1996 Model RPM Issues

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1996 Model RPM Issues

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1996 Model RPM Issues - 4/5/2008 1:01:47 AM

vinvelasco

Posts: 41
Joined: 4/5/2008
Status: offline

Noob here and this is my first post. I dont know if this problem has been posted before, but here goes...

First problem that i had was the idling was going up and down (mostly down) when i start it up. The engine dies out when i try to rev it up. I went to the mechanic and he managed to fix it and keep the idling steady. He said that 950 rpm is just about right. Is this number correct? Anyway, Everything else is ok until i turn the AC on. The rpm goes down, well actually i think the whole electrical output goes down. It normalizes again when the AC thermostat kicks in and then goes down again.

Can anyone advise me regarding this, please? Im getting worried specially if my family is on-board the vehicle.

Thanks.

Post #: 1

RE: 1996 Model RPM Issues - 4/5/2008 5:16:25 AM

Disco Mike

Posts: 10365
Joined: 4/27/2006
Status: offline

First of all, your idle should be around 750 rpm's, no higher.
Second, you need to clean out your throttle body and the throttle plate, then remove and clean your IAC, idle control unit or stepper motor, what ever you want to call it and you will be fine. Your mechanic is way off on this one.
On a side note, check and replace any old vacuum line and especialy the two hoses, one from either v/c to the manifold.

_____________________________

Mike
Retired service manager. Member of the Solihull Society, NCLR club,past member of the SCLR club and Santa Barbara 4 Wheelers.
99 D2, 3" lift, lockers, H.D. axles, 4:11 gears, Custom front and rear bumpers, Warn winch, HID lights and an Engel 45.

(in reply to vinvelasco)

Post #: 2

RE: 1996 Model RPM Issues - 4/5/2008 5:19:59 AM

Spike555

Posts: 4847
Joined: 6/22/2007
From: Grand Rapids MI
Status: online

950 is to high. Have him check your stepper motor (idle control valve), if it is bad the trk will not run below 550 rpm.
650-700 is normal.
As for slowing down when the A/C kicks in, it is normal for the rpm to drop and then come right back again. Should only drop 50-100 rpm though. And remember, your tach on the dash is not accurate. It's close, but not quite.

_____________________________

If it ain''''''''''''''''''''''''''''''''t leakin'''''''''''''''''''''''''''''''' it must be empty!
Yes, one man can change the world.
If the citizens are affraid then they are easier to control.

The "Storm Trooper",'''''''''''''''''''''''''''''

(in reply to vinvelasco)

Post #: 3

RE: 1996 Model RPM Issues - 4/5/2008 6:15:26 AM

vinvelasco

Posts: 41
Joined: 4/5/2008
Status: offline

WHEW!!! i was beginning to think that its a major electrical thingy. theres no certified rover shops anywhere near where i live (please dont ask me where

so its really hard to get an expert opinion. a lot of people i have spoken to had concerns though coz according to them when the AC kicks in, the idling control unit must compensate for the electrical demand... blah... blah... i'm sure you know what i mean. basically, the idling should not go down. i'm still new to engines and i just take their word for it so naturally i thought that there is a big electrical problem.

and speaking of being a novice at engines, which one is the throttle body and the throttle plate? is that the one at the right side of the IAC? do i need to take apart in order to clean it or can i just spray a contact cleaner or something? and how do i adjust the rpm? can i choke the air going in (thats how the mechanic adjusted it in the first place) or do i have to do the adjusting somewhere else? also, will it effect the timing? oh, and which ones are the vacuum lines?

thanks for the reply Disco Mike & Spike555. Its been ENLIGHTENING!!

< Message edited by vinvelasco -- 4/5/2008 6:19:34 AM >

(in reply to Spike555)

Post #: 4

RE: 1996 Model RPM Issues - 4/5/2008 6:21:42 AM

Disco Mike

Posts: 10365
Joined: 4/27/2006
Status: offline

call me and I'll walk you thru it.
303-862-7680
Colorado any day before 8 pm

_____________________________

Mike
Retired service manager. Member of the Solihull Society, NCLR club,past member of the SCLR club and Santa Barbara 4 Wheelers.
99 D2, 3" lift, lockers, H.D. axles, 4:11 gears, Custom front and rear bumpers, Warn winch, HID lights and an Engel 45.

(in reply to vinvelasco)

Post #: 5

RE: 1996 Model RPM Issues - 4/5/2008 6:28:09 AM

Spike555

Posts: 4847
Joined: 6/22/2007
From: Grand Rapids MI
Status: online

The throttle body is the thing that the air inlet tube attach's to. Follow from the airbox to the engine, that is your throttle body. The throttle plate is the, guess what, the plate inside the throttle body that allows/restricts air flow into the throttle body.
Remove that tube from the TB and get a can of TB cleaner and spray allover, open the plate, spray inside. If you park the drivers front wheel on a curb or 2x4 it will all run inside the TB and not all over the engine.
Use the whole can. Clean it good. Put the tube back on and start the trk. It will spit and sputter and smoke. Once it smooths out drive it around the block to suck in all the cleaner.
If your engine timing is off it may affect your rpm when your A/C kicks in.
Also, you know that you MUST use premium gas, right?

_____________________________

If it ain''''''''''''''''''''''''''''''''t leakin'''''''''''''''''''''''''''''''' it must be empty!
Yes, one man can change the world.
If the citizens are affraid then they are easier to control.

The "Storm Trooper",'''''''''''''''''''''''''''''

(in reply to vinvelasco)

Post #: 6

RE: 1996 Model RPM Issues - 4/5/2008 7:20:08 AM

vinvelasco

Posts: 41
Joined: 4/5/2008
Status: offline

thanks for the offer mike, but im in saudi arabia (im not an arab though)

i put in 95 octane premium. theres only 91 and 95 available in most gasoline stations here. really cheap too! about $0.16/liter. i guess thats mainly coz most of the world's supply comes from here. LOL!!!

anyway...

the mechanic cleaned the TB and plate using a spray (didn't use the whole can though). i don't know if wiped the inside of the TB with a cloth (is that advisable coz i'm thinking of doin it myself). he also cleaned and re-gapped the spark plugs. and adjusted the timing as well. basically your regular tune-up right? the only thing he messed up was, for the lack of technical knowledge, "air intake adjustment". you know, the screw you adjust on top of of the TB using an alen key wrench? he sort of choked it. and i forgot to mention earlier that the guy who said that the normal rpm is 950 was the 2nd mechanic i went to coz the first one didnt fix my idling problems. i know its a bit confusing but please bear with me. the engine didn't stall on me after the tune-up maybe because it was still at optimum temp during the time so i thought it was ok. but on the next day, the problem was back. so i went to this second mechanic who just adjusted the air intake by turning the screw in the TB and adjusting the throttle a bit. that was over a week ago and its been almost ok since then. i was and still am thinking about the rpm change when i turn the AC on. i'm guessing it goes down no less than 200 rpms and it still stalls on me sometimes specially in the mornings.

Im thinking of replacing the IAC but upon reading some threads here, it rarely solves the problem. could it have something to do with the compressor as well?

(in reply to Spike555)

Post #: 7

RE: 1996 Model RPM Issues - 4/5/2008 7:40:12 AM

Disco Mike

Posts: 10365
Joined: 4/27/2006
Status: offline

The IAC can be dirty or failing, it is common.
No wonder you have a high idle, 95 octane, I would idle higher also, just kidding.
The compressor is not the problem.
Check the hoses and for Vacuum leaks.
16 cents a liter, there should be a law against such cheap gas.
Take care,

_____________________________

Mike
Retired service manager. Member of the Solihull Society, NCLR club,past member of the SCLR club and Santa Barbara 4 Wheelers.
99 D2, 3" lift, lockers, H.D. axles, 4:11 gears, Custom front and rear bumpers, Warn winch, HID lights and an Engel 45.

(in reply to vinvelasco)

Post #: 8

RE: 1996 Model RPM Issues - 4/5/2008 8:24:12 AM

Spike555

Posts: 4847
Joined: 6/22/2007
From: Grand Rapids MI
Status: online

The IAC is a pretty cheap part. You might just want to throw one on and then have them re-adjust the idle screw.

_____________________________

If it ain''''''''''''''''''''''''''''''''t leakin'''''''''''''''''''''''''''''''' it must be empty!
Yes, one man can change the world.
If the citizens are affraid then they are easier to control.

The "Storm Trooper",'''''''''''''''''''''''''''''

(in reply to Disco Mike)

Post #: 9

RE: 1996 Model RPM Issues - 4/5/2008 10:38:01 PM

vinvelasco

Posts: 41
Joined: 4/5/2008
Status: offline

It used to be 23 cents. The government reduced it to 16 cents. That's one of the good things being here. But the spare parts are ridiculously high priced and almost unlawful!

I've been observing the tach this morning and the idling is a bit high according to the standard, specially when its at optimum temp. Its close to 1K and about 640-650 when the AC kicks in. I'll get a new IAC and then re-adjust the idle screw then post the result here.

1 more thing, the three motor pumps on the water tank for the windshield wipers, or whatever the heck its called, are all busted. I called the dealer and they don't have it in stock and will not get it anytime soon. Will pumps from other vehicles (not rovers) work? I've checked the pumps from a 92 and 94 model and I don't think they fit. Its beginning to be a problem now coz of the sandstorms. Even rain is like ashfall from a volcanic eruption!

I really appreciate the help guys. Thanks a million!

EDIT:

i just got off the phone with the dealer and asked about the stepper motor and motor pumps for the windshield. he said it's SR470/$125 for the IAC and about SR250/$66 for each of the pumps and that doesn't cover the mechanic!!! is that the same as the prices in the states or UK? i don't mind buying them particularly the IAC if it fixes the problem but personally i wouldn't call those prices cheap.

< Message edited by vinvelasco -- 4/5/2008 11:12:38 PM >

(in reply to Spike555)

Post #: 10