjust the timing chain. Ill keep everyone posted on what I find.

 

[Roastchestnuts]

I feel like I am on the up! things are going well even though it still does not sound great but its 10000x better. I still have alot to do still but I feel less stressed about it all. Here is what I figured out today: So turns out the crank pulley TDC mark is NOT TDC. (No Joke about 5 minutes before I figured this out I texted @theglob if he wanted help me pull the head when he is here this weekend.) I also was not getting any compression in #1 before I figured this out ZERO. I moved the crank where it felt like it was TDC in #1 by using a thick zip tie to feel the piston come up. Then I took the Dizzy and fuel pump out. fuel pump arm is in the way and you need to take the dizzy out to get the fuel pump out. I loosed the rocker assembly. Then I loosened the chain tensioner and unbolted the camshaft sprocket with chain still attached. I moved the cam shaft so It was oriented to TDC on #4. then bolted everything back up.

I knew as soon as I did about 4 or 5 revolutions of the engine without feeling a tight spot that I had figured out the main issue.

I am going to check compression again tomorrow on #1. It did run pretty well without any weird gallop. it I am hoping something weird happened with the rings... wishful thinking. I will also say It did run much better. No sputtering out the carb. Its still a little loud because I need to go through the valves another time and the valve cover is rattling but hey its running way better than before! Carb needed choke too. I may just send it tomorrow and button everything up after I adjust those valves again.

In the video you can hear the valve cover rattling because I did not tighten it down (its just laying on top.) and the valves are a little loud. but I am not hearing combustion through the carb!




Below is TDC on #4 according to the haynes which is why I guess you time it to #4. I kept confusing it with tdc on 1 witch is why I kept adjusting valves wrong.
View attachment 4015435

I figured out this lines up with TDC on #1 (for future reference.)
View attachment 4015436

This is a few degrees off TDC. I am guessing 20 degrees or so after TDC. Actual tdc seemed to be about an inch and half or more past here. I need to make a mark on the pulley so I can use a timing light.
View attachment 4015437

I still didn't figure out this. I didn't see a chain link that was any different.
View attachment 4015438

 

[Roastchestnuts]

I am stoked to get the rest of the Isuzu pup back together. Todays afterwork list of things to do is do not in order: 1. valve lash 1 more time, 2. Check compression on #1 (if this is bad I am not sure the plan), 3. I need to install the radiator belts and fan and components (I only ran it a couple of times a couple seconds at a time), 4. double check the torq on the intake and exhaust manifolds, 5. I want to see about pulling off the crank pulley to see if I can adjust the timing mark to where it should be, 6. install the reverse light switch on the transmission (I forgot to re install it when I stabbed it back), 7. bolt down valve cover with the gasket correct, 8. Tune the carb and set timing. I might put my rebuilt weber 38 on instead because I had just gone through it for the fj55. It might be too big for the little 1.9 though. any thoughts there?

My plan was to drive the pup as a daily while I start cranking on the fj55. SO I am very excited to get all this done I can finally move my fj55 into this spot and start cutting and welding in new rockers, front body mounts and floor pans and getting into that project deeper!

 

[Roastchestnuts]

Well I thought I was all good and had it fixed and had the Isuzu pup done NOPE! Ill start with the good. I drove it further up in my yard and It runs pretty good. sounds like a few valves maybe a little too tight but easy fix. you know the weird burble sound they make when its not quite right. The 0 compression went to 75psi witch again is not good... I suspect something else is going on there because it ran pretty good considering. Id be willing to bet after I ran it the psi is in the 150 range. I will check again tomorrow. Edit: I had the wrong video here is the good running video


Then Of course somthing had to go wrong to a point where I cant drive it. ughhhhhh well here it is, the new oil pain gasket completley failed and was pouring out. I lost half the oil moving 50 feet. I am wondering if I dont have a pcv or some vent hose hooked up. Ill look tomorow. I think I might be able to snake a gasket in without pulling the engine out... I pulled the engine to get oil pan off originally because it was leaking and it I needed to pull the pan to get the front cover off. I am in disbelief this happend to be honest.