Jeep stalls when giving gas

My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop briefly and then try to drive off. It runs great all other times, it's only in this particular situation it acts up. After it stalls, it starts right up and runs great. The same is true if I stop for a longer period of time, like for a red light.

I suspect the throttle body might be the problem, but before I do anything I thought I see if anyone here can confirm my suspicion, or come with better ideas.

It might not be related, but when I start the engine the rpms often rise to about 1.5k for 2-3 seconds, sometimes longer, before going back to normal idle speed. This happens hot or cold.

Ulf

Reply to
Ulf
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Check the Idle Air Controll and the EGR for carbon buildup.

do a repost

~:~ MarshMonster ~takes a toke.....~ ~:~

Reply to
Marsh Monster

That's normal.

Check your fuel line pressure into the injectors. Try replacing the fuel filter(s); they may be plugged. There could be one in the tank too.

Or, maybe the injectors are dirty. Chevron's "Techron" gas additive will fix that.

Reply to
Bob M.

Reply to
philthy

The high start up RPM is related.

Your trouble description is exactly the same as our 88 Cherokee would do when the TPS electrical connection got dirty. This is on the throttle body. We were told it was a bad TPS back in '98 so I figured I would just clean the connections first. My clean lasted over two years until it needed it again and then once every two year or so until we sold it this fall.

Lots of others have the same issue.

I recommend you use a spray electrical contact cleaner (electronic shops sell the best stuff) on it with some dielectric grease or even spark plug boot protector on the plug's seal skirt on 'all' your computer's electronic sensors, not just the TPS.

The CPS is also a known failure point to the point that DC even recommend cutting the plug out and soldering the thing in. When it gets it's bad connection, the engine just up and stops at speed, then will usually go again for a while.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:
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Reply to
Mike Romain

I believe the 1990 Renix System TPS can be manually adjusted using a digital multimeter and a screwdriver, no scan tool needed.

His issue is the TPS connection though. Been there, many times.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > they had bigtime issues with the tps and the plug would have to be cut off and
Reply to
Mike Romain

Thanks for your excellent reply. I'll try that as soon as I'm able to get the Jeep started. Issue #2 I have with it is that the battery keeps going flat when it's not driven for a few days.

BTW, I found the procedure on adjusting the TPS that was mentioned.

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Reply to
Ulf

WD40 will work in a pinch for cleaning it. The pins are small and the holes need to be sprayed out. I spray, wait a few seconds for it to dissolve stuff, then spray again to wash it out.

There is no real reason for them to go out of adjustment, ours never did. It just gave your symptoms until cleaned. I figured the adjustment is for the install setup.

Your TPS is different than the one in the link... Yours has a dedicated adjustment screw under a cap like a carb mix screw cap. There are voltage readings for the pins with the plug hooked up. The center and the top are the ones to use. If you have the engine off with the key in run and the throttle closed, the reading should be about 0.026V, greater than .02V. Then you go wide open and the voltage should read just under

4.8V. If you have an automatic, one set of wires will also give 4.8V at closed and .026V at open.

Mike

Reply to
Mike Romain

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