cruiser54

Larry, before you spend any more time or money on other things, please click on my link below and do posts 1 through 5, maybe even 27.

A failing CPS as Eagle states could be the starting issue. Test it. Post 7 in my Tips. 2.5s were notorious for piston slap also. Other driveability issues can be caused by poor grounding of the sensor circuit. see post 5. I would do posts 1,3,4, and 5 as a matter of course. I'm doubting your bearings are shot.

JB won't work. Doesn't stick well to that slick plastic.

That line could be the whole problem. They're not availalble new any more. How's the rubber end at the throttle body? Intact?

Have you tested the fuel pressure? What kind of shape is the line from the throttle body to MAP sensor? Must be perfect.

They all need to be adjusted on a Renix. Have you tried adjusting yours? Here's how: RENIX TPS ADJUSTMENT Before attempting to adjust your TPS, there are two things that need to be done. 1) Be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up. 2) With the Key OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed. TPS ADJUSTMENT FOR ENGINE ISSUES Both RENIX manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over. Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage. TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES RENIX automatic transmission equipped XJs and MJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as outlined above—FOR ALL ENGINE MANAGEMENT RELATED ISSUES. However, the automatic TPS also has a square four-wire connector, clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. First off, DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage between "A" positive and "D" ground by back-probing the connector. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can't, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU. For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. The square 4 wire connector is just not used. Revised 12-15-2013

Click on the link in my signature and do posts 1,3,4, and 5 before wasting any more time and money replacing parts.

1 through 5 for sure. 27 is always a good idea. CPS test is #7.

Typo. I meant 2 and 27. Sorry.

Only need to do 1,3,4, and 5. 3 and 27 don't apply to an 89.

Crappy caps. If you replaced that bottle with one with only one cap, and used a 703-1396 cap on the new bottle from Napa, you'd probably be just fine.

It's all in my link below. Posts 1 through 5, and maybe even 27. Thanks, Eagle.

Big cap and little cap? An 88 only has one cap, the one on the bottle on the passenger side firewall. If that pukes, try Napa 703-1396 on the bottle .

It seals better, has a lower profile, and holds higher pressure. Fact is, the standard replacement caps are just garbage.

Refresh me. What brand spark plugs are you using?

Have you done #9?

That's what you need. Why not get one at Napa with a lifetime guarantee and put a 703-1396 Napa cap on it?

Great explanation and clarification. I especially like the "doo-dad" technical term. LOL.

Not sure who you mean. If it was Precision, he's gone down hill since I first dealt with him. A guy on Cherokee forum does them.

They are for sure.

Best bet is the Volvo injectors 0-280-155-746 on a Renix.

At the Ignition Control Module connections.

Use 'em whenever you see fit.

My 90 has the lights wired like the later models. IIRC, 89 did also.

I tried one of those sites. Had trouble with it.