i am a proud owner of a 1987 jeep cherokee 4.0 i6. i have owned it for about 3 weeks now and since then i have put a 4.5in lift, 33in tires, new head gasket, valve cover gasket, cap, roter, plugs, plug wires, rewired near half the dash and just changed to 703 injectors. anyway getting to the point why i am posting this. i know my manifold is warped a bit so back pressure might be a bit low. im having a few issues with it that i cannot seem to figure out.
1-loses speed (slowly but noticeable) up long some what steep hills unless i put it in 1st (its an automatic tranny).
2-going from highway speeds 70-75mph and just letting off completely to coast down to slower speeds at times it will randomly die for no reason
3- 35-40mph the jeep will chug
4- idal seems to be a bit low at times anywhere from 1000 down to 400ish
5- if i rev the motor up to about 3k i can hear it sputter
6- before the plugs, wires, and all that stuff was changed gas had been miking with oil a little bit.
7- when the head gasket was popped i got 200+ to a tank... no im making something like 97insh to 100 miles to the tank....

anyone please help with suggestions. im new to the jeep community.

thanks, ronnie

 

anyone please!!!!!!!!!!!!!!!!

 

To start with the idle/dieing sounds like a tps adjustment issue. As for the mileage might be o2. The fact that this stuff happened after the gasket change.though.... hmm.

 

ya im not so sure. i can understand why the o2 would foul out becuase it was burning fuel and collant at the same time. so it most likly would mess with the o2 sensor. i know everything with the head gasket was done to spec by a chiltons... there was no warp or cracks in the head.

 

Betcha the idle is tps. Got mine on rockauto.com for 30$.... might as well replace it. Also when I set it to spec I had to move it .02 v to get the idle right. You could also try cleaning the iac

 

thanks i appreciate it. ya iv been doing alot of reading and im seeing alot to do with the tps and possibly IAC. i just can figure out why itll die and why it chugs as in cut in and out around 30-35 maybe 40..... and whats so odd about this is somedays is fine and others its just a paint in my *****. and im betting the sputter problem is the o2 sensor. thats all i can really think of. would the crank angle sensor have anything to do with this maybe??

 

Ya know I would go through and clean all your grounds first.

 

you know i never actully thought of that... but it just doesnt make sense to me because when i bought it it never did any of this till the head gasket and **** got fixed... its like i fix one thing then two more go wrong... lol i mean it is a 24 year old vehical. i know the ground off the block on the left side if your looking at the front is all oily front the valve cover leaking (messed up installing that. thats getting fixed again tomarrow) i also forgot do you happen to have or know anyone that has the stock valve cover gromets? the a hole that i bought this from broke one line and left it and changed the other out to a k&N junk breather that doesnt fit and likes to puke oil.

 

The back line can be purchased.. is go rockauto.com. the front I just used a grommet and elbow from the parts store with heater hose. The rear is metered and important. Without it the engine will be full of crap gasses and pressure.

 

im willing to bet thats why it sputters then. would make sense. chokes out the motor and also would probably use up even more gas. hmm...........

 

How about the bad gasket helping to finish the cat in that ole 87?

 

Good idear

 

bad gasket as in you mean the head gasket???? the cat doesnt exsist anymore. the stock junk exhust was rusting threw so i made my own exhust from the front axel to the back axel with a muffler. so if your referring to the cat possibly being plugged, not possible. lol.

oil pressure has seemed fine, i always got the smell of fuel before i changed the injectors to the 703s, and whats so strange with this chugging is it only when im barely on the gas. if i hit the gas quick itll stop unless i cut back. but i will say i bet the sputtering is odd also. only does it when its in park or Nuetral. rev it put 2k or higher and it just sputters like h***.

 

ever clean the IAC motor ,here a good free manual for renix fuel injectionhttp://www.eriejeeppeople.com/ejpfor...?showtopic=217

 

Clean the throttle body and IAC first. Then, check and adjust your TPS. If it's old, just replace it. PM me your email address and I'll send you a simple procedure for doing that, along with a method of checking the sensor grounds in less than 20 seconds.

When the head went back on, did the ground strap from the driver,s side rear head bolt get hooked up?