Head gasket replacement complete - engine will not start. ?

[herbiemercman]

Hi Guys, Worst case scanairio, everything has been replaced exactly as prior to the job, photographs and parts marked etc, but she will not start, plugs wet with fuel and good spark, but does not even kick.

 

So what are the potential failure modes?

 

1. We replaced the rear engine knock sensor, no red warning lights on dash.? If the new sensor is not the right one could this cause the problem?

2. The head gasket is 3 times thicker than the original.?

3. The TDC mark on the bottom crank pulley was spot on and so were the camshaft drive sprockets, checked it twice.

4. The compression on all cylinders was spot on.

5. The spark plugs are soacked in fuel and there is a good spark.

6. The distributer location pinch bolt was well marked.

7. There is a 3 ft length of 6mm ID rubber pipe that the NAT converter pushed a set screw into one end to block it off, but we do not know where the open end connects to?

8. We have not connected the end of the down pipe to the exhaust system, could this compromise the MAP.?

 

What i cannot understand is why when we have fuel being injected and a good spark will it not run? could it be flooded? I removed the front two plugs and burned off the the fuel, but it still would not fire on these cylinders?

Tomorrow i will connect the exhaust system as i know the pressure drop through the intake right through to the tail pipe affects the MAP, i will also check the knock sensor connection is good, and check where the 3 ft rubber pipe connects, i do not understand why the NAT expert would block one end of this pipe and connect the other end?

 

I am not a happy bunny, just spent 3 hrs in the rain trying to solve this, any advise will be much appreciated. Herbie.

[Style]

Your MAP sensor won’t be on the exhaust. It’ll be an o2 sensor if anything. MAP sensor is somewhere on the intake side.

 

And yes, a change in headgasket thickness will absolutely need an ECU remap. If you do get it started, get the map sorted as soon as you can.

 

Are your leads definitely connected up to the correct cylinders? Dizzy might be out by 180 degrees as well.

[herbiemercman]

Hi Style, How is it possible to put the dizzy 180 deg out? my mechanic who helped me with the job refitted the dizzy and he marked the slotted pinch bolt with white 'tipex', he said it was returned exactly as it was?

Where would the MAP sensor be located on the intake side? also what does it look like? does it have rubber pressure pipes or wiring?

With reference to the thicker gasket, these are widely used and the supplier said the compression would only reduce by 5%? he said a re-MAP was not in the question?

I am grateful for your reply but still confused. Herbie.

[Scooter]

Earths definitely ok? http://www.mkivsupra.net/vbb/showthread.php?336628-Car-not-starting-No-Check-Engine-Light!-Help-me-please!!!!&highlight=starting

[Mike2JZ]

Get a timing light and check your ignition timing whilst cranking. Very easy to get dizzy timing off if you have removed cams/cambelt etc. Engine will struggle to fire if dizzy is out.

 

Exhaust not being connected won't make a difference to the car starting.

 

Assuming you have put a TT headgasket into the car? In which case you have changed the VE of the engine. Ideally you need the fuel map looked at, but having less compression will just mean that you will run richer than previously. Again, shouldn't affect the engine starting.

 

If you have a greddy emanage then you should be running a 3Bar Map sensor. Check it's plugged in & vacuum hose is connected.

[tintinmt]

+1 for something like plug leads in wrong order. Good luck with this. Hope a new day brings a solution.

[herbiemercman]

Hi Mike2JZ, Thank you for the information, i have been studying the functional characteristics today and my money is on what you said about the ignition timing, it is also good to know that the engine should start without the exhaust connected to the down pipe.

With reference to the VE (Volumetric efficiensy), the gasket supplier claims it has a negligeable effect on the compression ratio, sort of 9.8 to 1 instead of 10 to 1. also i was lead to believe that a slight reduction is ok for a turbo as the combustion temps reduce?

Can you tell me what the firing order is and what the compression pressure range is?

Also Chris Wilson who i have met twice,(great guy), sorted a deep rooted problem on my brother's twin turbo Supra, Chris has pointed out to another member with a starting problem the importance of the ECU grounding connections, he sent a photograph and it shows two 8 mm diam cables with large connection tags connected to the base of the air intake manifold, all i have is one 10 amp single wire connected in the same location with a 6mm amp tag, do you know why this is? as my car did run fine prior to the recent cylinder head replacement.

 

Hi tintinmt, We numbered all the tops of the spark plug leads, also the length of the leads is a good guide. Thank you both once more, this club is a must for members who attempt complex jobs on their cars. Herbie.

Edited July 28, 2019 by herbiemercman (see edit history)

[Mike2JZ]

Hi Mike2JZ, Thank you for the information, i have been studying the functional characteristics today and my money is on what you said about the ignition timing, it is also good to know that the engine should start without the exhaust connected to the down pipe.

With reference to the VE (Volumetric efficiensy), the gasket supplier claims it has a negligeable effect on the compression ratio, sort of 9.8 to 1 instead of 10 to 1. also i was lead to believe that a slight reduction is ok for a turbo as the combustion temps reduce?

Can you tell me what the firing order is and what the compression pressure range is?

Also Chris Wilson who i have met twice,(great guy), sorted a deep rooted problem on my brother's twin turbo Supra, Chris has pointed out to another member with a starting problem the importance of the ECU grounding connections, he sent a photograph and it shows two 8 mm diam cables with large connection tags connected to the base of the air intake manifold, all i have is one 10 amp single wire connected in the same location with a 6mm amp tag, do you know why this is? as my car did run fine prior to the recent cylinder head replacement.

 

Hi tintinmt, We numbered all the tops of the spark plug leads, also the length of the leads is a good guide. Thank you both once more, this club is a must for members who attempt complex jobs on their cars. Herbie.

 

What headgasket are you using, what part number. Oem sizes are either 0.3mm (NA) or 1.2mm (TT), it makes a difference.

 

Firing order of all 2J's is 1536254. Compression pressure on most healthy 2JZGTE's with 8:5:1 is going to be in 180psi range. 2JZGE's with 10:1 are in the 200psi range.

 

Couldnt find a better photo online, but these are the two earths you need connected on the inlet. You can just about make out what they look like.

 

[herbiemercman]

Hi Mike, Many thanks for the info, my compression readings were all 178psi to 182 psi. The robust gasket has four steel laminates and from "Conceptua" Tuning, i miked up the thickness and it was 1.4 mm. This is meant to give longer life for a NAT and allows for your head to be skimmed 0.1 mm. Hope i do not need the remap, the guy in Cardiff who carried out the "Rocket Dog Racing" mapping for their conversions was fantastic, the performance was superb, you will know that good re-map guys are rare. Herbie.

[Style]

Right so it sounds like you’ve fitted a TT headgasket which will lower your compression ratio from 10:1 to around 9.2:1 or so. That’s been backed up by your compression test results. As Mike said, your gasket is over 1mm thicker as your old headgasket was only 0.3mm thick. This is a big enough drop to require the map to be looked at.

 

Hopefully it’s just something like earths that’s preventing it from firing

[herbiemercman]

Hi Everyone, The car started today after moving the distributer drive cog 2 notches and then moving the adjustment slot on the ali diecast body to the white 'tipex' mark we applied to the securing nut. We had not fitted the exhaust system to the downpipe but it was easy for us to see that she was running spot on. My friend who is a good mobile Mechanic had researched what he did and there was nothing in the OEM Toyota manual outlining the importance of the possible movement of the distributer drive cog when you have had the camshafts removed.

My Mechanic ran a wire in the diagnostics socket from two pin holes, then moved the engine to TDC, prior to adjusting the distrbuter drive cog.

We had spent 3 hrs in the pouring rain the previouse day , checking the continuity of the replacement knock sensors, double checking the valve timing, checking the compression, checking the fuel supply, observing the quality of the ht spark at the spark plugs, checking the HT leads were attached to the appropriate cylinders etc.

We put the bonnet down and walked away pissed wet through, totally frustrated. The issue with an NAT, and not being able to contact the guy who carried out the conversion in Cardiff, is that you cannot find out why 3 or 4 sensor plugs are not connected and three 6mm rubber pressure pipes are cut off and in one case just a 6mm set screw blocking off one end, i still do not know why? however the car is running perfectly and has the same power, i was 'over the moon' after such a 'walk in the fog' operation.

 

My Mechanic said it was the most complicated stressfull jobs he had carried out, i agree as i have messed with lots of engines,changing valves on a Porsche 911, and changing the piston liners in a boat etc.

 

The overall cost was circa 500 pounds for parts and with my Mechanic being a good friend 500 pounds labour, six days work.

 

I also want to thank the Members of this Club who were very helpfull, as well as Nick my local Mercedes man who gave advise and lent us essential special tools, also i would say the experience my Mechanic gained and myself means we could carry out the job again in half the time and with minimal frustration. Herbie.

[tintinmt]

Good news! Thanks for posting.

[Style]

I’ve got blocked off hoses and unused plugs in my bay too. I wouldn’t worry about it too much and good news it’s up and running again.

 

I’d still recommend having the map looked at though. Do you have an Air/fuel ratio gauge fitted at all?

[herbiemercman]

Hi Style, Thank you for your comments re the plug in connectors being disconnected post your NAT conversion, i guess they were made redundant due to the MAP?

 

With reference to the Air/Fuel gauge, no i do not have one, are you saying that this gauge will display information that will tell me that the "Fuel MAP software" in the MAP itself is keeping within the correct parameters?

 

Final question if my car is performing as near as i can remember to how it performed prior to the new thicker head gasket being fitted, then why would i need a re-MAP.? Herbie.

Edited July 31, 2019 by herbiemercman
spelling. (see edit history)

[Mike2JZ]

Hi Style, Thank you for your comments re the plug in connectors being disconnected post your NAT conversion, i guess they were made redundant due to the MAP?

 

With reference to the Air/Fuel gauge, no i do not have one, are you saying that this gauge will display information that will tell me that the "Fuel MAP software" in the MAP itself is keeping within the correct parameters?

 

Final question if my car is performing as near as i can remember to how it performed prior to the new thicker head gasket being fitted, then why would i need a re-MAP.? Herbie.

 

Because what you think you feel from the driver seat as being similar to what you remember could be different to what's actually going on. Always better to be sure after applying some science to the situation.

 

As an example I worked on a car yesterday that has been BPU for ages. Driver never mentioned any performance related issue, but as part of diagnosing another issue we put the car on the dyno. After watching air fuel ratios, we saw it was running 13.5:1 afr under full boost at 1.2 bar. Turns out the car needed a new fuel pump. Without having that dyno run or a way to monitor AFR to alert the driver, that engine would of grenaded itself eventually.

 

Now your case is different, I doubt you run the risk of your engine blowing. But it definitely wont be running as efficiently as it could with a drop in compression. I would at the very least take your car to a dyno, get the operator to check AFR's whilst cruising and boosting. If all is well then you wont need to bother with a remap.

 

If the map is out slightly, should take a decent tuner 15 minutes to adjust your fuel map and get everything back on target.

[mellonman]

Good information thread this

[Style]

Hi Style, Thank you for your comments re the plug in connectors being disconnected post your NAT conversion, i guess they were made redundant due to the MAP?

 

With reference to the Air/Fuel gauge, no i do not have one, are you saying that this gauge will display information that will tell me that the "Fuel MAP software" in the MAP itself is keeping within the correct parameters?

 

Final question if my car is performing as near as i can remember to how it performed prior to the new thicker head gasket being fitted, then why would i need a re-MAP.? Herbie.

 

Yeah that’s my best guess mate as I’ve never really traced the plugs and hoses back. Presumably they’re redundant vacuum lines and OEM plugs that have been replaced by aftermarket sensors.

 

An air fuel gauge indicates the ratio of fuel to air in the mixture entering your engine. It’s a good indicator on how your map is if you know what numbers to be looking out for. Mike’s explained the rest really

[herbiemercman]

Hi Style, If the technician who mapped my car had some reference numbers? and as i said previously i have no way of contacting him in Cardiff, ("Rocket Dog Racing"), then how would a more local mapper know what the details or the numbers of my MAP are?

If i obtain an Air/Fuel gauge, like Mike suggested, do they just read out numbers? or do they show the units of pressure etc. Herbie.