Engine starts chugging and will stall out

Vehicle had no previous signs that something was going bad. No sputtering, etc. Being that I had (within last 4 months) replaced the fuel filter along with a bad fuel pump, I looked elsewhere towards the problem. After noticing that I had a weak spark, further investigation revealed that I had a bad coil, cap and rotor. So I replaced all three, along with all new spark plugs and wires. Same problem still existed. I was then told that the distributor pick-up could be bad. Which it was severely worn, so I replaced it also. Same problem still existed. I then looked back towards the fuel. So I checked fuel pressure by dissconecting the fuel lines directly behind the carburator (to maybe rule out the possibility of a bad regulator. I did not test with a guage, but the fuel pressure was weak (5-10 lbs. maybe) streaming from the dissconected fuel lines.
This pressure I am told should be around 50 lbs. A mechanic that was standing there said that was definately a bad fuel pump. Telling him that I had recently replaced it, he still insisted that it was bad because I had bought a cheap one from the parts store. SO, I drained and dropped the tank again. Replaced a new sending unit (with new pump and new sock) and new fuel filter again. Started it back up . . . . thinking all was well . . . . then it stalled! It will sometimes restart right away again, and sometimes it will not. It will run for about 10-15 minutes before it stalls. But if I sit in the cab and keep my foot on the gas, I can keep it form stalling. Comepletely let up, and it stalls. Once the vehicle is cold again, it seems to start again. Once it warms up, it seems to stall as described (with no real sputtering or anything) it just dies.
I am now thinking that I could be dealing with a bad Coolant Sensor? Or could this be a bad crank sensor or something? But will say that I am leaning towards some kind of sensor, relay, or module. Where else can I check or look for faulty parts? Your guess could do no harm at this point! (lol) Thank you for any suggestions! My wife and daughter would be extremely grateful if I could get my truck running again and they could have the car back to themselves! Thanks from all of us!

First question for you is, is the SES light on? or intermittently on? If yes check for codes, if none found, check battery voltage with engine running and off, then a real fuel pressure test...you did not say if you replaced the ignition module, which seems more like your problem than the others, but before you go there, remove the idle air control valve and clean the hell out of it and the throttle, and if you have an oil soaked aftermarket air filter, replace the MAF! Read codes this way!

Cross these two terminals as shown, then turn the key on. Count the flashes, a 22 will flash as 2 flashes then a short pause, then 2 flashes, if more than one code is stored, the pause will be longer. The codes will display three times and end with 12. Write them down and post here.

Engine Performance problem
1993 Chevy Silverado V8 Four Wheel Drive Automatic

what will make a truck idle out of gear but when u put it in gear after a second it cuts off and if u reve it up to 2500 rpm it cuts out but u let off it stays running?

The system may be running lean? How long since a tune-up? Any applicable trouble codes? Check fuel pressure.

why do people change all other parts except what you tell them to change that will fix the problem.

Most people don't want to do any testing, they want you to tell them which part is causing the problem, so they can change that part. For the most part, I don't know for sure what is causing the problem without testing.

Hi, I have a 93 silverado truck with a 5.7 and was doing some trouble shooting. I unplugged my fuel pump relay while the truck was running and it died. The manual said to replace the oil pressure switch, which I did.

It's been an on going thing with the truck shutting off when driving or when I turned the truck off it wouldn't start back up for about 45 min. to an hour.I had it to the dealer twice and they couldn't tell me. The problem wouldn't happen all the time. It could be twice a week, twice a month or twice a year, so by the time I would get it there the truck would be running and they said they can't find nothing wrong because the problem is not happening now. So I started trouble shooting myself. When the truck would act up I check for fuel or spark, had spark no fuel. So I started at the fuel pump relay, replaced that and it ran fine for a while. Then it happened again. So I put my shop manual in the truck and test light in the truck and waited for the next time. When it did I probed the relay plug and it was fine and when it came to unplugging the relay when the truck was running that's when I found that the oil press switch was bad.

on some of those trucks they had issues with a engine ground. for some reason it used the distributor base as the ground.next time it acts up take a piece of insulated wire and make a ground from the engine to the chassie have someone to turn the key on and you listen to see if the fuel pump turns on. also have you had a engine scanner connected to it? does the scanner and the pcm communicate? if it doesnt you may have a computer iussue the fuel pump driver may be malfuntioning in the pcm. also you may want to get a repaire manual and check all your computer grounds if one is loosing its connection that could be the issue. i hope this helps with your problem.

there should be a ground cable form engine to body at back of right cylinder head as well as one from engine to frame. Atruck tis old may have a bad ground cable from the battery especially if you see corrosion at he terminal end on the battery.

I started having troubles with the fuel at first, so ended up replacing everything for the fuel system including, lines, filter, strainer, fuel filter, injectors, tbi rebuild kit and fuel pump assembly. It ran fine for about 2 weeks then had a loss of power, id hit the gas and it wouldn't seem to go anywhere. So I checked the fuel filter and strainer, both ending up to be fine and didn't throw any codes. so I replaced the tps sensor, egr vacuum solenoid, purge canister valve. everything short of a iac valve and new egr that had been put on 6 months ago along with my upper end head gasket set. Now once replacing everything just listed, it will run fine, but sometimes on start up, it will idle up to 1500 rpm and shift hard into gears, after a few mins of driving the code goes away, and proceeds to run better, but if you push the pedal to the floor to pass cars, there is little to no acceleration. Also while driving, there will be no codes, out of no where the check engine light will come on, the truck will stall out and want to die, (has died before but starts right back up) so I have to lightly feather the gas, it will start to pick up and the code will go away, and begin to run again as it was. im out of ideas and haven't had time to get the codes checked.

if check engine light is on there is a code, scan for it cross a & b and count light flashes with key on . check canister purge valve for being stuck open at idle it shouldn't be there is a vacuum line going to it . it should only have vacuum at one side or disconnect it and plug it see if truck runs better. it is underhood rh side I think and has a red valve on it. with tbi if it doesn't see ignition it won't work. so have ignition module in dist checked auto parts can do that as well

i was driving the other day, and i turned my truck off and when i started it back up, i backed up about 10 feet and it died. it wouldnt start back up. the same day i changed the fuel filter and it started up. the next morning i was driving and it died again on me. i let it sit at my house for a few hours and i tried to crank it and it started up again. ive noticed it seems it dies when it gets to operating temperture, and when i let it cool down it will start up. i need help to know why it may be doing this.

These are classic symptoms of an ignition module.

Remove module and have it tested at most autoparts stores for free.

i took the ignition module off and went and got it tested. It tested good, so what other reasons might it be that it dies on me.

I would go to a junk yard and get a different module, even though they test good, they can still be bad. Replace and see if it makes a difference.

Also when this no start condition happens, spray starting fluid in intake, if still no start, then fuel is ruled out.

The truck starts and runs fine until it is parked for a short while (maybe 15 min) then when I go to start it again (while still warm), it has a hard time running. It wants to stall unless the gas is pumped to keep it going (but then just barely). This only lasts for about a minute then it runs smooth again as if something just got cleared out of the gas line or the choke just got unstuck? I recently changed the fuel and air filter with no improvement. Any suggestions would be appreciated.

Has the check engine light come on?

[quote:45a0cb9a3a="Jacobandnickolas"]Has the check engine light come on?[/quote:45a0cb9a3a]

No, the check engine light has not come on. I found a similar question someone else asked that a technician answered. He said it could be the throttle position sensor, the idle air control valve, vacuum leaks, or the EGR. I will look at these things unless you think it might be something else.

I would start with the EGR / vacuum. As far as the other things, they would cause a rough idle but I've never seen them prevent an engine from actually starting.

[quote:34b4dbd030="Jacobandnickolas"]I would start with the EGR / vacuum. As far as the other things, they would cause a rough idle but I've never seen them prevent an engine from actually starting.[/quote:34b4dbd030]

Correction: the engine does start 99% of the time, but almost immediately it starts to idle rough and if I don't pulse on the gas it almost always dies. Again, it does this for about a minute, then its totally fine until the next time I stop for a while then try to start it again while still warm.

It could be any of the items mentioned. Start with the cheapest fixes first, vacuum leaks and check the EGR for carbon build up. Also, let me know when the last tune up.

Joe

[quote:87f78514f2="Jacobandnickolas"]It could be any of the items mentioned. Start with the cheapest fixes first, vacuum leaks and check the EGR for carbon build up. Also, let me know when the last tune up.

Joe[/quote:87f78514f2]

This afternoon I took off the EGR. It only had a bit of carbon build up - just a thin coating. The diaphram moved up and down freely by pressing it and air came out the little hole at the outlet spigot. I don't have a vacuum pump so I couldn't do an official test.

The throttle position sensor (TPS) test: With a voltmeter I checked terminals A and B. It was 5.03 volts with the key ON, engine off. However, terminals C&B only read 0.01 Volts. The Chilton manual states it should be 0.5-1.2 Volts. Also nothing happened to the voltage when I moved the throttle open and closed. Does this indicate a faulty sensor?

Idle Air Control Valve (IAC) test: Using an ohmmeter, terminals A&B and C&D both read on average 49 ohms which falls within the manuals parameters of 20-80ohms. However, when I went to remove the IAC, it unscrewed so easily that it was only about finger tight- maybe even less. The recommended torque is 13 ft lbs... for lack of a 1 1/4 socket to fit my torque wrench I don't know if this was correct but seemed not quite right to me. Everything looked ok with it so I put it back on... a little tighter this time. Could this looseness be a part of my problem?

Lastly, I found that a mouse had chewed the end of the vacuum hose going from the EGR solenoid to the EGR. The boot end separated from the hose so I reinserted it a little deeper and taped it with electrical tape. I live out in the boonies so I don't have immediate access to parts..... will replace it later.

I purchased the vehicle only last year and I have not had it tuned up... not sure when the previous owner had it tuned up last either.

Hope these small things I did will help... . Any feedback would be appreciated.
Thanks
Gerry

I have had problems in the past where the engine cuts out and truck dies. Sometimes I can start it up again sometimes not. Sometimes I can feel it starting to cut and give it more gas and it helps but most other times not. I have had the fuel pump replaced twice and it has helped both times only to have the problem occur later. Drove around with a technician who had a computer hooked up and everything registered okay (of course it didn't cut out with him inside). Latest repair has been a relay sensor under the hood that helped for a couple of months. Latest problem now is truck will start out in 1st and go right to 3rd or go from 2nd to 4th. Six months ago it quit starting and I haven't been in it since then (but I really need it!)

To start, have you had the fuel pressure tested?

Joe

Based on your info, it sounds like you need a new TPS. As the leaks you found, they could play a role in the problems too.

Let me know how it goes for you.

Joe

No, however, the technician who drove around with me had a computer hooked up and was monitoring all sorts of vitals from the truck. He indicated that all appeared okay - not sure if the pressure would have been tested in this situation.

Hi:
If he was scanning it while driving, the fuel pressure wasn't checked. He was monitoring the computer and sensors. I really think checking the fuel pressure is a good idea. If it's good, then we'll move on.

Joe

im having almost the same problem mine runs for 1-2 min. stalls and wont fire for about 10 min. i did my fuel pump, fuel pump relay, and grounds please help and i will let you know what i do if it fixes it

Hi,
Same here, but I have a 2005 Chevy Silverado. While driving feels like the engine it's going to die and eventually does. It starts up again but has the same problem, sometimes acceleration helps but sometimes does not work in 3rd gear, I step on the pedal but nothing happens, and If I stop it shuts off. No check engine light is on. Everything checks OK when tested, gas pump, air flow control averything ok. What the hell is it???
Please help out.
Thanks.
Joser.

why does my motor start cutting out when i run my heater on high and my headlights at the same time.my amps drop as well. i have changed my battery and alternator out

You need to have the system tested under a load. The alternator sends power through a fuseable link that can be going bad and not be able to handle the load. Also, check to make sure all grounds and battery connections are clean and tight.

Let me know what you find.

Joe