Cutting out

[Horse]

It’s a ‘89 350ci Suburban with a Tbi carb'. Problem: Keeps cutting out on tick over.
I’ve replaced: Fuel filter, spark plugs and leads, coil, full distributor, oxygen sensor, power steering pump, last month I replace both heads (not because of the problem). I thought this would do it, but alas I was wrong.

Motor is very strong, runs like new, no hesitation, just cuts out when stopped, I made a plate to fit on the carb’ which enabled me to adjust the tick over, but to adjust it to the point where it doesn’t cut out means setting it to a very high tick over rate.

Any advice would be greatly appriciated. BTW. You people in the USA. Stop bitching about the price of your gas, on this side of the pond we pay…..are you sitting down…….$9.20 per gal. ;o(

[Horse]

Cheers Denny, thanks for you response, when I say tick over I mean when I am stopped, say at a junction and the engine is idling in drive, the engine doesn't slow down and die, it just cuts out.

[lt1s10]

have you checked for codes?

[Horse]

Denny,
Cheers for that idea, I'll give it a go and let you know how I get on.
Stay out of trouble!!!!

[Horse]

Hello Mike,
I don't know what you mean by codes. My "Service Engine Soon" warning light doesn't come on, if that's what you mean.
BTW. I admire your site.. very impressive.

[Horse]

Denny,
Just a quick one, where will I find my IAC, and what does it look like?

[lt1s10]

Originally posted by Horse
Hello Mike,
I don't know what you mean by codes. My "Service Engine Soon" warning light doesn't come on, if that's what you mean.
BTW. I admire your site.. very impressive.

thanks horse, there is a place that you can plug a scanner to on your veh.(sitting in the drivers seat should be under the dash about knee high it will have 12 pin holes and only 8 pins) and get the codes. facing the plug or DLC its the 2 top right hand side pins. side by side jump them and it should give you a code 12 if its ok. it will flash the "SERVICE ENGINE" light. if your service engine light dont flash then its like denny said the fuse might be blown and thats the problem. if you get a code let me or denny know and well tell you what it is.


Turn ignition switch to OFF position
Locate Data Link Connector (DLC), .
Jumper the A&B terminals(a paper clip or a jumper wire work ok)
Turn Ignition switch to ON position.
Count the flashes on the "CHECK ENGINE" or "SERVICE ENGINE" light.
FLASH, pause, FLASH, FLASH = code 12
NOTE: Some 94 & 95 models do not have the B terminal. In which case a scanner is required.
NOTE: Some 94 & 95 models that DO have the A & B terminals still require a scanner.

12 Pin DLC
A - Ground F - TCC
B - Test Terminal G - Fuel Pump
C - Air Injection H - Brake Sense Speed Input
E - Serial Data M - Serial Data

[HWORRELL]

Simple check is turn the ignition on and see if you get a check engine light for a few seconds, If it comes on for a few seconds then goes out with just the ignition on you can presume the ECM is up and running, IAC on a Gm will not set trouble codes, I would pull the IAC and clean the pintle on it and the IAC seat in the throttle body as these have a tendency to carbon up and cause your very problem. If cleaning it doesn't help I would replace it. In either case you then need to disconnect the negative battery cable for a few minutes this will clear adaptive memory then start it (may not want to idle ) just keep it running for a bit then put it in drive,then back to nuetral,then back in drive and turn the air conditioning on, then back to park and it should have relearned its Idle.....

[lt1s10]

Horse there semes to be a ? about what to do first, but if its mine im gonna, check for codes first, if you dont have any thats great, so now you can move on to something else. checking for codes dont fix nothing, but it sure eliminate a lot of stuff. its a good time to be sure your "check engine light" burns. about 1/2 of all used cars in va. somebody has taken the light out and the new owners dont know its suppose to burn. i just dont trust the bulb and its a good thing to know how to do. then, when you talk to a mechanic you can give him a code, or tell him there is no code. JMO

[Horse]

Cheers Denny & Mike,
Did the service/light test, got a 12 code, so things appear to be alright there.

[Horse]

HWORRELL,
Did everything you suggested, I am going for a run to my doctors later, I'll let you know if it works...fingers Xed ya?

[HWORRELL]

Wow..... $322 bucks to fill that bugger up with 35 gallons.... man O man... And I rag on the wife when she puts 35 gallons in our Yukon @ $91 bucks..... Hows the wages compare over there ?
And what about the working class of folks ,do they use public transportation ????

[Horse]

WHorrall,
Just got back from the docs, the suburban still keeps cutting out at junctions, I'll replace the part, I can get one for $61 over here.

The price of petrol has come down this week to $8 per gallon.
I only use the Sub or my Olds for fun runs and shows, I can't afford to use either as my daily.

Public transport is not too bad in England, I went to Cambridge yesterday by train 160miles round trip, cost $30.

[Horse]

Hi there people
Got my new IAC valve today (Saturday) fitting it did all the setting up stuff as instructed....still no joy Still cuts out on idle.

Any more advice/ideas?

PS. I try questioning the marital status of its parents, when that failed I swore at it and kicked it.

[lt1s10]

Originally posted by Horse
Hi there people
Got my new IAC valve today (Saturday) fitting it did all the setting up stuff as instructed....still no joy Still cuts out on idle.

Any more advice/ideas?

PS. I try questioning the marital status of its parents, when that failed I swore at it and kicked it.

need to check close for a vac. leak. what is your vac.?