'88 S10 Blazer Timing Issue?

Hey everyone,
1988 Chevy Blazer S-10 4x4 4.3 TBI Z Engine was redone 52,000 miles ago Transmission was redone 3,000 miles ago.
Recently installed new water pump, viscious fan clutch.
About two months ago I started to lose coolant, but couldn't find a drip. The oil wasn't milky, nor the coolant brown, so it wasn't too far gone. I had vapor in the tail pipe and decided it was probally the head gasket. It ran ok for the most part, but the last 2 days before I pulled it apart, it barely could idle, would hesitate tremendiously, and stall. I pulled both heads, and sure enough the drivers side, rear cyl (#5) was full of coolant, I mean FULL. The gasket had a small defect in the side wall and I guess the winter (when I installed the new water pump) some small defect in the gasket was injected with water, then it froze, then it melted when I ran it, and then filled up again.. and so forth until I got had the hold that I did.
While doing the "clean parts as you go" thing, I noticed my PCV valve was kinda' gunked up, so I clean that out with carb cleaner(maybe this was bad?). I cleaned the valve covers (which were milky), pulled the rods out (thew them in cleaner for a few days), set the rods back (after blowing them out really well), new head gaskets, new intake gaskets, cleaned out the intake manifold, cleaned the gasket surfaced, replaced an aging vaccume line (from the top of the air intake block), cleaned the TBI, new air idle control valve (the old one was getting black and for $20...), new cap, plugs, rotor, wires.
I had a little trouble getting the distributor in place, but I did. We were trying to set the timing and had problems with the timing light. It would idle sometimes, but would stall. Black smoke would come out of the tail pipe, it was struggleing, and hesitated greatly, even in PARK! Forget under load, I could get it around the driveway. We knew the light to be good, but it was working erraticatly, and the timing mark was jumping around.
I did at one point get a ECM code 33 and 43 (knock sensor?)
I knew there was something else I was missing. My father and uncle (who are old-school mechainics working in a work of EMCs and whatnot) were of the idea that I just needed to "get it on the road, run it hard for a few days and it would staighten out". Then I remember about "the tan wire". So I grabbed a new timing light, and without disconnecting the timing connector (tan wire), tried the new (induction style -- fancy!) light. It jumped around just as before. I disconnected the connector, and tried again, and the mark was nice and steady -- but I would guess -- it was 15° ADVANCED. They wern't kidding in the book about the ECM being able to retard/advance 20°!.
So I set the mark right at where I think 0° BTDC is supposed to be. The scale on the damper pully is rusted a bit and I can't make out the numbers. I compared it to a '88 Silverado, and I think the markings are (from right to left) 0, 8, 12. 0 being the resessed arrow, then 8 being the 2nd protruding arrow, and the 12 being the third. So I set it to the 0° mark.
Reconnected the timing wire, reset the ECM, started it back up and it struggled to idle, then it idled after about 15-30 seconds. My SES came on, and idled a bit, then stalled. I checked the codes and got 33 (MAP sensor) but no more 42 (the 42 had to be because we were messing with thedistributor while it was trying to compensate.)
At this time I could mash the pedel and it would come back strong and no smoke, so I thought all was well. After about 1-2 minutes of idleing, it started to hesitate as I was going to take it for a test drive, then stalled.
So I said, ok, the MAP sensor was looking old -- So I bought a new one. Reset the ECM, no change. Then I started reading my books and said well maybe it's my EGR valve. I did warn about solvents, and I did have that can of carb cleaner ;) -- so off to the local store to get that.
Installed that with the correct restrictor washer and gasket, still the same.
I've checked every vaccume line I can see/find. They all look ok, but I THINK I can hear a vaccume leak. I know how the engine usually sounds, and there is an extra "sorta vaccume leak" sound.
I think that covers everything I did.
Any help is appreciated, Joe Webster
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks,
It wasn't something I had thought of -- perhaps I didn't get it all the way down. I'll give that a try -- thanks.
-Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'm going to give the intake manifold a shot. I didn't torque them correctly (brain fart) or in the correct order. If I loosen them, and re-torque in the correct order, might this work? Or am I better to remove, reapply some RTV, new gaskets, and do it correctly?
Thanks, Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I did correctly torque the head, but when it came time for the intake, I didn't know which bolts went where and was scrambling.
Last night I loosned all the bolts on the intake, and retorqued in the correct sequence. That seems to have solved the ECM error 33 (MAP) and the sucking sound.
However, it still hesitates, has no power under load, and won't idle.
No codes are ever set.
My markings on my timing plate are a bit rusted, so I'm not sure what the correct mark is. From right to left the timing plate looks like this: |_________/\___| \/ \/ \/
(I don't know if that came out -- or looks right)
I checked on a '88 Silverado and I think the 0°BTDC is the indented mark, is this the same on the '88 Blazer?
When timed to that mark, it didn't idle very high. I couldn't see the RPMs since I was in the engine compartment. It would stall as soon as it approached let's say 1200.
When timed to the first protruding mark, it idled a bit higher, but still stalled.
I didn't try any other marks, but as I went to the third protruding mark (12°) it did idle higher, but I didn't even try that one.
I know I have the correct mark on the damper pulley, and I disconnected the brown wire.
I decided that I needed to do something, so I was going to tighten my TBI. I checked the book and it said 144-inch pounds, but I was tired and read it as 144 foot pounds! This seemed wrong, and I looked twice more... and I said "well... maybe it needs to be thight!" So I set the torque wrench to 100 pounds and went nice and easy. It didn't get hard to turn, but I did break a bolt. After much cursing and telling myself how dumb I was (once I realized it was inch pounds) I pulled the TBI off and the broken bolt came right out.
Once I had the TBI off I realized my Air Idle Control Valve (6 months old) was not tight, although it was 1-1/8". The Throttle Position Sensor (12 months old?) was tight, and I checked with a voltimeter and it looked like "THROTTLE CLOSED" gave about 8 ohms of resistance, and "FULL OPEN" gave 1.5. I compared that to an old one I had lying around -- my new one had a better range where as the old one only went as high as 6.
My plan at the moment is to get a new TBI gasket, a new TBI mounting bolt and try that. I want to avoid buying more sensors ;)
Am I on the right track? or is there something else I'm missing?
Thanks, Joe Webster 'Truckless in RI'

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You said you pulled the push rods out? Maybe you got 1 or two too tight keeping the valve(s) open. Is it just low on power and stalls or is it a "miss"? If it is a miss it could be the valves or maybe just 2 plug wires switched. I would put a fuel filter on it too if you havent allready. The bigger or different mark is going to be 0° .

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Reluctor? What/Where is that? I don't have my book handy, but I'll look when I grab it
Thanks, Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi Everyone,
I've retorqued my intake, that stopped my error code 33 (MAP sensor) and the sucking sound. But it still had problems idleing and hesitation/no power under load. Actually even in neutral -- after about 1-2 mins -- it does the same thing.
So I replaced my TBI gasket and checked the TPS and IAC valve. Once again, I timed it. Still has problems. Actually, now I'm getting code 33 again -- and all I did was the new TBI,TPB,IAC -- and I'm sure they are tight enough. I don't hear a vacuum leak.
Something I did notice. When the engine is first starting up... it will hesitate a slight bit, the engine/computer recovers and sets a code 33. While the SES light is one, the engine runs great, not hesitation, and has power under load. Once that SES light turns off... it all goes south. Am I correct in assuming that this is when the emission system kicks in? If so, does that give anyone a clue to as what's wrong?
This one is driving me nuts... well -- actually I'm doing alot of walking and no driving!
Thanks for the help guys, Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Forgot to add that I tried to replace my fuel filter... but the connections were rusted a bit and didn't want to come loose. I sprayed with wd-40, we'll see how they do tomorrow.
-Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks,
I got a tube of RTV in the intake gasket. I didn't use it all, the instructions said just a 1/4" i think. I figured too much would be bad... ;) I'll try that tomorrow.. PITA -- but what you said does make sense.
Thanks for the info, I'll let you know how I make out.
-Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

MAP? This will put it into "limp in" mode and if it is the map it should run ok. If it does run better check very carefully the map vacuum hose. If it has good vacuum then replace the map. The intake torque is not *that* critical. You probably have it sealed well. GL

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I already replaced the MAP sensor =(.
I didn't check the vacuum of the hose. I'll check that and try the "Limp-Mode".
Thanks, Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

not air. You shouldn't be using silicon on the gasket itself. If you did, that's probably where the problem is, since it's just about impossible to get a nice even coat all the way around. I'd not look at the intake anymore for your problem, though. Time to look at wiring or a MAP sensor, or the hose going to it.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I did put RTV (not silicone) one the intake gasket around the water ports as
the book and directions that came with the gasket told me to.
If there is a leak at the front or back of the intake -- wouldn't that allow
the valley to also leak? Isn't that where the vaccuum is created?
I have replaced the MAP sensor, and checked the two hoses to and from it.
The connector looks good, but I'll give the wires another once-over.
Thanks,
Joe
says...

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

going to leak oil, not vacuum.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
How is it created?
-Joe

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
the vacuum is created by the piston moving down in the bore. the piston moves down faster than air can get by the throttle blades, creating a vacuum.
-Bret

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.