Stumped - Car runs like crap

Long story, I’ll keep it to the required details. I need help getting this thing running right.

I have an 86 Shelby Charger with a T2 swap. The engine is a non common block T2 out of an 89 Masi TC. I have not plumbed in an intercooler yet, and the turbo is connected directly to the throttle body. This was done just to get the car running and then figure out routing for an intercooler. The car has an 87 glhs mopar stage 2 LM. The car has a roller cam, but a square tooth pulley. I understand I need to get an offset cam key to fix this, but I don’t think it’s the main cause of my problem.

The car was completely drivable last summer, but lacked power. I diagnosed a restricted return line causing very high fuel pressure and a rich running condition. I dropped the tank last summer, then the car sat for a year as I lost interest in the project.

I picked back up on the project the past couple months. I installed a new fuel pump and repaired a bad ground to the Power module. I now have 52 psi fuel pressure at idle and 59 with the vacuum line off the regulator. The vacuum line does not smell like gas.

I installed a brand new set of spark plugs as the ones in it were fouled due to running rich.
I also installed a brand new O2 sensor as the one in it was not switching. I have a one wire sensor installed and the scan tool shows it switching at idle. These parts were all diagnosed and ordered last summer, but I just got around to doing the work. My assumption was that the car would run great after this. I was wrong.

The car will start and idle ok. It starts very hard, like long cranking time, sputter a little, die. Try that a couple times and it was finally catch and idle well. BUT, if you so much as just tap on the throttle, it just bogs down and sputters/almost dies. If you let go of the throttle it will come back to life and idle fine.

It throws a code for the charge air sensor and battery temp sensor, but the power loss light is NOT on. I have swapped in another MAP sensor, another ECT sensor, and another HEP. All one part at a time and nothing changed the running condition. The vacuum line going from the intake to the MAP inside the car is fine, no restrictions at all. I am using a snap on vacuum gauge to monitor vacuum there.

Yesterday I unplugged the ECT and the fan kicked on, along with the power loss light. With the ECT unplugged, the car runs much better. You can snap the throttle and it responds immediately. You can even drive the car around the neighborhood with base ignition timing. Plug the ECT back in and cycle the key, back to square one. So. I think I have a timing problem.

Hooked up my DRB3 with 83-97 super card. Enter legacy mode. It shows timing at 80 BTDC engine running at idle. What!? Why. What would cause that!!

This morning before work. I spun the crank by hand and lined up the flywheel timing mark to 0 on the transmission. The cam pulley has the hole on top slightly left of center when compared with the ground. Dead center when compared with how the engine sits in the car. The rotor in the distributor is pointing at cylinder one. Base timing was set to 12 BTDC with a timing light.

Any help would be appreciated. I am stumped. I have a DRB3, fluke 88 DMM, and access to a 4 channel pico scope if needed.


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Also, the shutter wheel in the distributor is in good shape and the plastic rivets are tight.


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I use a mirror to look at the arrows on the cam sprocket. They should line up with the seams in the camcap. I've never been able to use the hole in the cam unless I also have the upper timing cover with the window.

I really think it’s the LM. Key on/engine off. Looking at the timing data on the DRB3. It’s already asking for 80 degrees of timing. Before even cranking the engine. This explains why it starts so hard. All the sensor data used to calculate timing is decent, so it must be the calculation that’s off? That’s where I’m at.


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I would have to agree with Cordes.

What is the resistance of the coolant sensor?
should be approx 10K at room temp?
So if coolant sensor is disconnected it runs great, to me that means to look at what the ECU does in this limp mode
Also check the air charge resistance it should be the same

With it running and the ECT plugged in, what does the scan tool indicate the spark advance is? And what is it really? (an adjustable timing light should allow you to check it.) If timing is truly off, you should be able to adjust it and get it closer so the engine runs better.

How much compression does the engine have right now. (ie. how far off is the cam?)

If you key on with the engine cold, the temperature sensors should all read about the same and be ambient temperature. Is that the case?