[E31]

The car will crank but will not start.

History:
Did a single upgrade on car. Before upgrade car was starting fine. Did have a weak battery but I have a charge I used to bypass the problem. During the swap I replaced the timing belt and the front main seal. I added some gold gasket sealer around the seal to help prvent leaks. During the install I notice I broke the connector for the CPS sensor. Ordered and replaced

I've reviewed the forums I have checked and/or replaced the following in an attempt to resolve the issue:

Crank positioning sensor
ignitor
ECU

Checked all fuses, check CPS signal back to ECU (B7,B27) and there is a fluix when the car's cranked. Check fuel pressure and that the fuel pump is working (removed fuel line into filter and jumpered B+ and FP on DLC). When the key is turned to the on position the amouint of fuel dripping increases significantly. I can also feel the stream on the other side of the filter in the line to the fuel rail. I checked whether the timing belt was slipping. It does appear to be. Check the vacuum line to the FPR and it's connected. I can't see how this would prevent the car from starting but some suggested in one of the posts. I pulled all fuses and double checked. Check the IGN fuses in the kick panle on the drivers side.
Guys I'm stumped. ANY HELP would be greatly appreciated.

 

[scarface007]

Valave timing might be off , check it again.

 

[E31]

Interesting. How do I check value timing when the car won't start? An even better question is how do I make sure I'm at TDC after replacing front main seal and timing belt in regards to the cams can crankshaft? How far off does the cams have to be in relationship to the crank for the ECU to prevent the car from starting?

 

[Vu]

Everything you need to know about timing is in the FSM under "Engine-Mechanical"

When putting on the timing belt, be sure to leave the slack on the exhaust side so it's taken up by the tensioner.

 

[E31]

Everything you need to know about timing is in the FSM under "Engine-Mechanical"

When putting on the timing belt, be sure to leave the slack on the exhaust side so it's taken up by the tensioner.

Understood. I've been through the engine/mechanical section and I know that refers to TDC as it pertains to the markings on the cam gears and those on the harmonic balancer. Installing the timing belt is not a problem and has already been done. My question is, in the event I misjudged the markings on the balancer and used the yellow marker instead of the white, how far off will the tming needs to be before the car won't start.

 

[scarface007]

If the valve timing is off it fires the ignition and pulses the injectors on the wrong stroke.You dont need to have the car running to check Valve timing.It is the same process as putting on the timing belt.

 

[artbran]

Understood. I've been through the engine/mechanical section and I know that refers to TDC as it pertains to the markings on the cam gears and those on the harmonic balancer. Installing the timing belt is not a problem and has already been done. My question is, in the event I misjudged the markings on the balancer and used the yellow marker instead of the white, how far off will the tming needs to be before the car won't start.

That being the case, you have a VVT-i motor as they are the only ones that have the yellow mark.
To set the timing, you need to use the yellow mark on the crank and then the dots on the cam gears as opposed to the lines
When you rotate the motor to the white mark on the crank pulley, you will see that it matches up to the lines on the cam gears

If you used the yellow mark as TDC and set the cams to the lines as opposed to the dots, then you will be about 30 to 60 degrees off (I don't recall off the top of my head)

Basically, with a VVT-i you need to do what I posted above. Yellow line on crank pulley to dots on cams. White line on crank pulley to lines on cams. But you HAVE TO set timing with yellow and dots if VVT-i.
If non-VVT-i, then disregard the yellow line on the crank pulley as if it was not even there and ONLY use the white line.

 

[E31]

That being the case, you have a VVT-i motor as they are the only ones that have the yellow mark.
To set the timing, you need to use the yellow mark on the crank and then the dots on the cam gears as opposed to the lines
When you rotate the motor to the white mark on the crank pulley, you will see that it matches up to the lines on the cam gears

If you used the yellow mark as TDC and set the cams to the lines as opposed to the dots, then you will be about 30 to 60 degrees off (I don't recall off the top of my head)

Basically, with a VVT-i you need to do what I posted above. Yellow line on crank pulley to dots on cams. White line on crank pulley to lines on cams. But you HAVE TO set timing with yellow and dots if VVT-i.
If non-VVT-i, then disregard the yellow line on the crank pulley as if it was not even there and ONLY use the white line.

It's a non VVT-i engine. I 'm concern that during the process of replacing the seal, the crank may have moved off TDC. This would make the marks irrelevant and I would need another method to re-align both rotating parts without the convenience of the marks on the balancer. If I remove the belt leaving the cam position dots in place and rotate the crank I should be able to realign. My question is how will I know the crank is back @ zero? Also will this cause the car to crank but not start?

Here's a post for how to do it on an NA engine
http://www.supraforums.com/forum/showthread.php?25916-How-do-I-find-TDC-Compression
Is it the same for the TT's? We don't have distributors so is there anything else I need to be concern with other then the cam and balancer markings?

 

[dav0]

might be a longshot but is your fuel pump priming ?

 

[E31]

might be a longshot but is your fuel pump priming ?

Yes. I've check the fuel pump and verified that it's operating properly. I disconnected the fuel line tothe filter which already had gas present, jumpered B+ and FP on DLC (start pump) and confirmed there was a stream of fuel present. Also, once I reconnected the line to the filter, checked for flow in line leading to fuel rail.

 

[E31]

If the valve timing is off it fires the ignition and pulses the injectors on the wrong stroke.You dont need to have the car running to check Valve timing.It is the same process as putting on the timing belt.

scarface007 I see what you're suggesting. Will check valve timing tonight.

 

[scarface007]

scarface007 I see what you're suggesting. Will check valve timing tonight.

Hope you get it fixed , but if you are close to miami , I own a shop in Doral and i can take a look at it if you want.

 

[E31]

Hope you get it fixed , but if you are close to miami , I own a shop in Doral and i can take a look at it if you want.

Thanks scarface007 for the help AND the offer. I'll kept you posted.

 

[artbran]

If you look at the crank timing belt pully, you will also see a dot. That needs to be upward and aligned with the dot on the oil pump. You will see them there when you look at them.
You can also get it close by putting the keyway upward also, but you need the crank timing belt pully to get it perfect.

 

[E31]

If you look at the crank timing belt pully, you will also see a dot. That needs to be upward and aligned with the dot on the oil pump. You will see them there when you look at them.
You can also get it close by putting the keyway upward also, but you need the crank timing belt pully to get it perfect.

I will also check. Once I purchase a container to drain the coolant in I will have the rest of the accessory, covers, and radiator removed to get a better idea of how everythings aligned.
stay tuned......

 

[SUPRASSS]

if you are off by as much as 2 teeth the car should still start
what did you do with the maf btw.did you put it back or just gone vpc?
some more info would be usefull

 

[E31]

if you are off by as much as 2 teeth the car should still start
what did you do with the maf btw.did you put it back or just gone vpc?
some more info would be usefull

Agreed. Current setup: VPC and SAFC - these have been in the car since BPU++ which has been for at least 8 years. So MAF has been removed for that amount of time. AEM TRU BOOST and AEM WIDEBAND - The TRU Boost replace my old Greddy ProfecB and the Wideband is installed to help monitor and tune the SAFC and VPC once the car starts. So far, I've removed the radiator and will go to Advance Auto to get the puller loaner. LMK if anyone needs more info. BTW the plan is to verify the position of the cams (HKS adjustable) with the crankshaft along with verifying the crankshaft gear position, there's a dot that it is suppose to align with, also check and if necessary reposition the crank by reinstalling the cover and balancer without the timing belt and set it to zero. This should align all rotating components to TDC. Then reinstall the belt making sure nothing moves.

 

[E31]

UPDATE: Just removed harmonic balancer, timing cover, idle pully, and timing gear. Before removing the timing gear, I check that none of the RTV gasket maker blocked the opening for the CPS. There was no obstruction. After taking off the crank gear got a surprise, the sprocket didn't come off with it. This is the indicator the CPS sensor detects to create the pulse back to the ECU. It's suppose to be attached to the gear so when the belt revolves, so does it. If , however, it's not connected or loosely in place I would suspect the result would be an inconsistent strobe pulse to the ECU anbd thereby not allow the car to start. At least this is my theory which seems plausible. I remember another local supra owner suggesting I get these two parts welded to each other. I really didn't understand what he was saying until now. The test I did with the meter, while did show a change which indicated the sensor was operating, would have never help identify this type of failure. In any case, I will not put this back until I make sure the two parts are secured.

Was able to get the guy I use for welding to secure the sprocket and gear with a few tack welds. I will update once I get a new fron main seal and reassemble the forward engine section.

 

[E31]

After having the crankshaft timing gear (sprocket) welded to the crankshaft gear and rechecking all the timing related positions, i.e., the cams have the dots inline with the cover, the crankshaft gear indicator is aligned with the dot on the oil pan, and the harmonic balancer is at zero. With all these in place and the harmonic balancer torqued down, the car cranks but still won't start. Open for suggestions.

 

[botchilah]

Err, coolant sensors? If these are not attached, I understand the car will not start. There are two, one for the ECU and one for the factory gauge cluster. Make sure they are connected and working properly.