foppert

Hi all,
I recently went through the process of having a new long block installed in my 1989 runner, as the old one was down to half compression on cylinders 5 and 6.

Unfortunately the thing is still about as slow as it was before, if not slower. I have some hesitation issues at around 2000 to 2500 rpm when it is somewhat cold, and other than that it is just a dog.

So my plan so far is that i have a new o2 sensor, new injectors to install, and i am going to test the fuel pressure and tps tomorrow. The fuel filter was done about 20k miles ago and i have no check engine lights or codes. I was wondering if there were any more suggestions for reasons that a 3vze would be so slow. I remember this truck several years before being about as fast as a normal crv but now it isn't even close.

dropzone

iTrader: (6)

Rebuilt engine with the same clogged intake/fuel system from the old engine?
225k on an automatic transmission?

foppert

285k on a manual, still shifts well though, I'm looking for advice on how to unclog it. I would have done a swap to a 5vz but i didnt want to deal with smog issues, and finding a 3vze with under 100k miles isnt so easy anymore.

Charchee

First, change that fuel filter and check your air filter. Filters don't count against you as guesses and parts swaps. They are maintenance items.

Second, get you a fuel pressure test kit. Advance Auto sells a good one for about $50. It has a quick connect fitting that you can plumb into your rail and leave it until you are 100% done testing. I guess you could leave it there forever if you wanted. Be sure to get you some new crush washers for the banjo bolt. They need to be changed every time you remove the bolt.

Third, check for a dead cylinder. Let her idle and then start pulling plug wires off of each plug while listening for a change in idle speed. If you pull 5 of them and the engine bogs down and then you pull the 6th and you hear no change, that's a dead cylinder. Troubleshoot the distributor, plug wire or injector.

If you have access to a timing light, you might want to check your ignition timing. An issue here would give you low power issues without throwing up red flags elsewhere.

Those are a few simple tests that don't take much time or effort to perform and will give you some good information. Take good notes. You don't want something down the road to ring a bell and you not be able to recall your results.

foppert

I rented the fuel pressure test kit from autozone, it has the banjo fitting for the cold start injector (from what i read this is where we take the readings.) I'll grab/install another fuel filter just to say i did it. A buddy stole my timing light, so it might be a while for me to get it back.

Thanks for the tips, i'm at a bit of a standstill because one of the studs that holds the o2 sensor snapped, my plan is to drill it out and retap it for 8mm and if that doesn't work bump it to 3/8in. (sound like it is going to work?) So im working on dropping the exhaust... Doesnt help that my cat is welded in after some A!@#$%^ relieved me of my toyota oem one.

I'll report back with tps settings and fuel pressure once i get it back up and running.

Charchee

Ohhhh that sucks about the 02 stud. It's on the top of the pipe isn't it? Get your exhaust hot and hit it with some penetrating oil a few times this week before you try and drop the pipe. Use a 6 point socket so you don't round off the nuts. I can't remember but I think those bolts coming off the manifold can be hard to reach. Just take your time and don't round them off. Oh yea, call up a muffler shop and see what they would charge you to weld on two flanges and then take them the pipe sawed in half near the Cat. Draw you some paint lines several places up and down the pipe where you cut it though. I had a shop do a couple welds for me like this for $10 but since I didn't draw those lines and just made one mark, I was off by about 3 degrees. You wouldn't believe the headache that 3 degrees caused me 10 foot down the pipe.

On your broken stud. I drill out a ton of bolts in my line of work and I would strongly recommend against drilling a small hole and putting an ease out in there. Exhaust studs, for some reason, have a way of breaking ease outs. Once you have one of them broken off in the center of your bolt, drilling in that area is almost completely out of the question. I say work your way up to a 17/64 drill bit and try and pick out what's left of the stud's threads. Then run an 8mm tap through it. Keep your drill bit and tap lubricated and pull the tap every couple rotations if you aren't going to be tapping all the way through the flange.

Co_94_PU

iTrader: (-1)

I pretty much expected the new clean injectors would fix you up..

Only happens when cold and drops off at higher rpm, that fuel supply not keeping up with the cold start enrichment.

Charchee

Does it have new injectors?

Could unplug the harness from the CSI and see if it does the same thing. I like easy tests.

Also, with the quality of fuel being sold these days, 20K miles is more than enough reason to change a fuel filter. Not to mention, your tank is old. You'd probably be discusted at what's hovering around the bottom of it. I sizeable piece of trash may have made it's way down the line to the filter and clogged it.

It's also a newly installed engine. You need to double check for any vacuum leaks you might have. An old vac line may work fine indefinitely if left alone but jerking it off of a nipple during the removal or installation of the intake, can easily crack them and give you some very similar issues.

foppert

I have new injectors that arent installed yet. They are next on the list after the o2 sensor, they are the bosch 4 hole tan type based on some of the peoples reviews in this forum.

For the o2 sensor i'm going to try a right angle drill adapter first, because i'm scared to get the other exhaust bolts... back up plan is a whole can of pb blaster.

Charchee

That angle drill ain't going to cut it. You won't be able to see well enough or get enough pressure on your drill. Better start using that pb blaster. I just went and looked at mine. Two of the three nuts in the first flange I'm not scared of. The one closest to the top of the bell housing is going to be a nightmare. You can try your drill trick. There may be enough room but if it were mine, I would take it down to the muffler shop and have them grind off the O2 sensor flange and weld you in a new one. I can't see that costing more than $50. I'm telling you, I like to think of myself as a bolt drilling and tapping pro but there is no way I would waste a day and $30 worth of good drill bits on that project. You could also have the shop cut that section out and weld it back in with a flange joint downstream of the O2 so you can have a two piece pipe next time you have an issue down there or at the Cat.

By the way, I have some of those injectors in mine. Like them a lot.

foppert

You were right about the angle drill, after much cursing and wrestling the o2 sensor is in and i don't feel any exhaust leaks around it.

Now back to what i was trying, I have the new fuel filter but haven't installed it yet, the fuel pressure is reading 40psi running from idle, when revved it will bump then settle back to the constant 40psi. Fuel pressure was taken at the cold start injector. When turned off it actually has been rising in pressure to about 43psi, so i don't think i have a check valve leak.

When cold and revved off idle it has a bad stumble that if held it will recover...

So from this we can tell my fuel system seems to be with in spec, and i now feel ok about installing the injectors. Is there anything else i should check while it is running?

foppert

Does anyone know what this white garbage in my coldstart injector may be?

Co_94_PU

iTrader: (-1)

That white stuff is the gunk you get over time from moisture ECT (too lazy today to go dig out the chemistry info..). It's the root of your problem. Purge your lines, maybe change your pump sock and pump and clean your tank, and then change the filter.

You didn't properly test that fuel pressure regulator, goosing the throttle doesn't give full results just that it is appears to be sort of working. It could have been due to the voltage spike..

You haven't done the pump supply volume checks, it needs to flow in excess of the injector capabilities (injector size times injector count)..

foppert

Sorry, i didn't just goose it i held it and watched it resettle.. which is what i thought was functioning properly, my mistake.

I went ahead and took the manifold off to get at changing the injectors. I have a spool of 4mm vacuum line and ill be replacing each one along the way.

By purge the lines do you mean replace, clean, or just empty? And any advice on cleaning this coldstart injector? or is it toast?

Charchee

I think that gunk is your issue. If it isn't, it's still going to get your new injectors. Others may have a tried and true method but on my diesel machines, I try to find a connection in the fuel lines somewhere in the middle of the machine, and blow compressed air and maybe a solvent through them in both directions. Your fuel filter joint would be where to to this.

As to why it's shutting down completely, is suspect that your pump sock is getting covered up momentarily and giving you an intermittent loss of fuel flow. A clogged fuel filter fits the bill for why it might hesitate and then recover. One thing is for sure, you are going to have to get that fuel system cleaned out. If I were to want to clean out my system, I would blow it out, change the fuel filter, and then install a cheap, clear sided, inline fuel filter between the pressure regulator and the return line and then jump FP and B+ to let the fuel circulate. It will allow you to see what is purging from your rails and hopefully the main fuel filter will catch what is coming from the tank. I guess you could clean the rails up good before you put the injectors in them. I think I would also take a look at the pump, pickup sock and peek down into the tank and see what's in there.

Try cleaning your CSI. It is either working now or you don't need it to start your engine. It's easy enough to replace later if it fails.

Whatever you do, don't put in those new injectors until you know what you have in there.

foppert

I'll blast the csi with brakekleen and see if that helps it out. Noted on the fuel lines, ill blast compressed air through them while changing the filter. Its not shutting down completely it just stumbles, so fuel filter, which is on my laundry list.

Thanks for the response, i wont start it until i've finished those tasks.

While i have the intake out ill check the tps, and im up for more suggestions to do while im this deep.

Charchee

I had you confused with another thread where the guy's engine would completely die. Your issue is your fuel system. Clean out the lines, clean out the rails, install injectors and filter and you should have it. You might want to use something a little more mild to clean your CSI than brake cleaner. WD-40 or contact cleaner maybe. It shouldn't take much to clean it out.

foppert

Pulled the intake rails, no white goo as far as i can tell. The injectors don't look too bad but half of one of the plastic tips broke off into the intake. I shined a light around but i cant see any fragments of it. How screwed am i?

In the mean time i'm going to wait till next weekend to get the air compressor out and start blasting.

Charchee

Get a shop vac and clean out the tank so you'd know that you had it if thought you heard something. Adapt it down to some kind of fuel/vacuum line that you can fit down there and move around and see if you have any luck. When I was doing my injectors, I had paper shop towels stuffed down into my air intake ports to keep debris out. For some reason, and I don't remember why, I turned the engine over and it sucked one of the towels down so deep I couldn't see it. I eventually got it with a hook on the end of a piece of wire but I know the feeling. How much of a piece are we talking about?

Wait!, I just remembered why I turned the engine over. I had a tip fall in mine to. I was turning that piston up to TDC so I had a better chance of finding it. I was able to vac it out at that point.

foppert

Its the weekend so time for more truck misery!
I sucked and sucked... and nothing came out (har har har)... I'm going to assume that it broke off when the rebuilders had it apart. Meanwhile i am changing the fuel filter and will be blasting the lines with compressed air as i go. I cant get the pulsation damper off the right hand rail so i am going to blast it from the fuel filter side when i have it off. I've blasted the left fuel rail already, so other then the line from the filter and the right fuel rail am i missing anything? Also for a cork upper intake manifold gasket should i reassemble with rtv on one, both, or neither side?

Thanks again for the responses so far guys...