redeyez

First off when starting my blue beast the cranking time before it fires up takes longer than it seems it should, when its warm it'll start a bit faster but still slow.

Second when I'm idling it will go from 750 down to 500 for a few seconds a d then pop back to 750

Third when I'm Cruisin along I get a little puh puh every now and then that usually smooths out but comes back..

What I've done so far:
Sea foam in gas tank
Sea foam intake
Tune up along with a brand new distributor and wires plugs cap rotor
New timing chain and gears
Cleaned all electrical plugs and ground points
Sprayed water in engine compartment in search of vacuum leaks... None
Had a friend test my injectors and they turn on and off when they should


I have had this jeep for a while and these issues are drivin me batty, any insight would be greatly appreciated, I'm getting a new exhaust put on tomorrow because currently it's cherry bombed and dumps out in front of the rear axle and sounds like crap. I work nightshift so I don't get a lot of time to fix on this thing, but as previously stated any ideas of where to start or where to go would be awesome. Thank you

1976Mustang

I'm thinking Throttle position sensor, maybe the O2 sensor.

And what's this talk of it sounding like crap with a cherry bomb? LOL.

nickxj94

Cel on? If so have it checked for codes then post them here it will help with a diagnosis, but it does sound like o2 sensors and or tps. Also have you checked fuel psi at the rail?

redeyez

Yea I forgot to mention fuel pressure test, it was ok according to the guy who checked it for me. No check engine and even if there was, no one around here can get codes off of the old renix CPU.... My jeep is an 88. Ty for the fast responses, I've hooked my tips to a voltmeter and it seemed ok but I spose it could still be fubar; I believe I have a new o2 sensor just haven't had enough daylight/time to change it! And yes cherry bombs sound like crap IMHO I'm not used to vehicles with all the emissions garbage on them, so I'm changing the exhaust in case it might be a back pressure issue

freegdr

Ever clean throttle body and iac motor ?

redeyez

I sea foamed the crap out of the tb so that should've cleaned the iac too in theory?

freegdr

With tooth brush and scrubed it usind throttle body cleaner id say yes Seajunk in a can id say no.

MOvermyer

o2 typically throws a code.

redeyez

My tb doesn't look dirty at all... And I'm not even sure the engine light works, I'm gonna go outside and flip the key and check real quick :s got a little down time between parts here at work

redeyez

That's a negative on the cel, only lights that come on with key turned to on are emis maint, shift light, washer, and seatbelt.... So I think it must have been on for so long before I bought it that it is now burnt out

freegdr

89 dont have one

odgreen

This. From personal experience. All the same symptoms you have stated. Long crank ( renix 5-10 seconds is pretty normal) random misfire and funky idle. Mine was the CPS. Only thing mine did different was die randomly.

odgreen

Also.... Fuel filter?

redeyez

Funny enough I have a new cps just haven't put it in cus it seems like a pain in the rear to get to it without removing the manifold... And the fuel filter I changed a while back but probably not a bad idea after I seafoamed the gas tank it's probably plugged with more crap

odgreen

Go at it from under the jeep. 2 11mm bolts.