Timing Jumping and Boost spiking and holding

[gseclipse93]

OK, I bought a '92 gsx and it ran great besides it over heating due to a blown head gasket. so I had the head rebuilt, resurfaced all that good stuff and put a new head gasket it on it, new water pump, and new timing belt and balance shaft belt. I started it up and ran great besides it spiking to 22psi and holding. I have a mbc and have it turned all the way down. so I replaced my waste gate thinking it was staying stuck closed. I went to go test drive it and when i turned it over I heard a clunking noise and it wouldn't fire. I tried turning it over a couple more times and it wouldn't start. so I checked the timing and the timing was off. I pulled the timing belt off and that was fine but I found out that the auto tensioner was leaking oil so obviously its bad. I put a new auto tensioner on it and set the timing, and when I started it, it started but was running real rough and the car was vibrating real bad. I turned it off and checked the timing marks on the cams and they were off by a couple of teeth. so I reset the timing again, started it up and was running a little better but still rough and still vibrating but not as bad. I went and took it around the block and it ran pretty bad not under boost but when under boost it ran decent and had a lot of power but the boost was still spiking to like 20-22 psi. I pulled back into the garage and I checked the timing again on the cam gears and it was off again, this time by like 5 or 6 teeth. why do u guys think it keeps jumping timing and why else would my boost be spiking that much.

thanks
Josh

 

[tech27]

hey guy sounds to me like the first thing I would do is to take a look at your timing belt tensioner and make sure the bolts holding the camshafts to the cams are tight, also make sure you have the balance shaft rotated in the right direction as far as the boost spike i would not know other than double check your seals and vacumn lines. hope this was of some help

 

[luv2rallye]

Follow this exactly: http://www.vfaq.com/mods/timingbelt-1G.html.
And pay special attention to the notes on steps 22 and 24.

 

[ddavisaf]

Also, you may want to check out your valves again. You slipped timing 4 times, by 5 or 6 teeth... you probably have some valve damage.
For future reference. Always always always replace the auto tensioner.

 

[gseclipse93]

ya i paid extra attention to everthing, but it keeps jumping timing. i don't know what else it could be. i guess my best bet would be to replace the the tensioner pulley, since i have already replaced the auto tensioner. but the pulley is not seized up or anything, but i did notice the the pulley had a flat spot or it was dented some on one side of it. would that cause it to jump timing.

 

[ddavisaf]

When you replaced the auto tensioner you got the right one correct?
If you have a 6 bolt, order one for a 91. If you have a 7 bolt order one for a 93. This helps out with the confusion at the auto parts store.
It's possible that the pully is allowing the belt to much play with will cause the belt to slip.

 

[ddavisaf]

I want to focus on the 22 psi though for a minute. We'll leave the timing issue alone for now.

Your boost gauge... it is aftermarket right?
When the car is off, does the gauge needle rest at 0?

 

[gseclipse93]

yes i got the right one. i made sure i said for a 6 bolt. and i fixed the boost spiking. i was turning the mbc the wrong way. butnow back to the timing jumping, any one have any other suggestions?

 

[luv2rallye]

More timing belt tips:

1) Always buy the factory auto tensioner - never an aftermarket one (you will regret it).

2) And when you compress it to put the holding pin in (eg. allen wrench), compress it VERY, VERY, VERY slowly (like steps of: 1/3 turn of vise handle, then wait 30 seconds for it to settle, repeat) or you will damage the seals in the new one.

3) Sometimes measuring the distance between the tensioner arm and auto tensioner body (usually with a drill bit) is hard to see or do. Example: Can't get in there or see if drill bit is truly parallel to the tensioner top which affects measurement or you can’t get a 2.6 ft-lbs torque wrench on the tensioner pulley special tool #MLR-MD-998767. You can replace all that complicated tensioning torque stuff (which you can rarely get right with the engine in the car anyway - no room) with the following alternative. Just adjust the tensioner pulley so that the auto tensioner holding pin (eg. 1/16” allen wrench) moves freely all the way through the auto tensioner body and pin holes (after you turn the crankshaft and wait for the belt to stretch and auto tensioner to settle). Adjust the tensioner pulley to do this and it will automatically make the distance between the tensioner arm and auto tensioner body (drill bit measurement) be about .157 in. (spec is .150 - .177 in.). I've done over a dozen dsm TB's this way every one done correctly.