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RE: Difficulty timing a 1995 Chevy 454ci
Outcome?
I've had to put this project on the backburner at the moment. A deer totaled my wife's van and I've been quite busy fixing up the replacement for it. I picked up a Starcraft converted 1997 Ford E-150 as the replacement. The outside and inside are near perfect.. but it turned out the engine needed some serious love. And the brakes, and the O2 sensor, and the wheel speed sensors.... and so on and so on. After I get this new van up to my standards I'll pivot back to the RV.
Currently where we stand there is the old water pump is off and the new one is prepped and ready to go but needs to be installed.
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OutofTime
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05/17/23 06:06am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Fan clutch has already been swapped as part of doing the water pump. Plan is to replace pump, hoses, fan clutch and then do a flush with water, then fill with fresh coolant. That will stop the coolant leaks. Eventually the hydroboost and the steering lines will need to be replaced. Probably some brake lines as well. Only then will I not get covered in grease every time I poke under the front.
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OutofTime
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04/16/23 05:42pm |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
So at the beginning of the thread you said you got nothing.. nothing as far as the motor goes or nothing on your timing light.. then further down the thread you said it kicks but won't run.. that sounds like a bad distributor module.. could be lots of other things but that's cheap and easy to change
I know this thread is a bit of a saga at this point :). Over the course of this process I have replaced the entire ignition system with brand new ACDelco parts. It will now start at the bump of a key. However I need to do further testing with the engine warmed up, which currently I can't do because the water pump bearings are completely toast. That's why I'm pulling the pump. Since the pump is out of the way it isn't that much more effort to pull the timing cover and check for a jumped chain or a sloppy one, which could very well be why the engine is still not running right.
To be clear, all the work I've done is making it run better, but it's not right.
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OutofTime
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04/16/23 03:21pm |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Updates
After much sweating and swearing the water pump is off. Next step will be to pull the timing cover and check for a jumped tooth and/or sloppy chain.
There is a cross member underneath that can be removed for easier access to front of engine. This is the cross member to remove...
https://www.irv2.com/forums/f65/what-did-you-do-to-your-old-rv-today-133779-444.html#post5713099
Once out it gives this access...
https://www.irv2.com/forums/f65/what-did-you-do-to-your-old-rv-today-133779-443.html#post5712066
I pulled that crossmember at the very beginning so I could get clear access to the 5pm timing marks. I've also had the lower shroud dropped. Now I have the upper shroud off as well. A decent amount of real estate to get the timing cover off.
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OutofTime
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04/16/23 09:37am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Updates
After much sweating and swearing the water pump is off. Next step will be to pull the timing cover and check for a jumped tooth and/or sloppy chain.
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OutofTime
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04/16/23 05:47am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
I can check on this today. I have checked for vacuum leaks and did replace a few rotted out lines. I've also redone all the gaskets on the tbi, including the base plate gasket.
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OutofTime
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04/12/23 05:56am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Updates
Got the new injectors in and it is running better. Spray pattern looks better too.
Finally got down to checking the time under computer advance after setting it to 4 BTDC and I found today its advancing 20 degrees. I think that is why it's popping when under computer advance. Is 20 degrees normal at idle? A possible X factor would be that there really isn't much water in the cooling system at the moment so the ECT probably isn't reading as closely as it should.
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OutofTime
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04/11/23 05:32pm |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
I haven't had the tooling to check yet. I think I have a fuel pressure gauge somewhere but I need to find it again. I wasn't thinking lean because of the black smoke belching out but with much of that getting cleaned up by the TPS reset, now I'm wondering... First thing to sort maybe this weekend is the cooling system so I can run the engine longer to do more testing.
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OutofTime
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04/07/23 02:05pm |
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RE: Difficulty timing a 1995 Chevy 454ci
Indeed. At one point I did have the timing at TDC and the popping went away so.... but the rev issue was still there. That was pre messing with the TPS.
I can try to set it to 0 TDC now that it will rev and see what happens. I hope this weekend I'll have time to at least pull the water pump, but with 30 year old rusty bolts, that's a tall order.
At this point I can keep plugging away at it and fix it bit by bit. This also informs well for me as my housing plans include purchasing an RV eventually so that I can remove my current house and place a new one while still living on the property. I hope I don't wind up purchasing something as old as a '95 but you never know what your budget may wind up being.
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OutofTime
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04/07/23 10:53am |
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RE: Difficulty timing a 1995 Chevy 454ci
So after messing with the TPS, it will rev with advance connected. Still pops and such, but it will now rev.
Let also expand on what I mean by a slipped balancer. I have a '94 Mazda B3000 that when I first brought it back to life I could not get it to start when I set the balancer to 10 BTDC, which is Ford spec for a Vulcan 3.0 engine. Made sure I was on compression stroke, etc. When I finally timed it manually by putting something in the number 1 cylinder and checking tdc, then pointing the button at tower 1 on the hat, it ran. Once running I put a timing light on it and saw the balancer marks were not lining up.
What happened is the glue that holds the rubber ring of the balancer to the metal core had given up so the rubber ring was beginning to slid somewhat around the core. That is what I mean by "slipped". Failure in that way would not shear the woodruff key in the metal core of the balancer.
As to the timing marks next to the balancer, they are intact enough that I can read the numbers, so I am timing to the correct 4 mark. 4 is listed twice, but the BTDC marks are more numerous than ATDC so I've got the right one. It's the last peak before the big groove that is TDC.
I agree timing still could have jumped a tooth at the chain due to age and slop and that does need to be looked at. That will probably happen when I service the water pump since I'll have access at that time.
I also agree that I need to pop the valve covers and make sure I don't have a tight/loose valve(s) that are causing issues
Progress is being made. After getting it timed again at 4 BTDC and then doing some testing, I'm pretty sure the balancer has NOT slipped and that something else is causing the running issues. The PO mentioned he replaced the fuel pump. It very well could be he put the wrong one in. He wasn't very mechanically inclined and could have put a lower flow pump in that doesn't match up with the increased psi that is required for the 1994-1995 TBI setups. I need to check fuel pressures to verify that. If it's really been running lean all this time with a dodgy TPS it could have caused the issues I've seen.
I have a vacuum gauge on the way that should tell me quite a bit about the engine's health now that I have the engine running consistently
As far as loading the parts cannon goes, I have. This RV is not for me and will be a home for a relative for what I think will be a very long time given the relative's situation. For that reason I am more comfortable to load the cannon and go ahead and replace the 30 year old parts with OEM new parts as needed to make sure the service life of this engine will continue on for quite some time. If this was a project vehicle of mine I would be quite a bit more stingy.
You raise some excellent points, and I most certainly don't take offense. This engine platform is new to me, which is why I wound up posting here to tap the brain trust so I can learn more.
As to your offer of a consult, that would be a road trip for you I think. I'm south of the Capital and I see that Inverness is a bit north of Tampa. I'm totally open to a video call of some sort to swap knowledge though.
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OutofTime
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04/07/23 07:47am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Updates.
After much research and reading much spirited debate online, I've concluded a TBI dizzy with electronic advance cannot be a tooth off. Not possible. What it can be is wires setup in such a way that you can't rotate the dizzy hat enough to get the engine in time. In that situation you would need to adjust the dizzy a tooth so that things will work out.
There are some early Ford TPI fuel injected engines that need to reference the number 1 cylinder in a certain place or they won't work right. However those engine have the number one stamped on the correct tower to make all that work on the dizzy hat.
The origin of a dizzy being a tooth off goes back to the early days with distributors that still used points. If the dizzy was a tooth off the points would open/close at the wrong time, leading to rough running.
All that out of the way.... I have the engine timed to 4 BTDC. After timing it to that and seeing the engine operation still acting as it was before, I decided to remove the TPS and swap it with another I had from a 350 in another vehicle.
I did check and the TPS are supposed to be the same part... in any case engine would only run with the accelerator fully on the floor with the 350 TPS. After swapping the original TPS back in it wouldn't start at all. I then read that I should have done this with the battery disconnected so the TPS 0 point would reset.
After doing the reset with the original TPS installed I got it running again.
Interestingly enough, now when I rev the engine it actually revs! Still pops through the intake but it will rev now instead of falling flat on it's face. Smoke coming out the exhaust seems to cleaned up a bit too.
Only thing I can think if is the TPS was jammed up somehow and causing issues. I should have some new injectors coming in next week that I hope will make a difference. I can stare at the spray pattern coming out of the current ones and it is not even.
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OutofTime
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04/06/23 05:06pm |
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RE: Difficulty timing a 1995 Chevy 454ci
Yes, one tooth.
Remember that the oil pump runs off the distributor shaft. The distributor will not drop completely in until engine turns over to align shafts. I like to do this with socket on vibration damper retaining bolt.
Riddle me this then. As I've been moving the dizzy around, I've moved it by lifting up on it just enough to spin the button and then move it clockwise just enough that it will fully seat against the intake. So when I say move one tooth counterclockwise, I mean that I would "walk" the dizzy all the way around then stop one tooth shy of it's current position.
Are you saying that instead I should try to move it one tooth back, then spin the engine counterclockwise to get it to seat?
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OutofTime
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04/04/23 05:59am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Doing some more thinking about it, if I'm a tooth off as you claim, then to fix the advance problem the dizzy needs to move one tooth counterclockwise, correct?
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OutofTime
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04/03/23 09:17pm |
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RE: Difficulty timing a 1995 Chevy 454ci
I would say no on the vibration damper slipping.
Is popping through intake or exhaust?
Intake would be too far advanced, exhaust is ********. (opposite from advanced)
One tooth off on distributor one way or another!
The popping sound comes from the TBI, so intake.
That would line up with my thought that the engine is too advanced right now.
You've mentioned in several posts you think the dizzy is a tooth off. That doesn't make sense to me. If I can get the dizzy to point at the cylinder 1 terminal on the cap and the balancer is at 4 BTDC while on the compression stroke, how can it be off a tooth?
If I have room to adjust the dizzy by turning it by hand and I can bring it to within factory spec, how is it off?
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OutofTime
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04/03/23 09:01pm |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Updates
I did indeed have the distributor 180 out. Using an old compression tester fitting I had laying around I identified compression stroke on cylinder 1 and adjusted the distributor accordingly. After doing so the engine fired right up.
However... still the same issues. Popping, running extremely rich, falls on it's face when you attempt to rev. This is with using all ACDelco ignition basically and ECT.
One thing I noted is when I first got it running it was at around TDC, and no popping from the engine. After adjust the dizzy slightly to get timing to 4 BTDC the engine now pops with little backfires at idle.
Plugged the advance back in and computer advance is working as it should.
There's a fairly sizable difference in how the engine wants to run when it moves from open loop to closed loop. I can't do much more digging until I swap out the water pump and fan clutch as there isn't much coolant in the engine.
Based on what I saw with the engine popping, I'm wondering if the balancer has slipped a little and the engine is too advanced when you set it to 4 BTDC... thoughts?
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OutofTime
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04/03/23 06:54pm |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
There are also two other possibilities that you should diagnose before throwing more money at guesses. One, is it possible the engine has jumped time? As best I remember that engine has a timing chain. Second it is possible to install the distributor 180 out which will produce the results you are getting.
A trick for ensuring tdc is to screw a compression test hose in the spark plug hole, but instead of a gauge run the hose into a cup of water. When you reach tdc it will stop bubbling
If it's 180 out, that means the balancer has slipped 180. I'm going to clean plugs and see what happens. If I still get nothing I'll try flipping the dizzy.
Engine needs a new water pump and fan clutch anyway so when I'm working on that I can take a peek behind the timing cover and see if the chain is super sloppy or has jumped a tooth. I don't think the Mark V 454 had the nylon teeth on the gear, but I could be wrong.
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OutofTime
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04/03/23 09:44am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Did you raise number one cylinder to top dead center?
Was the timing mark on the crank at the pointer?
Was the distributor pointing to number one plug?
Did you verify the plug wires are in the correct place? Engine rotates clockwise. Did you diagram posted much earlier for plug locations?
I answered these questions in the previous post
1. I set the balancer to 4 BTDC and checked the cylinder position via a straw through the spark plug hole. It felt right
2. I had the groove in the balancer lined up with the "peak" of the timing mark at 4 BTDC
3. Yes, pointing at where the number 1 wire connects to the cap
4. Yes, firing order has been checked several times, checking in a clockwise direction from the number 1 terminal on the cap
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OutofTime
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04/03/23 06:11am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
Updates
Today I went full ACDelco. ACDelco ect, coil and full distributor stack. I realized my timing gun couldn't be fixed so I grabbed a new one and I could finally get a reading on an individual spark wire when cranking only.
With that knowledge I first timed to wire 5 to 4 BTDC then tried a crank... nothing.
I then was able to actually time wire 1 to the top timing marks to 4 BTDC and that's where I left it for the day. Kids needed to get in bed and the battery was about done after all the timing testing.
I'm totally confused by this engine. When I time it then crank with fuel basically nothing is happening. I did get a few backfires after I pulled the fuel injector fuse and was cranking for timing purposes.
I even as an experiment pulled the injector fuse then tried giving it a snort of ether to see if it would fire. Nothing.
At this point I'm down to the plugs have gotten so fouled again from the rich running that they need to be cleaned before they'll fire off properly again.
I also used a straw to check the accuracy of the timing marks on cylinder 1 and I think the balancer is ok. I set the timing marks to around 10 BTDC and tried to insert a straw and was able to, but I could feel the straw getting bent up a bit which told me the cylinder was close to TDC.
Next steps for me are to figure out how to clean fouled spark plugs and pray that it fires off after I set it to 4 BTDC on wire 1.
I think I'm also going to open valvecovers and see if I have stuck valves or something. I don't think I do because I didn't hear that when it was running but there has to be something that I'm missing. I've timed several engines before and none have acted like this.
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OutofTime
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04/02/23 07:36pm |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
How is this coming along?
Haven't had time to work on it, other more pressing projects had to get done. I hope to put a little time into it this weekend. I've got a brand new Delphi dizzy that is supposed to be the OEM one that's come in. I'm hoping with that, plus fixing my timing light that I'll be able to get this thing timed and running.
I'm also intending to inspect the vacuum passages the MAP is hooked into and clean those, along with making sure there are no blockages in the MAP tubing itself.
Lastly, my FPR spring arrived and I need to install that. Fingers crossed good things will happen this weekend.
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OutofTime
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04/01/23 04:23am |
Class A Motorhomes
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RE: Difficulty timing a 1995 Chevy 454ci
I realized this morning my timing gun's inductive clamp wasn't closing fully which would explain why I can't see spark on individual wires when testing. Fixing that particular issue should make timing much easier.
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OutofTime
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03/24/23 10:34am |
Class A Motorhomes
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