New to me Mystic Cobra...with a few issues

[LuckyDSquared]

hi all! New to the forums. I recently purchased a ‘96 Cobra. It has its problems and was priced accordingly. Ive already ordered a few things; plugs, wires, thermostat, and alternator. Any other insight about the problems I’ll describe below is appreciated.

First, my temperature gauge appears to be wrong...SCT shows temps of mid 190s while driving and low 200s while idling (sometimes will fall back to mid 190s). Is that normal? The gauge goes all the way to the L on NORMAL on the gauge.

Second, the car had a SCT chip installed on it and was throwing rich codes. I removed the chip and went back to stock. Now it is throwing IMRC codes (stuck open and something else with the IMRC sensor/P1516 and P1518). It also threw another rich code related to O2 sensor (P1152). The car doesn’t like to idle...like it’s idling too low and may stall out when idling. It also “pops” or somewhat misses and low RPMs. It also “pops” close to a backfire after stepping in on clutch while around 3000RPM range.

Obviously, I hope the stuff I bought fixes the problem. I plan to remove the manifold and inspect for vacuum leaks and clean the IMRC plates. Thanks for any insight.

 

[saleen97118]

Do this first make sure the imrc are shut you can reach them they are on the intake back by the fire wall,should have 2cables back there,make sure they are closed and then start the car and see if it idles ok.the imrc should not open until 3250 rpms.
Check vacume line in pass side inner fender the charcoal canister or evap canister is in their the vacume lines rot away check that.both of my hoses where real bad,it was causing a stumble in my car and o2s code along with evap.

 

[Tillerman77]

If/when you remove the intake manifolds to clean the IMRC plates, I would recommend bench testing the IMRC controller to validate that it is working as expected. Also, check the condition of the cables and cable ends while you are at it. The IMRC units can be repaired if needed.
What brand of spark plug wires? Many folks here have had trouble with FRPP wires, but excellent luck with Ford OEM.

 

[LuckyDSquared]

If/when you remove the intake manifolds to clean the IMRC plates, I would recommend bench testing the IMRC controller to validate that it is working as expected. Also, check the condition of the cables and cable ends while you are at it. The IMRC units can be repaired if needed.
What brand of spark plug wires? Many folks here have had trouble with FRPP wires, but excellent luck with Ford OEM.

Well, I cancelled the FRPP wires because they were out of stock. Are the OEM wires the Motorcraft brand?

 

[jman37]

Well, I cancelled the FRPP wires because they were out of stock. Are the OEM wires the Motorcraft brand?

Yes, they're blue. I got mine from Rock Auto when I changed out my plugs and wires.

 

[Tillerman77]

FRPP wires have been the source of misfires, which were solved by using the OEM wires. I am sure there are many users of FRPP wires that have had no problem. YMMV.
OEM # used on my 97 was F7PZ-12259-HA.

 

[Goose17]

Congrats on scoring a Mystic! Sorry for the problems. Post pics of the car when you get a chance. How many miles does it have on the clock?

 

[LuckyDSquared]

Congrats on scoring a Mystic! Sorry for the problems. Post pics of the car when you get a chance. How many miles does it have on the clock?

I tried posting a picture from my phone but it’s too big. It’s got 95k miles. It’s a clean car and I’m guessing it just wasn’t well maintained. Hopefully we can get her purring again for not too much money.

 

[LuckyDSquared]

Hey all,

One other thing I’ve noted. I believe this car used to blown. It has a vortec/procharger style coolant crossover on it. I’ve never installed a supercharger but want to make sure I’m getting this car back to stock. What should I be checking (injectors, fuel pump, etc.). I do have a tuner I can use to adjust for installed equipment but I’m not sure how to tell. But, this is probably why I’m getting a fuel rich code.