Ianmac

I first noticed a problem at the beginning of last week my truck was taking a bit longer to start than usual then began to idle a bit uneven (like it was running on 7 cylinders every now and again) but was fine underway. The plan was to take a look today (Sunday my day off work).
On Saturday I was driving and the engine sort of stumbled as I pulled away from a set of lights (it has never done this before) on my way it done this 2 more times.
I got to my destination and went to set off and it stalled when I accelerated in the parking lot.
I restarted and pulled away there was very little power at first then it picked up I decided to run for home. On the wayit stalled again and wouldn't resart.
I killed the battery trying to start it (not thinking at the time I took the batteryoff to recharge it that erased the codes on the ECU) this all happened within about 4 miles.
Today with fresh battery and a can of gas (the tank was under 1/4 full gas was just incase) I got it started straight away I let it idle for 5 minutes and as soon as I put it in drive it stalled and would not re start I gave it a whiff of starting fluid it started but died like it was starved of fuel.
I ran a scanner on it that Iborrowed and only got code 12 so I got it towed home.
Could it just be a plugged up fuel filter? or as I am thinking perhaps a vacuum leak? Or one of the sensors TPS. MAP Sensor, coolant temp / air temp sensors, EGR Valve, idle speed control? Without a code I am at a loss as to what is wrong. I have had the truck just over a year now I do get a check engine light but just assumed that it was because the cat had been bypassed the light only came on when it had been running about 15 minutes at normal temperature.
Will check the vacuum lines wnen I get home from work tomorrow.
Anybody have a better idea what could be the problem especially with the sensors etc so I can order any parts that I will need I am guessing I will need to get a fuel pressure testeras well.

oilcanhenry

My guess is a bad ignition control module or a bad fuel pump or fuel pressure valve. You need to test the fuel pressure on your vehicle first. If it's not a problem, then its likely an ignition issue.

Ianmac

I feel its a fuel problem too will order/beg/borrow/loan a fuel pressure gauge tomorrow. Do you know what the correct pressure should be I am thinking I read 9psi but not certain.
I dont know much about all the electronics stuff and injection systems more used to carburetor and point's
Thanks for the advice.

oilcanhenry

You must be near my age if you are used to carburetors and points.. That said I do know quite a bit about the newer vehicles and components. With a TBI unit 12-16 PSI is considered to be optimal. In either of the newer "spider" type fuel injection systems, 55-65 PSI is within normal parameters, with 60 PSI being the normal pressure expected by the regulator.

Sabino56

2nd on checking fuel pressure - I found it easiest to do after fuel filter under drivers door on my 93. It’s a pain to get space by TBI. I had drivability problems @ 10-11 psi with an Autozone pump a year old. Replaced with an ACDelco and got 13psi and problems went away.

Irish_alley

im willing to bet fuel pressure also. theres two different things that can pretty much go wrong. one is the fuel pump the other is the rubber hose that comes off the fuel pump and spring a leak.

Ianmac

Just had a good look around and found a few things.
1 vacuum line to EGR disconnected i reattached.
2 vent from rocker cover to base of throttle body was broken i fixed with a 3/8 pipe to join the tube.
3 tryed a few starts it didn't but i couldn't smell no fuel at the throttle body at all makes me feel it is definitely lack of fuel
4 ran another code scan i got code 54 " low fuel pump voltage, fuel pump relay, EGR solenoid #2 failure, quad-driver module output failure (i dont even know what that is) mixture control solenoid voltage to high.
I am going to get a fuel pressure tester gauge and see how that looks also a new fuel filter as well since that cant hurt.
Thanks for the advice will keep you updated

Irish_alley

i have most common tbi codes at this link
Obd1 code retrieval and decoding/troubleshooting



Code 54

oilcanhenry

We are lucky that our old pickups have an external fuel filter. Since 2004 or 2005 it's incorporated in the fuel pump, just like my 2015 Chevy Malibu. I don't worry too much about it since I buy quality fuel at high sales gas stations; mostly Chevron/Texaco, but Shell, Exxon/Mobile and 76 are good fuels. I'm a firm believer in the DCA "Techron" additive, which is what the gas direct injection valve cleaners like CRC use to decarbonize the intake valves. Seafoam seems to work well. Last year I had an old can of it,
so I used it up in my 1998 Chevy K-1500.

All kinds of smoke came out of the tailpipe, so I headed out in the country roads, to use it up. Hitting some high speeds, then stopping and adding some more a couple of times. By the time I used it up it had no smoke at all, so even though I take good care of her, she is an older vehicle. I hope I didn't damage my catalytic converter. MPG went up about 1.0 to 1.5 miles per gallon, or so that was great news.

I'm a bit worried about your EGR valve possibly being stuck if it was not moving at all with the hose being disconnected, but I don't think that is the main issue at all here.

oilcanhenry

I like Autozone better then other parts stores. Carb was wasted on my Husky 125b leaf blower, and the fuel lines that came with the new carb were too short. Looking on the internet and they had the right hose for a small engine like that. Saved me lots of time and cost was $3.50 USD for two feet of 1/8th inch hose. Can't beat that with a stick.