R33 GtsT No power and backfiring after Cam Belt change

[Skaith4224]

Hi all,

 

I've been around a few forums with this but I've had no answers back and was wondering if you could give me some ideas on what's going on here.

 

Car was running okay, boost was working but she needed more tlc in the long run.

 

Long story short, I needed a new water pump and had this installed by my local garage as I didn't have the tools to do this.

This require removing the Cam belt so I purchased a HKS belt and bearing set for the job.

After the work was done, I picked the car up and immediately noticed some hesitation when cold and next to no boost. Once the car gets to about 5k RPM the boost shows as jumping to about 10psi but it's like hitting the brakes. no power what so ever.

Staying off the boost and the car will run fine and she revs normally.

 

Took it back to the garage to check as they simply made marks and swapped the belt.

This time we checked the factory marks and they all lined up as expected. They said there was nothing else they could do...

 

I took her home and got a timing gun. Used a HT lead between the coil and spark plug to make sure the signal was correct. Checking the timing she was a tiny but off 15 degrees so I adjusted it accordingly.

No change

 

The only time I can get any power back is if I advance the timing to about 22 degrees. She boosts better but still not quite right and still tops out at high RPM.

Since this started I've also had a lot of popping and backfires from the exhaust. More than the usual as it's a straighthrough pipe.

Another thing since this issue started is I've had 2 fuel pumps fail. When testing them they seem fine however I've now installed a 3rd with the relay mod to make sure the voltage is at 13.5v. 

I've put in a new fuel filter to make sure there isn't any fuel issues since the pumps failed.

 

No mods have been added since changing the cam belt.

Currently installed mods:

Front mounted intercooler

Air filter

3.5inch straighthough exhaust

All new vacuum and boost pipes. checked for leaks and couldn't find any.

New coolant temp sensor

New O2 sensor

 

Anyone heard of anything like this before?

I'm worried about running 22 degrees timing as the gtst is supposed to be 15.

 

I will be changing coils and sparks soon but they seemed fine when tested. 

I've checked the MAF and it seems fine. I can't test boost with it disconnected as it goes into limp mode.

 

Would putting her on a rolling road/dyno help diagnose this? Standard ECU Obd1 so can't find anyone who can plug it in :(

 

Sorry for the babble, hope it makes sense.

 

Thanks in advanced for any replies.

 

A.

[Duncan]

I know you said you went back and the shop checked it again, but 99% this is a timing belt alignment issue. Perhaps they just made the same mistake twice because they are not familiar with the car

Unfortunately it's tricky to get pics with the right angles to check, so maybe just get another shop to have a look at the car.

It could also be a big air leak or fuel pressure issue (or a million other things) but what you are describing with the popping, running OK under low but not high load and just no zoom all point to badly retarded timing

[Skaith4224]

Hey Duncan,

 

Thanks for getting back to me so quickly on this.

 

While I was hoping you'd say that I was also kinda hoping you wouldn't say that 😛

 

Stuck in a bad place as the garage I've had the work done is a friend so it puts me in a tricky situation of, do I go somewhere else, get the issue fixed and have a chat with my local guys as i've already spend a lot of money getting this done or do I go back to them again for another check. They would be upset by this as it would be me asking for a 3rd time to take the front apart.

 

If I had a crank puller I'd have a look myself however not being a qualified mechanic, I'd worry about doing this myself. I do have a friend that may be able to help there though.

 

Any tips on making sure everything is lined up correctly? I was with the guys doing the work second time around and we found it tricky to make sure the bottom mark was correct as the angle is not ideal without taking the entire front end off.

 

Thanks.

[r32-25t]

Just take the top cover off and line up the lines on the balancer up to tdc. It will tell you if it’s out or not, 

[Dose Pipe Sutututu]

Sounds like the one of cam sprockets is off by 1x tooth and yes the OEM voltage drop resistor will torch fuel pumps. Constant power or PWM is the only way.

[Skaith4224]

Thanks for the updates guys.

 

I'll have a look at aligning the balancer tomorrow as it's 23:30 here now. I'll get some pics. Fingers crossed it's off by a tooth as this would be fixable! I feel like I've done nothing but chase issues all year and not been able to enjoy the damn thing!

 

Hopefully the fuel pump will now hold out and not give me any more issues.

Quick question regarding the fuel system, When priming, it takes about 6-8 seconds to prime. This seems like a long time to me. would I be right in thinking this is not quite right? also has a frothy sound going into the injectors. This has always been the issue long before I was getting any kind of performance issues.

 

Thanks.

 

[Dose Pipe Sutututu]

On 05/11/2021 at 10:34 AM, Skaith4224 said:

I feel like I've done nothing but chase issues all year and not been able to enjoy the damn thing!

standard Skyline ownership, mine spends more time on tow trucks, hoists and jackstands than at the track or streets. I pay registration and drive it like 4 weeks a year and the rest is spent as a garage ornament or parked at paid private parking on a hoist at a workshop LOL

[PLYNX]

On 11/5/2021 at 10:35 AM, Dose Pipe Sutututu said:

standard Skyline ownership, mine spends more time on tow trucks, hoists and jackstands than at the track or streets. I pay registration and drive it like 4 weeks a year and the rest is spent as a garage ornament or parked at paid private parking on a hoist at a workshop LOL

Oh Johnny,

Things are opening up now after covid and you know the cure to your woes . . . . . . . 

DRIVE BABY DRIVE . . . . . . .

And you know where.

Fix it fix it now . . . . . .

[Dose Pipe Sutututu]

On 05/11/2021 at 11:16 AM, PLYNX said:

Oh Johnny,

Things are opening up now after covid and you know the cure to your woes . . . . . . . 

DRIVE BABY DRIVE . . . . . . .

And you know where.

Fix it fix it now . . . . . .

a bit hard when I can't drive it (car doesn't work LOL)

[Skaith4224]

 

Hi Guys,

 

Back with some images.

 

Putting the balancer to TDC and the cover off it looks to line up pretty well however the intake cam seems to be maybe a quarter turn retarded. Could this be a tension issue?

The belt is a genuine HKS with bearings so I wouldn't have thought that would be the issue.

Would this be out enough to give me these issues? 

 

Thanks.

[r32-25t]

Looks good to me 

[Duncan]

yeah sadly, looks good to me to. Do you have a decent pic of where the balancer was when you checked or did you find TDC through cylinder 1?

If all 3 marks line up properly the timing is right. You can't be less than a tooth out, the belt has fixed teeth with fixed spacing. You can get a feeling for whether the tension is right with the cover off, you should get a cm or 2 but no more at the middle of the longest belt run

I can't see anywhere you said which car it is but I understand all the GTST are 15o base timing and you said you checked that with a lead on 1 (important because if you use the loop at the rear of the motor, some guns read double timing which means 22 could actually be 11...)

[Skaith4224]

Hi Duncan,

 

Yes to clarify, it's an R33 gtst series 2.

The second image should show the balancer lining up with the mark on the belt cover perfectly.

If that small amount of difference on the intake cam isn't an issue then I will say the belt is correct.

As the manual states, 15 degrees advanced is the correct position for the balancer when idling and the TPS disconnected.

Using the light gun on a HT lead from the coil to spark on cylinder 1. No bouncing so looks like signal was good.

Tension feels good from looking up a few how to's. My concern was if the tensioner bearing was placed upside down and if that would make a difference.

 

What I'm thinking now is there must be a leak somewhere that I can't find. I've been using a small airbrush compressor to check but it doesn't have enough flow to get to 5 psi so it's difficult. This may suggest a leak too!

I've also been trying to find instructions on how the factory hoses/vac lines should be as it looks like some were modded/changed by the previous owner.

Otherwise I'll be checking things like the BOV and regulator to see if they have anything to do with this,

 

It's just very odd as my boost gauge connected to the intercooler pipe just before the throttle body is showing about 6psi under load then jumping to above 11/12 psi under high RPM but it looses all power at this point.  This is T'd off to fit directly to the wastegate actuator and boost solenoid so it should cut off at around 7 psi I thought. maybe it's not moving enough? how far should it move?

 

Thanks.

[peanutpckrupper]

Sounds like fuel cut to me. Obviously check for boost leaks, but also make sure your wastegate is functioning properly. With your last message saying it hits 11/12 psi then cuts it sounds like you're getting a boost spike and the ECU is pulling fuel. I just dealt with this on my rb20. 

[Dose Pipe Sutututu]

Borrow a CAS and see if that is the issue, the OEM optical CAS (although great in theory) is actually flawed by the fact it is high resolution and with age fails to read properly.

This is why many drop to a 24 - 1 cam trigger setup (myself included) OR a crank/cam trigger setup.

 

[Humbla]

On 05/11/2021 at 6:26 AM, Duncan said:

I know you said you went back and the shop checked it again, but 99% this is a timing belt alignment issue. Perhaps they just made the same mistake twice because they are not familiar with the car

Unfortunately it's tricky to get pics with the right angles to check, so maybe just get another shop to have a look at the car.

It could also be a big air leak or fuel pressure issue (or a million other things) but what you are describing with the popping, running OK under low but not high load and just no zoom all point to badly retarded timing

Very well put Duncan, been through the same issues as well over the past 20 years. 😃😃

[Skaith4224]

Hi all,

 

Sorry Ive been away for a little while. Been working on a few bits and went to a meet to chat to some skyline owners. Didn't get much useful info unfortunately however I do have some updates.

 

Not been able to borrow a CAS yet, hoping to do so soon.

 

So the other day I broke down and it ended up being the fuel pump failing. This was an older pump that I had to put back in after my new pump failed. After some research, I performed the relay mod and installed a 3rd pump. so far so good.

This has no changed the car performance however :<

On my way back from a car meet I had some really weird juddering on trying to boost. This was intermittent but very concerning. So today I took off the wastegate actuator, tied the wastegate open and went for a drive. Apart from the lack of power and a lot more popping the car ran well. No hesitation or flat spots that I could notice.

However! when the RPM got to about 5k the boost pressure at the throttle body suddenly shot up to 12psi again. Below 5k I was seeing no pressure as to be expected with the wastegate open.

 

I'm now thinking the turbo is shot. Does anyone agree? It's original so 26 years old... 

 

Thanks.

[r32-25t]

Did you happen to change the plugs while doing the timing belt 

[Skaith4224]

I am getting new plugs tomorrow.

I'm hoping to get some new coils soon however I'm looking at all possibilities as OEM are expensive and second hand so might look at getting the R35 kit. Just need to make sure the standard ECU can handle them.

[Dose Pipe Sutututu]

Borrow a CAS first before you fry more money