I was advised by a friend to rent an HEI spark tester and test the ignition coil. What do you guys think?

So you're still unsure if it is spark or fuel? If so you need to get a can of ether and have someone spray it directly into the throttle body while you crank the engine and step on the gas. If it fires up for a bit you know you have spark if not you know you dont have fuel.

I love my HEI tester. They are cheap and fool proof. It's up to you to do the ether test or HEI

I tried spraying starter fluid in the intake and down the brake booster vacuum hose while the engine was being cranked with no success. I noted that in the first post. I am sure it's a spark problem now.

why did you use the brake booster line??? Did you try directly spraying it into the intake manifold via the throttle body? If not then Take the intake tube off where the butterfly valve is have someone spray it in there (keeping their hair and face off to the side) while you open the throttle and crank it.

Hmmm I'm thinking coil. I was getting an intermittent P0420 code and wasn't ready to part with 450 to replace the cat. When my car had its hot stall out issues I went through the basic ignition items first. When I pulled the coil out I noticed the back was scorched. I replaced it and since then I have not gotten the p0420 code back.



To my understanding a failing coil can cause inefficient ignitions causing the cat code.

I used the brake booster line because it's the biggest direct vacuum to the intake manifold. Afaik, that's where you're supposed to do stuff like that lol.

Thanks silver for the info on the 420. I'm def going to test the coil today. I will report back soon.

Ok guys, autozone didn't have an hei spark tester to rent so i just bought the coil. I replaced the coil now and still won't start. It's going "phuhh" when it's turning over. Does that noise mean anything? It's not even sputtering anymore... It used to sputter and at least think about starting. Now, nothing.

Noises are tough to diagnose over the web. You may want to post a link to a video.

Is there any chance the car ran out of gas?

Does the car have an alarm system installed?

You still haven't confirmed that the problem is due to lack of spark or lack of fuel. Here is a link on how to test for spark.

Starting Problems

P0420 is a bad cat may be a cloged cat If it were me I would put a cat on and retest it is bad anyway Ifyou go aftermkt. much less $ but will not last as long No matter what else it may be the cat is bad anyway

problem was a distributor, and the P0420 code no longer exists. I've driven the car for 2 weeks now. Thought I should follow up with you guys, if anyone else has this problem they can learn from my mistakes!