93 GC 4.0 won't start (fuel pump?)

[micallen]

It turns over, but won't start. Correct me if I'm wrong, but seems like I remember normally hearing the fuel pump for a few seconds when you turn the key to ON. Am I correct ? I'm not hearing it now.

Thanks !!

[bringselpup]

You are correct you hear the pump do a 1 second burst when you key on to pressurize the line. After that the PCM won't tell it to give you any more fuel until the motor is running.

Check my reponse at the end of this thread. You can proof the fuel pump to be sure it's good or not.

http://www.automotiveforums.com/vbul...d.php?t=273382

Key on (not all the way to start) and just sit in the vehicle quietly and see if the fuel pump goes after a little while. If there's a delay I bet you'll be needing to find a computer.

[micallen]

Originally Posted by bringselpup

You are correct you hear the pump do a 1 second burst when you key on to pressurize the line. After that the PCM won't tell it to give you any more fuel until the motor is running.

Check my reponse at the end of this thread. You can proof the fuel pump to be sure it's good or not.

http://www.automotiveforums.com/vbul...d.php?t=273382

Key on (not all the way to start) and just sit in the vehicle quietly and see if the fuel pump goes after a little while. If there's a delay I bet you'll be needing to find a computer.

I tried that yesterday. You never hear the fuel pump. Since that's what I was thinking, and with Christmas and travelling coming up, I had it towed to a mechanic last night. I talked to him a few minutes ago, and he said he is getting fuel pressure. He removed the d. cap and said it looks pretty rough in there. I changed cap, rotor, plugs, and wires about 2 years ago (10K ago). Not sure why that would happen that quick. I'm not lucky enough for that to be the problem though. I guess we will see.

[micallen]

I forgot in my original post to say that I checked the codes, they were fine.

[bringselpup]

Hey, no codes and the D cap looks nasty. Could be. If it runs after that consider yourself lucky.

[micallen]

Well mechanic #1 called me and says he thinks its the CPS. Unfortunately, he says he can't (won't) work on it because he doesn't have a lift. So, I had it towed to mechanic #2. Waiting to see if that indeed was the problem. I'm now out $100 for (2) tows, and $10 to mechanic #1 (he must have felt sorry for me.)

Will update again later.

[micallen]

Originally Posted by micallen

Well mechanic #1 called me and says he thinks its the CPS. Unfortunately, he says he can't (won't) work on it because he doesn't have a lift. So, I had it towed to mechanic #2. Waiting to see if that indeed was the problem. I'm now out $100 for (2) tows, and $10 to mechanic #1 (he must have felt sorry for me.)

Will update again later.

It WAS the CPS. Also, the coil. He said the CPS being bad may have caused the coil to go bad. So, 2 tows, a CPS, and a coil cost me $328.

[bringselpup]

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[ByronP]

Consider yourself lucky. I just had my fuel pump go out and having a new one put in cost me $565.

[oljeeptek]

Originally Posted by micallen

It WAS the CPS. Also, the coil. He said the CPS being bad may have caused the coil to go bad. So, 2 tows, a CPS, and a coil cost me $328.

Hate to bum you out, but a cps can no way in hell cause a coil to go out. Bad rotor to cap terminal alignment, or high resistance in the cap, rotor or coil wire could cause excess coil voltage output and burn out the coil, rotor etc. So could running with extremely wide or worn plug gaps.

Coil can't wreck a cps either.

Jeep did have a recall for defective ign coils when they were newer.

The good news is that for all your running around, it could have cost a hell of a lot more. Too many lazy techs just want to load that shotgun full of parts.. .. PULL!!!!! Damn, missed again! Quick, Reload!!!

......PULL!!!!! Damn!!

[micallen]

Originally Posted by oljeeptek

Hate to bum you out, but a cps can no way in hell cause a coil to go out. Bad rotor to cap terminal alignment, or high resistance in the cap, rotor or coil wire could cause excess coil voltage output and burn out the coil, rotor etc. So could running with extremely wide or worn plug gaps.

Coil can't wreck a cps either.

Jeep did have a recall for defective ign coils when they were newer.

The good news is that for all your running around, it could have cost a hell of a lot more. Too many lazy techs just want to load that shotgun full of parts.. .. PULL!!!!! Damn, missed again! Quick, Reload!!!

......PULL!!!!! Damn!!

The first mechanic mentioned the cap and rotor looked rough inside. So I guess that did the coil in. They didn't replace the cap and rotor, but I will this weekend.