WIERD problem

[GNSteve]

Hi all,

I'm hoping that someone can help with this problem I encountered while driving yesterday.
This problem occurred without any warning, symptoms, or codes. Basically what happens is that I cannot apply anything over one quarter throttle without the car completely falling flat on its face.
No accelleration, no revving, no nothing. It's like the engine just died. (although it's still running-kind of like a throttle stop) When I release the gas to below one quarter, the car returns to normal. At a stop, I put the car in neutral and revved it. It promptly died when the throttle went past that one quarter mark.
While trying to find out what couold be the cause of this problem, I looked to the Scanmaster. TPS voltage looked OK, even past the one quarter mark. The car wouldn't rev or accellerate, but the TPS voltage continued to rise as normal. No codes showing. Strange.
I checked the throttle linkages, gas pedal, and TB, and everything seemed to be normal.
When I took it back on the road after looking for clues, the problem was gone. Car seemed normal, and behaved as if nothing had happened. Can anyone help shed some light on what may have caused this? It may be gone for now, but I'd feel better knowing what caused this in the first place. It's hard to drive on the freeway when the car won't take more than a quater throttle at any given time. Please help!


Steve

 

[1970gsx]

Could be a MAF issue. Tap it with a srewdriver handle while it's idling and see if it stumbles.

 

[Darrell Jackson]

If the MAF turns out to be okay, check out the the intercooler hoses if your car is intercooled. I've had this happen to me before when checking the condition of the hoses, tightening the clamps back up (not tight enough), and taking the car out for a test run---- kicked back at about 25 MPH and wouldn't go any faster and found one of the hoses to be partially off.

Darrell Jackson
'87 GN

 

[Reginald West]

I will second the intercooler hose idea.

 

[TURBOV6]

Electrical problems?

Steve....

I would check the battery connections and the ground going into the body. Loose ignition module plug?

 

[blackbuick87]

I had the same i/c hose prob, would leak at anything over 4psi. You want to talk about a DOG.

It could be a fuel del problem, I would lean more towards fuel than electrical, since there is no bucking or popping.
You could be using up the avail fuel, then the car falls over, and then the pump can keep up again.

 

[charlloots]

dont forget the fuel filter when i first bought my car it was terrible cound not get out of my own way and would stall instantly after changing the fuel filter car off lift pull into the street smoking the tires fishtailing like a bat out of hell 25 foot patch after that i change it regularly

 

[GNSteve]

Thanks everyone for all the great replies!

I have a LT-1 MAF/Translator. It seems to work fine. I double checked all the IC hoses. They appear to be on pretty solid.
I suspect that it's an electrical problem as well, although I haven't pinpointed it to a specific area. The fuel filter was recently changed, too.
I call this problem "Wierd" because of the nature of how it occured. As soon as it started, it was gone. No running strange prior to the event, and it runs fine now.
As for how it ran when it had the problem, that was strange too. After pressing the gas past that "one-quarter" way, it was like something cut off the car's air supply. It was like the TB blade was shut completely. That's why I first checked the linkages and the gas pedal. They were fine.
I've had loose IC hoses before. This was not the same problem.
Anyone else have any ideas where I could check electric-wise?
As usual, TIA!


Steve

 

[Turbosix6]

check those hoses again - replace them if your unsure of their age.

 

[1BADT]

The same sort of thing has happened with my car. When my gas would get low, it would starve the fuel pump. Causing the same problem you are having. Was your fuel level low? Did you fill up shortly after the problem occured causinng the problem to go away? Just an idea, hope I'm of some help... JASON

 

[Brian Mc]

Sounds like maybe an engine or ign power feed wire losing contact when the engine torques, or a bad fuel pump pulsator. I agree on the fuel level thing too. maybe when the fuel level in the tank gets below a certain point there is a leak in the sending unit that is being exposed, and dumping fuel but isn't a problem when the fuel level is high.

 

[GNSteve]

Keep 'em coming...

Well, I checked all the hoses-twice. They are fairly new heavy-duty units, so I'm confident they aren't the culprit. Besides, why would it only happen that one time, and not again? If the hoses were indeed leaking, wouldn't the problem re-occur once in a while? After all, hoses don't retighten themselves.
When the problem occured, I had over a half-tank of gas.
I'm still leaning towards an electrical gremlin of some sort. Anyone have any ideas on where to start looking? TIA!


Steve

 

[striker_29]

I dont know man that is pretty weird, HAve you checked all your grounds? Just trying to throw something else out there. Good luck

 

[GNSteve]

Mark,

That's what I was thinking. Would you happen to know offhand where all the grounding points in our cars are?

Thanks!


Steve

 

[GN owner]

Ignition Module

Steve,

My friend had this problem that might be what you are experiencing. Here is what he wrote.


I read a thread written by "GNSTEVE" about a "weird problem". I once had a problem with my ignition module every couple of weeks the car would have a slight stumble at idle and the second I hit the throttle (normal driving) no power to accelerate. If I slowing press the throttle the car would at least move enough the get to the next parking lot. So I pulled the plug wire one at a time and some had spark some didn't but when I was done checking all six it would fire like normal. I could drive it for the next 3 to 4 weeks (sometime months) then it would happen again and I would do the same thing. Sometimes it would work after just pulling one or two. This went on for about a year or two. Then one day nothing would work I tried a new coil and all kinds of stuff. The only thing that would work was another module, the second I put the original back in it the problem would return. So far with the new module no problems for at least a year now. Just thought I'd pass it on because it reminded me of my problem.

Hope this helps!

 

[GNSteve]

Gay,


Sounds like the problem I have in the more *advanced* stages. Thanks for the heads-up. I'll be looking for a new ignition module sometime in the near future.
I narrowed the problem down to something electrical. Jackson guessed the same thing too.
Once again, thanks for the valuable info.


Steve

 

[Mac in SD]

Had a similar problem and it was the coil module. Complete nose-over...good luck.