After using seafoam engine clean through the intake, the vehicle keeps shutting off?

Tiny
WILL1313
  • MEMBER
  • 1994 GMC JIMMY
  • 4.3L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 150 MILES
I put seafoam engine clean through the intake, was running good before the seafoam now it idles fine. Try to put it into reverse or drive shuts off instantly. If I hold the break down and give it gas to get going it will drive come to a stop shuts off, I've been told spider injectors are clogged? EGR is clogged or bad IAC sensor. It was running good before the seafoam, Won't use seafoam ever again.
Thursday, June 29th, 2023 AT 1:06 PM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Did you place it directly into the throttle body? Were you using a product that was designed to be poured into the throttle body?

If that is how you installed it, there is a chance the air supply from the idle air control valve (IAC) was plugged with dirt or carbon.

Remove the IAC and see if there is dirt inside where it mounts. Here is a link that explains how to service one. Note: It is located on the side of the throttle body. See pic 1 below.

https://www.2carpros.com/articles/idle-air-control-valve-service

I attached the directions below specific to this vehicle for the removal and installation of the IAC.

Let me know what you find.

Take care,

joe

See pics below.
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Thursday, June 29th, 2023 AT 11:09 PM
Tiny
WILL1313
  • MEMBER
  • 6 POSTS
Thank you very much for the information and replying. The can of seafoam I used has a red plastic tube that gets injected into the intake while the vehicle is running, then turn off the vehicle for 30 to 45 minutes hot soak.
Started the vehicle white smoke came out of the exhaust. Drove it a half mile and it shut off at the stop sign. As I said in my post you answered idles fine shuts off when put in drive or reverse.
I put a can of seafoam in the gas tank, it was almost full.
Only other two things were an oil change filter, Castro and Lucas oil stabilizer and added Transmission fluid to the transmission.
I'll check the IAC sensor like you said and let you know what I find. Thank you again.
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Thursday, June 29th, 2023 AT 11:22 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

Thanks for the update. Let me know what you find.

Take care,

Joe
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Thursday, June 29th, 2023 AT 11:55 PM
Tiny
WILL1313
  • MEMBER
  • 6 POSTS
I removed the IAC, cleaned it and inside the intake where the IAC connects. I tried but couldn't move it manually spring tip pushing it didn't move at all like in the diagram you sent me.
Still shuts off in drive, my friend sprayed break cleaner on the vacuum hoses and around the intake checking for vacuum leaks didn't find any I did order a new IAC from AutoZone today.
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Monday, July 3rd, 2023 AT 11:58 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

If you couldn't move the pintel, there is a good chance the IAC is frozen. If it doesn't retract a little, it will starve the engine of air when you take your foot off the throttle.

Let me know if that takes care of the issue.

Take care and Happy 4th!

Joe
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Monday, July 3rd, 2023 AT 10:10 PM
Tiny
WILL1313
  • MEMBER
  • 6 POSTS
Happy 4th to you and thank you for all the excellent advice. I'll let you know Friday after the new IAC is installed.
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Monday, July 3rd, 2023 AT 10:12 PM
Tiny
WILL1313
  • MEMBER
  • 6 POSTS
We removed the IAC that we think might be the problem plugged it in an started the engine the pinter shot out of the IAC? Put it back in just turning the key on an off several times the pintel slowly moved back in hooked the IAC back to the intake still shut off in drive? Waiting on the new IAC on Thursday.
Could it be the spider fuel injectors? Are clogged or bad need replaced, or possibly the fuel filter.
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Tuesday, July 4th, 2023 AT 5:55 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

If it runs okay off idle, I don't think it's the injectors. The pintel should have only moved a small amount. How far did it move?

Joe
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Tuesday, July 4th, 2023 AT 10:31 PM
Tiny
WILL1313
  • MEMBER
  • 6 POSTS
It shot out of the IAC had to put it back into the IAC. The mechanic from the fire department stopped by to help troubleshoot the issue. He said it's the clutches in the transmission when put in drive or reverse they don't disengage, and the jimmy shuts off?
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Wednesday, July 5th, 2023 AT 11:49 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
If I understand correctly, when you place it in gear, there is no disengagement between the engine and transmission causing it to stall, correct? If that is what happens, it's not the clutches. It is more likely related to the torque converter.

The torque converter in an automatic transmission car allows the engine to keep running when the vehicle is stopped by providing a fluid coupling between the engine and the transmission. The slippage within the torque converter allows the engine to idle smoothly without stalling.

So, if what I described above is happening, this is the likely cause.

Let me know.

Take care,

Joe
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Thursday, July 6th, 2023 AT 8:49 PM

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