Question about 1990 Chevrolet C1500

1 Answer

Running extremly rich

I have a 1990 c1500 with a 4.3 vin. z motor and a th400 trans. I rebuilt the throttle body 6 months ago and it has been running rich for the last month. I am getting 6-8 mpg. It has a msd system with a hypertech chip and cold air intake. I put the factory items back on and still the same problem. The fuel pressure is good ang the o2 is new and i am going to replace the temp sensor soon. Did I rebuild the tbi wrong or is it somthing else?

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Chevrolet Master
  • 8,984 Answers

I recommend you check the fuel pressure regulator diaphragm for proper installation and tears. Did you get a new one with your rebuild kit?

Posted on Jul 01, 2017

Ad

6 Suggested Answers

6ya6ya

6ya staff

  • 2 Answers

SOURCE:

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Ad

Anonymous

  • 1 Answer

SOURCE: 82 corvette crossfire injection, engine

Please go to the crossfire injection forum to get some straight answers to the 82 corvette CFI system and how to troubleshoot it properly. There's a lot of misinformation given here, so much so, I don't know where to begin.

One thing is, the 82 corvette CFI does NOT have a MassAir Flow sensor system, it uses MAP and O2 mostly. The CTS sends a signal to the ECM telling it what the temp of the motor is and in turn the ECM controls the amount of fuel being dumped. On the older (orignal) CTS sensors, they have one wire and takes its ground from the threads. If any coorosion takes place, usually the CTS will report a cold engine and request lots of fuel.

To repair this issue, install one of the newer style CTS sensors that have two wires, one for signal and the other is ground.

Fuel pressure and vacuum leaks on any CFI motor play key roles. Set the FP to 14-15psi measured inbetween the TBs. The regulator is located on the rear TB and must be slightly moded to make it adjustable and can be done in a few minutes.

Posted on Mar 07, 2009

drallim

  • 4088 Answers

SOURCE: 1987 chevy s10 2.5l tbi will not start. changed

That eliminates the crankshaft and camshaft position sensors. Have you checked the fuel injector itself for an open winding or stuck valve plunger? There should not be a steady 12 volts to the injector--if good injector, it would be spraying fuel steadily into the throttle body. But at least the engine should try to run if poorly. Take the injector out, dry it off with air, and intermittently apply 12 volts to one terminal while grounding the other. You should hear a click from inside every time you touch 12 volts. If not, replace it. If it does, it may be plugged with debris. Try blowing through it in reverse with compressed air.

Posted on Jul 17, 2009

Anonymous

  • 5 Answers

SOURCE: 1987 chevy engine problem

you have to reset base idle see manual at library for procedure

Posted on Jul 19, 2009

Anonymous

  • 5 Answers

SOURCE: 1987 Chevrolet S-10 Pickup1987 chevy s10 2.5l tbi

Check the trottle body postioning sensor...

Posted on Jul 19, 2009

pippall

Philip Long

  • 1486 Answers

SOURCE: 1987 chevy S10 engine idle problem

relace the throtle air idle valve.The temp switch will allso cause this problem.

Posted on Jul 19, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

2005 dodge ram cummins diesel only getting 15 mpg


check that the rebuilt box is actually engaging OD. Run fault codes and check it electronically. Have the bands and clutch packs re adjusted as the run in may have put the adjustment out a bit..

Mar 17, 2014 | Dodge Ram 2500 Cars & Trucks

1 Answer

Instructions for 2006Painted Imaganirum Table Table


A.T., VIN model "C" (4x2), TH400, 6 cyl
A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-305 (5.0L)
}A}}400}466495" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-350 (5.7L)
}A}}400}466496" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-379 (6.2L, diesel)
E>}B}}400}466497" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH700, diesel
A.T., VIN model "K" (4x4), TH400, 6 cyl
B@}}}400}466499" type="radio" name="userInterchange" />A.T., VIN model "K" (4x4), TH400, 8 cyl, diesel
A.T., VIN model "K" (4x4), TH400, 8 cyl, gasoline
A.T., VIN model "K" (4x4), TH700, diesel
FFC}B}}400}466502" type="radio" name="userInterchange" />M.T., 4 spd, 4x2, VIN model "C"
FFC}A}}400}466503" type="radio" name="userInterchange" />M.T., 4 spd, 4x2, VIN model "R"
ECB}B}}400}466504" type="radio" name="userInterchange" />M.T., 4 spd, 4x4, (VIN model "K")
M.T., 5 spd, 4x2
M.T., 5 spd, 4x4
A.T., VIN model "C" (4x2), TH700, gasoline
F=A}B}}400}466508" type="radio" name="userInterchange" />A.T., VIN model "K" (4x4), TH700, gasoline
}B}}400}466509" type="radio" name="userInterchange" />A.T., VIN model "R" (4x2)

Oct 20, 2012 | Cars & Trucks

2 Answers

I have a 1990 chevy truck k1500. getting gas to throttle body but not to engine. new fuel pump new fuel filter rebuilt throttle body. do you have any ideas


Throttle body injection? replace the injectors. First check for power to them. 12 volts from one of the wires with key on

Sep 05, 2011 | 1990 Chevrolet K1500

1 Answer

What year/model transmissions will fit a 1989 GMC sierra, 2500, 350 engine, 2-wheel drive? Thanks


A.T., VIN model "C" (4x2), TH400, 6 cyl
A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-305 (5.0L)
}A}}400}466495" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-350 (5.7L)
}A}}400}466496" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH400, 8 cyl, 8-379 (6.2L, diesel)
E>}B}}400}466497" type="radio" name="userInterchange" />A.T., VIN model "C" (4x2), TH700, diesel
A.T., VIN model "K" (4x4), TH400, 6 cyl
B@}}}400}466499" type="radio" name="userInterchange" />A.T., VIN model "K" (4x4), TH400, 8 cyl, diesel
A.T., VIN model "K" (4x4), TH400, 8 cyl, gasoline
A.T., VIN model "K" (4x4), TH700, diesel
FFC}B}}400}466502" type="radio" name="userInterchange" />M.T., 4 spd, 4x2, VIN model "C"
FFC}A}}400}466503" type="radio" name="userInterchange" />M.T., 4 spd, 4x2, VIN model "R"
ECB}B}}400}466504" type="radio" name="userInterchange" />M.T., 4 spd, 4x4, (VIN model "K")
M.T., 5 spd, 4x2
M.T., 5 spd, 4x4
A.T., VIN model "C" (4x2), TH700, gasoline
F=A}B}}400}466508" type="radio" name="userInterchange" />A.T., VIN model "K" (4x4), TH700, gasoline
}B}}400}466509" type="radio" name="userInterchange" />A.T., VIN model "R" (4x2)

Jan 14, 2011 | 1989 GMC Sierra

1 Answer

How can I fix the engine from running rich? It runs so rich. It doesn't pass CA Smog? How can I isolate the problem? Also the car has been sitting in driveway for a couple years. But I started it for first...


this is what i did when my 89 chevy beretta failed and the guy handed me a pamphlet on turning in your junker car for a $1000...and he was kind of laughing like you failed and i got you money anyway because he thinks he knows that there's no way my car will pass again.
here's what i did.
#1 changed out all plugs and wires
#2 changed my oxygen sensor
#3 inspected all my vacuum hoses found a crack going to the MAP sensor
i just cut off that end and shoved it back on. and changed out the PCV valve and also found a crack in that hose but couldnt replace it, so i just rapped it real tight with black electrical tape.
#4 cleaned up throttle body real good and the IAC sensor with throttle body cleaner
#5 replaced the oil and filter
#6 serviced the transmission fluid
#7 replaced my catalytic convertor
#8 ran my car around and got it real hot before taking it in
retested and you should have seen the look on his face and i said thanks to him my car was only getting 19 to 20 miles to the gallon my dash computer says im getting 28 now. it was really low smog readings and he couldnt believe it.
so if you do all these things it cost $150 for a cheap cat
i think $40 for oxygen sensor
$30 for oil and filter
$60 for trans service
$40 plugs and wires
$7 throttle body cleaner
$8 PCV
total $335 it should pass
on my other car it failed smog so i went this time and just changed the cat and it passed..not quite as good as my beretta but a pass is a pass. try this and you'll probably at least pass! who knows you might even increse your mpg. Can you rate this, thanks!

May 09, 2010 | 1990 Pontiac Grand Prix

1 Answer

1990 gmc truck 5.7 liter. won't start after throttle body spacer


PVC simply recycles the blow by gases. You have either blown a fuse, or your fuel pump is not delivering gas to the motor.

Jun 29, 2009 | 2003 Chevrolet Malibu

3 Answers

2002 Honda Civic Lx - TPS Sensor


The sensor does control trans.It takes a reading to where the throttle is and tells the trans what gear to be in and when to shift,down shift.So if your getting that reading and the car does not seem to be shifting right suspect that sensor..Hope this helps you and have a great day>>>

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_a3369546f8067589

Apr 01, 2009 | 2002 Honda Civic

3 Answers

Jeep stalls



I had the same problem... frustrating.

I picked up a repair manual at the parts store. I took off the throttle body and cleaned it with throttle body cleaner spray. I changed the Idle Air Control Valve (idle speed motor) which was very clogged. While I had the throttle body off I also changed the Map Sensor and Throttle Position Sensor. The manual will walk you through the steps. I had never done anything like this before. If I can do you so can you.
My Jeep has never run better. Good Luck

Sep 26, 2008 | 1991 Jeep Comanche

1 Answer

Fuel injection? 1990 Topaz-4 cylinder


since the car sat for 6 months it could be a vaccuum line the lines are rubber or hard plastic the tend 2 dry rot or chewed by small rodents, while the car is running listen 4 whistle or check for cracks or lines off completely

Jun 17, 2008 | 1990 Mercury Topaz

Not finding what you are looking for?
1990 Chevrolet C1500 Logo

Related Topics:

72 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

Marvin
Marvin

Level 3 Expert

85223 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...