Luckyhollow

Hey People,
This one has me stumped, anyone ever hear of this?
I have a 1987 Jeep Cherokee 2.5 liter 4 cyl with a throttle body injection system.
When I am driving at about half throttle, the engine hesitates for a second or two, then comes back to life without any change in throttle position.
It doesn't do it when the throttle is floored or when it is coasting with throttle off.
The problem is intermitent and it runs and idles fine the rest of the time.
I have already replaced the tps sensor and have done a full tuneup including the fuel filter.
It seems to get worse when it is hot out.
Any ideas?

fantic238

Probably a coil wire missfire or the crankshaft sensor starting to act up.

dilljeepo

Please someone tell me what it is... I think it's broken and I don't know what it even does. I've tried finding it but every engine diagram I've looked at doesn't even have it. Or not that I can see.

BUELLIGAN

DJ, I dont know what it is myself. I would get 1 from the bone yard to see if that is the problem . Then buy a new 1 and keep the bone yard 1 handy if you need it on the fly.

BUELLIGAN

I just went out to look at mine . I dont think my 94 has that thing. It has a vac thing tied into the heater hoses , thats what I thought u were talking about.

Pluckxj

a friend of my gave me a three inch lift. doesnt have shocks.. does anyone know of what kind of shocks i could put on there?

dilljeepo

Buelligan, I think that's the problem, not many other years seem to have them, My haynes manual has an illustration of the engine compartment but of course doesn't have the Vac thing. What's really weird is that when I unplug the two prong electrical thing..... nothing changes! Idle is the same (finicky to begin with) all controls work etc. No check engine light even after leaving it for a week. Thanks for looking and yeah, I think I'll go to pick n pull soon to get some spare "if I really need it" parts, good advice!

jeepinMD

I'm new here, so forgive me if this is covered elsewhere--I've looked, and found good stuff, but just want to make sure.

Here's the deal: CEL comes on yesterday and AUTOZONE gives me the P0705 code. Most here seem to suggest that this is connected to the NSS (which makes sense, as I've had backup light issues and the heap doesn't seem to be running poorly at all). Here's the questions:

1. How do I know it's the NSS and not the Trans range sensor?
2. How does the NSS being gunked up affect the trans range sensor?
3. If the NSS can't be repaired by cleaning it, anyone ever heard of the "Replacement" brand of NSS? I've found them for very cheap (about $50) as opposed to around $300 at other places. Anyone ever used one of these? Here's a link: http://www.car-stuff.com/carparts/je...+Part+Page%3A1

Any and all suggestions welcome.

Thanks in advance!

#999

so i took it apart there was no loose connection and i cleaned the contats with contact cleaner and a q tip but still not working,like i said its not the cluster itself that works.....the female connector and wires leading to it weretn that long to be able to pull out....do i have to replace that whole thing and how do i go about that
stefano chim in whenever man
P

D_Conrad

my jeep NEVER starts on the first try. but always on the second. i think it could be the fuel injectors leaking but not sure. any ideas?

Luckyhollow

Thank you Fanatic.
I will check into that.
I replaced the wires with the tune up.
Do you think the MAP sensor could have anything to do with it?

BUELLIGAN

DJ, may be ur jeep is from KALIFORNIA or some state that has high emissions , and that thing is for the emissions or some thing like that.

fantic238

Posting a picture of it would help to identify what you are talking about.

fantic238

Transmission range sensor? no such thing on a AW4 tranny. The TCU knows in what gear it is from the NSS.

fantic238

Either that or the check valve in the fuel pump. Try the check valve first cuz it's cheaper, buy one in your favourite auto parts shop, it goes on the rubber hose near the tank.