Dave Ott

Hello everyone

I have a truck which has cost close to 1,500 in repairs so far and they still have not found the problem I brought it in for.

The truck is an 1989 Chevy 1 Ton Extended cab Dually (Older Bodystyle)

Engine is 454 7.4 liter TBI with dual gas tanks and pumps.

The engine is rebuilt about 3 years ago now if I remember right since time flies so fast. Used for pulling work trailers across the state so it is mostly highway miles.

The truck would pull like no tomorrow, this included it would smoke the tires off a light with a trailer hooked to it. Not that it happened, but a couple on accident. Don't tell the cops that though

The problem started with a catalytic converter in the front blowing it's belly in the driveway about a year before. It was hard to start and constipated. Fixed that one

In the past year it has started to act up again with blowing exhaust manifold gaskets so we fixed the one side that went and then the other side went recently. I blamed the one side on the catalytic converter that was plugged before

The truck then overheated without warning and was full of fluids. We then put a radiator cap on it since the other one didn't seem to release pressure into overflow. The system was rock hard and swollen. To this day it has not gotten that high again, but I even replaced the thermostat that was replaced the year before anyways, and was wide open when checked and tested

The truck now has been to the shop for running poorly, wouldn't make it up a driveway or if needed do a brake torque for example, and to fix the other side exhaust manifold gasket. They had to put a new exhaust manifold on (Cracked in rear near o2 sensor) and put another gasket on other side since they were in their anyways. They said it was firing on six cylinders and the cap was crossfiring so they gave it a major tuneup which I didn't think it needed (was done year before) and the truck ran fine down the road just not on idle or pulling at start

The truck runs fine when going on highways, but has no power for backing up driveways or really pulling the trailer. It reminds me of a rubber band toy car, when you let it go it takes off slow and then picks up speed gradually. If stomped while moving it will move fine and throw you back in the seat.

Needless to say they did not find the problem, but they thought the tuneup would fix it.

I have not been back because they want to start replacing everything again.

I called many shops and have taken it to a few more with no luck just scratching heads and even contacted a dealer.

Tried to get codes with nothing available from ECM
Tested all cylinders for compression in case head cracked or other and was fine Runs like a champ except for idle then takeoff

So now I have
replaced the o2 sensor since they should have

replaced the coolant temperature in the front near thermostat

replaced fuel filter

replaced both gaskets for TBI since the old ones hated when I sprayed carb clean near them checking for leaks

took the truck in and had the cats removed since they seemed to be plugged again for the time being to help the truck exhaust (At Witts end) also thought to much back pressure was why it may seem to be running hot, but it could be me since now I stare at the temp guage and when it hits 220 and stays I get worried. I was told this is normal

yesterday had it tested again for codes at a good friends trans shop and finally got a code 22 TPS and a code 34 MAP

The truck during the period from the first shop to yesterday at trans shop has been
blowing black smoke at idle and takeoff with hints of gray (No blue) and the exhaust could clear a block with the smell of raw fuel and no wonder why I feel like crap lately is what was mentioned because of fuel smell, but I must have been used to it.

Now before any of this happened the truck also had a problem with after a run and then stop somewhere for about 15 minutes at idle it would want to die out and you would have to feather the pedal as it bogged and bogged until it would clear up as you took off. If it stalled you would also have to feather it as it bogged, but that problem went away (Lasted about 2 weeks but no smoke)and I mentioned it to them and they dismissed it. I think that that problem turned into what I have now with the black smoke and poor takeoff so I mentioned a fuel pressure regulator since it would do it on either fuel pump switched to. Maybe I am wrong but it seems strange and I am getting ready to get the TBI rebuild kit with fuel pressure regulator

Also my truck has a broken sensor on the passenger side in the block right above the exhaust manifold that is broken from the shop. I noticed this last night and when I found the only wire that looks like it could be hanging I accidentally grounded on the engine while looking and with the key on the injectors sprayed and the truck tried to start. So I then moved the wire and during this I heard the relay near the washer pump click and then the one on firewall near passenger side (Fuel Pump relay?) I was told that this is my secondary fan switch sensor. Why would it do what it did though? It is a green wire that is not listed on my wiring diagram and the fan has never worked anyways. I know it is not the temperature sensor since that is on the drivers side of block (Tested it and checked guage to make sure) So I will dismiss this one for now I guess but strange

Now today it has gotten alot worse with smoke and then idle up and down sometimes so I got irritated and I

Bought a TPS for it with no luck again after we tested this when we looked for codes in the beginning. Voltage was fine thoughout test so oh well I am stuck again We even tested the MAP so I didn't touch that yet but give me chance

One thing I now notice after I start the truck and put the brake on and hit gas it will smoke the tires if needed but after letting off and trying again for hopes it will not do it but loads up, blows its usual smoke and clear the neighborhood of raw eye irritating fuel smelling exhaust.

So sorry for the long story but I am hoping someone will listen to the symptons that I have had and have still unlike the shops and help me out.