QJet issue?

cdnpont · Canadian Poncho Superstar!

QJet issue?

ABC123 · Uber Guru

Maybe a dumb question but,

Are you sure it's not ignition related ?

65Camino · Uber Guru

Had something similar happen when I put headers on my El Camino. Did the laser heat gun aimed at the individual pipes. After watching it at night the wires were shorting out against the headers. Would foul plugs.
Solved it with woven/ceramic spark plug sleeves.
Been fine ever since.

Prefectca · Poncho Master!

The plugs were probably gas fouled. Friends have had problems like this when cars are started and moved around but not driven. The combustion temperature doesnt get high enough and additives in the fuel dont burn off and foul the plugs.

Paul

4SPEED427 · A Poncho Legend!

I'm with Paul, pretty good chance it just has been started and stopped too many times without a good drive.

Let it sit a couple of days, pop the hood, take off the air cleaner and give it a couple of pumps. If it gives a couple of shots of gas you're fine I'd say.

I have seen a new fuel pump cure fuel drain-back issues though. The 427 in my Acadian years back did that and a new pump fixed the problem.

JC2+2 · Poncho Master!

Paul is correct. Back in the day we used to get these yard welding trucks towed to our shop all the time. Start and move in their yard and shut off never warming up. If they ran it was the rear cylinders gas fouled. If not it was all of them fouled. Make sure you check your oil. In most cases the oil was diluted down with gas. Or just change it to be safe.

4SPEED427 · A Poncho Legend!

In the 80's there was a Superior school bus manufacturing plant here in Morris. I worked at the GM dealership here. We rescued a huge percentage of the GM buses at the end of the assembly line because they would barely run or not run at all. Every station on the line, the bus was started, moved the length of the bus and shut off. Of course the choke was on to start it. We put new spark plugs in brand new buses on a daily basis. Worst thing ever is all the starts and stops for a minute or less.

prototypefan · Member

As an aside consideration to the plug fouling is water.

When you start and stop an engine for a short period of time the amount of water that gets into the engine can cause all kinds of corrosion and more permanent damage.

I rarely start a car without being able to bring it up to temperature and keep it at temperature for a period of time. Saves engine internals and exhaust systems.

cdnpont.....I hope you find your problem!

cdnpont · Canadian Poncho Superstar!

I'm thinking it's entirely from the lack of warming up as well. Makes sense. After all, it always starts on the choke.

Hopefully soon she'll be on the road and see some heat.

cdnpont · Canadian Poncho Superstar!

As a footnote to close this thread, as it turns out, simply changing all the spark AC Delco R45 plugs brought the engine back into a perfectly smooth idle and cruise (I did go for a little run). All the plugs were black and sooty as found. Just like they always used to say, idling in the driveway does the engine no good.

Thanks for all the suggestions.

4SPEED427 · A Poncho Legend!

Nice, a happy ending and relatively easy solution!

65 SD L79 · Canadian Poncho Superstar!

I thought for sure you were gona pull it for a big block

cdnpont · Canadian Poncho Superstar!

I'm really enjoying the SB with the 4 speed Kevin. It makes it so much more fun.

65 SD L79 · Canadian Poncho Superstar!

cdnpont wrote:
I'm really enjoying the SB with the 4 speed Kevin. It makes it so much more fun.

Easier to pull the front wheels with out that extra weight

OURWAGON · Guru

Prefectca wrote:
The plugs were probably gas fouled. Friends have had problems like this when cars are started and moved around but not driven. The combustion temperature doesnt get high enough and additives in the fuel dont burn off and foul the plugs.

Paul

x2

cdnpont · Canadian Poncho Superstar!

The one thing is, when the plugs are fouled, you cannot always clean them to the point they'll work reliably. Sometimes they're basically junk at that point. At least that's been my experience.

I tried brake cleaner and acetone on the worst two at the back, and while they kind of came back, there was still a miss. Fresh plugs were the only solution, and the difference was immediate.

Is there a way to bring fouled plugs back?

ARCADIAN · Poncho Master!

I remember something about cleaning them with Benzene. ????

4SPEED427 · A Poncho Legend!

Those old school spark plug cleaners that used sandblasting actually worked very well. We had one at the dealership and if you've read through this thread you saw my note about the new buses off the assembly line with fouled plugs. After literally seeing hundreds of warranty claims over the years, GM finally refused to cover spark plugs under warranty on new school buses. We had to pull the plugs and run them through the spark plug cleaner, then put them back in. That actually worked very well, I would say as good as new.