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mrmomo · Jun 17, 2006, 06:51 PM

Ok, here we go…. 1990 CRX DX 1.5 Manual Trans, Canada

Driving to work the other morning, came to a stop and my 1990 CRX quit. I tried to re-start but it would not fire. Rolls over just fine but not even a hint of starting. Got it back home and broke out the Honda manual.. Yes, I have the HONDA (not haynes) manual for my year/model.

Back up about a year. It quit on me on the way home from work. Came to find that my distributors guts had smoked themselves. Replaced with a new cap, rotor and ignition coil. Ran fine after that. I have also replaced my main relay as I was having trouble starting when the interior of the car was hot. – No troubles with that since. Timing belt was changed at 160K km when I bought it, and again at 260K, it currently has 276K km on it

Back to present day… First thing I did was listen for the fuel pump when I turned the key – it is running. Second thing I did was rip back the carpet to view the codes – no codes. One “hello” blink then nothing. Started through the troubleshooting part for checking the ignition coil & igniter.

With the distributor cap off I cranked the motor and got confirmation that the rotor was spinning (TB OK)

Couldn’t confirm that I had spark, I don’t have my timing light with me, but I did not appear to have spark

Coil checks out seeming to be OK, resistance on the primary winding was a little higher than what the book says but I don’t think that’s my problem. (then again, maybe it is)

Did the igniter input testing, Had voltage between Blk/Yel and gnd, Had voltage between Wht/Blu and gnd, DID NOT have continuity between Wht and gnd.

Pulled the ECU out and checked for continuity between the white wire and pin 10 on the PGM-FI harness, it was good. Checked for continuity between PGM-FI harness pins a4/a16/a18 and gnd 101/151 it was good. Checked continuity between gnd 101/151 and it was good.

At this point I figured the only part I couldn’t test was the PGM-FI ECU. Grabbed on from the wreckers. My ECU was stamped 89.12.04 The one I got was an ’88, both were DX model. $50.

Got home and plopped the new computer in, cranks, but no start. Checked the new ECU for codes and it was flashing a 20 code (bad Electric load detector)

Removed the hazard fuse for 30 seconds (not that it should matter as the ECU was out of the car for longer than that) Still no changes. Ran through the checks for the load detector, but mine is not located where the manual says it is…

Got frustrated at this point. Went to mow the lawn, hopped on my John Deere and… crank crank crank crank crank crank crank crank crank crank crank crank ***?? No spark. Am I contagious?

PLEASE HELP ME!!

TxGreaseMonkey · Jun 17, 2006, 07:11 PM

Sounds like it could be a faulty MAP Sensor. MAP sensors provide information to the ECM, which affects timing advance and fuel/air mixture. When they go, your engine will crank but not start. Any checks for spark will be futile. New MAP sensors are very expensive--a new one from Honda will cost around $350. An aftermarket from RockAuto.com is $220. Odds are that the problem is in the electrical side of the sensor, not the vacuum.

mrmomo · Jun 18, 2006, 04:39 PM

Any way to check it before I go out and buy one for that much $$ ? (resistance check?) Would the computer not show a code 3 or 5 for that? My check engine light is not coming on. Is it worth getting one from the wreckers or should I only buy a new one?

TxGreaseMonkey · Jun 22, 2006, 09:37 AM

Run the tests in your Shop Manual. Normally, disconnect 3P connector going to the MAP sensor and turn ignition ON. Should have approximately 5v. Between reference wire [YEL/GRN (could be RED)]+ and body ground-, 5v. Between reference wire+ and [GRN/BLU (could be WHT)]-, 5v. Between signal wire (WHT)+ and [GRN/BLU (could be WHT)]-. The MAP sensor is a transducer and the voltage should drop (resistance increase) as you apply vacuum to the hose. Jump wires are installed to check voltages, while the engine runs. Make sure that the hoses going to the MAP sensor are in good shape. This is an expensive sensor, so be sure it's bad before replacing it. Mine did not throw a code 3 or 5, so I can't really advise in your case. Primarily, I'm trying to suggest checking out an area that is often overlooked, even by Honda repair technicians. I don't think Honda anticipated this problem, where no codes are thrown when the car tries to start and the MAP sensor is so marginal that electricity/fuel are shut down. In your case, it might be affecting your timing and not your air/fuel mixture. Remember the ECM uses the MAP sensor to control fuel delivery and ignition timing. The MAP sensor is similar to the old vacuum advance on distributors, as far as ignition is concerned.

mrmomo · Jun 22, 2006, 05:54 PM

I will look into that. I hooked up my timing light and I am getting absolutely NO spark whatsoever. I also got a bit confused trying to measure the electrical load detector, as the wiring was not as shown in my manual... it showed it in the main fuse box (by the strut top) with a 3 wire plug. I do not have one there, but I have a 6 or 8 pin plug with what seems to be matching wire colours for some of the wires. Just wondering where it would be located if it is not in the main fuse box, and how do I test it if the wiring is not as in my book?

Thanks!

Bruce