Car nosedives upon hitting secondaries.

[vortex2450]

I'm still troubleshooting possibilities but here's the issue.

When accelerating anywhere over 1/2 throttle the car nosedives once it hits secondaries. The secondaries are audibly opening but the power just isn't getting put down to the wheels. If I try to gun it while past 4000 rpm the car just stumbles.

The clutch in this car is definitely old but there is no apparent slippage going on. Another issue I have is that the MAF is from a 93' Cobra, it is 73mm ( I believe) and uses the same internal sensor as the stock MAF. I've tried changing it out for 2 known working stock MAFs and both times the car refuses to even idle. There is no LPM either.

Voltage is good, oil pressure is good. I plan on pulling the spark plugs and checking them soon. Grounds are all good.

Still debating what exactly to go after.

-Josh

 

[msteiny]

Any Codes?

 

[vortex2450]

NO codes KOEO or KOER. Possibly ignition issues?

-Josh

 

[msteiny]

Possible, if you can get your hands on another DIS module and try that. Hows your fuel pressure? Could be a weak pump. I had the same experience with my truck, ran great at idle and going down the road. Go to stand on it and it fell on its face, wouldnt even spin the tires in the grass. I had a fuel pump going bad, might want to look into that.

 

[zach44102]

This is something to look at. Have you ever changed the pump?

 

[sheenut]

Check fuel pressure at the rail running and not running. Also fuel filtered could be dirty try the simple stuff first

 

[vortex2450]

The fuel pump IS old. I have a 155lph one, just haven't installed it yet. I have been suspicious that I haven't been getting the pressure I need. Every once in a while I can smell unburnt fuel after stepping on it.

Video to come shortly. Fuel filter has 20k on it. Will check it but it should be good.

[YOUTUBE]5WxwWglq-UU[/YOUTUBE]

[YOUTUBE]aD0w1LUxj9Y[/YOUTUBE]


Yes, I know I grinded 2nd a little. Wasn't pushing enough on the clutch.

To reiterate, if I start at an rpm above the the secondaries opening the power seems to be there. But the initial kick doesn't exist.

-Josh

 

[rubydist]

typical symptoms of a sick tps. however, it could be a number of other things as well, including the dis, coil pack, plug wires, fuel pump or filter, etc.

 

[vortex2450]

typical symptoms of a sick tps. however, it could be a number of other things as well, including the dis, coil pack, plug wires, fuel pump or filter, etc.

Basically , jsut starting replacing stuff until I corrects itself? The usual mantra with these turds. I was thinking it might but a TPS problem. The issue is most prevalent when I punch the throttle, if i ease into the gas I seem to have power.


-TPS
-DIS
-Coilpack
-Plugs
-Plug wires
-Grounds
-Fuel Pump
-Fuel Filter

^ That seems to be an inclusive list.

Time to get crackin..

-Josh

 

[rubydist]

a tps issue will be pretty consistent with throttle position, not how fast/slow you got to that throttle position.

 

[vortex2450]

a tps issue will be pretty consistent with throttle position, not how fast/slow you got to that throttle position.

This is true. No matter the case, the car will bog to some level around 4000rpm. The amount it bogs is dependent on how much throttle I'm giving it. I'm definitely going to start here.


-Josh

 

[Vnuk1]

I'm going to say mass air flow sensor. Mine had the same issue, when it hit the secondaries it would bog because the MAF was retarding the timing. Same with above it, it had no power..

 

[TopGunnYFZ]

Add in checking for full plug wells when your inspecting things.

 

[zach44102]

Unplug the maf

 

[kevinspann]

I told him to, he said it runs worse without it plugged in.

I don't get it.


Edit: Unless someone repinned the MAF wiring for a Cobra/other MAF. But even then it should run right unplugged.