well, i've been been getting really frustrated with the engine in our '93 lwb...Elisa started coplaining it was gutless..and i fiddled around, including rebuilding the orig distributor and re-installing than taking part of that one and part of the '89 dist. and combine as the '89 at least worked some...but by than had frozen top/bottom so no mechanical advance...anyway

so here i am today after replacingt he fuel filter, che3cking and cleaning the iac valve(but not sure if it works or not? hmm! maybe need to replace? what was that generic one? searching..aha!Wells AC102 from Autozone )
anyway i decided to check the dreaded compression(a thing I have avoided like the plague as it does have 235,000 miles withought the heads even coming off..turns out it's pretty good
1---162
2---162
3---166
4---161
5---166
6---151
7---160
8---159
all within a decent amount, but what is a good comp # for this engine? i can't find the manuals handy now...grr

the rover runs ok when driving but just doesn't have the power my friend's same year/model has...so something id fefinately wrong as Joe's rangie isn't tuned up right, is stating to leak coolant etc..)
with these comp numbers I wouldn't think it's losing much from a head gasket leak..which I am pretty sure it must have as it does use coolant...but that is another story.
i want to get it all fixed quick before Elisa carries out her threat of getting a "new car" not like we can afford one, but...you know women...


right now am thinking need to replace the iac valve, than find a known good distributor unit and install that in case there still is something wrong here? than maybe check the fuel pump? could it have too low pressure at idle than be better under powr? ...but still low causing the lesser power?
it has new oxygen sensore using the generic bosch ones for a nissan and the wires, coil and plugs are within six months
any ideas would be great.

Paul

IAC valve problems usually manifest themselves at stop lights. What happens when you turn the A/C on? The IAC valve is intimately involved in keeping idle up when the A/C is turned on.

Check your fuel pressure, although, this isn't usually associated with poor idle quality. As much as I ahte to say it, with the miles, poor idle and low power sounds like cam wear, or timing chain wear-although, the good compression numbers don't bear this out either.

Vacuum?

what's the idle doing? stalling out, idling high then dropping, just irratic...

Dodgy fuel pressure regulator, ignition amp?

235k is not an unreasonable mileage to put a new cam & chain in, hell I'd be happy if I got away with 50k.

IAC valve problems usually manifest themselves at stop lights. What happens when you turn the A/C on? The IAC valve is intimately involved in keeping idle up when the A/C is turned on.

hmm...well teh a/c is acting up so kinda afraid to ewven turn it on! :(


Check your fuel pressure, although, this isn't usually associated with poor idle quality.
yeah, i will probably end up at NAPA again and buy htat fuel pressure kit they have and see...



As much as I ahte to say it, with the miles, poor idle and low power sounds like cam wear, or timing chain wear-although, the good compression numbers don't bear this out either.
huh? not sure I understand that statememt? say again
well could this affedt teh timing? for a while it appeared that the timing pulley had rotated on the crank?? was running perfrct at 26 degrees..


Vacuum?
it showed to be fine the other day...and when wifes friend, Richard was playing around with teh gagues he tested for ohter issues you nca see witht hte vac gague..said all was good.i don't have a gague(or the know-how like he to really test everything.but he has 40 years experience

what's the idle doing? stalling out, idling high then dropping, just irratic...
stalling out at times...going up and down erraticly just not working right ever

Dodgy fuel pressure regulator, ignition amp?

235k is not an unreasonable mileage to put a new cam & chain in, hell I'd be happy if I got away with 50k.

fuel press reg? do we have one on a rr? don't remember one being there anywhere...but the fuel pump is definately high on my list

also was thinking the cam...is there a simple way to see if the cam has gone bad?
and what is a good cam to put in the 4.2? i know the stock cam is a good upgrade for the 3.9 engine...never replaced a cam in a v-8..how hard is it in situ?

Cam replacement in situ requires removal of the A/C condenser.

Good vacuum points away from cam.

Fuel pressure regulator is in the return line from the fuel rail.

Napa fuel pressure setup likely won't work well on an early Rangie as you must break the fule line to insert the guage due to no shrader valve.

Ignition amplifier? Might be although not likely.

Replace the IAC valve and see what that gets you. In the grand scheme of things, it's not expensive. the stalling out and erratic nature might point to the IAC, but is more likely a vacuum leak problem. Make damn sure your emissions hoses are good. I just replaced a set on a '92 and the only hose tha was any good was the one to the plenum at the intake (by the throttle butterfly) both of the other two were shot!

Vacuum gauges can show an awful lot, I'm glad you already tried it.

Good luck,
PT

Cam replacement in situ requires removal of the A/C condenser.

Good vacuum points away from cam.

Fuel pressure regulator is in the return line from the fuel rail.

Napa fuel pressure setup likely won't work well on an early Rangie as you must break the fule line to insert the guage due to no shrader valve.

Ignition amplifier? Might be although not likely.

Replace the IAC valve and see what that gets you. In the grand scheme of things, it's not expensive. the stalling out and erratic nature might point to the IAC, but is more likely a vacuum leak problem. Make damn sure your emissions hoses are good. I just replaced a set on a '92 and the only hose tha was any good was the one to the plenum at the intake (by the throttle butterfly) both of the other two were shot!

Vacuum gauges can show an awful lot, I'm glad you already tried it.

Good luck,
PT

now my main question is where has the power gone? i am about to install teh new plugs and iac valve(had to deal with other issues until now) and will seel
Friend will come by to check teh fuel pressure at the fuel filter...but that is what is coming from the tank...so if the pressure reg is bad, than we won't know...maybe we can attatch at teh inlet of teh fuel rail...than the outlet and see difference too? we'll see

Paul

If you put the pressure gauge in the line at any point prior to the pressure regulator, you will be able to monitor the dynaimc pressure. If you put the gauge in the circuit in such a fashion that the lline deadheads into the gauge, you will read a higher pressure than what the injectors are seeing and it won't really show you much.

It doesn't matter where you put the gauge in the circuit as long as it is in the line-law of partial pressures applies!

IT's a rover :shaking: :shaking: :shaking:

If you put the pressure gauge in the line at any point prior to the pressure regulator, you will be able to monitor the dynaimc pressure. If you put the gauge in the circuit in such a fashion that the lline deadheads into the gauge, you will read a higher pressure than what the injectors are seeing and it won't really show you much.

It doesn't matter where you put the gauge in the circuit as long as it is in the line-law of partial pressures applies!

but I thought you needed to check pressure at idle, and than under revs...but under load not just reving in park?

Richard left the Snap-on fuel pressure gauge setup here tonight while I was running off to pick the iac from autozone..and left as he was tired. he told Elisa to make sure i useed the manuals to find the correct fuel pressure...hmm!
I told her I trusted you and Pendy(and any other rover mechanics we have here...) more than the manuals....so...guys? what are the likely expeced numbers here? what is "correct" and what is acceptable etc...

thanks!

Paul(tires so will continue in the morning..but at least I now have new brakes installed..amongst other things while waiting for parts to arrive..)

Oops I worked early this morning. Is it AFI who made the statement above in my name? If not I have a problem!
To clarify, I did not write the statement above, but perhaps someone I know!

T

Oops I worked early this morning. Is it AFI who made the statement above in my name? If not I have a problem!
To clarify, I did not write the statement above, but perhaps someone I know!

T

LOL, I don't believe you used a computer at my house and forgot to log off:flipoff2: :laughing:

Fuel pressure should be somewhere in the vicinity of 35 psi at idle. I wouldn't get too worked up about checking the pressure at idle and under load. If you have a problem, it will likely manifest itself immediately. FWIW, in spite of what many may say, I have seen many Rover fuel pumps go bad and produce low fuel pressures, rather than just shutting down completely. When they go bad and pressure drops, two things are evident, power goes away and the computer shows the engine running lean. Yet another case where the brute force troubleshooting comes into play to recognize why the engine appears to be running lean.

When you get the gauge attached, after you check the pressure under regular conditions, turn the engine off, clamp the return line shut, turn the ley on, but do not start the engine, and see what the pressure goes up to. This will show you a coupla things, including just how good the pump is and the condition of your injectors. The pressure should peg your pressure gauge (depending upon the maximum indicated pressure range) and hold for awhile. If it does neither, or only one, you either have a bad pump or leaky injectors.

PT

LOL, I don't believe you used a computer at my house and forgot to log off:flipoff2: :laughing:

Fuel pressure should be somewhere in the vicinity of 35 psi at idle. I wouldn't get too worked up about checking the pressure at idle and under load. If you have a problem, it will likely manifest itself immediately. FWIW, in spite of what many may say, I have seen many Rover fuel pumps go bad and produce low fuel pressures, rather than just shutting down completely. When they go bad and pressure drops, two things are evident, power goes away and the computer shows the engine running lean. Yet another case where the brute force troubleshooting comes into play to recognize why the engine appears to be running lean.

When you get the gauge attached, after you check the pressure under regular conditions, turn the engine off, clamp the return line shut, turn the ley on, but do not start the engine, and see what the pressure goes up to. This will show you a coupla things, including just how good the pump is and the condition of your injectors. The pressure should peg your pressure gauge (depending upon the maximum indicated pressure range) and hold for awhile. If it does neither, or only one, you either have a bad pump or leaky injectors.

PT

peg the gauge? it's a 100 psi gauge...what pressure would it pump up to when clamped off? so let me get this straight... if it doesn't peg the gauge it's...
and if it does but bleeds down quickly its...

guessing first would be pump...second would be leaky injectors...
what other tests can you do with the injectors in situ to check them? curious as the ones on the disco may be questionable, and it is soon to start it's ressurection as well..

Paul

If the pump is in good shape, the pressure will rise to near the limit of your gauge. If the pressure falls soon after the pump shuts off, it is indicative of most likely a leaking injector. To isolate the injector, you should also clamp the line before the gauge to isolate the pump from the system under test (the pressure can bleed down through the pump).

If the pressure bleeds down in less than say, ten minutes, it's a leaky injector.

That's about all you can do to test injectors in situ unless you have a bore scope and can see the pattern inside the cylinder-and even then, it's not easy:flipoff2:

If the pump is in good shape, the pressure will rise to near the limit of your gauge. If the pressure falls soon after the pump shuts off, it is indicative of most likely a leaking injector. To isolate the injector, you should also clamp the line before the gauge to isolate the pump from the system under test (the pressure can bleed down through the pump).

If the pressure bleeds down in less than say, ten minutes, it's a leaky injector.

That's about all you can do to test injectors in situ unless you have a bore scope and can see the pattern inside the cylinder-and even then, it's not easy:flipoff2:

ok, just came back in:
i hooked up the fuel pressure gauge and:
on key on it ready 35 psi
on start it goes down for a few secs to 20 than stabilized at 30-32
on shut-off goes to 25.......than creaps back up to ~37??? in a minute or so tried this twice and it did same.

than I clamped off the return line at teh rail and turned key on
it read 54 psi and after five minutes read 55. i am about to go back down and see at ten minutes and report

regarding the IAC? I pulled it and inspected it compared to teh new one. the old one was retracted when not unde power, while the new one was not! Hmm! interesting..installed ans it was better but...

i still was having idle issues though so I started thinking of all and any vac lines i didn't check...i had even replaced the line from the IAC mount to the fuel pressure regulator already...anyway after a minute i realized the vac line from dash to throttle for cruise control was cracked...traced itr down and saw that all hoses from the vac ball on drivers side throughout the cc system were broken at each end...so clamped off the line and it idles much better. now to remove the fuel pressure gauge and reinstall teh fuel pump and see how it drives.

ok final note (this is confusing here)
I went down at twn minutes, than at twenty
here are the numbers

innitially at 54psi
five min. 55
ten min. 65
twenty min. 65 still stable hmm!
now this is not a pos $15 unit. it is a known good span-on set that is used daily by richard, and does not fluctuate, so why would it do this?
anyway, what would these numbers meen to y'all?
it sounds like the pump is down ten percent or so? is thas is the good range? or would this show the need to replace now?

Paul

no feedback at all? damn!
well after trial runs, it appears to be back to snuff 90 percent now...but I am curious about the fuel pump numbers...

just need to replace or permanently block off the vac line to the cruise control(told Elisa she shouldn't be using it anyway..:D )

now to determine if the coolant cap is bad or if there is too much pressure in there from a possible head gasket leak...the comp #'s do not lean to that really, so I am thinking the cap is going...it does hiss a bit when warm/hot bleading off...but it's suppposed to above a certain pressure ..right?

Paul(maybe I should have started another thread for that?)

Paul:
You're confusing me here. This is a LWB, right? So that indicates it's probably a '93-'95... The cruise control should be completely independent of engine vacuum. If the vacuum reservoir is attached tot he cruise control, Houston, we have a problem! (note, the '95s did not have the vacuum reservoir).

This might be a problem,if not the problem.

As for the IAC valve, the position of the valve is set by the operating conditions encountered by the engine at the time the engine is shutdown (to some extent), hence, the fact that the vlave may be in one position versus another is not critical. What is critical is that the valve moves and seals well into its home.

Your fuel pressure readings indicate that the pump is presumably good and that the injectors are not leaking appreciably.

PT

Paul:
You're confusing me here. This is a LWB, right? So that indicates it's probably a '93-'95... The cruise control should be completely independent of engine vacuum. If the vacuum reservoir is attached tot he cruise control, Houston, we have a problem! (note, the '95s did not have the vacuum reservoir).

This might be a problem,if not the problem.
PT
yes it's a '93 lwb
one of the vac lines on right side of the plenum goes accross to the black vac accumulatotr? ball, with a second line going from there through the firewal to what I understood was the cruise control? if not what is it going to?

there is a second vac line coming our of the firewall that t's off into the cruise control diaphram thingie on the throttle-body area...the other part of the t goes to the front left fender area behind headlignt where there is some sort of electrical/vac stabilizer? unit (need to look in manuals..) which I assumed was part of the cruise control?
if not what is this "stuff"??
I clamped off the return line from the dash area and all is well for now??hmm!


As for the IAC valve, the position of the valve is set by the operating conditions encountered by the engine at the time the engine is shutdown (to some extent), hence, the fact that the vlave may be in one position versus another is not critical. What is critical is that the valve moves and seals well into its home.

Your fuel pressure readings indicate that the pump is presumably good and that the injectors are not leaking appreciably.

PT
good! well at least I know that's not the problem. :D

when I started it up last night an hour after the test drive it immediately died twice, but has been perfect since?? strange. this morning it started up fine and Elisa marveled how I have given her "old rover bacl instead of the worn out pos she was thinking it was recently, while planning on buying a "new car" :eek:
thank god it is working good now, as money is tight again here with a single income again(gottaq stop taking on these "temp" type deals...they didn't need me anymore since hiring another journeyman with 20 years more skills than me! go figure! now time to put all energy back into working on our rovers and sell off the series IIA when it's finallt finished...funny when you work on others cars all day your own ones just don't get taken care of as well, so it's a good thing here. too bad teachers didn't make more $$ I could be a house husband/personal mechanic, huh? :grinpimp: and maybe finally get some of my $$ making projects going


anyway! Thanks for teh help!

Paul

The vacuum line that goes into the bulkhead goes to the heater box to control one of the flaps (fresh air?).

Welcome to the world of cobbler's children! Keep it up and you'll find yourself here talking about all the great ideas you have, but no time to do more than draw them up (all too often on a barrom napkin). Then, once you get embarrassed at never finishing a project, you only discuss your ideas on the phone with folks like Keith and Pendy. Then your wife begins to complain about the time on the phone.

The vacuum line that goes into the bulkhead goes to the heater box to control one of the flaps (fresh air?).

Welcome to the world of cobbler's children! Keep it up and you'll find yourself here talking about all the great ideas you have, but no time to do more than draw them up (all too often on a barrom napkin). Then, once you get embarrassed at never finishing a project, you only discuss your ideas on the phone with folks like Keith and Pendy. Then your wife begins to complain about the time on the phone.

sounds like my life already...if keith and pendy get sick of listening to ya...call me!
now I have all the time in the world to do them...just no place to do most as my tool/tooling etc sit and $$ is always a factor. I think I will throw myself back into starting the bench-jeweler career and see where that goes..unless other career open up soon...

Paul, have you checked the backpressure? When my 89 started doing this, it turned out that one cat had melted shut, and another - broken up and chunks ending up in the muffler. You can watch the manifold vacuum when you rev the engine under load (have somebody in the car keeping the brakes on, and transmission in gear) - if it goes down to nothing around 2k rpm (where the t/c locks up), it may be your problem.

Paul, have you checked the backpressure? When my 89 started doing this, it turned out that one cat had melted shut, and another - broken up and chunks ending up in the muffler. You can watch the manifold vacuum when you rev the engine under load (have somebody in the car keeping the brakes on, and transmission in gear) - if it goes down to nothing around 2k rpm (where the t/c locks up), it may be your problem.

both cats are a month old or so...i asked the muffler guy to check, and he confirmed that the cats had only broken in front, and no chunks in muffler..honestly I don't think he checked the backpressure like I asked with that special tool a good shop would have....we did a vac check for this, but not at 2000 in gear, was in park..but showed up to be fine.


but may try your suggestion anyway

Paul

When I bought my 89, it ran fine and smooth, but had no power beyond 2500 rpm. Replaced vacuum advance, a bit better, but still not there. Then it dawned on me to check the intake vacuum under load - then I banged the cats and muffler, and it all fell in place together.

where is the IAV located on a disco I...I am having similar problems

how old are the plug wires? Had similar issues on my 95 lwb classic, worked well.

where is the IAV located on a disco I...I am having similar problems

Depends. If it's a Lucas EMS, the IAC valve is located on the back of the plenum and has a big-ass hex. If GEMS, it's on the plenum adjacent to the TPS-you got the memo, didn't you?

a 300tdi fits nicely in a rrc

Going through the usual RV8 list, given the miles that thing has done, the top checklist is:

Fit genuine parts cap, rotor, HT leads, NGK BPR6ES plugs. You would not believe the problems some non-genuine parts cause.
Dizzy / ignition amp (you seem to have check most of it out)
Fuel pressure / injector leaks etc. (you've done that)
Vacuum leaks
Check / adjust EFi system (throttle pot, butterfly clearance, idle valve operation, airflow meter known good, other sensor readings checked, ECU swapped for known worker (borrow a friend's unit for an hour))

Once you have the above all as it should be, then you can start running round waving dead chickens over it and offering smoky sacrifices to Lucas, Prince of Darkness :p

I would be inclined to borrow a known good airflow meter from somewhere as a first step, that short-circuits the list above somewhat but it's one of the more common sources of failure in the system, especially if you have fitted an oiled air filter.