lemonth68

got the head gasket job done on my 89 pickup, 3vze, auto. After rebuild truck would randomly die while driving and have a rough idle at when warmed up but good idle cold. the truck randomly dies while driving, I put the truck in neutral and fires right back up until it decided to stall again. it always started right up every time no issues. new ngk plugs, denso wires, intake hose, crank case vent hose, fuel filter, fuel pressure regulator, solved the rough idle. The cold start injector is good, did the jar test and it sprays and shuts off. the rotor button, rotor cap, egr modulator is new and the pcv valve is fairly new too. it idles good but sputters/jerks with the pedal pressed to the floor and the CEL will flash. Its also harder to start back once it does die. I feel like its the fuel pump getting ready to go out but IDK. The o2 sensor needs to be changed as well as the cat converter, but the cat shouldn't cause the random shut off. that's the first time to see the CEL and only does it with the pedal pressed to the floor. Have not check the TPS yet but I feel its the fuel pump going out cause if the start issues but what about the randomly shutting off? There has to be some air/fuel mix not right Need some yota tech wisdom!

yodafan93

check the timing?

lemonth68

have not checked timing with light. checked the timing numerous times after the belt was reinstalled. really don't want to check the front again unless i have too. u think its a fuel pressure problem or tps?

mitutoyo

Jerking is usually fuel (or lack of) related. Attach a fuel pressure gauge and have a buddy watch it while revving. If it runs good while cold it may be O2 sensor related. The engine runs in open loop mode when cold enrichening the air/fuel mixture. A warm engine will run in closed loop using per-programmed ecu air/fuel settings and a leaner mixture. Bad TPS causes bucking as well so just ensure those readings are within spec.

lemonth68

Will check timing and tps this week when i get time, busy week. i'll let ya'll know what happens

James Woods

iTrader: (1)

Actually if your cat is clogged it can cause the truck to stall, it would also be harder to start after the truck dies. The O2 sensor being bad can cause all sorts of issues since the ECU adds and takes away fuel depending on what the O2 sensor tells it, as long as this is a pre-cat sensor we are talking about. I have had cars that fall on their face when accelerating from a stop because of O2 sensors. You said you feel that the air/fuel mix isn't right, the O2 sensor reads and controls that mixture.

Nik

Could it be igniter/coil related? I had an 82 truck that would run like crap and die/surge when it warmed up and I ran in circles forever looking for a fuel issue, swapped out my igniter and coil and that fixed it for good

lemonth68

Do I have to have a hand held tach to check timing or just jump te1 and E1? Also, today I replaced o rings on the injectors, truck started right up and idle was good. I got a wild hair and decided to bump the VAFM with the palm of my hand and the engine instantly changed idle and went back up. Every time I bump it acts like it wants to choke out but never does. If I leave it alone it idles good.

lemonth68

A friend is going to put a timing light on Friday after work

lemonth68

The connecter on the left side of the AFM would touch a small piece of metal that was connected to one of the pins that was broke. I removed the broken piece and It hasn't stalled out today or jerked at full throttle while test driving today. Not sure how this metal piece is supposed to be soldered on

lemonth68

truck has been running great since the TPS isn't shorting out. Getting good mpg since rebuild on 31s