98 Vortec 4.3 Issues

[kmcminn]

I have a 98 4.3 in a Samurai that is giving me problems. The motor is cutting out when i press the gas at idle.But after a split second of this, it catches up and revs up like is suppose to. I have read the code and it is saying Manufacturer Contol System or Misfire. I have put new spark plugs in and properly gapped them, new fuel pump. new plug wires and also changed the fuel filter? The harness had been cut down and computer has been flashed both by Jims Performance.
If anyone has any ideas of what it could be let me know. ???

 

[Dwalk]

Kevin, we were working on one that had the same problem, it was the EGR.

 

[onetoncrawler]

Kevin, we were working on one that had the same problem, it was the EGR.

EGR should be eliminated by the tune/harness chop from Jim's

 

[kmcminn]

Yes, the EGR was eliminated when Jim chopped the harness down. I have heard a couple people say some about fuel pressure bleeding down inside the intake manifold?

 

[smurfy90]

Do they have throttle position sensors?

 

[kmcminn]

Yes it does have a throttle position sensor.

 

[benfowler87]

Could be a TPS or a CPS (crank position sensor) throwing the timing off then it's catching back up.

 

[kmcminn]

Hopefully jim performance will call back and give me a clue

 

[Hotrod]

Mine was haven the same issue. I tried everything stated on here plus fuel regulator and screen in the intake. Nothen helped. I just reached up and unplugged the mass air and it runs spot on- I mean really good. But my 02's are also unplugged. May help u to check urs and c if it's bad.

 

[kmcminn]

I talked to Jims and he said probably the the injector is more than likely the culprit. Jim also siad to get the new designed fuel injector that has an injector for each cyclinder. Unfortunately they are nearly $300 for new design injectors then an additional $75.00 for bracket and gasket. :'(

 

[onetoncrawler]

I would try hotrod's suggestion first

 

[kmcminn]

I am for sure going to try this.

 

[kmcminn]

Tried Hotrods suggestion unfortunately it didnt work. Put a fuel pressure gauge on it and it is running at 52psi then when i hit the gas it jumps up to 60psi. ANy Help?

 

[87yjtoy]

Does it throw any codes?

 

[kmcminn]

yeah manufacturer ignition control system or misfire?

 

[87yjtoy]

My code was cam sensor replaced it its all good now.

 

[kmcminn]

I think may have it figured out I will post up in a day or two.

 

[CSMITH]

sound like its trying to fire on number 7 and 8 cylinder and they're not there.



you coulda had a V-8

 

[kmcminn]

Got it Fixed. Got the rev limiter set at 5200, vroom pow.

 

[BamaTJ]

I had the V-8 version of that motor and I learned to always start with a tune up (plugs, wires, cap, rotor button, etc) for sluggish performance. That was always my culprit, changed them all about twice a year.