420a low compression

[rocker_topper]

Hi guys, Im having some problems here with my 98 eclipse RS. Did a head gasket change on the POS (quite frustrated by now) and got everything back together. Put a new water pump and timing belt on it while i had it torn apart. Upon cranking the first time the motor ran, and idled fine i might add. I shut the car off and closed the hood. Went inside to get my wallet and came back outside. Cranked the car once more and upon giving it a tiny bit of throttle it died. Havent been able to get it to crank again since. Have since then had the head checked and milled down. It checked out ok on pressure test. Ive reassembled everything and still can not get more than 30 PSI on each cylinder. Im 100% certain the timing is dead on, and that the head and everything in the head is good. I've done tons of research and can't seem to come up with anything. My initial problem was that i wasent getting spark to the plugs. Tracked from the plugs back and never got any power to the ignition coil. Im assuming that was due to low compression, and the engine computer cutting it out (maybe not 100% certain). Anyone got any suggestions before i scrap this thing? Its a wonderful car, looks great, and ran great before the head gasket job.. . Has barely over 100k miles on it, full body kit, leather interior, great A/C and lambo doors.... i hate to trash a nice show car because of this motor problem. Ive dumped so much money into this thing though that it has become outrageous. Any help or suggestions would be appreciated.

 

[starfish]

check for melted wires,bad fuse.Any codes?

 

[2GCruiser]

How about a leakdown test. Should give u an idea of why the compression test was low

Not to insult but are you sure your doing the comp test correctly

 

[Anubis_4_99]

I've never seen an ecu not let a car run due to low compression. I would say your problem is elsewhere.

Also a cold compression test wont give you an accurate reading. As suggested do a leak down test and start from there for your low compression.

As for the no spark, there is still more testing to be done.

 

[rocker_topper]

check for melted wires,bad fuse.Any codes?

no melted wires or bad fuses and no codes either

How about a leakdown test. Should give u an idea of why the compression test was low

Not to insult but are you sure your doing the comp test correctly

thanks, and to be 100% honest, no i'm not 100% positive i am. Give me a step by step and ill tell you if thats what ive been doing. im getting around 60PSI in cylinders 1 and 4 and about 50 in cylinder 2 and 3. i believe the service limits for my motor are100PSI with a 25% difference between cyliders (does that sound right)? Ive also heard a healthy motor for this car has between 170-225 PSI, is that right? Also how do i do a leakdown test on it? The machine shop said they did a pressure test and resurfaced the head. They said it all looked ok, so im pretty sure the head is solid.

I've never seen an ecu not let a car run due to low compression. I would say your problem is elsewhere.

Also a cold compression test wont give you an accurate reading. As suggested do a leak down test and start from there for your low compression.

As for the no spark, there is still more testing to be done.

What do you think the no spark could be without the car having any burnt wires or missing grounds? I have searched this thing over and over and even had a mechanic friend of mine take the car for about 2 weeks and he found nothingthat could cause it either, short of the ECU being bad. Only problem I have found with that though is that all the parts houses around here have to special order the ECU and its nonreturnable if its not my problem. I dont see wasting $300 on an ECU and that not be the problem...

 

[Anubis_4_99]

no melted wires or bad fuses and no codes either



thanks, and to be 100% honest, no i'm not 100% positive i am. Give me a step by step and ill tell you if thats what ive been doing. im getting around 60PSI in cylinders 1 and 4 and about 50 in cylinder 2 and 3. i believe the service limits for my motor are100PSI with a 25% difference between cyliders (does that sound right)? Ive also heard a healthy motor for this car has between 170-225 PSI, is that right? Also how do i do a leakdown test on it? The machine shop said they did a pressure test and resurfaced the head. They said it all looked ok, so im pretty sure the head is solid.



What do you think the no spark could be without the car having any burnt wires or missing grounds? I have searched this thing over and over and even had a mechanic friend of mine take the car for about 2 weeks and he found nothingthat could cause it either, short of the ECU being bad. Only problem I have found with that though is that all the parts houses around here have to special order the ECU and its nonreturnable if its not my problem. I dont see wasting $300 on an ECU and that not be the problem...

Find a junkyard and buy one for $30, try e-bay, craigslist, or even your local area forum and see if a member near you might be willing to swap there ECU in for you to test if its your problem, i've seen a few people do that on here. An ECU in no way needs to cost $300 unless a shop is trying to bend you over, or its something like a used link ECU.

And it doesn't have to be a missing ground, it can be a dirty ground, the wire itself can be corroded inside and you wouldn't be able to tell. There are also sensors related to the presence of spark that could be the issue as well.

And i know you said your 100% sure your timing is right, but it's always worth a second, or even third check.

Compression test ideally is done on a motor that is at operating temp, with the ECU fuse unplugged, wide open throttle, and cranked until the gauge stops moving. A cold motor will throw the numbers off, fuel entering the cylinder can throw numbers off, etc.

 

[92awddsm]

Were the cams and lifters removed? Did you bleed the lifters before reinstalling them?

For the lack of firing, I would go back over everything and make sure every wire is reconnected.

 

[rocker_topper]

Were the cams and lifters removed? Did you bleed the lifters before reinstalling them?

For the lack of firing, I would go back over everything and make sure every wire is reconnected.

the cams and lifters were removed, as far as bleeding them before reinstalling them no. I havent found a bleeding procedure for my specific lifters. Every bleeding procedure ive found is for the lifters with the hole in the top. Mine dont have those. they have 1 tiny little hole on the side of them but thats it.

 

[92awddsm]

the cams and lifters were removed, as far as bleeding them before reinstalling them no. I havent found a bleeding procedure for my specific lifters. Every bleeding procedure ive found is for the lifters with the hole in the top. Mine dont have those. they have 1 tiny little hole on the side of them but thats it.

Put them in a vice and squeeze them down to bleed the oil out. If not, they will hold the valves open and you wont get any compression.

 

[rocker_topper]

Find a junkyard and buy one for $30, try e-bay, craigslist, or even your local area forum and see if a member near you might be willing to swap there ECU in for you to test if its your problem, i've seen a few people do that on here. An ECU in no way needs to cost $300 unless a shop is trying to bend you over, or its something like a used link ECU.

And it doesn't have to be a missing ground, it can be a dirty ground, the wire itself can be corroded inside and you wouldn't be able to tell. There are also sensors related to the presence of spark that could be the issue as well.

And i know you said your 100% sure your timing is right, but it's always worth a second, or even third check.

Compression test ideally is done on a motor that is at operating temp, with the ECU fuse unplugged, wide open throttle, and cranked until the gauge stops moving. A cold motor will throw the numbers off, fuel entering the cylinder can throw numbers off, etc.

Ive double, triple, and quadruple checked the timing and its spot on. Both cam gear marks are dead on and the crank is at TDC when the marks align. Are there any members on here local to the 850 area code who might be willing to give me a hand with this thing? Its my only ride and as its down right now im screwed. Replaced the crank and cam sensores already as well. the ECU i priced was through, autozone, advance auto parts, and oriellys. They all range from $289 - $319.

 

[Anubis_4_99]

Ive double, triple, and quadruple checked the timing and its spot on. Both cam gear marks are dead on and the crank is at TDC when the marks align. Are there any members on here local to the 850 area code who might be willing to give me a hand with this thing? Its my only ride and as its down right now im screwed. Replaced the crank and cam sensores already as well. the ECU i priced was through, autozone, advance auto parts, and oriellys. They all range from $289 - $319.

Thats your problem, you don't need to go to a parts store, or even the dealer to get a new ECU. Hell even try the classifieds on here. I'm sure you can find one under $100.

It's always nice to have a spare anyway

 

[92awddsm]

Thats your problem, you don't need to go to a parts store, or even the dealer to get a new ECU. Hell even try the classifieds on here. I'm sure you can find one under $100.

It's always nice to have a spare anyway

But remember, it has to come from the same year with the same tranny

 

[rocker_topper]

But remember, it has to come from the same year with the same tranny

thats the problem i cant find any with the same as mine. Mines a 5 speed manual tranny with an ECU p/n of P05269833AH and according to something ive found in my research it suggests this ECU was recalled and a new one was released with a part number of 05269833AI. Anyone know if this is true?

this is a link to mopar recalls.

http://board.moparts.org/ubbthreads/upload2/5798559-DodgeFlashAvail.pdf

do a quick search of the info with the p/n P05269833AH, and you'll see what im talking about. also found this ECU on ebay. Will it work for my car?

http://www.ebay.com/itm/dodge-chrys...Parts_Accessories&vxp=mtr&hash=item4cfe2e2ac7

Put them in a vice and squeeze them down to bleed the oil out. If not, they will hold the valves open and you wont get any compression.

ok so these lifters must be in the down position when installed? Do they pump back up after the first crank or do they need to be filled before being re-installed?

 

[92awddsm]

thats the problem i cant find any with the same as mine. Mines a 5 speed manual tranny with an ECU p/n of P05269833AH and according to something ive found in my research it suggests this ECU was recalled and a new one was released with a part number of 05269833AI. Anyone know if this is true?

this is a link to mopar recalls.

http://board.moparts.org/ubbthreads/upload2/5798559-DodgeFlashAvail.pdf

do a quick search of the info with the p/n P05269833AH, and you'll see what im talking about. also found this ECU on ebay. Will it work for my car?

dodge chrysler sebring avenger mitsubishi eclipse | eBay



ok so these lifters must be in the down position when installed? Do they pump back up after the first crank or do they need to be filled before being re-installed?

Bleed them and install them. They will pump back up with oil pressure

 

[rocker_topper]

Bleed them and install them. They will pump back up with oil pressure

thanks, gonna give this a try im thinking it might help as they are all in the up position.

 

[rocker_topper]

But remember, it has to come from the same year with the same tranny

JW if you have any clue as to whether or not this computer will work for my car? Picking it up for around $35 with $12 shipping. Couldn't really pass it up.

dodge chrysler sebring avenger mitsubishi eclipse | eBay

Its got the same part number as my ECU.

 

[92awddsm]

JW if you have any clue as to whether or not this computer will work for my car? Picking it up for around $35 with $12 shipping. Couldn't really pass it up.

dodge chrysler sebring avenger mitsubishi eclipse | eBay

Its got the same part number as my ECU.

I cant open the link but if its the same part # it will work