Check timing 1995 Suburban

I need some help in checking the timing on my truck. I have a timing light with a dial on the back for direct reading advance scale. How do I actually know where to set this dial to get the correct timing adjustment?

Thanks-Rob

Reply to
Robert Le Feve
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What engine? what year? everything stock?

If it's a '90s style TBi with a 350, then you're looking at 0 degrees. If it's a 454, then it is 4 degrees, I believe.

Snowman

Reply to
Snowman

The dial should be set at 0 deg. You dont need to degree in these years, so the dial is useless. Also dont forget to pull the timing connector.

Cheers

Reply to
Martin Riddle

there is a lable on the fan shroud at the top (at least it may still be readable) that shows the degre setting for base timing. This is all you check, since the computer controls the advance. I know on a 92

350 base timing is 0 . I don't know what the base timing is on a 95 454.

If the tim>I need some help in checking the timing on my truck.

Reply to
Elbert

Reply to
Robert Le Feve

I don't think its a timing problem. If the timing is way off you'll have performance issues and most likely you set hard codes on the ECM.

You need to do a pressure test of the cooling system. At this point I would suspect a head gasket issue, cracked head, radiator fan clutch faulty.

I still lean towards the fan clutch..... based on what you have said.

In my view if it were a cracked head or head gasket the truck would for sure over-heat.... as far as running warm (close to hot but not overheating ) then I would look to something in the cooling system performing marginally.

Reply to
Elbert

At what temp would a properly operating radiator fan clutch kick in?

Reply to
Robert Le Feve

What temp should a properly operating radiator fan clutch kick in? The reason I ask is now that I have replaced everything BUT the fan clutch I am getting a "slightly different" symptom. The truck takes its time wharming up then the guage "parks" just to the left of the 215 mark for about a min. Then it starts to get wharmer, then eth electric fan comes on. I have only herd the fan clutch kick in once since this problem started happening, I had 6 people and all their luggage in the vehicle, it kicked in for a few seconds and there was no temp change. Should I stay away from aftermarket and just stick with OEM on a fan clutch?

Reply to
Robert Le Feve

I belive with Fan Clutchs on a car its a combination of temp and engine rpm when the radiator fan clutch engages. I think it would be in the temp range of 210-230F before you would "hear" the sound of the clutch pulling air through the radiator.

As far as brands of fan clutches I would only buy a GM fan clutch and I would get the HD version if they have one for your truck. They are kind of expensive but worth it in the long run.

I also found that TV cable adjustment on the transmission makes a difference on the performance of the fan clutch... How is this??? Well the TV cable adjustment allows the engine to rev higher through the gears on the transmission before it shifts to the next gear. The upper rpms allow the fan clutch to come on and perform like its designed to. ON the other side of the coin, if the TV cable is adjusted to where it allows the trans to shift to soon you don't get into the rpms "upper range" so the radiator fan clutch does not come on like it should. I've seen this first hand and it does make a difference.

IF I recall, one way to check a fan clutch is to get the engine up to operating temp............ drive it around a while............ then cut the enigne off and open the hood and see if you can turn the radiator fan by hand easy... if you don't have much resistance then the fan clutch is faulty. You'll need to reference the appropriate service manual for your truck.

Reply to
Elbert

Reply to
Robert Le Feve

Guess its time to suspect the guage is not working properly???

I'm not sure what to reccomend now, since you've basically replaced the cooling system. The sensor in the cylinder head is not hard to replace. Not sure how you can test the accuracy of the factory temp guage, unless you were to use an aftermarket guage with the built in mechanical temp sensor.. I know on some ECM scan tools you can see the temp. as the ECM sensors reads it , and compare to the dash gauge.

Can you tell that the fan clutch is working?

Time to carry truck to a local mechanic you trust.... some of these problems can't be solved >Well today I replaced the Fan Clutch and that had no effect.

Reply to
Elbert

I am going to try a guage/sensor solution. If that is not it I will have a mechanic test the exaust for coolant and coolant for exaust.

Reply to
Robert Le Feve

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