1988 Chevrolet C1500 - Page 9 - Answered Questions & Fixed issues

you may have a bad platium gasket or a bad choke give these websites a try www.alldatadiy.com and www.autozone.com if all fail stop by your local library and get you hands on a Haynes auto repair manual for you truck wish you the best of luck Michigan Man.

yea thats possible, the trans has servos that change gears, have a diagnostic done at a trasmission shop, a quick hook up to a computer will tell if there are any servo faults, it may be a minor issue and just needs a adjustment, or could be a sign that the whole trans is on its way out. but you should have it checked as soon as possible. good luck and take care

Replace the pick up coil if there is fuel to the injector.If there is fuel pressure at the injector,then it is the pick up coil.If the fuel pump is working,and the fuel filter is new,then there is fuel at the injector,just no pulse,correct?

My earlier problem was instantly solved by Grue Thanks. my problem with the 2 sensors required a cash commitment and this is why I changed the engine myself ( lack of funds) However I did research on the web and now completly know how the senders work w/gauge & other with fuel pump relay and ECU.there location and time delay &
power source and fuse location.Thang you for your help.

speedo went bad, real common on these trucks.
First check to make sure cable didnt break!

I had a similar problem on an 84 Lincoln Mark VII. Found out it was a ground wire that had broken running from the wiring harness to the fender well. The wire was broken inside the shielding and not visible. You might consider going through and checking all of the plug connections for corrosion as well. This may not solve the problem but certainly easy to check.

You wll need to first undo the heater hoses at the firewall to the core, then under the dah you will need to dismantle the heater box, the core is located inside this box, assembly is the reversal, heater core is about $40. time consuming and hard on the back but not hard. Remember we are here to give as much help as we can without seeing the car so, I hope this helps somewhat, good luck.

you need a new speed sensor its located on the trans where the speedo cable would have been

The engine quit working? Assuming the starter is turning over the engine check for spark. If spark is purple/white then check the fuel pump to make sure it is still working. The fuel pumps fail at about 100,000 to 130,00 miles. The fuel pump makes a whining or buzzing noise from the fuel tank when operating so if you don't hear it for a few seconds when the key is in the on position then it probably failed. Check power and ground to fuel pump if you suspect it. You can disconnect the fuel line at the throttle body to see if there is any fuel flow with the key on if you want to verify.

Do a Compression check on each cylinder. They should be really close, not 10-15-20 pound different. Make sure when you do the compression check, you first do it will all plugs out, let engine spin a couple times, put in one plug at a time and write down the pressure reading you get. Then pull plug again, squirt in about 3-4 squirts of motor oil into the firing chamber, turn engine a couple times, put back in plug and write down the new reading you get. Do the same to each cylinder.... That is called a DRY/WET compression check.... Dry or Wet the variation should be 5 pounds or less either way. If your WET pressures go up significantly, then you have weak rings... The Dry test is test both piston rings and values. The WET test ONLY checks the rings. If all is well there, then with the new items you have on your engine, take it to a Dynometer Tuner and have it tuned for about $150.00... It will be the best money you ever spent. Doing the WET/DRY test yourself will save you a bunch of money and be very very important information to the tuner guy. Be sure you write down the readings completely and clearly. Good luck...

check the bolts that hold it on the trans they come loose

Just disconnect battery overnight. Computer will 're-learn' as you drive it.

If only under a load, it is possible that the fuel filter is mostly clogged. Also check air cleaner (you probably already did). The concept is that under a load, your throttle body is mostly open, requiring high volume of air and fuel flow. Restrictions in either of these will make it run bad.

need to check vss sensor is your check engine light on is the speed omt working

Did you disconnect the timing feedback connector above the distributer when timing? If the cat. converter is plugged the engine will run like it has no power and usually sets a rich mixture or O2 sensor code.

Check the fuel filter for clogs and water in tank. Check timing and remember to disconnect timing feedback connector above distibuter (see timing placard under hood). There is a ground at the thermostat housing for the computer that needs to be good.

Well, something is broken, somewhere. Start by removing batteries from remote key fobs, ALL of them, then pull apart each lock control switch, testing after each one is disconnected...the the ares of suspect is wires going through the door jambs. Starting with the drivers door.

If you find wiring damaged at the door jamb, you must replace the wire, rather than repair, so that there is NEW wire completely through the jamb area, anything else fails really fast, due to the flexing... At least cut damaged wire inside the door and inside the vehicle at kick panel...

I assume you are disassembling to rebuild. A manual is your best bet. Haynes shows a GM auto trans manual,#10360. You could also look at faxonautoliterature. They have the original GM service manual for your truck, which would have a section on auto transmissions. They also list a GM trans rebuild book for that specific transmission. Hope this helps.

I personally have 1988 GMC truck and had to replace the fuel pump. I found all the info including wiring diagram in a haynes repair manual. These can be purchased in most automotive parts stores. Something I found interesting is that the fuel pump's operation works through the oil pressure switch, located by the distributor screwed into the engine block. If this switch is stuck or sticking it will affect the fuel pump. Replaced a good fuel pump for nothing! The truck had sit up for awhile and the ground wire connections had to be cleaned as well.

hi did you check the ignition switch unplug it and check for burned connectors good luck