Car dies coming to a stop, and needs throttle on startup??? HELP!!!

[muddin'metal]

Like the title says, rpms shoot from 1200ish to 400ish 3 or four times then goes dead!!!! Tps, o2, Iac, fuel pressure, and Af ratios, all seem well inside acceptable limits... New plugs, AC tps and iac, new fuel filter and newish wires... What gives?

 

[818GN]

Do you have a Scanmaster? If so, does it go blank before the car dies?

I had a similar issue and it turned out I had a bad ECU that needed replaced.

 

[muddin'metal]

it does not, but thanks for the input, anyone else?

 

[TurboBuRick]

If it's something that just all the sudden started happening, I would take a look at the maf pipe going to the turbo. Also look for vacuum lines that blew off.

Whats you blm# engine warm at idle?

 

[muddin'metal]

Car had a trans pro, BLM locked at 128 but Int is also almost always 128 too. All Scanmaster readings look very normal as far as that goes, thus adding to the confusion!

 

[TurboBuRick]

Had or has a Tpro?

 

[muddin'metal]

sorry, can't type. Car HAS a Tpro... thanks

 

[TurboBuRick]

K, got it.

Key on engine off, get some readings from the tpro sensor monitor page.

mp

ve

ut

mt

 

[muddin'metal]

mp=98.1

ve=75.5

ut=-4 (have tried from-7 to 13 and nothing has helped this problem)

mt=94.7 (within 2 degrees of outside temp here in Alabama)

 

[GNRick]

What brand spark plugs? I installed the E3 plugs and they caused similar symptoms. Went back to AC plugs and returned the E3's for a refund. I still received the free lawnmower plug in the mail though

 

[muddin'metal]

Ar23s, thanks for the input, but they have done me well for years so no reason to suspect them

 

[muddin'metal]

Anybody else? I really need some help with this? Cam or crank sensor?

 

[Sweetwater GN]

When mine would occasionally stall at stops it was the IAC, don't remember if it had starting problems at that time. Double check your iac, might of got a bad one, do the reset procedure.

 

[muddin'metal]

I have since installed a new 340 pump because I was having a High boost fuel pressure issue (boost would build and fp would drop way down) and fixed the boost/fp issue, but it did nothing to cure the stalling issue... Help please

 

[bmackinnon]

Replied to your PM Tyler... bumping this for some input from Bob and Dave!! :wink:

 

[TurboBuRick]

mp=98.1

ve=75.5

ut=-4 (have tried from-7 to 13 and nothing has helped this problem)

mt=94.7 (within 2 degrees of outside temp here in Alabama)

OK, lets change mt to rpm and try and get some readings at idle or as close as you can get to idle.

The TPS and IAC are set right?

When the car starts to die, take note of the afr. Is it rich or lean? My guess would be lean.

 

[muddin'metal]

Readings were at idle, chip is burned at 850, but i see 830-925 ish due to bad idle and a/f was at 12to1ish if i put it back into closed loop and a/f is at 14.7ish it idles like it's on the verge of death if it idles at all. Brian, no maf, set to speed density. idle is terrible, cruise is not as smooth as I'd like sometimes I have a low cruise rpm miss (1850-2350ish), half throttle is very good, and wot feels mechanically fine, but I have noticed a loss of power. If I rev it in park and try to hold a certain rpm(like 3000) for example, it revs smoothly, holds momentarily, starts to stumble and drops a couple hundred rpms and then holds with a noticeable miss...

 

[Underboost]

Try pulling your IAC " Idle air control"out under your throttle body. Be Careful it's plastic then spray the spring with brakekleen.

 

[muddin'metal]

brand new, squeaky clean, so I don't believe carbon to be the problem.

 

[Underboost]

Can you crawl under the car while it's off and see if your crank is walking back and forth. Use a good size pry bar gently see if the crank walks back and forth. You could be getting an intermittent crank signal. Couldn't hurt.