8 cranks to start engine

I have an 88 cherokee, that i just bought and it takes 8 revolutions of the engine to start. on the 8th starts right up. sometimes if it's cold 15 degrees outside or so it takes 8-10. someone said something about a cams syncronyzer? what could cause this probably and how to i fix it?

DAMN! It only takes 8 for you..... My 89 on a cold day will take near 15.....

Jeep Freak said:

I have an 88 cherokee, that i just bought and it takes 8 revolutions of the engine to start. on the 8th starts right up. sometimes if it's cold 15 degrees outside or so it takes 8-10. someone said something about a cams syncronyzer? what could cause this probably and how to i fix it?

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Go see Kurt in Anchorage at Kodiak Offroad/5 Star Auto and have him look it over, or get ahold of Brooke at the AK Fab Shop in Soldotna.

That's mormal for a Renix motor (87-90 4.0l). I've heard several reason posted as to why, but it takes the Renix motor several revs to check everything before it'll fire. Make sure you have a good battery when it's really cold outside. Good Luck.

Woody

Normal.

For the RENIX 4.0 (1987-1990,) there are two key sensors in play - the CPS (Crankshaft Position Sensor) and the SYNC (Camshaft Position Sensor, this one is in the distributor.)

I've read a few reasons myself, but there are two that stick out in my mind...

1) The ECU won't put out any pulses to fire the coil or fuel injectors until it reads 300 crankshaft RPM (probably apocryphal, don't know where I read that one.)

2) The ECU waits until it gets a valid signal from BOTH the CPS and SYNC sensors before it fires anything else. This one makes a little more sense - but the RENIX ECU is able to "guess" when it can't get a SYNC input (takes a while - I've tried!) and get things running anyhow.

If you suspect your SYNC sensor, unplug the connector at the distributor and see if it changes anything. The distributor, in the case of the RENIX system, actually has very little to do with ignition timing - I've been able to turn it 180* EACH WAY with the engine RUNNING, and it won't even skip or stumble...

As far as the other reason (300 RPM,) all I can suggest to you is you make sure to stay on top of your battery. I've replaced my battery with a Red Top, I've got a high-output alternator in place, and I've replaced all the mains leads with heavier - and cleaner - wiring, and my 88 now starts fairly quickly (3-5 cranks, I believe.) If you'd like information on the wiring or the alternator, check the link in my sig - Rod (San Jose Generator) will ship, and I've sent stuff all over...

5-90

Have somebody get in and crank the engine while you watch for the rotations. What sounds like a complete revolution of the engine is normally only a single cylinder or two. You will be surprised how little rotation it really takes to fire.

do you put your key in and imediately try to crank it or do you let the fuel pump prime the fuel system first? I only have delayed starts if I dont let the fuel pump run before I kick the starter.

Badcop said:

Go see Kurt in Anchorage at Kodiak Offroad/5 Star Auto and have him look it over, or get ahold of Brooke at the AK Fab Shop in Soldotna.

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must be you were up here. what rig did you have? i've been running a blue yj for two years, i'm sure i saw you. ak board i'm Rolling Rock

i let the fuel pump prime. thanks for all the info. i'm running a red top, a better alternator would probably be good. thanks for the information.

X2 5-90...couldn't have put it better my own self....lol....now just what is this thing-a-ma-jigee that goes on the doo-hickey.....I'd be happy with with half 5-90's knowledge of XJ's.....oh yeah....mine cranks for about 3 seconds too.

(its a Jeep Thing you must understand)

just a little humor..My Comanche takes its time as well but allways starts

dizzymac said:

X2 5-90...couldn't have put it better my own self....lol....now just what is this thing-a-ma-jigee that goes on the doo-hickey.....I'd be happy with with half 5-90's knowledge of XJ's.....oh yeah....mine cranks for about 3 seconds too.

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Well, what do you expect? I've got a total of four XJ's so far (87/88/89/89,) and I'm looking for an MJ and I've got my wife to entertain the idea of buying all that I can find room for.

The only non-XJ/MJ vehicles I'd care to get are an M151 MUTT or three (for runabouts,) and an M35A2 (for a working truck - HARD working truck!)

I've managed to research enough to write my first book (on the AMC/Jeep inline sixes...) and I've got two more planned (currently working on the second, in between everything else, and now that I've nearly knit together again...)

If I could be said to have specialised in anything, it would be in the automotive field - on the XJ and the MJ. Otherwise, I'm a generalist.

Thanks, tho - I've really worked hard to get all this wedged into my head - I'm surprised I didn't lose any with my incident in November - and I still find out I'm wrong every now and again (although I find it happening less and less. Errors here are typically due to my hamfisted typing, rather than anything else... If I could only hook my computer up right to my head...)

5-90

Jeep Freak said:

i let the fuel pump prime. thanks for all the info. i'm running a red top, a better alternator would probably be good. thanks for the information.

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I was running a red tj on 35's when I was up there, and a member of Ak Extreme.....

I also had a green xj that only made it to the trail a couple of times...

Wish I had the space...I'd be stockpiling xj's/mj's too. Had to pass up real nice 89 xj this past summer...free of charge....always started right up..until...the girls boyfriend replaced the ehaust downpipe....can we say CPS harness...told them about it, couldn't be bothered with it...went to the boneyard...i'm not sure but I think that might fall into the mortal sin category...lol