Troubleshooting and repairing DTC H42 on a C4 Corvette

[@Amundred]

Tried to take it for a spin...no luck 😭

[@101LPSHearts]

❤sooo gooood this helped me tremendously...I’ve been immobile since Feb 2023.

[@Amundred]

Glad to hear! Thanks for commenting!

[@eljavi3954]

Excelente video amigo

[@Amundred]

Gracias!

[@halietrappe]

Glad to see you’re using Derick’s old manuals!!

[@Amundred]

They definitely come in handy! I am thankful that Derick gave them to me! I use them a lot! 😂

[@geneyus6411]

I wish he gave them to me!

[@mrdeanv4414]

Great video and great information... 👍🏻 I have replaced everything on my 95 Vette except the Optispark... the code showed H34 which is the Map Sensor so I replaced it and the pigtail to the Map Sensor and there was no change... The H34 code is gone but it still runs like crap but it will start on the 1st crank... Everyone is saying change the Optispark but I don't want to do that unless I know for a fact that it is actually the Optispark.... I'm so frustrated 😠

[@Amundred]

You and I are having the same issue...I decided to go ahead and rebuild the engine, I will replace the computer when I reinstall and am replacing every sensor on the engine at the same time!

[@mrdeanv4414]

My 95 used the same paper clip trick as your 94. #4 pin and #12

[@robertmendenhall1350]

I like your videos got my exhaust off my car would have a really hard time starting and idling everytime it warms up they would die I think I got bad Cadillac converters or a muffler that's backing up and then it just backs up

[@spryfry9367]

Thank you for this video. I am running into the same issue unfortunately on my 93. Fortunately, I do have a service manual and will try to follow the charts like you did. I couldn't find any other information on this and didn't even know these type of charts existed in the service manual. Hopefully it's a dirty connector like yours!

[@geneyus6411]

Parts canon picture is hilarious 🤡💣💥

[@Amundred]

Haha...I need to go back and make Parts Canon thumbnails for all of my older vids now!

[@geneyus6411]

@@Amundred The knock sensor thumbnail actual looks like a cannon projectile, lol. Make sure it's aimed at gm headquarters! That's also the video you gave me a shoutout and dissed my funnel🤣😥😱

[@geneyus6411]

@@Amundred Something tells me your C4 was a Garage Queen before you had it.☠ None of the threads on your old parts are corroded or even break when replacing on your videos, unless you cut those parts out. You're lucky with that.

[@geneyus6411]

@@Amundred What technique did you use for getting the ball joint rivets off?? I have to do all that soon also. Have you seen the videos of dry ice being used to clean up cars?? I wish I had that tool/ business🤑🤑🤑

[@Amundred]

@@geneyus6411 that sucked! I used a grinder and chisel

[@robertmendenhall1350]

I replace my timing chain my car has 170,000 miles on it but the old one still wasn't tight some people have told me that you never really have to change that timing chain they're really a good timing chain but I replaced my knee and I was there right when I replace my distributor I've got my throttle body off right now I've had it clean now I'll replace those parts that you just did

[@Amundred]

I will be replacing mine with the engine rebuild...better safe than sorry and all of that! 😲

[@Christopher-p2l]

You forgot to mention to put dielectric grease on surface between ignition control module and heat sink If you don’t it will burn up and have to replace

[@Amundred]

Yes, this is very important!

[@PipeWagonTV]

Use a quality thermal paste instead

[@jeepguymb45]

I have a code 25. Module 1. It reads H25. I’ve looked it up but what’s confusing is it’s not engine related. But on the web it seems to be engine related. One reads courtesy issue and also Air intake. I’m a bit confused.

[@Amundred]

Are you 100% sure it was Module 1? WHat year are you working on?

[@jeepguymb45]

@@Amundred yes. 93. H25

[@Amundred]

@jeepguymb45 I'd say it is probably the code for the IAT sensor circuit or whatever that references - maybe test the sensor if you have the info

[@jeepguymb45]

@@Amundred any luck with rhe computer cable link ?

[@Amundred]

@@jeepguymb45 the cable is simply a connection from the car to the pc using a special cable that has the USB on one end to connect to the PC - then you need software to read the info Cable: obd2allinone.com/products/aldlobd2u.asp Software options: obd2allinone.com/diagnosticsoftware.asp

[@geneyus6411]

Awesome video. You speak clearly and look like you know what you're doing! Some pretty good diagnostic tests and repair. You also don't have annoying background music or work in your sandals or flip flops showing your nasty feet! I didn't see you put that thermal paste on the backside of the ICM. Maybe you did it off camera. Car starts , idles very good, sounds good. I have the same coil👍

[@Amundred]

Thanks! I added the thermal paste off camera...it is the clear goopy stuff you can sort of see on the bottom of the ICM when I put the new one on the heat sink. Figured that the process was pretty straight forward so didn't include it. Yeah, it is definitely getting closer to running correctly! It definitely sounds like a timing issue to me as it misfires when cold or warm. At least there is throttle response now! I would not attempt to drive it anywhere...but it does run better than it has in awhile!

[@geneyus6411]

@@Amundred it really needs a drive for the computer to relearn the new injectors. You've made a lot of progress. You replaced a lot of parts without breaking things.

[@geneyus6411]

@@Amundred The wiring issue was exactly like my alternator plug. I ended up having to take the rear bracket off and cut the tape/loom go further down. Tape was all dried like yours, the plastic loom was soo brittle, needs replacing. I should have that done tomorrow. ON the stock harness, there's a red wire and 2 smaller brown wires. Thanks GM!!!

[@Amundred]

@@geneyus6411 I would love to go through at some point and replace ALL of my wire loom...it is so old and brittle! 😲

[@geneyus6411]

When I put my new injectors on, With the car running, it wouldn't let me do revs, like when you tap the pedal several times. I thought something was mucked up.also had a little blip in the idle. Those both went away after driving on the street. Your engine has been taking abuse just sitting, idling, loading up on fuel.

[@alexl9334]

Don't start the car with the car jumped with that pin. You can damage your vehicle, pull it out then start.

[@geneyus6411]

Wow! 1st time you pulled no new codes after repairs???👍

[@Amundred]

Yes!!! The first time!

[@geneyus6411]

@@Amundred That must be a relief! You pretty much have nothing to change. I'm code free too,lol😲

[@geneyus6411]

@@Amundred The butt connectors that came with the pigtail kit for the alternator are very generic, Like they are a size to big for each wire. 2 smaller wires that are 12-14 1 larger(power)wire that is roughly 10 gauge. What a pain!

[@Amundred]

@@geneyus6411 yeah, I try to not use the ones included in pigtail kits for this reason! 👍

[@geneyus6411]

@@Amundred Probably have to make a home cheapo run,ugh!😡 I bet a lot of guys, girls have used the generic ones and made crappy connections 🤔

[@PipeWagonTV]

Did you ever figure out what the issue was??

[@guitariste47]

Just subscribed! What year is this C4 please? I am considering buying a 1990 model

[@Amundred]

This is a 1994 with the LT1 engine. Amazing cars! Thanks for subscribing!!!! ❤️

[@robertmendenhall1350]

Could be bad plugs and wires

[@Amundred]

I did replace plugs and wires...I was hoping that it was this easy! 😂 Unfortunately, it wasn't the issue 😢

[@deney54]

How many miles do you have on that motor? And before you pull the timing cover put a stethoscope on the cover and listen while the motor is running and have someone rev it up a little, if the chain is bad, you will hear it.

[@Amundred]

101,000 miles and I think that the stethoscope idea would definitely save time!

[@geneyus6411]

If it is timing chain, just fix it up! Then you have fresh crank seal seal, timing cover seal.😳

[@geneyus6411]

For that to work accurately, you would have to know what a good one sounds like. A real stethoscope would be picking up a lot of noises!🤔

[@Amundred]

@@geneyus6411 to be fair...this is an accurate statement!

[@geneyus6411]

@@Amundred If I was listening, I wouldn't know the difference, would you??