ibayne

first off want to say Hi im a newbie here i came looking for some help. i bought a 94 pickup, 5 speed with the 3.0. ive been driving this truck for a few weeks now and its started dying at stop signs and red lights. ran fine down the interstate and ran fine once it got passed idle it just had as lil skip and hesitation on take off. so saturday i put new plugs in it (factory Denso K16r-u), had 2 plug wires that the ends pulled out so i got new wires. Yota place was closed so i got the NGK's from Advance....now i have a serious problem of backfiring, skipping, when it cranks runs for about 5 seconds and dies. So got a new Denso cap an rotor button from Yota place, still nothing...it ran on all the old crap but will not run on the new stuff...im to the point of i dont know that to do next...truck didnt have a O2 sensor in it when i got it so one of them is on the way. What i cant figure out is why i was able to drive this thing all over before but it wont move out of its tracks now.....please help

RJR

Are you sure you didn't swap a couple of plug wires? That's pretty easy to do using an aftermarket set of wires that may not be specifically marked or cut for your engine. Trace out the wires carefully. Cylinders 1,3, and 5 (front to back) are on the passenger side; 2, 4, and 6 are on the driver's side. The distributor cap should be marked with the cylinder numbers. Firing order is 1-2-3-4-5-6.

ibayne

yeah ive had them off a few times they are all marked and yes the cap is marked too. i had the wife looking under the hood when it was dark to see if the wires were arcing off each other or anything else she said she didnt see any sparks

Ott47

Might be a dumb question but did you make sure that your spark plugs were gapped correctly?

ibayne

tried that too when i got the cap at the yota place the aprts guy told me 31thousands he also printed me off a sheet with all kinds of specs and stuff for the distributor air gap and stuff

Marc

Did you remove any of the intake tubing to change the plugs?
Did you rotate the distributor at all?

ibayne

no didnt do anyhing to the intake tubes,i tool the lil box off to get to one of the plugs the distributor is next on the list of things to check. ive got an idea that the guy that had it before me set the timing with all the old junk in it an when i put the new stuff in it the timing might be off....the thing cranks right up and sounds good but after a few seconds starts going crazy

ibayne

thanks for the help everyone, kinda leaning towards a timing issue. gonna try that route on my next day off. thanks again looking forward to getting alot of info on here

Ott47

have you figured anything out yet?

ibayne

No not yet was working on it them the rain came. I put the old wires back on it an still ran terrible...it starts up very easy then dies, so I moved passed the timing stuff and now leaning towards a fuel problem. It kinda done this after I put some fuel system cleaner in it so I grabbed a fuel filter and go from there

RJR

Double check you got all the intake tubing and the VAFM reconnected properly. Starting instantly and then dying is a classic symptom of a disconnected VAFM. (Volume air flow meter.)

Just to cross-check, jumper Fp to B+ in the diag connector and see what happens.

ibayne

Ok I can check to see all is hooked up but that jumping stuff is all Chinese to me. ..don't have a clue what to do

ibayne

Would there be any harm done if I took my compressor and blew out the fuel lines while there on the truck or would that hurt an injector

RJR

Find the diag connector. It's a little gray plastic box with a hinged lid about 1.5 x 2 inches square next to the fuse box under the hood on the passenger side fender. Pop the lid off and there'll be a diagram inside telling you which terminal is which. A paperclip makes a good jumper. Bend it to fit and push it into the appropriate terminal sockets.

Jumpering Fp to B+ will force the fuel pump to run any time the key is on, regardless of whether the VAFM is connected and working properly. If the truck now runs, you know the problem is in the VAFM fuel pump circuit.

Don't drive around with the jumper in place. The normal VAFM cutoff for the fuel pump is there as a safety feature so that if you get in a wreck that stops the engine, the fuel pump will stop pumping gas into the wreckage possibly incinerating you.

ibayne

Ok just put new fuel filter in and nothing still cranks then dies. ...I have to pump the gas for it to half way run. ..then it sputters terribly gonna try your idea then drain the fuel out

ibayne

Hey bud just tried it no dice still fires off then tries to die

ibayne

It's alive after all the help and everything drained the fuel put new fuel in it and it's alive again. ...no more fuel injector cleaner and 93 octane for me learned my lesson

naward1996

Your problem sounds really similar to when my MAF sensor went out, I put a new throttle body gasket on mine... And bam. It would run about 5 seconds and sputter out, costed me a pretty good chunk too

Rubadub

Just curious: What kind of injector cleaner did you put in it. I am having this same problem on a '94 3VZE. But I doubt it is the injector cleaner; I used Red Line. Still trying to trouble shoot my rig.