2G 2g 6-bolt swap won't start

[Jman9912]

Hey guys, i've got a 96 GST with a 6-bolt swap. Well I haven't been able to get the car started.

After doing a bunch of research I've come to conclude it's the coolant temp sensor.The starter relay isn't working so I'm having to bypass it by jumping the connector. It cranks but just keeps cranking and doesn't start. It seems like it's running too rich and dumping too much fuel. When I looked at the thermostat housing, there is only one plug plugged in and it's the very top one.

I've been searching like crazy but I can't figure out if that plug needs to plug in somewhere else or what. I've read something about changing it. I think it's the 1g CTS. I can snap a pic shortly.

I'm not sure what to do.

 

[phr0st]

The very top one on a 2g thermostat housing is the sender for the temp gauges. There is a plug below it with two wires (black w/ white stripe and black) for the CTS. If it has one spade connector it's the sender if it has a two-wire plug its the CTS.

One a 1g housing the top sensor is the temperature switch for A/C operation. The CTS on the 1g housing is on the front of the housing at the bottom closer to the engine block.

 

[NHerron]

Bam
http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html

 

[Jman9912]

I've already gone through the no start guide. Its a 2g car with a 6-bolt. The 6-bolt CTS is still in the housing but the 2g wire is plugged into the top most sensor.

There is RTV silicone around the top sensor so it could be the 2g sensor swapped in but IDK. I'm gonna connect it to the lower 6-bolt CTS and see what happens.

 

[phr0st]

You can't connect a 2g CTS plug onto a 1g CTS they are two different connectors. You would have to cut the plug off or de-pin it. Chances are the person swapped a 2g CTS into the 1g thermostat housing. Have you testing the resistance of the CTS to determine if it's within spec?

Get out your multimeter and measure the resistance across the two prongs. * Edit just realized you read the "no start" thread. The specs for a 2g sensor are in that thread.

 

[Jman9912]

It seems as though it has a 1g cts and a 2g cts in it. The 2g CTS looks like it's above the thermostat which I know it's suppose to be below it..I'm going to run two wires with spade connectors from the pins to the 1g and see if that changes anything. I'll snap some pics while i'm at it to show you..I'm not 100% sure that it is a 2g cts..It could just be the switch or something.

 

[byebye_sti]

Subscribed.

Dealing with a similar issue.

 

[Jman9912]

I spliced the wire in and it seems like it's trying to start...i'm gonna try to swap the firing order and see if that helps. I swap the two outer and the two inner i'm pretty sure.

It cranks and seems like it's doing good, but then it catches and then keeps cranking but sounds kind of like the battery is dying. That's not the case though. I've got it hooked up to jumper cables too.

 

[phr0st]

Try grounding the wires on the t-stat housing and starting it. Some people have used this as a workaround for a bad CTS. I don't recommend you leave it that way if it works.

If you did an entire swap (6 bolt head/block) the firing order should stay the same as factory. Only the 2Ga cars that kept the 7 bolt head had to invert the signal/swap wires.

Is the CAS wired into the 2g harness or did you(or previous owner) buy an adapter harness. Either way check the connections(more so if it's wired in). These are very crucial signals for the 2g ECU to see.

 

[Jman9912]

It's a black CAS (hall effect) and it's wired into the harness. It was done by a garage. It looks like they did it right. I've been going behind them trying to check everything. It was a shady ass garage so it's hard to tell. Even if they did put the 2g CTS in it, they put it in the wrong spot...

How would I go about grounding it to the housing?

 

[miguelmcv]

I will assume you have a 1g thermostat housing,.
If you do, then here is a thread where shows a 1g and a 2g thermostat housing,.

Take a look at this pics so you know what you have (post #9).

http://www.dsmtuners.com/forums/newbie-forum/431888-different-thermostat-housings.html

I see you have a 2ga,, Then you have to swap firing order, Just swap the once in the middle (2,3) with the outer one (1,4), It doesn't matter which one goes where, as far the middle once are on the outer side and the outer side are on the innerside then you should be OK.

 

[phr0st]

Most people who do the grounding trick do so because the wires broke out of the plug (some with bad CTS's) so if the wires were broken its as easy as touching the housing with the bare ends. Since your plug is still on get creative with a paperclip or something. You just want to see if the car will start with it grounded so have the wife/girlfriend/mom/sister/brother/uncle/grandpa turn the key while you ground it.

 

[Jman9912]

Most people who do the grounding trick do so because the wires broke out of the plug (some with bad CTS's) so if the wires were broken its as easy as touching the housing with the bare ends. Since your plug is still on get creative with a paperclip or something. You just want to see if the car will start with it grounded so have the wife/girlfriend/mom/sister/brother/uncle/grandpa turn the key while you ground it.

So basically just touch both wires to the tstat housing?

miguelmcv

It's a 1g thermostat housing, I already know this. I'm just not sure which CTS they used but i'm pretty sure it has both tapped into it. The original 1g CTS in the correct spot and a 2g CTS in the topmost port above the tstat.

 

[miguelmcv]

Ho I see, Then you are on the right track, The way you are describing the issue, looks like you just need to clean the spark plugs, recharge the battery and give it a try, it should start right after.

Just connect the wires to the CTS, Try one first and if it doesn't work, then try the other one, If it still doesn't start, then try to play a little with the Cas, It might be off a bit.

 

[Jman9912]

Wow, I just checked out the CAS and the bolt that you can use to adjust it was loose. The CAS was down as far as it would go. I put it in the middle and tightened the bolt. I'm giving it a few minutes for the battery to charge then I'm going to try to start it again.

It's still not starting.

How do I make sure the CAS is in the right position? Or how do I know where to set it?

 

[miguelmcv]

You have to set the motor to TDC, line up the marks on the crank and the cams as well, once you have all the marks line up (TDC), then remove the CAS and check the marks on the CAS, here is a good pic of the cas showing the marks.http://www.dsmtuners.com/forums/maintenance-repairs/472097-cam-angle-sensor-set-up.html

The marks needs to be line up, once you have all set up and cas installed, then give a try,. Now, when cranking the engine, if it doesn't start, rotate the cas lightly to one side and see if it starts, if it doesn't, then rotate the cas to the other side, the noise of the engine will tell you which side the cas needs to be rotated.

When the firing detects the right spot on the cas, it will start,.

You need to set the timing with a gun after it starts to make sure you are at 5 and not be to advance which you will risk your engine.

 

[Jman9912]

I'm hoping something isn't already messed up..I think it was advanced as much as it could be and loose as shit. I tightened it up and moved the CAS around a little..It almost started. Came closer than it has before. This car has been SOOO frustrating. I'm ready to drive it off a cliff...I'd have to push it though .

I don't have a timing light though.

 

[miguelmcv]

You don't need a timing light right now, its only used after it starts.

Did you clean the spark plugs?, a dirty plug will not help at all, specially if its wet.

 

[Jman9912]

Yeah I just cleaned them off real well.

Its still acting weird as hell. I'm done with it for the day, but tomorrow i'll take a video of how it's acting. I'm stumped.

 

[phr0st]

We started off this thread with your statement "I have narrowed the issue to the coolant temp sensor". It looks like the CTS is not the issue since you have tried 2 and none work. The car may have a blown sensor ground in the ecu as well. A logger would be the best to see this with as it will show at -74 degree coolant temp. This should also trigger a check engine light for all sensors missing that ground (MAF, Baro, TPS).

Has the car EVER ran since you've owned it? Did you just wake up one day and it didn't start? Did you hit a cow, pothole, old lady?(Plead the 5th on the latter)

I think it's important to take a step back and check the basic things.
Adjust the CAS somewhere in the middle of it's range as a start, my cars and most I've seen will start and idle even with the CAS all the way advanced. It is not advised to leave it running this way and you definitely don't want to go boosting around town like this.

-Check the mechanical timing on the car. Make sure all marks line up when the motor is at TDC.

- Then check for the BIG 4 (Fuel, Spark, Air, Compression)

-- Fuel; When you turn the key on do you hear the pump prime? Is it making it's way past the fuel filter and into the rail? Are your injectors firing during cranking? A can of starting fluid can be useful here but be careful as it is extremely flammable.

-- Spark; Pretty obvious, pull one of the plugs and crank the engine to see if the plug is firing. It will need to be in a very dim/dark place in order to see the plug arc from electrode to grounding strap.

-- Air; We'll assume the car is getting this unless a squirrel is living in the UICP.

-- Compression; This one is pretty self explanatory, do a simple compression test.

Let us know which of the 4 is the issue. Also a nice cold beer will help with the frustration a bit.

 

[Jman9912]

Its getting fuel and air. Im not 100% sure but I dont think its getting spark or its getting intermittent spark. I haven't checked compression but im pretty sure its good.

Anybody?

 

[NHerron]

Like he said, starting fluid is a quick way check for spark.

A compression test would also be helpful in that it let's you know if your timing is off enough to cause a no start (low compression)

 

[Jman9912]

Oh okay I see. I used starter fluid once but it was acting weird so I stopped. It was probably from the CAS being off so much. When I go back over there ill try the starter fluid again and check compression.

 

[Jman9912]

I'm still having trouble getting my car to start. It's a 96 with stock ECU and a 6 bolt with blacktop CAS.

When I looked at the CAS the adjusting bolt was completely loose. I tightened it back up and moved it to the middle and it seems like it was closer to starting. Do I need to take the whole CAS off and reinstall it?

Also I'm a little confused about inverting the CAS and which order my plugs should be in? I've searched around but am still confused. I'm getting spark just not sure if its at the right time or if I'm getting spark at all 4 cylinders or not.

This cars been a nightmare

 

[bryanwheat]

Im having trouble getting my car to start. Ive had another thread with other issues. Its a 96 with stock ecu and a 6bolt with blacktop cas. When I looked at the cas the adjusting bolt was completely loose. I tightened it back up and moved it to the middle and it seems like it was closer to starting. Do I need to take the whole cas off and reinstall it? Also im a little confused about inverting the cas and which order my plugs should bein. Ive searched around but am still confused. Im getting spark just not sure if its at the right time or if im getting spark at all 4 cylinders or not. This cars been a nightmare

Did you search for this, I have a feeling that you didn't. It is very,very very simple.