Newbie with no spark

[wayja]

Hey Forum,

I am a Supra newbie so don't flame me too hard, ok? I have a 1989 Supra with a 7MGTE that I bought as a project. It doesn't run, but it is in good shape. Anyway, I have sorted through testing all ECU connections and everything seems to be as it should be with one exception. The TPS voltage values are the same whether the throttle is opened or not (about 11v). That being said, can this cause a no spark situation? The engine cranks good and sounds healthy, but no spark. Is there any quick and easy way to "jumper" the igniter to create a spark to the plugs to verify wiring and components?

Thank you in advance for any help provided,

Wayja

 

[IBoughtASupra]

The TPS values are wrong, it should only be up to 4.9-5V max.

Are the grounds on the intake manifold connected? Look down at where the two runners join, there should be a bunch of brown wires connected with a ten bolt there.

Giggle the CPS plug, located on the front passenger side of the head, and see if the car starts. Common issue where the wires for the CPS get brittle.

Have you checked for codes? Do so and report back.

Checking codes
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx

 

[wayja]

Okay. I could not locate the bunch of brown wires but did check the CPS and Coil connectors and found some very brittle wires. I replaced the connectors and wires as well. Still no spark after cranking. I ohmed all the wires for continuity and everything checks good. This time when I checked the TPS, I get about 5v whether the throttle is open or closed. The check engine light just flashes quickly when I try and retrieve the codes. Doesn't that mean no error codes? The weird part is while wiggling connectors, I found that the water temp connector was not making contact and very loose. I just wiggled it where I thought it was tight. During the numerous wiggles and cranks, lo and behold I had a spark and it tried to start, then nothing. I pulled the water sensor plug apart and pushed the connectors directly to the sensor. Still no spark. Any thoughts? Anything would be greatly appreciated.

 

[hvyman]

If nake sure the grounds are on the intake and not the starter. It's 2white wires and 2brown.

Does the check engine light come on with the key only in the on position?
Have any codes?

 

[AJ'S 88NA]

This is how you check the TPS, http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=101

 

[wayja]

I checked the TPS and it reads about 5v whether throttle is open or not. No change. I am not getting any error codes either. When I turn on the key the check engine light is on solid, and when I jumper the check connector, the light just flashes rapidly. Still no spark, although it did spark for a very short time, and now nothing.

 

[IBoughtASupra]

How are you checking the TPS? There will always be a constant 5V and ground whether the throttle plate is open or closed. The voltage signal back to the ECU is what changes.

DISCLAIMER: I was told by Nick M that I post incorrect info in the tech section, so wait for someone to verify what I just said....

 

[kotu100]

Are you checking the correct terminals?

Does the tach move when cranking the car, if not then likely the CPS is the culprit. Also check to make sure the coilpack is plugged in, and that the plug wires are running to the correct plugs.

 

[AJ'S 88NA]

I checked the TPS and it reads about 5v whether throttle is open or not. No change. I am not getting any error codes either. When I turn on the key the check engine light is on solid, and when I jumper the check connector, the light just flashes rapidly. Still no spark, although it did spark for a very short time, and now nothing.

It has to be set.

 

[wayja]

I think I did check the TPS wrong according to the diagram. I will check again. In the meantime, the tach does not move at all when cranking. I am still not getting any error codes, though. Would a CPS problem cause this?

 

[kotu100]

The CPS is most likely your problem, double check your wiring for cps.