I've read a lot of good things on this forum and decided to sign up to see if anyone could help me with this. It's driving me crazy.

Son threw a rod in his 97 RS and got another 420A from a 99 RS. Engine is in and all connected up. Spins and gets fuel, but no spark. No juice to coil or cam sensor. ECU was fine prior to the rod problem and have swapped all sensors from the blown engine to the replacement with no luck getting spark. Will try replacing the ASD relay today, but if not that, is the ECU most likely fried or are there differences between wiring on the two engines that need to be addressed? I see the pinouts are slightly different between the 97 and 99 ECUs. Does this mean I will need to swap some wires to make the 99 engine work with the 97 ECU? Any other ideas to check. Thanks for any help/suggestions.

nope, block is the same, I have a 95 with a 97 long block in it, only difference I had was 1 vacuum line (the one that runs over the valve cover, pre 95 cars don't use it) just swap over everything from the old block to the new one and enjoy!

Originally posted by RoninEclipse2G
nope, block is the same, I have a 95 with a 97 long block in it, only difference I had was 1 vacuum line (the one that runs over the valve cover, pre 95 cars don't use it) just swap over everything from the old block to the new one and enjoy!

I was hoping to hear that. Now I just need to get spark and fire this thing up. Thanks.

BTW, I noticed that change in the vacuum line. The 97 had it, the 99 didn't. Strange.

git R done! good luck with that!

Originally posted by 2G_Dad

Originally posted by RoninEclipse2G nope, block is the same, I have a 95 with a 97 long block in it, only difference I had was 1 vacuum line (the one that runs over the valve cover, pre 95 cars don't use it) just swap over everything from the old block to the new one and enjoy!

I was hoping to hear that. Now I just need to get spark and fire this thing up. Thanks. BTW, I noticed that change in the vacuum line. The 97 had it, the 99 didn't. Strange.

97 -> 99, even the sensor harness connectors are the same. All the sensor outputs are the same across all years. Mechanically, there is no difference in a 95-99 420A powerplant (save some bearing retainer tabs on the 95's).

if you're having a problem with power tot he cam and crank sensors, check the ASD relay - you're more likely having an electrical problem than something relating to the engine change. For all intents and purposes, that 99 longblock becomes a 97 longblock when connected to a 97 ECU.

Interesting. Everything plugged up fine and I too thought that there were no differences between the two engines. What threw me was the two slightly different pinout tables I saw here for a 97 vs 98 ECU. I replaced the ASD today and checked all fuses. Still no luck. I don't know what else to check next other than replacing the ECU. Any recommendations on a shop to check/repair/replace this? Anyone have a known good ECU for a 97 to sell cheap (okay reasonably priced)?

If anyone is interested, or it helps in any way, I checked for voltage to the various ECU pins (actually the plugs not the pins on the ECU). With the ignition on I found voltage at the following locations:
Pins 20, 23, 38, 40, 46, 55, 56, 64, 66, 67, 68, 69, 72, 73, 74, 77

Any idea if this is normal?

Welcome 2Gdad. I know you probably checked and double checked but there are two connections I'd like you to check. One is under the intake manifold. It is a larger one that comes out of the main wiring harness. It points down from the wiring harness and goes under the intake so it can be missed (I've done it). Also, just plug and unplug the crank sensor connector (while you're down there). Just to be sure.

Since she was running OK before the pull (albeit with rod problem), I suspect this is just a missed connection. These two are a couple that could be missed.

Originally posted by bullettdsm
Welcome 2Gdad. I know you probably checked and double checked but there are two connections I'd like you to check. One is under the intake manifold. It is a larger one that comes out of the main wiring harness. It points down from the wiring harness and goes under the intake so it can be missed (I've done it). Also, just plug and unplug the crank sensor connector (while you're down there). Just to be sure. Since she was running OK before the pull (albeit with rod problem), I suspect this is just a missed connection. These two are a couple that could be missed.

Thanks for the suggestions. Certainly worth checking. I'll put my son on it tomorrow. ; )

As well, i believe that on the 97+ setups the speed sensor and coil still have interchangeable plugs and enough length on them to be mistaken for one another. You might want to verify they're not swapped.

Originally posted by DarkOne
As well, i believe that on the 97+ setups the speed sensor and coil still have interchangeable plugs and enough length on them to be mistaken for one another. You might want to verify they're not swapped.

Are you talking about the plug to the coil vs the two plugs that attach to the IAC? I'm not near the car now, but I know the two plugs attached to the IAC have different connectors (3 vs 4 wires)and the coil connector also has 3 wires so it may be possible to swap them. Not sure if there is enough wire length to get them swapped, but will check when I get home. I think the cam sensor is also 3 wires but again the harness splits with those wires coming out right at the cam sensor, so I think they are connected properly. At this point I certainly won't assume anything and will re-check all of the plugs again this afternoon with an eye towards swapped rather than loose connections. Thanks for the suggestions.

Originally posted by 2G_Dad

Originally posted by DarkOne As well, i believe that on the 97+ setups the speed sensor and coil still have interchangeable plugs and enough length on them to be mistaken for one another. You might want to verify they're not swapped.

Are you talking about the plug to the coil vs the two plugs that attach to the IAC? I'm not near the car now, but I know the two plugs attached to the IAC have different connectors (3 vs 4 wires)and the coil connector also has 3 wires so it may be possible to swap them. Not sure if there is enough wire length to get them swapped, but will check when I get home. I think the cam sensor is also 3 wires but again the harness splits with those wires coming out right at the cam sensor, so I think they are connected properly. At this point I certainly won't assume anything and will re-check all of the plugs again this afternoon with an eye towards swapped rather than loose connections. Thanks for the suggestions.

No, the VSS (vehicle speed sensor ont he back of the MTX trans) and the coil. Both 3-wire, same plug.

Originally posted by DarkOne

Originally posted by 2G_Dad

Originally posted by DarkOne As well, i believe that on the 97+ setups the speed sensor and coil still have interchangeable plugs and enough length on them to be mistaken for one another. You might want to verify they're not swapped.

Are you talking about the plug to the coil vs the two plugs that attach to the IAC? I'm not near the car now, but I know the two plugs attached to the IAC have different connectors (3 vs 4 wires)and the coil connector also has 3 wires so it may be possible to swap them. Not sure if there is enough wire length to get them swapped, but will check when I get home. I think the cam sensor is also 3 wires but again the harness splits with those wires coming out right at the cam sensor, so I think they are connected properly. At this point I certainly won't assume anything and will re-check all of the plugs again this afternoon with an eye towards swapped rather than loose connections. Thanks for the suggestions.

No, the VSS (vehicle speed sensor ont he back of the MTX trans) and the coil. Both 3-wire, same plug.

Thanks for the clarification. I'll check it out when I get home and post back with results.

I had those 2 switched when i put my motor in a long time ago, and it blew my ecu. If they are switched, my guess would be that a blown ecu is your culprit. Just trying to help :thumbsup

Originally posted by Murfsmaster
I had those 2 switched when i put my motor in a long time ago, and it blew my ecu. If they are switched, my guess would be that a blown ecu is your culprit. Just trying to help :thumbsup

Hey, I surely appreciate the help. I checked the wires and it appears there is only one connector that plugs into the transmission. If this is the VSS then it does indeed have three wires similar to the coil connector, but where one has 3 flat blades inside the connector, the other has 3 round pins. They are connected correctly. I rechecked all other plugs and they are secure. I think my next move has to be the ECU. I just wanted to be sure before spending the money. Thanks again for the help.

If you live in Ct, I got a known good that you can try.

Also, if you want you can check out this thread our FS section.

http://forums.2gnt.com/dcboard.php?az=show_topic&forum=16&topic_id=107360&mesg_id=107360&page=

Originally posted by bullettdsm
If you live in Ct, I got a known good that you can try. Also, if you want you can check out this thread our FS section. http://forums.2gnt.com/dcboard.php?az=show_topic&forum=16&topic_id=107360&mesg_id=107360&page=

Appreciate the offer, but I live in VA. I've purchased an ECU from another board member. Can't wait for it to arrive. Thanks again for the offer.

Okay, got the known good ECU from a member here (you know who you are and thanks). Plugged it up and the car still cranks but won't fire. Have checked/replaced MFI and ASD relays, coil pack and plug wires,have voltage to coil, cam and crank sensors, but no spark. Have compression and plugs are wet after cranking. If timing is off (perhaps timing belt slipped a bit) would this fit the symptoms? Don't know what else to check. Is there an easy way to check the timing before taking this to the dealer? While I can easily see the marks on the cams, I can't see any marks on the crank pulley.

The markings for the crank are behind the pulley. Are the clips still good on the ecu plugs? Maybe try holding in on them while cranking it, could have a bad connection.

Originally posted by Nightfall
The markings for the crank are behind the pulley. Are the clips still good on the ecu plugs? Maybe try holding in on them while cranking it, could have a bad connection.

Tried this with no luck. Thanks for the suggestion.

Have you verified the cam sensor is right side up? The harness plug faces down. Have you verified you have ~9v at the cam and crank sensors? (i believe power is the yellow wire in both harnesses)

It almost has to be a sensor problem at this point. Even three teeth off it'll still start.

Originally posted by DarkOne
Have you verified the cam sensor is right side up? The harness plug faces down. Have you verified you have ~9v at the cam and crank sensors? (i believe power is the yellow wire in both harnesses) It almost has to be a sensor problem at this point. Even three teeth off it'll still start.

Cam sensor is installed correctly. I believe the voltage at both sensors was a bit less than 9v but at least 7v (may not have had a really good ground). I finally had to give up on solving this at home and had the car towed to the local dealer. They will check it tomorrow. I'll post back with their findings. Thanks for the suggestions.

Originally posted by 2G_Dad
I believe the voltage at both sensors was a bit less than 9v but at least 7v (may not have had a really good ground).

That's fine, they'll run on anything between 5 and 12v from what I understand, but are regulated at ~9v.

Originally posted by 2G_Dad
I finally had to give up on solving this at home and had the car towed to the local dealer. They will check it tomorrow. I'll post back with their findings. Thanks for the suggestions.

That's terrible. My next suggestion was going to be to verify you were seeing signal on both output wires for those sensors while cranking (voltage high-low-high-low as the engine turns). I bet one of them is internally broken or has a slight fray on the wire.

Did the fuel pump ever do more then prime?

Originally posted by DarkOne

Originally posted by 2G_Dad I believe the voltage at both sensors was a bit less than 9v but at least 7v (may not have had a really good ground).

That's fine, they'll run on anything between 5 and 12v from what I understand, but are regulated at ~9v.

Originally posted by 2G_Dad I finally had to give up on solving this at home and had the car towed to the local dealer. They will check it tomorrow. I'll post back with their findings. Thanks for the suggestions.

That's terrible. My next suggestion was going to be to verify you were seeing signal on both output wires for those sensors while cranking (voltage high-low-high-low as the engine turns). I bet one of them is internally broken or has a slight fray on the wire. Did the fuel pump ever do more then prime?

Interesting. If there is a bad wire, is the solution to just splice new ones from the ECU to the sensors? As for the fuel pump, I can't say for sure. It can be heard when the ignition is switched on and runs for several seconds before quieting down. I assume this is the priming, but don't know what else it should do after that. Please keep the ideas/info coming. I don't know how good the local dealer is and if they call to say they can't find the problem, I may be back to home trouble shooting.

Originally posted by 2G_Dad
Interesting. If there is a bad wire, is the solution to just splice new ones from the ECU to the sensors? As for the fuel pump, I can't say for sure. It can be heard when the ignition is switched on and runs for several seconds before quieting down. I assume this is the priming, but don't know what else it should do after that. Please keep the ideas/info coming. I don't know how good the local dealer is and if they call to say they can't find the problem, I may be back to home trouble shooting.

What Dino was suggesting is back probing both the CAS and CMP sensors while cranking. You should see 5vdc alternating at crank speed from the CAS and, of course, half crank speed from the CMP. If you don't, then you want to ohm the lines out back to the ECU connectors to check for continuity. If you get continuity, but no functionality, then it's a good bet that one of those sensors is dead. Loss of signal from either of them results in a no-run condition. Trips the ASD relay.

If you hear the fuel pump for a second or two when you first turn the key to the ON position, then it's priming. I think you said the plugs were wet too, which I'd say is a safe bet that the pump is working.

Originally posted by DR1665

Originally posted by 2G_Dad Interesting. snip

What Dino was suggesting is back probing both the CAS and CMP sensors while cranking. You should see 5vdc alternating at crank speed from the CAS and, of course, half crank speed from the CMP. If you don't, then you want to ohm the lines out back to the ECU connectors to check for continuity. If you get continuity, but no functionality, then it's a good bet that one of those sensors is dead. Loss of signal from either of them results in a no-run condition. Trips the ASD relay. If you hear the fuel pump for a second or two when you first turn the key to the ON position, then it's priming. I think you said the plugs were wet too, which I'd say is a safe bet that the pump is working.

Thanks for the clarification. Car has been at dealer for 5 days now. They have repeated all tests I ran and back probed all wires/sensors. Their conclusion is that all wiring and sensors are fine; timing is correct. They are sure my original ECU is bad and the replacement is either bad or not the correct one for my car. They are getting a third ECU in tomorrow to try and are "99% sure" that will solve the no spark/no start issue. I'm not totally convinced, but don't know what else is left to try, so am keeping my fingers crossed. Should know tomorrow. Wish us luck.

Well, the dealer tried the new computer and still no spark and they also say there is no pulse to the injectors. They are as frustrated as my son and I. They have been very pleasant to deal with and vowed to continue with diagnostics tomorrow and are very interested in finding the problem. They asked about aftermarket security systems and although I'm not aware of one, I don't know where to look for one or if it would cause this problem. Anyone have any info to share on this? I'll update again when I have more info.

Originally posted by 2G_Dad
Well, the dealer tried the new computer and still no spark and they also say there is no pulse to the injectors. They are as frustrated as my son and I. They have been very pleasant to deal with and vowed to continue with diagnostics tomorrow and are very interested in finding the problem. They asked about aftermarket security systems and although I'm not aware of one, I don't know where to look for one or if it would cause this problem. Anyone have any info to share on this? I'll update again when I have more info.

i'd be willing to paypal you 1$ as a lost bet if it turns out to be something *not* related to the cam sensor, crank sensor, or the wiring leading to them.

Originally posted by DarkOne

Originally posted by 2G_Dad Well, the dealer tried the new computer and still no spark and they also say there is no pulse to the injectors. They are as frustrated as my son and I. They have been very pleasant to deal with and vowed to continue with diagnostics tomorrow and are very interested in finding the problem. They asked about aftermarket security systems and although I'm not aware of one, I don't know where to look for one or if it would cause this problem. Anyone have any info to share on this? I'll update again when I have more info.

i'd be willing to paypal you 1$ as a lost bet if it turns out to be something *not* related to the cam sensor, crank sensor, or the wiring leading to them.

Appreciate the thought. I would be absolutely THRILLED if you are right, since it beats any of the alternatives I can think of... wait a minute, I can't think of any serious alternatives. Hopefully the dealer will be able to pinpoint the problem. They told me they had back probed all the sensor wires and found no problems, so I'm not sure where they will go next. Is it possible or likely that I could have a bad connection inside one of the 2 large connectors that plug into the ECU (although they were fine with the original engine)? Just for my peace of mind, do most security systems prevent the starter from turning, or just cut the spark/fuel?

That really sucks man, hopefully they can get it figured out though, I know it must be VERY frustrating. As far as the security system goes, every one I've ever seen disables the starter.

Originally posted by 2G_Dad
Just for my peace of mind, do most security systems prevent the starter from turning, or just cut the spark/fuel?

Every one I've ever seen is just a starter lockout. If you had something advanced enough to completely cut spark and fuel, you'd probably know it.

Thanks. That's what I thought about the alarm systems. Just needed some reassurance. At this point I'm guessing my problem may be similar to this one http://forums.2gnt.com/dcboard.php?az=show_topic&forum=4&topic_id=91568 I wonder if I can get the dealer to try replacing the crank and or cam sensors without making me buy them? Probably depends on if they stock them. I saw a couple of complete engine wiring harnesses on ebay. That may be my last resort if dealer comes up empty.

Dealer called and they think they may be onto something. One of the items I asked about on day one. They think cam timing may be off. They will check it out tomorrow and I'll post back after I hear from them.

Latest from the dealer is that the timing is way off. They also boro-scoped the engine and believe that the valves have contacted the pistons to some extent and that number 3 cylinder may be washed. Looks like someone sold us a junk engine. Anyone care to hazard a guess on if it's cheaper to replace or rebuild this engine? I can do the swap myself and if rebuilding, can do all but the machine work. Not sure if I'd take a chance on another used engine without actually hearing it run first. Maybe I should just sell everything as is and cut my losses. Son needs a car soon and can't yet afford the "performance rebuild" he would like to do. Life's all about choices and he's got an interesting one ahead of him right now. Decision time.

Interesting. Did you ever do a compression test on the "new" motor?

Originally posted by DarkOne
Interesting. Did you ever do a compression test on the "new" motor?

Yes, when the engine failed to start after installation. Compression was very low at 120psi, but even across all cylinders. Because the engine had been sitting for many months before we got it, I wasn't too sure what to make of that. Dealer also confirmed the low but even compression and attributed it to the timing problem.

If there was valve contact, compression would be nonexistent to very low... and iirc, these cars will still run (though throw a CEL) with the timing off up to three cam teeth...

just trivia at this point, really.

Originally posted by DarkOne
If there was valve contact, compression would be nonexistent to very low... and iirc, these cars will still run (though throw a CEL) with the timing off up to three cam teeth... just trivia at this point, really.

Hmmm...I wonder if the dealer is just getting tired of dealing with this. I was told the timing was "way off" which I'm interpreting as more than a few teeth off, hence the posssibility of bent valves. They even mentioned something about one of the cams being "wrong". I don't know what to make of that, but it sounds virtually impossible and very strange for them to suggest. I may just tow the car home and pull the head to see what there is to see.

Makes me wonder if you got a cam gear on backwards. They both should say 2.0 on the front. 120ish even is pretty low, but not really an indicator that you have bent valves. That would mean that each valve in each cylinder would have to be bent just the right way for you to lose just that slight amount of pressure by the valve. While possible, generally bent valves put you a whole lot closer to 0.

Originally posted by bullettdsm
Makes me wonder if you got a cam gear on backwards. They both should say 2.0 on the front. 120ish even is pretty low, but not really an indicator that you have bent valves. That would mean that each valve in each cylinder would have to be bent just the right way for you to lose just that slight amount of pressure by the valve. While possible, generally bent valves put you a whole lot closer to 0.

I totally agree. Normally, when I think low compression I think worn/broken rings, but I've never seen rings all wear to give the exact same low reading in all cylinders. Would you guess the cause of the low compression to be more of a valve/timing issue? I'm trying to decide if I want the dealer to check anything else or just give up and bring it back home to pursue on my own. It's like a game of twenty questions getting info from the dealer. Any other questions I should be asking (besides what the bill is so far)?

By the way, thanks to everyone that's been following/participating in this thread. I really appreciate all the thought that has gone into this. I probably should have let this car go when it threw a rod, but there's something about them that makes that hard to do. I would love to get this car in shape for my son to enjoy for a few years, but have limited resources to make that happen.

This thread is done, but wanted to follow up with the latest from the dealer. They found that the problem was the locating pin on the intake camshaft had sheared off, allowing the cam gear to turn without spinning the intake camshaft. I had the head from the 97 engine rebuilt and the dealer will swap them (along with timing belt kit, water pump, etc.). If interested, see my latest post concerning overheating after dealer service. The saga continues.